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Repetitive exposure to bioaerosols in swine production facilities (SPF) promotes respiratory dysfunction in workers and animals. An adequate understanding of the impact of the SPF environment on pulmonary physiology is needed. However, there is currently no sufficient ex vivo model to investigate the cause for agriculture-related lung disease. The precision cut lung slices (PCLS) technique represents a practical and useful procedure for ex vivo studies. Our goal was to use the PCLS technique to develop a model of agriculture-related lung diseases using a physiologically relevant animal model, the domesticated pig. Freshly prepared pig lung tissue cores were sectioned into 300 µm slices and viability was measured by lactate dehydrogenase activity and live/dead staining. Airway contractility in response to a methacholine (MCh) dose gradient (10(-7)-10(-4) M) was measured. After the last MCh dose, PCLS were incubated with 1 mM chloroquine to allow airways to relax. Time-lapse images were taken every minute for 35 minutes and used to determine airway lumen area changes. Porcine PCLS remained viable and demonstrated metabolic activity for three days. PCLS from indoor and outdoor pigs contracted in response to MCh exposure and relaxed when incubated with chloroquine. Notably, PCLS of indoor pigs showed greater airway constriction in response to 10(-5) M MCh exposure compared to outdoor pig PCLS (P

Magnesium (Mg)-based alloys have the potential for bone repair due to their properties of biodegradation, biocompatibility, and structural stability, which can eliminate the requirement for a second surgery for the removal of the implant. Nevertheless, uncontrolled degradation rate and possible cytotoxicity of the corrosion products at the implant sites are known current challenges for clinical applications. In this study, we assessed in vitro cytotoxicity of different concentrations (0 to 50 mM) of possible corrosion products in the form of magnesium oxide (MgO) and magnesium hydroxide (Mg(OH)2) nanoparticles (NPs) in human fetal osteoblast (hFOB) 1.19 cells. We measured cell proliferation, adhesion, migration, and cytotoxicity using a real-time, label-free, non-invasive electric cell-substrate impedance sensing (ECIS) system. Our results suggest that 1 mM concentrations of MgO/Mg(OH)2 NPs are tolerable in hFOB 1.19 cells. Based on our findings, we propose the development of innovative biodegradable Mg-based alloys for further in vivo animal testing and clinical trials in orthopedics.

Biodegradable magnesium (Mg) alloys have potential applications in orthopedic implants due to their mechanical and osseointegration properties. However, the surface characteristics, biocompatibility, and toxicity of the released corrosion products in the form of magnesium oxide (MgO) and magnesium hydroxide (Mg(OH)2) nanoparticles (NPs) at the junction of implants and in the surrounding tissue are not completely understood. Here, we investigated in vitro cytotoxicity and morphological changes in human fetal osteoblast (hFOB) 1.19 cells in response to various concentrations (1 mM, 5 mM, 10 mM, and 50 mM) of MgO/Mg(OH)2 NPs by live/dead assay and scanning electron microscopy (SEM). In this study, we performed a surface characterization of MgO/Mg(OH)2 NPs to evaluate the size of the NPs. Further, an immersion test was performed in Dulbecco&rsquo, s Modified Eagle&rsquo, s Medium (DMEM) with randomly selected various concentrations (1 mM, 5 mM, 10 mM, 50 mM, and 100 mM) of MgO/Mg(OH)2 NPs to understand the degradation behavior of the NPs, and the change in the pH values from days 1 to 7 was measured. After conducting an immersion test for seven days, the highest concentration (100 mM) of MgO/Mg(OH)2 NPs was selected to study the element depositions on nanoparticles through scanning electron microscopy&ndash, energy-dispersive X-ray spectroscopy (SEM&ndash, EDX) mapping. The results from this in vitro cytotoxicity study suggest that less than or equal to 5-mM concentrations of MgO/Mg(OH)2 NPs are tolerable concentrations for hFOB 1.19 cells. This study provides a foundational knowledge of MgO/Mg(OH)2 NP cytotoxicity in hFOB 1.19 cells that can help to develop future sustainable biodegradable magnesium-based alloys for orthopedic applications.

