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Background: Living in poverty in the midst of caring for a child with sickle cell disease (SCD) presents with challenges that may be overwhelming for caregivers. Prior research has shown a relationship between poverty and poor outcomes in children; however, no study has investigated the mediating role of parenting stress on health-related quality of life (HRQOL) for such children., Procedure: A total of 150 patients, ages 8-17 years and their parents, were enrolled and completed measures of parenting stress (caregivers) and HRQOL (patients). Caregivers also completed a demographic information questionnaire, which was used to determine poverty status. The Sobel test was used to analyze the association between poverty and HRQOL by way of parenting stress., Results: The series of linear regression results show poverty was a significant predictor for decreased HRQOL (B = -7.01, p = .05) among pediatric patients with SCD. Moreover, the regression coefficient measuring the indirect effect of the model measuring the mediating role of parenting stress was statistically significant (B = -1.05, p = .05)., Conclusion: The current study found an association between poverty status and HRQOL scores by way of parenting stress. Findings highlight the need for appropriate resource allocation to caregivers in addition to pediatric patients living with SCD., (© 2023 Wiley Periodicals LLC.)

Central B cell tolerance is believed to be regulated by B cell receptor signaling induced by the recognition of self-antigens in immature B cells. Using humanized mice with defective MyD88, TLR7, or TLR9 expression, we demonstrate that TLR9/MYD88 are required for central B cell tolerance and the removal of developing autoreactive clones. We also show that CXCL4, a chemokine involved in systemic sclerosis (SSc), abrogates TLR9 function in B cells by sequestering TLR9 ligands away from the endosomal compartments where this receptor resides. The in vivo production of CXCL4 thereby impedes both TLR9 responses in B cells and the establishment of central B cell tolerance. We conclude that TLR9 plays an essential early tolerogenic function required for the establishment of central B cell tolerance and that correcting defective TLR9 function in B cells from SSc patients may represent a novel therapeutic strategy to restore B cell tolerance., (© 2023 Çakan et al.)

Context: Sickle cell disease (SCD) may cause significant complications leading to increased disease burden and poor psychosocial functioning. Yet, little is known about specific disease-related variables associated with decreased health-related quality of life (HRQOL) of this population., Objectives: This study aims to discover whether pain and disease-related symptoms are associated with the HRQOL of pediatric patients diagnosed with SCD., Methods: A total of 150 patient (ages 8-17 years) and parent dyads were enrolled in this cross-sectional quantitative research study. Measures of HRQOL were gathered using the Pediatric Quality of Life (PedsQL) 3.0 SCD module, while the frequency of pain and SCD-related symptoms was reported by parent-proxy. Linear regression was deployed to analyze whether pain and SCD-related symptoms separately predict HRQOL scores in youth with SCD., Results: Study results revealed that the frequency of pain (P < 0.001) and SCD-related symptoms (P < 0.001) predicted lower HRQOL scores in children and adolescents with SCD. Moreover, age (P < 0.05) emerged as a significant predictor of HRQOL in this sample., Conclusion: Pain and disease-related symptoms separately predicted lower HRQOL scores in the study sample, which shows that other SCD-related symptoms aside from pain has the potential to negatively impact youth with SCD. Implications for these findings extend the knowledge of clinicians in the healthcare setting to recognize the detriment of other SCD-related symptoms that may be overlooked, as pain is often the focus., (Copyright © 2022 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.)

Background/objective: Youth diagnosed with sickle cell disease (SCD) are at increased risk of poor health-related quality of life (HRQOL) due to the complexities associated with this disease. The literature notes that predictors such as pain and poor mental health are associated with increased healthcare access; however, the connection between healthcare use and their overall well-being has been understudied. This study investigates whether healthcare utilization predicts the HRQOL in youth with SCD., Design/methods: Patients completed the Pediatric Quality of Life (PedsQL) 3.0 SCD module, whereas the researcher conducted a retrospective chart review to gather patient characteristics such as emergency room (ER) and hospitalization occurrences over the past 12 months., Results: The study consisted of 150 pediatric patients with SCD, ages 8-17 years old, and their parents. Patients with ≥ 4 ER visits and hospitalizations reported worse HRQOL scores than their respective counterparts. Additionally, a higher frequency of ER visits (P = 0.05) and hospitalizations (P = 0.005) predicted lower HRQOL scores. Age (P = 0.04) also emerged as a significant predictor for both regression models, as increased healthcare access among older patients with SCD was associated with poorer HRQOL., Conclusion: This study found that as youth with SCD require ER treatment and/or hospital admission, they are at increased risk for lower HRQOL, specifically as they get older. Findings suggest that attention should be paid to patients who require more frequent healthcare intervention. Improvement in outpatient care of pediatric patients with SCD may help to mitigate ER and inpatient use., (© 2022 Wiley Periodicals LLC.)

