[Effect of airway humidification on lung injury induced by mechanical ventilation].

PubMed

Song, Junjie; Jiang, Min; Qi, Guiyan; Xie, Yuying; Wang, Huaiquan; Tian, Yonggang; Qu, Jingdong; Zhang, Xiaoming; Li, Haibo

2014-12-01

To explore the effect of airway humidification on lung injury as a result of mechanical ventilation with different tidal volume (VT). Twenty-four male Japanese white rabbits were randomly divided into four groups: low VT with airway humidification group, high VT with airway humidification group, low VT and high VT group without humidification, with 6 rabbits in each group. Mechanical ventilation was started after intubation and lasted for 6 hours. Low VT denoted 8 mL/kg, while high VT was 16 mL/kg, fraction of inspired oxygen (FiO₂) denoted 0.40, positive end-expiratory pressure (PEEP) was 0. Temperature at Y piece of circuit in airway humidification groups was monitored and controlled at 40 centigrade. Arterial blood gas analysis, including pH value, arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), lung mechanics indexes, including peak airway pressure (P(peak)) and airway resistance (Raw), and lung compliance was measured at 0, 2, 4, 6 hours of mechanical ventilation. The levels of tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in plasma and bronchoalveolar lavage fluid (BALF) were determined by enzyme linked immunosorbent assay (ELISA). The animals were sacrificed at the end of mechanical ventilation. The wet to dry (W/D) ratio of lung tissues was calculated. Histopathologic changes in the lung tissueies were observed with microscope, and lung injury score was calculated. Scanning and transmission electron microscopies were used to examine the integrity of the airway cilia and the tracheal epithelium. Compared with low V(T) group, pH value in high V(T) group was significantly increased, PaCO₂was significantly lowered, and no difference in PaO₂was found. P(peak), Raw, and lung compliance were significantly increased during mechanical ventilation. There were no significant differences in blood gas analysis and lung mechanics indexes between low V(T) with airway humidification group and low V

Upper airway resistance syndrome.

PubMed

Montserrat, J M; Badia, J R

1999-03-01

This article reviews the clinical picture, diagnosis and management of the upper airway resistance syndrome (UARS). Presently, there is not enough data on key points like the frequency of UARS and the morbidity associated with this condition. Furthermore, the existence of LIARS as an independent sleep disorder and its relation with snoring and obstructive events is in debate. The diagnosis of UARS is still a controversial issue. The technical limitations of the classic approach to monitor airflow with thermistors and inductance plethysmography, as well as the lack of a precise definition of hypopnea, may have led to a misinterpretation of UARS as an independent diagnosis from the sleep apnea/hypopnea syndrome. The diagnosis of this syndrome can be missed using a conventional polysomnographic setting unless appropriate techniques are applied. The use of an esophageal balloon to monitor inspiratory effort is currently the gold standard. However, other sensitive methods such as the use of a pneumotachograph and, more recently, nasal cannula/pressure transducer systems or on-line monitoring of respiratory impedance with the forced oscillation technique may provide other interesting possibilities. Recognition and characterization of this subgroup of patients within sleep breathing disorders is important because they are symptomatic and may benefit from treatment. Management options to treat UARS comprise all those currently available for sleep apnea/hypopnea syndrome (SAHS). However, the subset of patients classically identified as LIARS that exhibit skeletal craneo-facial abnormalities might possibly obtain further benefit from maxillofacial surgery.

N2 Gas Flushing Limits the Rise of Antibiotic-Resistant Bacteria in Bovine Raw Milk during Cold Storage

PubMed Central

Munsch-Alatossava, Patricia; Jääskeläinen, Susanna; Alatossava, Tapani; Gauchi, Jean-Pierrre