Exposure to hog barn organic dust contributes to occupational lung diseases, which are mediated by inflammatory and oxidative stress pathways. Isoprostanes—a family of eicosanoids produced by oxidation of phospholipids by oxygen radicals—are biomarkers of pulmonary oxidative stress. Importantly, 8-isoprostane has been implicated as a key biomarker and mediator of oxidative stress because it is a potent pulmonary vasoconstrictor. Antioxidants found in fruits and vegetables hold promise for preventing or reducing effects of oxidative stress-related diseases including chronic bronchitis and chronic obstructive pulmonary disease (COPD). Here, we investigated 8-isoP and oxidant production by organic dust-exposed airway epithelial cells and the inhibitory effects of an extract from calyces of the sorrel plant, Hibiscus sabdariffa, on oxidant-producing pathways. Confluent cultures of normal human tracheobronchial epithelial cells were pretreated or not with 1% sorrel extract prior to 5% dust extract (DE) exposure. Following DE treatments, live cells, cell-free supernatants, or cell extracts were evaluated for the presence of 8-isoprostane, superoxide, hydrogen peroxide, nitric oxide, hydroxyl radical, peroxynitrite, and catalase activity to evaluate sorrel’s inhibitory effect on oxidative stress. The well-known radical scavenging antioxidant, N-acetyl cysteine (NAC), was used for comparisons with sorrel. DE exposure augmented the production of all radicals measured including 8-isoprostane (p value < 0.001), which could be inhibited by NAC or sorrel. Among reactive oxygen and nitrogen species generated in response to DE exposure, sorrel had no effect on H2O2 production and NAC had no significant effect on NO⋅ production. The observations reported here suggest a possible role for sorrel in preventing 8-isoprostane and oxidant-mediated stress responses in bronchial epithelial cells exposed to hog barn dust. These findings suggest a potential role for oxidative stress pathways in mediating occupational lung diseases and antioxidants within sorrel and NAC in reducing dust-mediated oxidative stress within the airways of exposed workers.

Exposure to indoor swine production facilities (SPF) environments causes airway inflammation and diseases including asthma, chronic bronchitis and chronic obstructive pulmonary disease (COPD) in facility workers. However, less is known about the impact of SPF exposures on the respiratory health of pigs. Respiratory symptoms are associated with repeat exposure to SPF, specifically inhalation of organic dust and other air pollutants therein. A thorough understanding of the molecular pathways regulated by SPF exposure is needed to understand airway inflammation and chronic inflammatory lung disease. The present study measured the expression of proteins associated with oxidative stress and antioxidant defenses in the tracheal epithelial tissues of pigs reared in SPF or on pasture. Proteome profiler cell stress arrays, western blotting and enzyme activity assays were utilized to measure protein expression and activity levels in tracheal epithelial tissue extracts of pigs. It was determined that pigs raised in SPF express significantly less enzymatic antioxidants, including superoxide dismutase (SOD), within their tracheal epithelial tissues compared to pasture raised pigs. Concomitantly, tracheal epithelial tissues of SPF raised pigs had lower SOD and catalase antioxidant activity levels compared to pasture raised pigs. The observations summarized herein provide evidence that exposure to swine production environments influence endogenous enzymatic antioxidant defenses within the tracheal epithelial tissues of pigs. This study offers insight for understanding the effect of continuous exposure to SPF pollutants on endogenous antioxidant defenses in the airway epithelial and may be helpful in understanding human airway responses to swine barn exposures.

