Enhanced β(2)-adrenergic receptor (β(2)AR) signaling by adeno-associated viral (AAV)-mediated gene transfer

BACKGROUND: β(2)-Adrenergic receptors (β(2)AR) play important regulatory roles in a variety of cells and organ systems and are important therapeutic targets in the treatment of airway and cardiovascular disease. Prolonged use of β-agonists results in tolerance secondary to receptor down-regulation resulting in reduced therapeutic efficiency. The purpose of this work is to evaluate the signaling capabilities of the β(2)AR expressed by a recombinant adeno-associated viral (AAV) vector that also included an enhanced green fluorescent protein (EGFP) gene (AAV-β(2)AR/EGFP). RESULTS: By epifluorescence microscopy, ~40% of infected HEK 293 cells demonstrated EGFP expression. β(2)AR density measured with [(3)H]dihydroalprenolol ([(3)H]DHA) increased either 13- or 77-fold in infected cells compared to mock infected controls depending on the culture conditions used. The [(3)H]DHA binding was to a single receptor population with a dissociation constant of 0.42 nM, as would be expected for wild-type β(2)AR. Agonist competition assays with [(3)H]DHA showed the following rank order of potency: isoproterenol>epinephrine> norepinephrine, consistent with β(2)AR interaction. Isoproterenol-stimulated cyclic AMP levels were 5-fold higher in infected cells compared to controls (314 ± 43 vs. 63.4 ± 9.6 nmol/dish; n = 3). Receptor trafficking demonstrated surface expression of β(2)AR with vehicle treatment and internalization following isoproterenol treatment. CONCLUSIONS: We conclude that HEK 293 cells infected with AAV-β(2)AR/EGFP effectively express β(2)AR and that increased expression of these receptors results in enhanced β(2)AR signaling. This method of gene transfer may provide an important means to enhance function in in vivo systems

Perspectives of older adults on co-management of low back pain by doctors of chiropractic and family medicine physicians: a focus group study.

BACKGROUND: While older adults may seek care for low back pain (LBP) from both medical doctors (MDs) and doctors of chiropractic (DCs), co-management between these providers is uncommon. The purposes of this study were to describe the preferences of older adults for LBP co-management by MDs and DCs and to identify their concerns for receiving care under such a treatment model. METHODS: We conducted 10 focus groups with 48 older adults who received LBP care in the past year. Interviews explored participants\u27 care seeking experiences, co-management preferences, and perceived challenges to successful implementation of a MD-DC co-management model. We analyzed the qualitative data using thematic content analysis. RESULTS: Older adults considered LBP co-management by MDs and DCs a positive approach as the professions have complementary strengths. Participants wanted providers who worked in a co-management model to talk openly and honestly about LBP, offer clear and consistent recommendations about treatment, and provide individualized care. Facilitators of MD-DC co-management included collegial relationships between providers, arrangements between doctors to support interdisciplinary referral, computer systems that allowed exchange of health information between clinics, and practice settings where providers worked in one location. Perceived barriers to the co-management of LBP included the financial costs associated with receiving care from multiple providers concurrently, duplication of tests or imaging, scheduling and transportation problems, and potential side effects of medication and chiropractic care. A few participants expressed concern that some providers would not support a patient-preferred co-managed care model. CONCLUSIONS: Older adults are interested in receiving LBP treatment co-managed by MDs and DCs. Older adults considered patient-centered communication, collegial interdisciplinary interactions between these providers, and administrative supports such as scheduling systems and health record sharing as key components for successful LBP co-management

Development and Application of a Functional Human Esophageal Mucosa Explant Platform to Eosinophilic Esophagitis.

There is an increasing prevalence of esophageal diseases but intact human tissue platforms to study esophageal function, disease mechanisms, and the interactions between cell types in situ are lacking. To address this, we utilized full thickness human donor esophagi to create and validate the ex vivo function of mucosa and smooth muscle (n = 25). Explanted tissue was tested for contractile responses to carbachol and histamine. We then treated ex vivo human esophageal mucosa with a cytokine cocktail to closely mimic the Th2 and inflammatory milieu of eosinophilic esophagitis (EoE) and assessed alterations in smooth muscle and extracellular matrix function and stiffening. We found that full thickness human esophagus as well as the individual layers of circular and longitudinal muscularis propria developed tension in response to carbachol ex vivo and that mucosa demonstrated squamous cell differentiation. Treatment of mucosa with Th2 and fibrotic cytokines recapitulated the majority of the clinical Eosinophilic Esophagitis Diagnostic Profile (EDP) on fluidic transcriptional microarray. Transforming growth factor-beta-1 (TGFβ1) increased gene expression of fibronectin, smooth muscle actin, and phospholamban (p < 0.001). The EoE cocktail also increased stiffness and decreased mucosal compliance, akin to the functional alterations in EoE (p = 0.001). This work establishes a new, transcriptionally intact and physiologically functional human platform to model esophageal tissue responses in EoE

Characterization of a panel of six β2-adrenergic receptor antibodies by indirect immunofluorescence microscopy