2017-01-01

Antibiotic resistance has been noted to be a major and increasing human health issue. Cold storage of raw milk promotes the thriving of psychrotrophic/psychrotolerant bacteria, which are well known for their ability to produce enzymes that are frequently heat stable. However, these bacteria also carry antibiotic resistance (AR) features. In places, where no cold chain facilities are available and despite existing recommendations numerous adulterants, including antibiotics, are added to raw milk. Previously, N2 gas flushing showed real potential for hindering bacterial growth in raw milk at a storage temperature ranging from 6 to 25°C. Here, the ability of N2 gas (N) to tackle antibiotic- resistant bacteria was tested and compared to that of the activated lactoperoxidase system (HT) for three raw milk samples that were stored at 6°C for 7 days. To that end, the mesophiles and psychrotrophs that were resistant to gentamycin (G), ceftazidime (Ce), levofloxacin (L), and trimethoprim-sulfamethoxazole (TS) were enumerated. For the log10 ratio (which is defined as the bacterial counts from a certain condition divided by the counts on the corresponding control), classical Analyses of Variance (ANOVA) was performed, followed by a mean comparison with the Ryan-Einot-Gabriel-Welsch multiple range test (REGWQ). If the storage “time” factor was the major determinant of the recorded effects, cold storage alone or in combination with HT or with N promoted a sample-dependent response in consideration of the AR levels. The efficiency of N in limiting the increase in AR was highest for fresh raw milk and was judged to be equivalent to that of HT for one sample and superior to that of HT for the two other samples; moreover, compared to HT, N seemed to favor a more diverse community at 6°C that was less heavily loaded with antibiotic multi-resistance features. Our results imply that N2 gas flushing could strengthen cold storage of raw milk by tackling the bacterial spoilage

SUBCHRONIC ENDOTOXIN INHALATION CAUSES CHRONIC AIRWAY DISEASE IN ENDOTOXIN-SENSITIVE BUT NOT ENDOTOXIN-RESISTANT MICE

EPA Science Inventory

SUBCHRONIC ENDOTOXIN INHALATION CAUSES CHRONIC AIRWAY DISEASE IN ENDOTOXIN-SENSITIVE BUT NOT ENDOTOXIN-RESISTANT MICE. D. M. Brass, J. D. Savov, *S. H. Gavett, ?C. George, D. A. Schwartz. Duke Univ Medical Center Durham, NC, *U.S. E.P.A. Research Triangle Park, NC, ?Univ of Iowa,...

Relationship Between Respiratory Dynamics and Body Mass Index in Patients Undergoing General Anesthesia with Laryngeal Mask Airway (LMA) and Comparison Between Lithotomy and Supine Positions

PubMed Central

Zhao, Xiao; Huang, Shiwei; Wang, Zhaomin; Chen, Lianhua; Li, Shitong

2016-01-01

Background This study aimed to compare respiratory dynamics in patients undergoing general anesthesia with a laryngeal mask airway (LMA) in lithotomy and supine positions and to validate the impact of operational position on effectiveness of LMA ventilation. Material/Methods A total of 90 patients (age range, 18–65 years) who underwent general anesthesia were selected and divided into supine position (SP group) and lithotomy position groups (LP group). Vital signs and respiratory dynamic parameters of the 2 groups were measured at different time points and after implantation of an LMA. The arterial blood gas was monitored at 15 min after induction. The intraoperative changes of hemodynamic indexes and postoperative adverse reactions of LMA were recorded. The possible correlation between body mass index (BMI) and respiratory dynamic indexes was analyzed. Results With prolonged duration of the operation, the inspiratory plateau pressure (Pplat), inspiratory resistance (RI), and work of breathing (WOB) gradually increased, while chest-lung compliance (Compl) and partial pressure of carbon dioxide in end-expiratory gas (PetCO2) gradually decreased (all P value <0.05). The mean airway pressure (Pmean), Pplat, and expiratory resistance (Re) in the LP group were significantly higher than in the SP group (P<0.05), while the peak inspiratory flow (FImax), peak expiratory flow (FEmax), WOB, and Compl in the LP group were significantly lower than in the SP group (P<0.05). BMI was positively correlated with peak airway pressure (PIP/Ppeak), Pplat, and airway resistance (Raw) and was negatively correlated with Compl; the differences among patients in lithotomy position were more remarkable (P<0.05). Conclusions The inspiratory plateau pressure and airway resistance increased with prolonged duration of the operation, accompanied by decreased chest-lung compliance. Peak airway pressure and airway resistance were positively correlated with BMI, and chest-lung compliance was

Coaxial Tubing Systems Increase Artificial Airway Resistance and Work of Breathing.