This paper investigates the direct-write inkjet method for depositing multi-layer coatings of biodegradable polymers on magnesium alloy surface. Immersion studies were conducted on Poly(lactic-co-glycolic) acid (PLGA), polycaprolactone (PCL), and poly-ester urethane urea (PEUU) coatings to determine the corrosion behavior of different samples based on their varying degradation properties. Using the inductively coupled plasma spectroscopy, a reduction in magnesium ion concentration was observed from the polymer-coated samples indicative of the lower corrosion rates as compared to the uncoated Mg substrate. Findings also showed correlation between the release of the magnesium ions and the health of fully differentiated normal human bronchial epithelial (NHBE) cells via evaluation of key biomarkers of inflammation and toxicity, cyclooxygenase-2 (COX-2) and lactate dehydrogenase (LDH), respectively. The induction of COX-2 gene expression was proportional to the increase in magnesium exposure. In addition, the release of higher magnesium content from uncoated and PCL polymer coated samples resulted in lower LDH activity based on the favorable response of the NHBE cells. PEUU and PLGA polymer coatings provided good barrier layer corrosion protection. This research evaluates candidate polymer coatings as a source for therapeutic agents and barrier layer to control the corrosion of magnesium alloys for tracheal applications.

The levels and composition of agricultural dusts ar e influenced by animal species, production strategy , housing type and ventilation efficiency. Agricultural dust within animal houses is complex and consists of fee d particles, microbes and their products, dander, fecal matter, gases, metals and other organic and inorganic components. Livestock and poultry production facilities may be categorized as confinement, semi-confinement or pasturebased. Characterization of animal husbandry buildin g dust will provide insight into understanding expo sures experienced by animals, workers and farm visitors. The goal was to characterize biophysiochemical feat ures of livestock dusts from swine, small ruminant, equine, poultry and cattle husbandry units. Settled dust s amples were collected from livestock and poultry housing units at the University Farm and other livestock farms ac ross the state. Morphological features were determined by el ectron microscopy and gravimetry. Biochemical evaluation consisted of pH determination and trace metal detec tion via mass spectrometry. Biological assessment c entered on bacterial characterization via selective media, DNA analysis and endotoxin quantitation. Morphological analyses revealed higher levels of respirable and t horacic particles in poultry, swine, small ruminant and equine units compared to the dairy unit (p

Plant based products represent a promising alternat ive to conventional treatments for inflammation. Moringa oleifera Lam is a tree rich in proteins, vitamins, minerals and a variety of phytochemcals with health benefits. Among the reported health benefits are antioxidant and anti-inflammatory properties. The purpose of th is study was to investigate whether tea brewed from dried Moringa leaves would abrogate inflammation in a mouse model of acute lung inflammation induced by LPS or extracts prepared from dust collected from a swine confinement facility (DE). Mice were offered water or Moringa tea for seven days. Tea consumption was significantly greater than that of water consumptio n on days 1 and 6, but there were no significant di fferences in weight gain or food consumption. On day seven, mice from both groups were forced to inhale, via int ranasal challenge, either Phosphate Buffered Saline (PBS), Lipopolysaccharide (LPS) [10 μg mL -1 ] or DE [10%]. Compared to mice that drank water, mice that drank Moringa tea had significantly less protein (p

Swine Confinement Facility (SCF) dust consists of a complex mixture of feed grain particles, bacterial components, organic particulates and gases. When these particles are inhaled they deposit along the respiratory tract and mediate respiratory symptoms and disease in swine farmers and facility workers. Macrophages ingest and eliminate microbes and debris under chronic conditions; however, the role of macrophages in agricultural-related respiratory dis ease has not been fully elucidated. The goal was to evaluate the hypothesis that chronic exposure to SC F dust causes inflammation by modulating pulmonary protein levels and macrophage function. Balb/c mice were exposed to 5, 12.5 and 25% SCF Dust Extract (DE) via nebulization 30 min/day five days a week, for eight weeks with weekends excluded. Bronchoalveolar Lavage Fluid (BALF) was collected and analyzed for protein concentration, leukocyte distribution and macrophage morphology. For comparison, THP-1 monocytic cells were exposed to 0.110% DE overnight and evaluated for phagocytosis and reactive oxygen species production. Repeated exposure to DE via nebulizer caused a significant i ncrease in protein concentration and inflammatory c ell number, namely macrophages, in a dose-dependent manner within the lung as compared to controls. Macrophages with pseudopods and vacuoles were the most abundant leukocytes within BALF of mice exposed to DE. Similarly, in vitro studies with 10% DE treated THP-1 cells revealed e nhanced phagocytosis (p