Objective: The objective of this study was to investigate the relationship between parental stress and health-related quality of life (HRQOL) among children with sickle cell disease (SCD)., Methods: A cross-sectional correlational survey research design was used for this quantitative study. One hundred-fifty patients between the ages of 8-17 years old and their caregivers were enrolled from an outpatient comprehensive sickle cell program within a hospital setting. Patients completed the Pediatric Quality of Life Scale 3.0 SCD Module, whereas parents completed the Parental Stress Scale and demographic information questionnaire. Multiple regression analysis was used to determine if parental stress scores predicted the HRQOL of children diagnosed with SCD after controlling for demographic variables., Results: The sample included 150 patients (median age: 12 years old; female: 52%) who were diagnosed with SCD along with 150 of their caregivers. Higher levels of parental stress predicted lower HRQOL scores (p < .001)., Conclusion: As parents reported elevated levels of stress related to caring for their child with SCD, patients reported worsening HRQOL. More evidence is needed in order to determine, which constructs of parental stress had a significant impact on HRQOL. It may be helpful for healthcare workers to be aware of familial influences of reduced HRQOL among children diagnosed with SCD. Parents reporting increased stress related to raising their child with SCD may benefit from additional support and resources., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The etiologic agent of plague, Yersinia pestis , is a globally distributed pathogen which poses both a natural and adversarial threat. Due largely to the rapid course and high mortality of pneumonic plague, vaccines are greatly needed. Two-component protein vaccines have been unreliable and potentially vulnerable to vaccine resistance. We evaluated the safety and efficacy of eight live Y. pestis strains derived from virulent strains CO92 or KIM6+ and mutated in one or more virulence-associated gene(s) or cured of plasmid pPst. Stringent, single-dose vaccination allowed down-selection of the two safest and most protective vaccine candidates, CO92 mutants pgm - pPst- and Δ yscN . Both completely protected BALB/c mice against subcutaneous and aerosol challenge with Y. pestis . Strain CD-1 outbred mice were more resistant to bubonic (but not pneumonic) plague than BALB/c mice, but the vaccines elicited partial protection of CD-1 mice against aerosol challenge, while providing full protection against subcutaneous challenge. A Δ yscN mutant of the nonencapsulated C12 strain was expected to display antigens previously concealed by the capsule. C12 Δ yscN elicited negligible titers to F1 but comparable antibody levels to whole killed bacteria, as did CO92 Δ yscN . Although one dose of C12 Δ yscN was not protective, vaccination with two doses of either CO92 Δ yscN, or a combination of the Δysc N mutants of C12 and CO92, protected optimally against lethal bubonic or pneumonic plague. Protection against encapsulated Y. pestis required inclusion of F1 in the vaccine and was associated with high anti-F1 titers.

Sickle cell disease (SCD), a common hematological disorder, has received increased interest from researchers who set to discover whether individuals with SCD are at risk for depression. However, the prevalence of depression varies substantially between published studies. Therefore, two aims were identified in this critical review: (1) to summarize the prevalence of depression among children and adolescents diagnosed with SCD and (2) identify if disease severity predicts rates of depression within this population. Results from the 13 studies included in this review show the prevalence of depression was between 4%-46%. Pain predicted a higher occurrence of depression within this population.