PubMed

Wenzel, Christin; Schumann, Stefan; Spaeth, Johannes

2017-09-01

Tubing systems are an essential component of the ventilation circuit, connecting the ventilator to the patient's airways. Coaxial tubing systems incorporate the inspiratory tube within the lumen of the expiratory one. We hypothesized that by design, these tubing systems increase resistance to air flow compared with conventional ones. We investigated the flow-dependent pressure gradient across coaxial, conventional disposable, and conventional reusable tubing systems from 3 different manufacturers. Additionally, the additional work of breathing and perception of resistance during breathing through the different devices were determined in 18 healthy volunteers. The pressure gradient across coaxial tubing systems was up to 6 times higher compared with conventional ones (1.90 ± 0.03 cm H 2 O vs 0.34 ± 0.01 cm H 2 O, P < .001) and was higher during expiration compared with inspiration ( P < .001). Additional work of breathing and perceived breathing resistance were highest in coaxial tubing systems, accordingly. Our findings suggest that the use of coaxial tubing systems should be carefully considered with respect to their increased resistance. Copyright © 2017 by Daedalus Enterprises.

Antibiotic resistance of Campylobacter in raw retail chickens and imported chicken portions.

PubMed Central

Wilson, I. G.

2003-01-01

Campylobacter isolates from raw retail chickens (n = 434) sampled between 1998 and 2000 were tested for resistance to 12 antibiotics. Among 208 campylobacters tested, more than 90% of isolates were susceptible to 4 out of 9 antibiotics (nalidixic acid, erythromycin, chloramphenicol and gentamicin). Most campylobacters were resistant to 3 antibiotics and multiple resistance was found in 4%. Ciprofloxacin resistance was 11%. Campylobacter contamination (28%) in imported chickens (n = 150) was almost half that found in local whole chickens (50%), but the resistance of imported isolates (n = 42) was similar to that of local campylobacters. Resistance in isolates from imported chicken breasts was generally more common, but to only 4 antibiotics. Resistance patterns of chicken isolates were compared to human clinical isolates (n = 494), and a greater similarity was found between the clinical and local isolates than with imported campylobacters. Lower chloramphenicol resistance was found in clinical Campylobacter isolates than in those from chicken sources. PMID:14959786

Prevalence and antimicrobial resistance profile of Staphylococcus species in chicken and beef raw meat in Egypt.

PubMed

Osman, Kamelia M; Amer, Aziza M; Badr, Jihan M; Saad, Aalaa S A

2015-05-01

Coagulase-positive (CPS) and coagulase-negative (CNS) staphylococci cause staphylococcal food poisoning. Recently, CPS and CNS have received increasing attention due to their potential role in the dissemination of antibiotic resistance markers. The present study aimed to evaluate CPS and CNS species distribution and their antibiotic resistance profile isolated from chicken and beef meat. Fifty fresh, uncooked chicken parts and 50 beef meat cuts (local n=27; imported n=23) were used. One hundred staphylococcal isolates belonging to 11 species were isolated and identified from chicken (n=50) and beef (n=50) raw meat samples. Staphylococcus hyicus (26/100), lugdunensis (18/100), aureus (15/100) and epidermidis (14/100) were dominant. S. aureus was 100% resistant to penicillin and sulfamethoxazole/trimethoprim. Vancomycin-resistant S. aureus showed intermediate resistance (51%), which might indicate the dissemination of vancomycin resistance in the community and imply food safety hazards. The percentage of resistance to β-lactams was variable, with the highest resistance being to penicillin (94%) and lowest to ampicillin-sulbactam (22%). Antimicrobial resistance was mainly against penicillin (94%), clindamycin (90%) and sulfamethoxazole/trimethoprim (82%). The results indicate that chicken and beef raw meat are an important source of antibiotic-resistant CPS and CNS.

Emodin mitigates diesel exhaust particles-induced increase in airway resistance, inflammation and oxidative stress in mice.