The global orthopedic device market is expected to grow by 9% annually, which will equate to US$50 billion by 2015, necessitating innovation in medical devices that improve the quality of life. The first step in the creation of a foundation of knowledge and technology to improve these implant devices is through the creation of new materials with the capabilities of biodegradation and bioabsorption without a toxicity effect that will pass through Food and Drug Administration regulatory procedures. Magnesium and its alloys have gained attention as biomedical implant materials based on biocompatibility and biodegradability. The objective of this study is to investigate the cytocompatibility effects of adding zinc to a magnesium–calcium system through in-direct cell culture assays utilizing MC3T3-E1 preosteoblast mouse cells. Cell culture assays indicate that there is a level of cytotoxicity that develops from adding zinc to a magnesium–calcium system, but descriptive evidence suggests that solution heat treatment may reduce these cytotoxic effects.

Tracheomalacia is a relatively rare problem, but can be challenging to treat, particularly in pediatric patients. Due to the presence of mechanically deficient cartilage, the trachea is unable to resist collapse under physiologic pressures of respiration, which can lead to acute death if left untreated. However, if treated, the outcome for patients with congenital tracheomalacia is quite good because the cartilage tends to spontaneously mature over a period of 12 to 18 months. The present study investigated the potential for the use of degradable magnesium-3% yttrium alloy (W3) to serve as an extraluminal tracheal stent in a canine model. The host response to the scaffold included the formation of a thin, vascularized capsule consisting of collagenous tissue and primarily mononuclear cells. The adjacent cartilage structure was not adversely affected as observed by bronchoscopic, gross, histologic, and mechanical analysis. The W3 stents showed reproducible spatial and temporal fracture patterns, but otherwise tended to corrode quite slowly, with a mix of Ca and P rich corrosion product formed on the surface and observed focal regions of pitting. The study showed that the approach to use degradable magnesium alloys as an extraluminal tracheal stent is promising, although further development of the alloys is required to improve the resistance to stress corrosion cracking and improve the ductility. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 611–620, 2014.

While the swine industry has made incredible stride s to improve ventilation, air quality in confinemen t buildings remains an issue. The goal of this study is to char acterize correlation between large airway metrics a nd growth performance in piglets reared indoors and outdoors on pasture. Three experimental trials were conducte d: Trial 1 included three breed types that were strictly raise d indoors, Tamworth X Berkshire, Berkshire X Berkshire and Hereford X Berkshire (n = 4-5 each). Trials 2 and 3 consisted of animals reared in both environments; trial 2 had 28 pigs (n = 14, indoor and n = 14, outdoor) and tr ial 3 had 48 pigs (n = 24, indoor and n = 24, outdo or). For trial 3, body weights were recorded weekly for seven weeks to adjust tracheal measure for body size. Total t racheal and lumen diameters were determined for all animals on trial. Histological evaluations were performed to evaluate potential differences among indoor and out door pig populations. One-way and two-way Analyses of Variance (ANOVA) were performed and LS means with the PDIFF option was used to separate means as applicable. Animals reared indoor shad significantl y larger tracheal diameters and lumens compared to those reared outdoors (p-value

Synthetic grafts comprised of a porous scaffold in the size and shape of the natural tracheobronchial tree, and autologous stem cells have shown promise in the ability to restore the structure and function of a severely damaged airway system. For this specific application, the selected scaffold material should be biocompatible, elicit limited cytotoxicity, and exhibit sufficient mechanical properties. In this research, we developed composite nanofibers of polycaprolactone (PCL) and depolymerized chitosan using the electrospinning technique and assessed the properties of the fibers for its potential use as a scaffold for regenerating tracheal tissue. Water-soluble depolymerized chitosan solution was first prepared and mixed with polycaprolactone solution making it suitable for electrospinning. Morphology and chemical structure analysis were performed to confirm the structure and composition of the fibers. Mechanical testing of nanofibers demonstrated both elastic and ductile properties depending on the ratio of PCL to chitosan. To assess biological potential, porcine tracheobronchial epithelial (PTBE) cells were seeded on the nanofibers with composition ratios of PCL/chitosan: 100/0, 90/10, 80/20, and 70/30. Transwell inserts were modified with the nanofiber membrane and cells were seeded according to air-liquid interface culture techniques that mimics the conditions found in the human airways. Lactase dehydrogenase assay was carried out at different time points to determine cytotoxicity levels within PTBE cell cultures on nanofibers. This study shows that PCL/chitosan nanofiber has sufficient structural integrity and serves as a potential candidate for tracheobronchial tissue engineering.