<p>Abstract</p> <p>Background</p> <p>The β₂-adrenergic receptor (β₂AR) is a primary target for medications used to treat asthma. Due to the low abundance of β₂AR, very few studies have reported its localization in tissues. However, the intracellular location of β₂AR in lung tissue, especially in airway smooth muscle cells, is very likely to have a significant impact on how the airways respond to β-agonist medications. Thus, a method for visualizing β₂AR in tissues would be of utility. The purpose of this study was to develop an immunofluorescent labeling technique for localizing native and recombinant β₂AR in primary cell cultures.</p> <p>Methods</p> <p>A panel of six different antibodies were evaluated in indirect immunofluorescence assays for their ability to recognize human and rat β₂AR expressed in HEK 293 cells. Antibodies capable of recognizing rat β₂AR were identified and used to localize native β₂AR in primary cultures of rat airway smooth muscle and epithelial cells. β₂AR expression was confirmed by performing ligand binding assays using the β-adrenergic antagonist [3H] dihydroalprenolol ^([3H]DHA).</p> <p>Results</p> <p>Among the six antibodies tested, we identified three of interest. An antibody developed against the C-terminal 15 amino acids of the human β₂AR (Ab-Bethyl) specifically recognized human but not rat β₂AR. An antibody developed against the C-terminal domain of the mouse β₂AR (Ab-sc570) specifically recognized rat but not human β₂AR. An antibody developed against 78 amino acids of the C-terminus of the human β₂AR (Ab-13989) was capable of recognizing both rat and human β₂ARs. In HEK 293 cells, the receptors were predominantly localized to the cell surface. By contrast, about half of the native rat β₂AR that we visualized in primary cultures of rat airway epithelial and smooth muscle cells using Ab-sc570 and Ab-13989 was found inside cells rather than on their surface.</p> <p>Conclusion</p> <p>Antibodies have been identified that recognize human β₂AR, rat β₂AR or both rat and human β₂AR. Interestingly, the pattern of expression in transfected cells expressing millions of receptors was dramatically different from that in primary cell cultures expressing only a few thousand native receptors. We anticipate that these antibodies will provide a valuable tool for evaluating the expression and trafficking of β₂AR in tissues.</p

Diagnosis, Management, and Investigational Therapies for Food Allergies

Food allergies have increased in prevalence over the past 20 years, now becoming an important public health concern. Although there are no therapies currently available for routine clinical care, recent reports have indicated that immunotherapies targeting the mucosal immune system may be effective. Oral immunotherapy is conducted by administering small, increasing amounts of food allergen; it has shown promise for desensitizing individuals with peanut, egg, or milk allergies. Sublingual immunotherapy also desensitizes allergic patients to foods—2 major studies have examined the effects of sublingual immunotherapy in subjects with peanut allergies. We review the complex nature of IgE-mediated food allergies and the therapies being evaluated in clinical trials. We focus on the diagnosis and management of food allergies and investigational therapies

Early-life gut microbiome composition and milk allergy resolution

Gut microbiota may play a role in the natural history of cow’s milk allerg

Patient-Clinician Decision Making for Stable Angina: The Role of Health Literacy

Background: Stable angina patients have difficulty understanding the tradeoffs between treatment alternatives. In this analysis, we assessed treatment planning conversations for stable angina to determine whether inadequate health literacy acts as a barrier to communication that may partially explain this difficulty. Methods: We conducted a descriptive analysis of patient questionnaire data from the PCI Choice Trial. The main outcomes were the responses to the Decisional Conflict Scale and the proportion of correct responses to knowledge questions about stable angina. We also conducted a qualitative analysis on recordings of patient-clinician discussions about treatment planning. The recordings were coded with the OPTION12 instrument for shared decision-making. Two analysts independently assessed the number and types of patient questions and expressions of preferences. Results: Patient engagement did not differ by health literacy level and was generally low for all patients with respect to OPTION12 scores and the number of questions related to clinical aspects of treatment. Patients with inadequate health literacy had significantly higher decisional conflict. However, the proportion of knowledge questions answered correctly did not differ significantly by health literacy level. Conclusions: Patients with inadequate health literacy had greater decisional conflict but no difference in knowledge compared to patients with adequate health literacy. Inadequate health literacy may act as a barrier to communication, but gaps were found in patient engagement and knowledge for patients of all health literacy levels. The recorded patient-clinician encounters and the health literacy measure were valuable resources for conducting research on care delivery

Impact of Allergic Reactions on Food-Specific IgE Concentrations and Skin Test Results

Although there is concern that food allergic reactions may negatively affect the natural history of food allergy, the impact of reactions on food-specific IgE (sIgE) or skin prick tests is unknown

Long-term treatment with egg oral immunotherapy enhances sustained unresponsiveness that persists after cessation of therapy

We previously reported results of a randomized, placebo-controlled study of egg oral immunotherapy (eOIT), in which 27.5% of subjects achieved sustained unresponsiveness (SU) after 2 years. Here we report results of treatment through 4 years and long-term follow-up