PubMed

Nemmar, Abderrahim; Al-Salam, Suhail; Yuvaraju, Priya; Beegam, Sumaya; Ali, Badreldin H

2015-08-15

Clinical and experimental studies have reported that short-term exposure to particulate air pollution is associated with inflammation, oxidative stress and impairment of lung function. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) has a strong antioxidant and anti-inflammatory actions. Therefore, in the present study, we evaluated the possible ameliorative effect of emodin on diesel exhaust particles (DEP)-induced impairment of lung function, inflammation and oxidative stress in mice. Mice were intratracheally instilled with DEP (20 μg/mouse) or saline (control). Emodin was administered intraperitoneally 1h before and 7h after pulmonary exposure to DEP. Twenty-four hours following DEP exposure, we evaluated airway resistance measured by forced oscillation technique, lung inflammation and oxidative stress. Emodin treatment abated the DEP-induced increase in airway resistance, and prevented the influx of neutrophils in bronchoalveolar lavage fluid. Similarly, lung histopathology confirmed the protective effect of emodin on DEP-induced lung inflammation. DEP induced a significant increase of proinflammatory cytokines in the lung including tumor necrosis factor α, interleukin 6 and interleukin 1β. The latter effect was significantly ameliorated by emodin. DEP caused a significant increase in lung lipid peroxidation, reactive oxygen species and a significant decrease of reduced glutathione concentration. These effects were significantly mitigated by emodin. We conclude that emodin significantly mitigated DEP-induced increase of airway resistance, lung inflammation and oxidative stress. Pending further pharmacological and toxicological studies, emodin may be considered a potentially useful pulmonary protective agent against particulate air pollution-induced lung toxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

Forced oscillometry track sites of airway obstruction in bronchial asthma.

PubMed

Hafez, Manal Refaat; Abu-Bakr, Samiha Mohamed; Mohamed, Alyaa Abdelnaser

2015-07-01

Spirometry is the most commonly used method for assessment of airway function in bronchial asthma but has several limitations. Forced oscillometry was developed as a patient-friendly test that requires passive cooperation of the patient breathing normally through the mouth. To compare spirometry with forced oscillometry to assess the role of forced oscillometry in the detection of the site of airway obstruction. This case-and-control study included 50 patients with known stable asthma and 50 age- and sex-matched healthy subjects. All participants underwent spirometry (ratio of force expiration volume in 1 second to forced vital capacity, percentage predicted for forced expiration volume in 1 second, percentage predicted for forced vital capacity, percentage predicted for vital capacity, and forced expiratory flow at 25-75%) and forced oscillometry (resistance at 5, 20, and 5-20 Hz). By spirometry, all patients with asthma had airway obstruction, 8% had isolated small airway obstruction, 10% had isolated large airway obstruction, and 82% had large and small airway obstruction. By forced oscillometry, 12% had normal airway resistance, 50% had isolated small airway obstruction with frequency-dependent resistance, and 38% had large and small airway obstruction with frequency-independent resistance. There was significant difference between techniques for the detection of the site of airway obstruction (P = .012). Forced oscillometry indices were negatively correlated with spirometric indices (P < .01). Forced oscillometry as an effortless test, conducted during quiet tidal breathing, and does not alter airway caliber; thus, it can detect normal airway function better than spirometry in patients with asthma. Forced oscillometry detects isolated small airway obstruction better than spirometry in bronchial asthma. Copyright © 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Quantification, serovars, and antibiotic resistance of salmonella isolated from retail raw chicken meat in Vietnam.

PubMed

Ta, Yen T; Nguyen, Trung Thanh; To, Phuong Bich; Pham, Da Xuan; Le, Hao Thi Hong; Thi, Giang Nguyen; Alali, Walid Q; Walls, Isabel; Doyle, Michael P

2014-01-01

The objectives of this study were to quantify Salmonella counts on retail raw poultry meat in Vietnam and to phenotypically characterize (serovars and antibiotic resistance) the isolates. A total of 300 chicken carcasses were collected from two cities and two provinces in Vietnam. Salmonella counts on the samples were determined according to the most-probable-number (MPN) method of the U.S. Department of Agriculture, Food Safety and Inspection Service (USDA-FSIS). A total of 457 isolates were serotyped and tested for antibiotic susceptibility. Overall, 48.7% of chicken samples were Salmonella positive with a count of 2.0 log MPN per carcass. There were no significant differences (P > 0.05) in log MPN per carcass by the study variables (market type, storage condition, and chicken production system). There was a significant difference (P < 0.05) in Salmonella-positive prevalence by chicken production system. Among the 22 Salmonella serovars identified, Albany was the most frequent (34.1%), followed by Agona (15.5%) and Dabou (8.8%). Resistance to at least one antibiotic was common (i.e., 73.3%), with high resistance to tetracycline (59.1%) and ampicillin (41.6%). Resistance to three antibiotics was the most frequently found multidrug resistance profile (17.7%, n = 81); the profile that was resistant to the highest number of drugs was resistant to nine antibiotics (0.7%, n = 3). Only Salmonella Albany posed phenotypic resistance to ceftriaxone (a drug of choice to treat severe cases of salmonellosis). The data revealed that, whereas Salmonella prevalence on raw poultry was high (48.7%), counts were low, which suggests that the exposure risk to Salmonella is low. However, improper storage of raw chicken meat and cross-contamination may increase Salmonella cell counts and pose a greater risk for infection. These data may be helpful in developing risk assessment models and preventing the transmission of foodborne Salmonella from poultry to humans in Vietnam.