Purpose of review Modern food animal production is a major contributor to the global economy, owing to advanced intensive indoor production facilities aimed at increasing market readiness and profit. Consequences of these advances are accumulation of dusts, gases, and microbial products that diminish air quality within production facilities. Chronic inhalation exposure contributes to onset and exacerbation of respiratory symptoms and diseases in animals and workers. This article reviews literature regarding constituents of farm animal production facility dusts, animal responses to production building and organic dust exposure, and the effect of chronic inhalation exposure on pulmonary oxidative stress and inflammation. Recent findings Porcine models of production facility and organic dust exposures reveal striking similarities to observations of human cells, tissues, and clinical data. Oxidative stress plays a key role in mediating respiratory diseases in animals and humans, and enhancement of antioxidant levels through nutritional supplements can improve respiratory health. Summary Pigs are well adapted to the exposures common to swine production buildings and thus serve as excellent models for facility workers. Insight for understanding mechanisms governing organic dust associated respiratory diseases may come from parallel comparisons between farmers and the animals they raise.

The biodegradable ability of magnesium alloys is an attractive feature for tracheal stents since they can be absorbed by the body through gradual degradation after healing of the airway structure, which can reduce the risk of inflammation caused by long-term implantation and prevent the repetitive surgery for removal of existing stent. In this study, the effects of bicarbonate ion (HCO3−) and mucin in Gamble’s solution on the corrosion behavior of AZ31 magnesium alloy were investigated, using immersion and electrochemical tests to systematically identify the biodegradation kinetics of magnesium alloy under in vitro environment, mimicking the epithelial mucus surfaces in a trachea for development of biodegradable airway stents. Analysis of corrosion products after immersion test was performed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). Electrochemical impedance spectroscopy (EIS) was used to identify the effects of bicarbonate ions and mucin on the corrosion behavior of AZ31 magnesium alloys with the temporal change of corrosion resistance. The results show that the increase of the bicarbonate ions in Gamble’s solution accelerates the dissolution of AZ31 magnesium alloy, while the addition of mucin retards the corrosion. The experimental data in this work is intended to be used as foundational knowledge to predict the corrosion behavior of AZ31 magnesium alloy in the airway environment while providing degradation information for future in vivo studies.

A bottom-up based pulsed laser deposition technique has been used to grow titanium nitride (TiN) nanowires on single crystalline substrates. The first step of this method is the dissolution of laser ablated gaseous TiN material in the nanodimensional catalytic gold (Au) liquid islands located on the substrate surfaces. The continuous dissolution of TiN results in the supersaturation of liquid Au with TiN followed by extrusion of solid TiN material in the nanowire form at the liquid/solid interface. The growth of TiN nanowires continues as long as its dissolution rate into the catalyst Au matches the extrusion rate of solid TiN. This bottom-up approach gives rise to a one-dimensional TiN nanowire structures (length: 200-300 nm and diameter: 20-30 nm) capped with Au. The ascent of Au nanodots to the top of TiN nanowires can be explained based on breaking of weaker bonds and building of stronger bonds. The TiN nanowires are provided vertical alignment by selecting a plane of the substrate that provides the least lattice mismatching to the (111) plane of TiN which has lower surface energy than its other planes: (100) or (110). After the successful formation and structural characterization, a lactate dehydrogenase (LDH) release assay has been used to confirm the biocompatibility and cytotoxicity of these nanowires.