High titers of autoantibodies reactive with DNA/RNA molecular complexes are characteristic of autoimmune disorders such as systemic lupus erythematosus (SLE). In vitro and in vivo studies have implicated the endosomal Toll-like receptor 9 (TLR9) and Toll-like receptor 7 (TLR7) in the activation of the corresponding autoantibody producing B cells. Importantly, TLR9/TLR7-deficiency results in the inability of autoreactive B cells to proliferate in response to DNA/RNA-associated autoantigens in vitro, and in marked changes in the autoantibody repertoire of autoimmune-prone mice. Uptake of DNA/RNA-associated autoantigen immune complexes (ICs) also leads to activation of dendritic cells (DCs) through TLR9 and TLR7. The initial studies from our lab involved ICs formed by a mixture of autoantibodies and cell debris released from dying cells in culture. To better understand the nature of the mammalian ligands that can effectively activate TLR7 and TLR9, we have developed a methodology for preparing ICs containing defined DNA fragments that recapitulate the immunostimulatory activity of the previous "black box" ICs. As the endosomal TLR7 and TLR9 function optimally from intracellular acidic compartments, we developed a facile methodology to monitor the trafficking of defined DNA ICs by flow cytometry and confocal microscopy. These reagents reveal an important role for nucleic acid sequence, even when the ligand is mammalian DNA and will help illuminate the role of IC trafficking in the response.

Objectives: The goal of this study was to determine whether endosomal Toll-like receptors (TLRs) contribute to the clinical manifestation of systemic autoimmunity exhibited by mice that lack the lysosomal nuclease DNaseII., Methods: DNaseII/IFNaR double deficient mice were intercrossed with Unc93b13d/3d mice to generate DNaseII-/-mice with non-functional endosomal TLRs. The resulting triple deficient mice were evaluated for arthritis, autoantibody production, splenomegaly, and extramedullary haematopoiesis. B cells from both strains were evaluated for their capacity to respond to endogenous DNA by using small oligonucleotide based TLR9D ligands and a novel class of bifunctional anti-DNA antibodies., Results: Mice that fail to express DNaseII, IFNaR, and Unc93b1 still develop arthritis but do not make autoantibodies, develop splenomegaly, or exhibit extramedullary haematopoiesis. DNaseII-/- IFNaR-/- B cells can respond to synthetic ODNs, but not to endogenous dsDNA., Conclusions: RNA-reactive TLRs, presumably TLR7, are required for autoantibody production, splenomegaly, and extramedullary haematopoiesis in the DNaseII-/- model of systemic autoimmunity.

Endosomal TLRs play an important role in systemic autoimmune diseases, such as systemic erythematosus lupus, in which DNA- and RNA-associated autoantigens activate autoreactive B cells through TLR9- and TLR7-dependent pathways. Nevertheless, TLR9-deficient autoimmune-prone mice develop more severe clinical disease, whereas TLR7-deficient and TLR7/9-double deficient autoimmune-prone mice develop less severe disease. To determine whether the regulatory activity of TLR9 is B cell intrinsic, we directly compared the functional properties of autoantigen-activated wild-type, TLR9-deficient, and TLR7-deficient B cells in an experimental system in which proliferation depends on BCR/TLR coengagement. In vitro, TLR9-deficient cells are less dependent on survival factors for a sustained proliferative response than are either wild-type or TLR7-deficient cells. The TLR9-deficient cells also preferentially differentiate toward the plasma cell lineage, as indicated by expression of CD138, sustained expression of IRF4, and other molecular markers of plasma cells. In vivo, autoantigen-activated TLR9-deficient cells give rise to greater numbers of autoantibody-producing cells. Our results identify distinct roles for TLR7 and TLR9 in the differentiation of autoreactive B cells that explain the capacity of TLR9 to limit, as well as TLR7 to promote, the clinical features of systemic erythematosus lupus., (Copyright © 2015 by The American Association of Immunologists, Inc.)