Protective effects of valproic acid against airway hyperresponsiveness and airway remodeling in a mouse model of allergic airways disease.

PubMed

Royce, Simon G; Dang, William; Ververis, Katherine; De Sampayo, Nishika; El-Osta, Assam; Tang, Mimi L K; Karagiannis, Tom C

2011-12-01

Airway remodeling and airway hyperresponsiveness are major aspects of asthma pathology that are not targeted optimally by existing anti-inflammatory drugs. Histone deacetylase inhibitors have a wide range of effects that may potentially abrogate aspects of remodeling. One such histone deacetylase inhibitor is valproic acid (2-propylvaleric acid). Valproic acid is used clinically as an anti-epileptic drug and is a potent inhibitor of class I histone deacetylases but also inhibits class II histone deacetylases. We used valproic acid as a molecular model of histone deacetylase inhibition in vivo in chronic allergic airways disease mice with airway remodeling and airway hyperresponsiveness. Wild-type Balb/c mice with allergic airways disease were treated with valproic acid or vehicle control. Airway inflammation was assessed by bronchoalveolar lavage fluid cell counts and examination of lung tissue sections. Remodeling was assessed by morphometric analysis of histochemically stained slides and lung function was assessed by invasive plethysmography measurement of airway resistance. Valproic acid treatment did not affect inflammation parameters; however, valproic acid treatment resulted in reduced epithelial thickness as compared to vehicle treated mice (p < 0.01), reduced subepithelial collagen deposition (p < 0.05) and attenuated airway hyperresponsiveness (p < 0.05 and p < 0.01 for the two highest doses of methacholine, respectively). These findings show that treatment with valproic acid can reduce structural airway remodeling changes and hyperresponsiveness, providing further evidence for the potential use of histone deacetylase inhibitors for the treatment of asthma.

Occurrence of antimicrobial-resistant salmonella species in raw and ready to eat turkey meat products from retail outlets in the midwestern United States.

PubMed

Khaitsa, Margaret L; Kegode, Redempta B; Doetkott, Dawn K

2007-01-01

To investigate occurrence of Salmonella in raw and ready to eat (RTE) turkey from retail outlets, determine factors associated with its occurrence and antimicrobial-resistance patterns. A total of 959 turkey products (raw, n = 345; and RTE, n = 614) were purchased in 3 months from four stores in one city in the midwestern United States. Chi-square and logistic regression analyses were used to test for associations of microbial contamination with product type and brand, expiration date, sampling time, and retail store. Antimicrobial resistance of Salmonellae was determined using a National Antimicrobial Resistance Monitoring System (NARMS) panel of antimicrobials. Overall, 2.2% (21/959) of the samples (4.1% [14/345] raw and 1.1% [7/614] RTE) were contaminated with Salmonella. A significant difference in Salmonella occurrence (p < 0.05), between meat type (raw vs. RTE; OR = 4.2, 95% CI = 1.6, 10.8); and sampling month (p < 0.05) was reported, but not between retail stores and product brands. Salmonellae belonged to 6 serotypes: Hadar, Heidelberg, Typhimurium var. Copenhagen, Newport, Saintpaul, and Agona. Salmonellae from raw turkey exhibited higher antimicrobial resistance (53%) compared to those from RTE products (33%). Multidrug resistance was exhibited by 62% of Salmonellae (86% RTE, 50% raw meats). CONCLUSION AND CLINICAL APPLICATIONS: Turkey (both raw and RTE) may occasionally be contaminated with antimicrobial-resistant Salmonellae whose occurrence was influenced by sampling month and meat type. Continued surveillance of Salmonella occurrence in meat products, in particular RTE ones, is warranted in order to ensure a safe food supply.

