Publications by authors named "Yocum M"

Vasodilation of lower leg arterioles is impaired in animal models of chronic peripheral ischemia. In addition to arterioles, feed arteries are a critical component of the vascular resistance network, accounting for as much as 50% of the pressure drop across the arterial circulation. Despite the critical importance of feed arteries in blood flow control, the impact of ischemia on feed artery vascular reactivity is unknown.

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Objective: Th17 cells (interleukin-17 [IL-17]-secreting T helper cells) have been implicated in the pathogenesis of rheumatoid arthritis and other autoimmune diseases, but the soluble factors that influence human Th17 differentiation have yet to be fully elucidated. This study was undertaken to investigate the hypothesis that the cytokines secreted by human peripheral blood mononuclear cells (PBMCs) in response to a subset of Toll-like receptor (TLR) ligands would influence Th17 polarization.

Methods: Supernatants from human PBMCs treated with a panel of TLR agonists were tested for their ability to induce de novo IL-17 production in naive T helper cells.

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We study the phase behavior and microstructure of alkyl-beta-monoglucosides with intermediate chain lengths (octyl- and nonyl-beta-glucoside) in aqueous solutions containing ammonium sulfate and poly(ethylene glycol) (PEG). When the glucoside surfactants are mixed with PEG of molecular weight 3350 or larger, two different phase transitions are observed in the temperature range 0-100 degrees C, with lower and upper miscibility gaps separated by a one-phase isotropic region. Isothermal titration calorimetry is used to quantify the effect of PEG on the micellization properties of the alkyl monoglucosides, whereas small-angle neutron scattering gives insight into the microstructure of the surfactant/polymer mixtures near the liquid-liquid phase boundary.

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Background: Awareness of the clinical features of anaphylaxis and its causative triggers is important if recurrent episodes are to be avoided. The incidence of anaphylaxis in the general population is often underreported, and epidemiologic studies are few. Because an accurate profile of anaphylaxis could heighten awareness of this problem, we investigated the epidemiology of anaphylaxis in the general population of Olmsted County, Minn.

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Objective: To report the clinical responses and mediator-release profiles of an aspirin-sensitive man with systemic mast cell disease during aspirin desensitization.

Material And Methods: We quantified the release of six mediators during aspirin desensitization.

Results: Although aspirin was administered cautiously with an initial dose of 20 mg, successful aspirin desensitization necessitated complete monitoring and resuscitation capabilities of a medical intensive-care unit for 4.

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Background: Only a few groups have reported on idiopathic anaphylaxis. We analyzed our experience with idiopathic anaphylaxis, especially in regards to prognosis.

Methods: Thirty-seven patients with the diagnosis of idiopathic anaphylaxis were retrospectively identified by a medical records search from 1989-1992.

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Aspirin therapy for patients with systemic mast cell disease (SMCD) decreases the production of prostaglandin D2, which is thought to be a major mediator of flushing. Paradoxically, in 5 to 10% of patients with SMCD, administration of aspirin causes massive mediator release and an anaphylactoid reaction. We attempted aspirin desensitization in a 34-year-old man with SMCD (confirmed by bone marrow biopsy) who was incapacitated by severe flushing episodes and hypotension.

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Design: A quality-control retrospective review of medical records was conducted for cases of anaphylaxis encountered at Mayo Clinic Rochester during a 3 1/2-year period.

Patients: For inclusion in the study, all patients had to manifest general symptoms of mediator release such as generalized pruritus, urticaria, angioedema, and flushing. Of the 179 patients with anaphylaxis (mean age, 36 years), 66% were female, 49% had atopy, and 37% had a previous history of immediate reactions to allergens.

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A case of common variable immunodeficiency, a relatively rare disorder, is presented. This case was complicated by the presence of an anti-IgA antibody in the patient's serum and a history of a possible anaphylactic reaction to a prior intravenous infusion of gamma-globulin. Common variable immunodeficiency is actually a heterogeneous group of demonstrable immunoglobulin deficiencies that have in common low levels of most immunoglobulin isotypes, the inability to form antibodies to antigen, an absence of gross defects in cell-mediated immunity, and the presence of recurrent bacterial infections.

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Intravenous pretesting with radiocontrast media (RCM) was performed in 204 RCM-sensitive patients considered for repeat contrast radiography. Group 1 had vague histories of prior anaphylactoid reaction and negative pretests, and 2 of 41 (4.9%) had reactions upon contrast radiography.

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Anaphylactoid reactions to protamine sulfate have been attributed to its capacity for nonimmunologic mast cell degranulation and/or complement consumption. In the current study, evidence is presented for the occurrence of an immunologic anaphylactic reaction mediated by a complement-dependent IgG skin-sensitizing antibody. A retrospective study of blood component donors given protamine for heparin neutralization revealed that prior exposure to protamine is associated with increased risk of adverse reaction to the drug.

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Three weeks after a massive inhalation of mold present on infected oats, a farmer's wife had extrinsic allergic alveolitis. Aspergillus fumigatus was cultured from the moldy oats and from deep bronchial washings obtained at fiberoptic bronchoscopy. Spores and hyphae characteristic of Aspergillus species were demonstrated within granulomas in the pulmonary tissue obtained by transbrochial biopsy.

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Two adult men with recurrent pyoderma due to Staphylococcus aureus and a selective deficiency of immunoglobulin M (IgM) antibody synthesis are described. An analysis of each patient's polymorphonuclear leukocyte chemotaxis, phagocytosis and killing of Staph. aureus, serum opsonizaiton of Staph.

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Parameters of cell-mediated immunity (CMI) were studied in 17 allergic rhinitis patients selected for markedly elevated total serum IgE levels (greater than 300 IU/ml) and 14 normal controls. Mean serum IgE levels were 1,421 IU/ml and 101 IU/ml in the allergic and control groups, respectively (p less than 0.001).

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A pair of monozygotic twins discordant for systemic lupus erythematosus(SLE) were studied and no differences noted in their immune respose to tetanus toxoid, keyhole lympet hemocyanin, DNCB, delayed sensitivity, or antibody titers to viruses. Both were noted to have biologically false positive serology at an early age, but only one twon developed SLE. The clinically unaffected twin underwent castration at an early age, suggesting that ovarian hormones may play an important role in the development of SLE.

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