Animal models of acute and chronic pancreatitis have been created to examine mechanisms of pathogenesis, test therapeutic interventions, and study the influence of inflammation on the development of pancreatic cancer. In vitro models can be used to study early stage, short-term processes that involve acinar cell responses. Rodent models reproducibly ...

The characteristics of respiratory tuberculosis (TB) favour the appearance of clusters of cases in space and time. It is important for public health authorities to know which clusters occur randomly and which merit further investigation. To detect spatial and spatio-temporal clusters of respiratory TB in Spain during the period from ...

The bioconcentration factor (BCF) of neutral and weakly polar organic chemicals in fish is modeled using independently calibrated models of chemical partitioning (φsys , KFW ), respiratory exchange (k1 , k2  = k1 /KFW ), and biotransformation (kM ) as BCF = φsys KFW /(1 + kM /k2 ). Existing k1 models tend to overestimate ...

Severe convective ventilation heterogeneity occurring in CF lung disease requires a modified method to determine acinar and conductive components of ventilation heterogeneity from normalized phaseIII slope (Sn) curves. Modified Sacin* and Scond* (as opposed to standard Sacin and Scond) are proposed and interpreted on the basis of 2 conceptual mechanisms: ...

In robotic radiosurgery, it is necessary to compensate for systematic latencies arising from target tracking and mechanical constraints. This compensation is usually achieved by means of an algorithm which computes the future target position. In most scientific works on respiratory motion prediction, only one or two algorithms are evaluated on ...

P-glycoprotein (P-gp) mediated efflux is recognised to alter the absorption and disposition of a diverse range of substrates. Despite evidence showing the presence of P-gp within the lung, relatively little is known about the transporter's effect upon the absorption and distribution of drugs delivered via the pulmonary route. Here, we ...

Control of ventilation dictates various breathing patterns. The respiratory control system consists of a central pattern generator and several feedback mechanisms that act to maintain ventilation at optimal levels. The concept of loop gain has been employed to describe its stability and variability. Synthesizing all interactions under a general model ...

BACKGROUND: Migraine is a chronic neurovascular disease characterized by recurrent unilateral headache, which induces incapacity. Despite all the progress that migraine research has provided, the neural mechanisms underlying the onset and maintenance of migraine attacks are poorly understood. Due to the complex characteristics of the disorder, it is difficult to ...

BACKGROUND: Determining the fate of inhaled contaminants in the human respiratory system has challenged scientists for years. Human and animal studies have provided some data, but there is a paucity of data for toxic contaminants and sensitive populations (such as children, elderly, diseased). METHODS: Three-dimensional modeling programs and publicly available ...

Hexabromocyclododecane diastereoisomers (α, β, and γ-HBCD) and tetrabromobisphenol A (TBBPA) were investigated in air conditioning filter dust (designated as particulate phase of indoor air, PPIA) collected from an office building in Shenzhen, China in 2009. Concentrations of ΣHBCD (sum of α-, β-, and γ-HBCD) ranged from 652 to 122, 973ng/g ...

Acute respiratory distress syndrome (ARDS) is acute lung failure secondary to severe systemic inflammation, resulting in a derangement of alveolar mechanics (i.e. the dynamic change in alveolar size and shape during tidal ventilation), leading to alveolar instability that can cause further damage to the pulmonary parenchyma. Mechanical ventilation is a ...

OBJECTIVE: The 2004 amendment to the Control of Substances Hazardous to Health 2002 regulations (COSHH 2004) introducing workplace exposure limits (WELs) was enacted in the UK in 2005. This study aimed to determine whether introducing this legislation coincided with a reduction in the incidence of work-related short latency respiratory disease ...

BACKGROUND: Particle size-selective sampling refers to the collection of particles of varying sizes that potentially reach and adversely affect specific regions of the respiratory tract. Thoracic and respirable fractions are defined as the fraction of inhaled particles capable of passing beyond the larynx and ciliated airways, respectively, during inhalation. In ...

  Laninamivir octanoate (LO) is a new neuraminidase inhibitor for inhalation. The objectives of this study were to model the population pharmacokinetics of LO and its active metabolite laninamivir after inhaled administration of LO using pooled population of healthy subjects, and adult and pediatric patients with influenza virus infection from 8 ...

ABSTRACT: The dominant contribution to the uncertainty in internal dose assessment can often be explained by the uncertainty in the biokinetic model structure and parameters. The International Commission on Radiological Protection (ICRP) is currently updating its biokinetic models, including the Human Respiratory Tract Model (HRTM). Gregoratto et al. (2010) proposed ...

Latent class transition models track how individuals move among latent classes through time, traditionally assuming a complete set of observations for each individual. In this paper, we develop group-based latent class transition models that allow for staggered entry and exit, common in surveys with rolling enrollment designs. Such models are ...

