Development of a novel air-liquid interface airway tissue equivalent model for in vitro respiratory modeling studies.

The human airways are complex structures with important interactions between cells, extracellular matrix (ECM) proteins and the biomechanical microenvironment. A robust, well-differentiated in vitro culture system that accurately models these interactions would provide a useful tool for studying normal and pathological airway biology. Here, we report the development and characterization of a physiologically relevant air-liquid interface (ALI) 3D airway 'organ tissue equivalent' (OTE) model with three novel features: native pulmonary fibroblasts, solubilized lung ECM, and hydrogel substrate with tunable stiffness and porosity.

Step Length Estimation with Wearable Wrist Sensor using ANN.

Step Length is an important metric that can be used for the analysis and assessment of the gait. Proper dynamical models are not available in current literature associated with the wrist that can adequately determine the step length using recursive estimation techniques. This study presents a method to estimate the step length using angular velocity data from the wrist sensor.

Estimation of Step Length With Wearable Thigh Sensor Using an Unscented Kalman Filter.

The determination of step length, an important gait parameter, has been a challenging task. Although unobtrusive sensors (inertial measurement units) have been developed recently, they cannot facilitate the automatic estimation of step length. In this article, we use a model-based technique to determine the step length using the Unscented Kalman Filter with angular velocity from a gyroscope inside the thigh pocket.

Noninvasive cuffless blood pressure estimation using pulse transit time, Womersley number, and photoplethysmogram intensity ratio.

Objective: Continuous cuffless blood pressure (BP) monitoring research has emerged as blood pressure is one of the dynamic parameters which reflects cardiac arrhythmias and rheological disorders without the drawbacks of current techniques. All the existing measurement techniques are cuff-based with drawbacks such as being discontinuous in nature, being uncomfortable for the patient, etc. Therefore, the goal is to develop an algorithm to estimate BP accurately using the pulse transit time (PTT), photoplethysmogram intensity ratio (PIR) and Womersley number (α) in a noninvasive way.

Autoinducer 2 (AI-2) Production by Nontypeable Haemophilus influenzae 86-028NP Promotes Expression of a Predicted Glycosyltransferase That Is a Determinant of Biofilm Maturation, Prevention of Dispersal, and Persistence .

Nontypeable (NT) is an extremely common human pathobiont that persists on the airway mucosal surface within biofilm communities, and our previous work has shown that NT biofilm maturation is coordinated by the production and uptake of autoinducer 2 (AI-2) quorum signals. To directly test roles for AI-2 in maturation and maintenance of NT biofilms, we generated an NT 86-028NP mutant in which transcription was under the control of the promoter (NT 86-028NP ::), rendering AI-2 production inducible by xylose. Comparison of biofilms under inducing and noninducing conditions revealed a biofilm defect in the absence of xylose, whereas biofilm maturation increased following xylose induction.

Unmasking of atrial repolarization waves using a simple modified limb lead system.

Objective: In the present study, a modified limb lead (MLL) system was used to record the Ta wave in sinus rhythm and with AV block in male patients.

Methods: Eighty male subjects (mean age 36 ± 7 years) in sinus rhythm and 20 male patients with AV block (mean age 72 ± 5 years) were included in this study. Standard limb lead (SLL) ECGs and MLL ECGs were recorded for 60 seconds each with an EDAN SE-1010 PC ECG system.

Replication of type 5 adenovirus promotes middle ear infection by Streptococcus pneumoniae in the chinchilla model of otitis media.

Adenoviral infection is a major risk factor for otitis media. We hypothesized that adenovirus promotes bacterial ascension into the middle ear through the disruption of normal function in the Eustachian tubes due to inflammation-induced changes. An intranasal infection model of the chinchilla was used to test the ability of type 5 adenovirus to promote middle ear infection by Streptococcus pneumoniae.

Normal limits of ECG measurements related to atrial activity using a modified limb lead system.

Objective: The present study was designed to derive the normal limits of a new ECG lead system aimed at enhancing the amplitude of atrial potentials through the use of bipolar chest leads.

Methods: Sixty healthy male subjects, mean age 38.85±8.

Aging and oxidative stress reduce the response of human articular chondrocytes to insulin-like growth factor 1 and osteogenic protein 1.

Objective: To determine the effects of aging and oxidative stress on the response of human articular chondrocytes to insulin-like growth factor 1 (IGF-1) and osteogenic protein 1 (OP-1).

Methods: Chondrocytes isolated from normal articular cartilage obtained from tissue donors were cultured in alginate beads or monolayer. Cells were stimulated with 50-100 ng/ml of IGF-1, OP-1, or both.

Endogenous Gs-coupled receptors in smooth muscle exhibit differential susceptibility to GRK2/3-mediated desensitization.

Although G protein-coupled receptor (GPCR) kinases (GRKs) have been shown to mediate desensitization of numerous GPCRs in studies using cellular expression systems, their function under physiological conditions is less well understood. In the current study, we employed various strategies to assess the effect of inhibiting endogenous GRK2/3 on signaling and function of endogenously expressed G s-coupled receptors in human airway smooth muscle (ASM) cells. GRK2/3 inhibition by expression of a Gbetagamma sequestrant, a GRK2/3 dominant-negative mutant, or siRNA-mediated knockdown increased intracellular cAMP accumulation mediated via beta-agonist stimulation of the beta-2-adrenergic receptor (beta 2AR).

Cooperative mitogenic signaling by G protein-coupled receptors and growth factors is dependent on G(q/11).

Previously we reported that the G protein-coupled receptor (GPCR) agonist thrombin potentiated the mitogenic effect of epidermal growth factor (EGF) on human airway smooth muscle (ASM) by promoting sustained late-phase activation of PI3K and p70S6K via a pathway dependent on Gbetagamma subunits of heterotrimeric G proteins. Here, we provide additional mechanistic insight and reveal the robustness of this phenomenon by demonstrating that H1 histamine and thromboxane receptors utilize the same mechanism to augment ASM growth via specific activation of the heterotrimeric G protein G(q/11). Thrombin, histamine, and U46619 all enhanced EGF-stimulated [3H]-thymidine incorporation as well as late-phase Akt and p70S6K phosphorylation in ASM cultures.