Parallel transmit is an emerging technology to address the technical challenges associated with MR imaging at high field strengths. When developing arrays for parallel transmit systems, one of the primary factors to be considered is the mechanism to manage coupling and create independently operating channels. Recent work has demonstrated the use of amplifiers to provide some or all of the channel-to-channel isolation, reducing the need for on-coil decoupling networks in a manner analogous to the use of isolation preamplifiers with receive coils. This paper discusses an eight-channel transmit/receive head array for use with an ultra-low output impedance (ULOI) parallel transmit system. The ULOI amplifiers eliminated the need for a complex lumped element network to decouple the eight-rung array. The design and construction details of the array are discussed in addition to the measurement considerations required for appropriately characterizing an array when using ULOI amplifiers. B1 maps and coupling matrices are used to verify the performance of the system., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Many bacterial species use secreted quorum-sensing autoinducer molecules to regulate cell density- and growth phase-dependent gene expression, including virulence factor production, as sufficient environmental autoinducer concentrations are achieved. Bacillus anthracis, the causative agent of anthrax, contains a functional autoinducer (AI-2) system, which appears to regulate virulence gene expression. To determine if the AI-2 system is necessary for disease, we constructed a LuxS AI-2 synthase-deficient mutant in the virulent Ames strain of B. anthracis. We found that growth of the LuxS-deficient mutant was inhibited and sporulation was delayed when compared with the parental strain. However, spores of the Ames luxS mutant remained fully virulent in both mice and guinea pigs.

Investigation of highly accelerated MRI has developed into a lively corner in the hardware and methodology arena in recent years. At the extreme of (one-dimensional) acceleration, our group introduced Single Echo Acquisition (SEA) imaging, in which the need to phase encode a 64×N(readout) image is eliminated and replaced with the well-localized spatial information obtained from an array of 64 very narrow, long, parallel coils. The narrow coil width (2mm) that facilitates this is accompanied by a concomitant constraint on the useful imaging depth. This note describes a 64-element planar array, constructed within the same 8×13cm total footprint as the original SEA array, still enabling full acceleration in one dimension, but with an element design modified to increase the imaging depth. This was accomplished by lowering the outer conducting legs of the planar pair with respect to the center conductor and adding a geometric decoupling configuration away from the imaging field of view. The element has been called a dual-plane pair in that the current carrying rungs in the imaging FOV function exactly as the planar pair, but are simply placed in two separate planes (sides of PCB in this case).

At the genomic level, Yersinia pestis and Yersinia pseudotuberculosis are nearly identical but cause very different diseases. Y. pestis is the etiologic agent of plague; whereas Y. pseudotuberculosis causes a gastrointestinal infection primarily after the consumption of contaminated food. In many gram-negative pathogenic bacteria, PhoP is part of a two-component global regulatory system in which PhoQ serves as the sensor kinase, and PhoP is the response regulator. PhoP is known to activate a number of genes in many bacteria related to virulence. To determine the role of the PhoPQ proteins in Yersinia infections, primarily using aerosol challenge models, the phoP gene was deleted from the chromosome of the CO92 strain of Y. pestis and the IP32953 strain of Y. pseudotuberculosis, leading to a polar mutation of the phoPQ operon. We demonstrated that loss of phoPQ from both strains leads to a defect in intracellular growth and/or survival within macrophages. These in vitro data would suggest that the phoPQ mutants would be attenuated in vivo. However, the LD(50) for the Y. pestis mutant did not differ from the calculated LD(50) for the wild-type CO92 strain for either the bubonic or pneumonic murine models of infection. In contrast, mice challenged by aerosol with the Y. pseudotuberculosis mutant had a LD(50) value 40× higher than the wild-type strain. These results demonstrate that phoPQ are necessary for full virulence by aerosol infection with the IP32953 strain of Y. pseudotuberculosis. However, the PhoPQ proteins do not play a significant role in infection with a fully virulent strain of Y. pestis., (Published by Elsevier India Pvt Ltd.)

