Background: Histamine is a critical mediator of anaphylaxis, a neurotransmitter, and a regulator of gastric acid secretion. Histidine decarboxylase is a rate-limiting enzyme for histamine synthesis. However, in vivo regulation of Hdc, the gene that encodes histidine decarboxylase, is poorly understood.
View Article and Find Full Text PDFJ Allergy Clin Immunol
February 2022
Background: Administering allergens in increasing doses can temporarily suppress IgE-mediated allergy and anaphylaxis by desensitizing mast cells and basophils; however, allergen administration during desensitization therapy can itself induce allergic responses. Several small molecule drugs and nutraceuticals have been used clinically and experimentally to suppress these allergic responses.
Objectives: This study sought to optimize drug inhibition of IgE-mediated anaphylaxis.
Background: Mast cell and basophil activation by antigen cross-linking of FcεRI-bound IgE is central to allergy pathogenesis. We previously demonstrated global suppression of this process by rapid desensitization with anti-FcεRIα mAbs.
Objectives: We sought to determine whether use of monovalent (mv) anti-FcεRIα mAbs increases desensitization safety without loss of efficacy.
Arthrosc Sports Med Rehabil
November 2019
Purpose: To define a distraction distance (pull length) cut-off that would differentiate those patients with hip microinstability and those without the disorder, called the Pull-Out Test.
Methods: In total, 100 consecutive patients undergoing hip arthroscopy were included in the study. Patients were separated into a hip microinstability group (HMI) and non-hip microinstability group (NHI) based on the results of Beighton's score, the abduction-extension-external rotation test, hip extension-external rotation examination, and the prone instability test.
Oseltamivir is an antiviral drug approved to treat influenza in humans. Although the dosing regimen of this drug is well established for non-pregnant patients, it is not clear if the significant physiological alterations associated with pregnancy affect the pharmacokinetics of oseltamivir and, thus, warrant different dosing regimens to assure efficacy. In this study, we investigated the suitability of rhesus macaques as an animal model for studying oseltamivir pharmacokinetics during all trimesters of pregnancy in comparison to pre-pregnant conditions.
View Article and Find Full Text PDFBackground: Anaphylaxis is classically mediated by allergen cross-linking of IgE bound to the α chain of FcεRI, the mast cell/basophil high affinity IgE receptor. Allergen cross-linking of the IgE/FcεRI complex activates these cells, inducing release of disease-causing mediators, cytokines, and enzymes. We previously demonstrated that IgE-mediated anaphylaxis could be safely prevented in wild-type BALB/c mice by rapid desensitization with anti-mouse FcεRIα mAb.
View Article and Find Full Text PDFCD1d-deficiency results in a selective deletion of NKT cells in mice that is reported to prevent murine allergic airway disease (AAD). Because we find 2-3 fold lower basal IL-4 production in CD1d- mice than in wild-type (WT) mice, we hypothesized that the contribution made by NKT cells to AAD would depend on the strength of the stimulus used to induce the disease. Consequently, we compared CD1d-deficient mice to WT mice in the development of AAD, using several models of disease induction that differed in the type and dose of allergen, the site of sensitization and the duration of immunization.
View Article and Find Full Text PDFDue to the distinctive physical, electrical, and chemical properties of graphene nanomaterials, numerous efforts pursuing graphene-based biomedical and industrial applications are underway. Oxidation of pristine graphene surfaces mitigates its otherwise hydrophobic characteristic thereby improving its biocompatibility and functionality. Yet, the potential widespread use of oxidized graphene derivatives raises concern about adverse impacts on human health.
View Article and Find Full Text PDFIL-4 has been shown to suppress acute graft vs. host disease (GVHD) in irradiated hosts. Here we evaluated whether IL-4 suppresses acute GVHD in the un-irradiated parent-into-F1 GVHD model with relevance to renal allograft rejection.
View Article and Find Full Text PDFVirtual memory (VM) CD8 T cells are present in unimmunized mice, yet possess T-cell receptors specific for foreign antigens. To date, VM cells have only been characterized in C57BL/6 mice. Here, we assessed the cytokine requirements for VM cells in C57BL/6 and BALB/c mice.
View Article and Find Full Text PDFBackground: Research has identified the core skills that predict success during primary school in reading and arithmetic, and this knowledge increasingly informs teaching. However, there has been no comparable work that pinpoints the core skills that underlie success in science.
Aims And Method: The present paper attempts to redress this by examining candidate skills and considering what is known about the way in which they emerge, how they relate to each other and to other abilities, how they change with age, and how their growth may vary between topic areas.
Mutat Res Genet Toxicol Environ Mutagen
January 2016
Closely related TK6, WTK1, and NH32 human B-lymphoblastoid cell lines differ in their p53 functional status. These lines are used frequently in genotoxicity studies and in studies aimed at understanding the role of p53 in DNA repair. Despite their routine use, little is known about the genetic status of these cells.