Publisher Summary This chapter discusses various sources of oxygen radicals and antioxidant defenses in the airways, and the role of the oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF- κ B), and its downstream targets on airway epithelial function. Reactive oxygen species (ROS) in airways may originate from endogenous and/or exogenous sources. Endogenous sources include respiratory bursts from activated inflammatory and immune cells, normal metabolic reactions with the electron transport chain of the mitochondria being the major source and resident airway epithelial cells themselves. Exogenous sources of ROS include exposure to environmental air pollutants, ozone and cigarette smoke. Cigarette smoke, an extremely rich source of oxidants, elicits proinflammatory response in the airways via NF- κ B activation, and resultant cytokine production and release. In the airways, systemic inflammatory responses, such as sepsis, severe trauma, and burns, as well as many noxious and/or inflammatory stimuli including bacterial products and ozone, have been known to activate the transcription factor, NF- κ B. In quiescent cells, NF- κ B is sequestered to the cytosplasm in an inhibitory complex with inhibitor of kappa B (IκB). Following cellular stimulation, IκB molecules become phosphorylated at several serine residues in the amino terminus by IκB kinase 2 (IKK2), which targets them for ubiquitination and proteosome-degradation. This process allows nuclear translocation of NF- κ B for transcriptional activation of a variety of pro-inflammatory genes.

The presence of a divalent metal ion in a negatively charged aspartic acid pocket is essential for phosphorylation of response regulator proteins. Here, we present metal binding studies of the Bacillus subtilis response regulator Spo0F using NMR and microESI-MS. NMR studies show that the divalent metals Ca(2+), Mg(2+) and Mn(2+) primarily bind, as expected, in the Asp pocket phosphorylation site. However, identical studies with Cu(2+) show distinct binding effects in three specific locations: (i) the Asp pocket, (ii) a grouping of charged residues at a site opposite of the Asp pocket, and (iii) on the beta 4-alpha 4 loop and the beta 5/alpha 5 interface, particularly around and including H101. microESI-MS studies stoichiometrically confirm the NMR studies and demonstrate that most divalent metal ions bind to Spo0F primarily in a 1:1 ratio. Again, in the case of Cu(2+), multiple metal-bound species are observed. Subsequent experiments reveal that Mg(2+) supports phosphotransfer between KinA and Spo0F, while Cu(2+) fails to support KinA phosphotransfer. Additionally, the presence of Cu(2+) at non-lethal concentrations in sporulation media for B. subtilis and the related organism Pasteuria penetrans was found to inhibit spore formation while continuing to permit vegetative growth. Depending on the type of divalent metal ion present, in vitro phosphorylation of Spo0F by its cognate kinase KinA can be inhibited.

Magnesium (Mg) based alloys are the most advanced cardiovascular stent materials. This new generation of stent scaffold is currently under clinical evaluation with encouraging outcomes. All these Mg alloys contain a certain amount of rare earth (RE) elements though the exact composition is not yet disclosed. RE alloying can usually enhance the mechanical strength of different metal alloys but their toxicity might be an issue for medical applications. It is still unclear how RE elements will affect the magnesium (Mg) alloys intended for stent materials as a whole. In this study, we evaluated MgZnCaY-1RE, MgZnCaY-2RE, MgYZr-1RE, and MgZnYZr-1RE alloys for cardiovascular stents applications regarding their mechanical strength, corrosion resistance, hemolysis, platelet adhesion/activation, and endothelial biocompatibility. The mechanical properties of all alloys were significantly improved. Potentiodynamic polarization showed that the corrosion resistance of four alloys was at least 3-10 times higher than that of pure Mg control. Hemolysis test revealed that all the materials were non-hemolytic while little to moderate platelet adhesion was found on all materials surface. No significant cytotoxicity was observed in human aorta endothelial cells cultured with magnesium alloy extract solution for up to seven days. Direct endothelialization test showed that all the alloys possess significantly better capability to sustain endothelial cell attachment and growth. The results demonstrated the promising potential of these alloys for stent material applications in the future.