Zebrafish (Danio rerio) are emerging as a promising model organism for experimental studies relevant to biological psychiatry. The objective of this study was to develop a novel video-based movement tracking and analysis system to quantify behavioral changes following psychoactive drug exposure in zebrafish. We assessed the effects of withdrawal from ...

Purpose: The accuracy of motion prediction, utilized to overcome the system latency of motion management radiotherapy systems, is hampered by irregularities present in the patients' respiratory pattern. Audiovisual (AV) biofeedback has been shown to reduce respiratory irregularities. The aim of this study was to test the hypothesis that AV biofeedback ...

BACKGROUND:: In Ontario, Canada, the respiratory syncytial virus (RSV) prophylaxis period onset is defined by a fixed-date set provincially each year and offset by local hospital RSV admission activity. Inaccurate timing can result in inadequate or more costly prophylaxis. METHODS:: RSV positivity (2002/03-2010/11) was obtained from a local database. RSV ...

BACKGROUND: Ambulatory care sensitive hospitalizations (ACSHs) are commonly used as measures of access to and quality of care. They are defined as hospitalizations for certain acute and chronic conditions; yet, they are most commonly used in analyses comparing different groups without adjustment for individual-level comorbidity. We present an exploration of ...

Abstract Respiration-related movement of organs is a complication in a range of diagnostic and interventional procedures. The development and validation of techniques to compensate for such movement requires appropriate models. Human cadavers embalmed with the Thiel method remain flexible and could provide a suitable model. In this study liver displacement ...

Classification algorithms with unbalanced datasets tend to produce high predictive accuracy over the majority class, but poor predictive accuracy over the minority class. This problem is very common in biomedical data mining. This paper introduces a Support Vector Machine (SVM)-based optimized feature selection method, to select the most relevant features ...

An internal contamination with (241)Am was detected in a worker during a routine monitoring of workers from a company producing Am sources for smoke detectors and Am-Be neutron sources. During the 4-year period after the exposure, the number of urine and faecal samples from the worker were analysed; in vivo ...

BACKGROUND: Glycopyrronium bromide (NVA237) is a once-daily long-acting muscarinic antagonist recently approved for the treatment of chronic obstructive pulmonary disease (COPD). In this study we used population pharmacokinetic (PK) modeling to provide insights into the impact of the lung PK of glycopyrronium on its systemic PK profile and in turn ...

Animal models are vital instruments of the drug discovery process. In addition to assessing the efficacy of candidate molecules, in vivo disease models also help validate the therapeutic potential of molecular targets. Over recent years, several molecules that have shown efficacy in preclinical models of respiratory diseases have failed to ...

SUMMARY We investigated the cost-effectiveness of different influenza control strategies in a school setting in Taiwan. A susceptible-exposure-infected-recovery (SEIR) model was used to simulate influenza transmission and we used a basic reproduction number (R 0)-asymptomatic proportion (θ) control scheme to develop a cost-effectiveness model. Based on our dynamic transmission model ...

Objective: The aim of this study was to use meta-analytic techniques to compare self-concept between children and adolescents (abbreviated to youth) with a chronic illness versus healthy controls, and to examine methodological influences on effect sizes. Method: Databases were searched for asthma, cerebral palsy, diabetes, epilepsy, and juvenile arthritis. Inclusion ...

ABSTRACT: Americium-241 (Am) is the second most significant radiation hazard after Pu at some of the Mayak Production Association facilities. This study summarizes current data on the accumulation, distribution, and excretion of americium compared with plutonium in different organs from former Mayak PA workers. Americium and plutonium were measured in ...

Multiple imputation is a common technique for dealing with missing values and is mostly applied in regression settings. Its application in cluster analysis problems, where the main objective is to classify individuals into homogenous groups, involves several difficulties which are not well characterized in the current literature. In this paper, ...

There is still an unexplored potential for exhaled nitric oxide (NO) in many clinical applications. This study presents an overview of the currently available methods for monitoring NO in exhaled breath and the use of the modelling of NO production and transport in the lung in clinical practice. Three technologies ...

A biomathematical model was previously developed to describe the long-term clearance and retention of particles in the lungs of coal miners. The model structure was evaluated and parameters were estimated in two data sets, one from the United States and one from the United Kingdom. The three-compartment model structure consists ...

We present a novel method for estimating respiratory rate in real-time from the photoplethysmogram (PPG) obtained from pulse oximetry. Three respiratory induced variations (frequency, intensity, and amplitude) are extracted from the PPG using the Incremental-Merge Segmentation algorithm. Frequency content of each respiratory induced variation is analyzed using Fast Fourier Transforms. ...

The response of respiratory tract tissue target sites to inhaled vapors depends on the amount of inhaled vapor that is delivered to those sites. Direct measurement of vapor absorption within a specific airway of the living animal requires that the airway be isolated, which currently can only be performed on ...

Subtle changes in either breathing pattern or cardiac pulse rate alter blood oxygen level dependent functional magnetic resonance imaging signal (BOLD fMRI). This is problematic because such fluctuations could possibly not be related to underlying neuronal activations of interest but instead the source of physiological noise. Several methods have been ...