View Article and Find Full Text PDFThe U.S. Food and Drug Administration (FDA) and other federal agencies partner to ensure that medical countermeasures (e.
View Article and Find Full Text PDFThe widespread usage of methylphenidate (MPH) in the pediatric population has received considerable attention due to its potential effect on child development. For the first time a physiologically based pharmacokinetic (PBPK) model has been developed in juvenile and adult humans and nonhuman primates to quantitatively evaluate species- and age-dependent enantiomer specific pharmacokinetics of MPH and its primary metabolite ritalinic acid. The PBPK model was first calibrated in adult humans using in vitro enzyme kinetic data of MPH enantiomers, together with plasma and urine pharmacokinetic data with MPH in adult humans.
View Article and Find Full Text PDFBackground: Stimulatory IgG receptors (FcγRs) on bone marrow-derived cells contribute to the pathogenesis of several autoimmune and inflammatory disorders. Monoclonal antibodies that block FcγRs might suppress these diseases, but they can induce anaphylaxis.
Objective: We wanted to determine whether a rapid desensitization approach can safely suppress IgG/FcγR-mediated anaphylaxis.
Background: Rapid desensitization, a procedure in which persons allergic to an antigen are treated at short intervals with increasing doses of that antigen until they tolerate a large dose, is an effective, but risky, way to induce temporary tolerance.
Objective: We wanted to determine whether this approach can be adapted to suppress all IgE-mediated allergies in mice by injecting serially increasing doses of monoclonal antibodies (mAbs) to IgE or FcεRIα.
Methods: Active and passive models of antigen- and anti-IgE mAb-induced IgE-mediated anaphylaxis were used.
Furan, a potent rodent liver carcinogen, is found in many cooked food items and thus represents a human cancer risk. Mechanisms for furan carcinogenicity were investigated in male F344 rats using the in vivo Comet and micronucleus assays, combined with analysis of histopathological and gene expression changes. In addition, formamidopyrimidine DNA glycosylase (Fpg) and endonuclease III (EndoIII)-sensitive DNA damage was monitored as a measure of oxidative DNA damage.
View Article and Find Full Text PDFAttention deficit/hyperactivity disorder (ADHD), a common children's behavioral disorder, is characterized by inattention, hyperactivity and impulsivity. The disorder is thought to stem from abnormalities in the catecholamine pathway and the symptoms of the disorder have been successfully treated with methylphenidate (MPH) since the FDA approved the drug in the 1950s. MPH underwent the appropriate safety testing as part of the FDA approval process; however, a publication in 2005 that reported significant increases in cytogenetic damage in the lymphocytes of MPH-treated pediatric patients caused concern for patients and their families, the pharmaceutical industry and regulatory agencies.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2011
Juvenile male rhesus monkeys treated with methylphenidate hydrochloride (MPH) to evaluate genetic and behavioral toxicity were observed after 14 mo of treatment to have delayed pubertal progression with impaired testicular descent and reduced testicular volume. Further evaluation of animals dosed orally twice a day with (i) 0.5 mL/kg of vehicle (n = 10), (ii) 0.
View Article and Find Full Text PDFOur laboratory is conducting experiments designed to characterize the role of p53 in gene expression in the TSG-p53® mouse model. In the study reported here, gene expression levels in tissue derived from the testis, liver, and heart of male, 8-9 week old, p53 wild-type (WT), heterozygous (HET) or knockout (KO) mice were determined utilizing a targeted qPCR 84-gene array. The heart, liver and testis were selected because of the unique function and rate of cell division of each tissue.
View Article and Find Full Text PDFDuring an immune response, most effector T cells die, whereas some are maintained and become memory T cells. Factors controlling the survival of effector CD4(+) and CD8(+) T cells remain unclear. In this study, we assessed the role of IL-7, IL-15, and their common signal transducer, STAT5, in maintaining effector CD4(+) and CD8(+) T cell responses.
View Article and Find Full Text PDFErythrophagocytosis and inflammation from activated macrophages occur in distinct clinical scenarios. The presence of CD8(+) T cells and interferon-γ (IFN-γ) production is required to induce disease in mouse models of hemophagocytic lymphohistiocytosis. We investigated the roles of a different class of proinflammatory cytokines, interleukin-4 (IL-4) and IL-13, in the induction of inflammatory tissue macrophage accumulation and/or hemophagocytosis.
View Article and Find Full Text PDFMethylphenidate hydrochloride (MPH), a widely prescribed pediatric drug for attention deficit hyperactivity disorder, induced liver adenocarcinomas in B6C3F1 mice exposed to 500 ppm in feed for 2 years (Dunnick and Hailey (1995) [14]). In order to determine if the induction of liver tumors was by a mutagenic mode of action, groups of male Big Blue (BB) mice (B6C3F1 background) were fed diets containing 50-4000 ppm MPH for 4, 12, or 24 weeks. At sacrifice, the livers were removed and the cII mutant frequency (MF) and spectrum of cII mutations were determined.
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