[Arousal of respiratory origin and upper airway resistance syndrome: pathophysiological and diagnostic aspects].

PubMed

Puertas, F J; Ondzé, B; Carlander, B; Billiard, M

The description of Upper Airway Resistance Syndrome (UARS) let us to recognize the importance of the pair 'respiratory effort-arousal' on sleep-disordered breathing pathophysiology. First part of this paper reviews knowledge about respiratory arousal pathophysiology. Arousal response is normally needed to end obstructive respiratory episodes, but it is also the cause of sleep fragmentation. Among respiratory stimuli able to provoke arousal (respiratory effort, hypoxemia and hypercapnia), respiratory effort is the most constant. Neurophysiological mechanisms involved in arousal, sleep and vegetative consequences, and the possible role of non visible arousals, are also discussed. In UARS, because of the absence of apnea/hypopnea and significative O2 desaturations, arousals are induced by the increased respiratory effort. Diagnosis needs the simultaneous recording of polysomnography and esophageal pressure. Some symptoms and signs of UARS are similar to those of Obstructive Sleep Apnea Syndrome. However, UARS shows any differences: a lower Body Mass Index, less constant snoring, males and females are similarly affected or higher frequency of craniofacial abnormalities. Diagnostic difficulties may be due to confusion between hypopneas and episodes of increased resistance of upper airway, or to the lack of definitive diagnostic criteria. Finally, differential diagnosis needs a broad knowledge of disorders of excessive daytime sleepiness.

Salmonella in raw chicken meat from the Romanian seaside: frequency of isolation and antibiotic resistance.

PubMed

Tîrziu, Emil; Lazăr, Romeu; Sala, Claudia; Nichita, Ileana; Morar, Adriana; Şereş, Monica; Imre, Kálmán

2015-05-01

The purpose of this study was to investigate the occurrence of Salmonella in raw chicken meat samples collected at the Romanian seaside and to evaluate the antimicrobial susceptibility of the isolates. In 2012, 317 chicken meat samples from slaughterhouses (n = 289) and retail markets (n = 28) were evaluated. Overall, 13.2% (42) of the samples contained Salmonella; 12.8% (37) and 17.8% (5) from the chicken carcasses at slaughterhouses and the fresh meat from retail markets, respectively. Eight serotypes of Salmonella enterica subsp. enterica were identified: Infantis (18 isolates), Bredeney (7), Virchow (6), Djugu (4), Grampian (4), Brandenburg (1), Derby (1), and Ruzizi (1). The isolates were resistant to tetracycline (66.6% of isolates), nalidixic acid (64.3%), sulfamethoxazole (64.3%), ciprofloxacin (61.9%), streptomycin (59.5%), trimethoprim (33.3%), ampicillin (9.5%), chloramphenicol (7.1%), and gentamicin (2.4%). No resistance was found to cefotaxime and ceftazidime. Thirty (71.4%) of the 42 tested isolates had multidrug resistance patterns to at least two antimicrobials. This survey highlighted a multidrug-resistant Salmonella contamination rate in raw chicken meat in this area of Romania, which can seriously threaten human health.

Public health significance of antimicrobial-resistant gram-negative bacteria in raw bulk tank milk.

PubMed

Straley, B A; Donaldson, S C; Hedge, N V; Sawant, A A; Srinivasan, V; Oliver, S P; Jayarao, B M

2006-01-01

The dairy farm environment and animals on the farm serve as important reservoirs of pathogenic and commensal bacteria that could potentially gain access to milk in the bulk tank via several pathways. Pathogenic gram-negative bacteria can gain access to bulk tank milk from infected mammary glands, contaminated udders and milking machines, and/or from the dairy farm environment. Contaminated raw milk when consumed by humans or fed to animals on the farm can result in gastroenteric infections in humans and animals and also provide an opportunity for organisms to colonize the farm environment. This scenario becomes much more complicated when pathogenic bacteria such as Salmonella, Shiga toxin-producing Escherichia coli, and commensal gram-negative enteric bacteria encode for antimicrobial resistance determinants. In recent years, the role of commensal bacteria as reservoirs of genetic determinants for antimicrobial resistance has come under closer scrutiny. Commensal bacteria in bulk tank milk can be a significant reservoir of antimicrobial determinants. Raw milk consumption can result in exposure to antimicrobial-resistant commensal gram-negative bacteria. This paper examines the prevalence and role of commensal gram-negative enteric bacteria in bulk tank milk and their public health significance.