It has been suggested that loss of the astrocytic water channel aquaporin-4 (AQP4) from perivascular endfeet in sclerotic hippocampi contributes to increased seizure propensity in human mesial temporal lobe epilepsy (MTLE). Whether this loss occurs prior to or as a consequence of epilepsy development remains to be resolved. In the ...

Our understanding of the sites and mechanisms underlying rhythmic breathing as well as the neuromodulatory control of respiratory rhythm, pattern, and respiratory motoneuron excitability during perinatal development has advanced significantly over the last 20 years. A major catalyst was the development in 1991 of the rhythmically-active medullary slice preparation, which ...

This study provides for the first time the 96h toxicity of 30 phenols to Chlorella vulgaris. Analysis of the novel data set revealed that the algal toxicity of polar narcotics and respiratory uncouplers was correlated strongly to the pH corrected hydrophobicity parameter, Log D, demonstrating the importance of ionization in ...

We design a impulse radio ultra-wideband (IR UWB) radar monitoring system to track the chest wall movement of a human subject during respiration. Multiple sensors are placed at different locations to ensure that the backscattered signal could be detected by at least one sensor no matter which direction the human ...

Chronic hepatitis B (CHB) is a serious public health problem, and Traditional Chinese Medicine (TCM) plays an important role in the control and treatment for CHB. In the treatment of TCM, zheng discrimination is the most important step. In this paper, an approach based on CFS-GA (Correlation based Feature Selection ...

Due to the constant expansion within the nanotechnology industry in the last decade, nanomaterials are omnipresent in society today. Nanotechnology-based products have numerous different applications ranging from electronic (e.g., advanced memory chips) to industrial (e.g., coatings or composites) to biomedical (e.g., drug delivery systems, diagnostics). Although these new nanomaterials can ...

Parkinson's disease (PD) is characterized by a progressive degeneration of dopamine (DA) neurons and a chronic loss of motor functions. The investigation of progressive degenerative mechanisms and possible neuroprotective approaches for PD depends upon the development of an experimental animal model that reproduces the neuropathology observed in humans. This chapter ...

The medullary respiratory network generates respiratory rhythm via sequential phase switching, which in turn is controlled by multiple feedbacks including those from the pons and nucleus tractus solitarii; the latter mediates pulmonary afferent feedback to the medullary circuits. It is hypothesized that both pontine and pulmonary feedback pathways operate via ...

Current trends in US population growth, age distribution, and disease dynamics foretell rises in the prevalence of chronic diseases and other chronic conditions. These trends include the rapidly growing population of older adults, the increasing life expectancy associated with advances in public health and clinical medicine, the persistently high prevalence ...

We tested whether snow gum (Eucalyptus pauciflora) trees growing in thermally contrasting environments exhibit generalizable temperature (T)-response functions of leaf respiration (R) and fluorescence (F(o) ). Measurements were made on pot-grown saplings and field-grown trees (growing between 1380-2110 m asl). Using a continuous, high-resolution protocol, we: quantified T-response curves of ...

Vlemincx, E., J. L. Abelson, P. M. Lehrer, P. W. Davenport, I. Van Diest and O. Van den Bergh. Respiratory variability and sighing: A psychophysiological model. Whereas respiratory psychophysiological research has mainly studied respiratory time and volume, variability in these parameters has been largely disregarded, even though it may provide ...

Noninvasive mechanical ventilation is today often used to assist patient with chronic respiratory failure. One of the main reasons evoked to explain asynchrony events, discomfort, unwillingness to be treated, etc. is the occurrence of nonintentional leaks in the ventilation circuit which are difficult to account for because they are not ...

ABSTRACT: Biologically motivated mathematical models, which describe the dynamics of the thrombocytopoietic, granulocytopoietic, and erythropoietic systems in irradiated humans, are thoroughly investigated. These models are the systems of nonlinear ordinary differential equations, whose variables and constant parameters have clear biological meaning. The modeling studies reveal general regularities and peculiarities of ...

There is an increasing interest in the use of hospital admission for Chronic obstructive pulmonary disease (COPD) in studies of short-term exposure effects attributed to air pollutants. However, little is known about the effect of air pollutants on COPD symptoms. This study was undertaken to determine whether there was an ...

The aim of this work is to study the morphological characteristics of the trachea of Saimiri sciureus through quantification and measurement of the cartilaginous rings, providing information to facilitate the election of more appropriate endotracheal tube, laryngeal mask or tracheostomy tube for anesthetic and emergency procedures, as it is a ...

Knowledge of the mechanical behavior of immature airways is crucial to understand the effects exerted by ventilation treatments, namely by Total Liquid Ventilation (TLV). A computational approach was adopted to investigate preterm airways in the range of pressure applied during TLV. A 3D finite-element model of the tracheal bifurcation was ...