All Bacillus spores are encased in macromolecular shells. One of these is a proteinacious shell called the coat that, in Bacillus subtilis, provides critical protective functions. The Bacillus anthracis spore is the infectious particle for the disease anthrax. Therefore, the coat is of particular interest because it may provide essential protective functions required for the appearance of anthrax. Here, we analyse a protein component of the spore outer layers that was previously designated BxpA. Our data indicate that a significant amount of BxpA is located below the spore coat and associated with the cortex. By SDS-PAGE, BxpA migrates as a 9 kDa species when extracted from Sterne strain spores, and as 11 and 14 kDa species from Ames strain spores, even though it has predicted masses of 27 and 29 kDa, respectively, in these two strains. We investigated the possibility that BxpA is subject to post-translational processing as previously suggested. In B. subtilis, a subset of coat proteins is proteolysed or cross-linked by the spore proteins YabG or Tgl, respectively. To investigate the possibility that similar processing occurs in B. anthracis, we generated mutations in the yabG or tgl genes in the Sterne and Ames strains and analysed the consequences for BxpA assembly by SDS-PAGE. We found that in a tgl mutant of B. anthracis, the apparent mass of BxpA increased. This is consistent with the possibility that Tgl directs the cross-linking of BxpA into a form that normally does not enter the gel. Unexpectedly, the apparent mass of BxpA also increased in a yabG mutant, suggesting a relatively complex role for proteolysis in spore protein maturation in B. anthracis. These data reveal a previously unobserved event in spore protein maturation in B. anthracis. We speculate that proteolysis and cross-linking are ubiquitous spore assembly mechanisms throughout the genus Bacillus.

The significance of Bacillus anthracis as an agent of bioterrorism has been well established. An understanding of both the pathogenesis and the host response is required to elucidate approaches to more rapidly detect and effectively prevent or treat anthrax. Current vaccine strategies are focused primarily on production of antibodies against the protective antigen components of the anthrax toxins, which are secreted by the bacilli. A better understanding of the dynamic morphology of the dormant and germinating spore and its interaction with the host immune system could be important in developing an optimally efficacious anthrax vaccine. A spore-associated protein was identified that was specific to the Bacillus cereus group of bacteria and referred to as spore opsonization-associated antigen A (SoaA). Immuno-electron microscopy localized this protein to the area of the cortex beneath the coat of the dormant spore. Although our data suggested that SoaA was found below the coat layers of the ungerminated spore, SoaA was involved in the interaction of spores with macrophages shortly after infection. To investigate further the specific properties of the SoaA protein, the soaA gene was inactivated in the B. anthracis Ames strain. The SoaA protein in the Ames strain of B. anthracis increased the phagocytic uptake of the spores in the presence of anti-spore antibodies. Unlike the wild-type strain, the mutant soaA : : Kan strain was not readily opsonized by anti-spore antibodies. While the mutant spores retained characteristic resistance properties in vitro and virulence in vivo, the soaA : : Kan mutant strain was significantly less suited for survival in vivo when competed against the wild-type Ames strain.

Bacillus anthracis is the causative agent of anthrax, and the spore form of the bacterium represents the infectious particle introduced into a host. The spore is surrounded by an exosporium, a loose-fitting membrane composed of proteins and carbohydrates from which hair-like projections extend. These projections are composed mainly of BclA (Bacillus-collagen-like protein of B. anthracis). To date, exact roles of the exosporium structure and BclA protein remain undetermined. We examined differences in spore binding of wild-type Ames and a bclA mutant of B. anthracis to bronchial epithelial cells as well as to the following other epithelial cells: A549, CHO, and Caco-2 cells; the IMR-90 fibroblast line; and human umbilical vein vascular endothelium cells. The binding of wild-type Ames spores to bronchial epithelial cells appeared to be a dose-dependent, receptor-ligand-mediated event. There were similar findings for the bclA mutant, with an additional nonspecific binding component likely leading to significantly more adherence to all nonprofessional phagocytic cell types. In contrast, we detected no difference in adherence and uptake of spores by macrophages for either the wild-type Ames or the bclA mutant strain. These results suggest that one potential role of the BclA fibers may be to inhibit nonspecific interactions between B. anthracis spores with nonprofessional phagocytic cells and thus direct the spores towards uptake by macrophages during initiation of infection in mammals.

The BclA protein is the immunodominant epitope on the surface of Bacillus anthracis spores; however, its roles in pathogenesis are unclear. We constructed a BclA deletion mutant (bclA) of the fully virulent Ames strain. This derivative retained full virulence in several small-animal models of infection despite the bclA deletion.