Airway mechanics and lung tissue viscoelasticity: effects of altered blood hematocrit in the pulmonary circulation.

PubMed

Peták, Ferenc; Fodor, Gergely H; Babik, Barna; Habre, Walid

2016-07-01

The contribution of the hematocrit (Hct) of the blood in the pulmonary vasculature to the overall lung mechanics has not been characterized. We therefore set out to establish how changes of the Hct level in the pulmonary circulation affect the airway and lung tissue viscoelastic properties. The Hct level of the blood in an isolated perfused rat lung model was randomly altered. Intermediate (26.5%), followed by low (6.6%) or normal (43.7%), Hct was set in two consecutive sequences. The pulmonary capillary pressure was maintained constant throughout the experiment, and the pulmonary hemodynamic parameters were monitored continuously. The airway resistance (Raw), the viscous (G) and elastic (H) parameters, and the hysteresivity (η = G/H) of the lung tissues were obtained from measurements of forced oscillatory input impedance data. Raw was not affected by the alterations of the Hct levels. As concerns the lung tissues, the decrease of Hct to intermediate or low levels resulted in close to proportional decreases in the viscoelastic parameters G [16.5 ± 7.7% (SD), 12.1 ± 9.5%, P < 0.005] and H (13.2 ± 8.6%, 10.8 ± 4.7%, P < 0.001). No significant changes in η were detected in a wide range of Hct, which indicates that coupled processes cause alterations in the resistive and elastic properties of the lungs following Hct changes in the pulmonary circulation. The diminishment of the viscous and elastic parameters of the pulmonary parenchyma following a reduction of blood Hct demonstrates the significant contribution of the red blood cells to the overall lung viscoelasticity. Copyright © 2016 the American Physiological Society.

Microbial exposure early in life regulates airway inflammation in mice after infection with Streptococcus pneumoniae with enhancement of local resistance.

PubMed

Yasuda, Yasuki; Matsumura, Yoko; Kasahara, Kazuki; Ouji, Noriko; Sugiura, Shigeki; Mikasa, Keiichi; Kita, Eiji

2010-01-01

The immunological explanation for the "hygiene hypothesis" has been proposed to be induction of T helper 1 (Th1) responses by microbial products. However, the protective results of hygiene hypothesis-linked microbial exposures are currently shown to be unlikely to result from a Th1-skewed response. Until now, effect of microbial exposure early in life on airway innate resistance remained unclear. We examined the role of early life exposure to microbes in airway innate resistance to a respiratory pathogen. Specific pathogen-free weanling mice were nasally exposed to the mixture of microbial extracts or PBS (control) every other day for 28 days and intratracheally infected with Streptococcus pneumoniae 10 days after the last exposure. Exposure to microbial extracts facilitated colonization of aerobic gram-positive bacteria, anaerobic microorganisms, and Lactobacillus in the airway, compared with control exposure. In pneumococcal pneumonia, the exposure prolonged mouse survival days by suppressing bacterial growth and by retarding pneumococcal blood invasion, despite significantly low levels of leukocyte recruitment in the lung. Enhancement of airway resistance was associated with a significant decrease in production of leukocyte chemokine (KC) and TNFalpha, and suppression of matrix metalloproteinase (MMP-9) expression/activation with enhancement of tissue inhibitor of MMP (TIMP-3) activation. The exposure increased production of IFN-gamma, IL-4, and monocyte chemoattractant-1 following infection. Furthermore, expression of Toll-like receptor 2, 4, and 9 was promoted by the exposure but no longer upregulated upon pneumococcal infection. Thus, we suggest that hygiene hypothesis is more important in regulating the PMN-dominant inflammatory response than in inducing a Th1-dominant response.

Smooth muscle in the maintenance of increased airway resistance elicited by methacholine in humans.

PubMed

Chapman, David G; Pascoe, Chris D; Lee-Gosselin, Audrey; Couture, Christian; Seow, Chun Y; Paré, Peter D; Salome, Cheryl M; King, Gregory G; Bossé, Ynuk

2014-10-15

Airway narrowing is maintained for a prolonged period after acute bronchoconstriction in humans in the absence of deep inspirations (DIs). To determine whether maintenance of airway smooth muscle (ASM) shortening is responsible for the persistence of airway narrowing in healthy subjects following transient methacholine (MCh)-induced bronchoconstriction. On two separate visits, five healthy subjects underwent MCh challenges until respiratory system resistance (Rrs) had increased by approximately 1.5 cm H2O/L/s. Subjects took a DI either immediately after or 30 minutes after the last dose. The extent of renarrowing following the bronchodilator effect of DI was used to assess the continued action of MCh (calculated as percent change in Rrs from the pre-DI Rrs). We then used human bronchial rings to determine whether ASM can maintain shortening during a progressive decrease of carbachol concentration. The increased Rrs induced by MCh was maintained for 30 minutes despite waning of MCh concentration over that period, measured as attenuated renarrowing when the DI was taken 30 minutes after compared with immediately after the last dose (7 min post-DI, -36.2 ± 11.8 vs. 14.4 ± 13.2%; 12 min post-DI, -39.5 ± 9.8 vs. 15.2 ± 17.8%). Ex vivo, ASM shortening was largely maintained during a progressive decrease of carbachol concentration, even down to concentrations that would not be expected to induce shortening. The maintenance of airway narrowing despite MCh clearance in humans is attributed to an intrinsic ability of ASM to maintain shortening during a progressive decrease of contractile stimulation.

Prevalence and behavior of multidrug-resistant Salmonella strains on raw whole and cut nopalitos (Opuntia ficus-indica L.) and on nopalitos salads.

PubMed

Gómez-Aldapa, Carlos A; Gutiérrez-Alcántara, Eduardo J; Torres-Vitela, M Refugio; Rangel-Vargas, Esmeralda; Villarruel-López, Angelica; Castro-Rosas, Javier

2017-09-01

The presence of multidrug-resistant Salmonella in vegetables is a significant public health concern. Nopalito is a cactaceous that is commonly consumed either raw or cooked in Mexico and other countries. The presence of antibiotic-resistant Salmonella strains on raw whole nopalitos (RWN, without prickles), raw nopalitos cut into squares (RNCS) and in cooked nopalitos salads (CNS) samples was determined. In addition, the behavior of multidrug-resistant Salmonella isolates on RWN, RNCS and CNS at 25° ± 2 °C and 3° ± 2 °C was investigated. One hundred samples of RWN, 100 of RNCS and 100 more of CNS were collected from public markets. Salmonella strains were isolated and identified in 30, 30 and 10% of the samples, respectively. Seventy multidrug-resistant Salmonella strains were isolated from all the nopalitos samples. Multidrug-resistant Salmonella isolates survived at least 15 days on RWN at 25° ± 2 °C or 3° ± 2 °C. Multidrug-resistant Salmonella isolates grew in the RNCS and CNS samples at 25° ± 2 °C. However, at 3° ± 2 °C the bacterial growth was inhibited. This is the first report about multidrug-resistant Salmonella isolation from raw nopalitos and nopalitos salads. Nopalitos from markets are very likely to be an important factor contributing to the endemicity of multidrug-resistant Salmonella-related gastroenteritis in Mexico. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Anatomic Optical Coherence Tomography of Upper Airways

NASA Astrophysics Data System (ADS)

Chin Loy, Anthony; Jing, Joseph; Zhang, Jun; Wang, Yong; Elghobashi, Said; Chen, Zhongping; Wong, Brian J. F.

The upper airway is a complex and intricate system responsible for respiration, phonation, and deglutition. Obstruction of the upper airways afflicts an estimated 12-18 million Americans. Pharyngeal size and shape are important factors in the pathogenesis of airway obstructions. In addition, nocturnal loss in pharyngeal muscular tone combined with high pharyngeal resistance can lead to collapse of the airway and periodic partial or complete upper airway obstruction. Anatomical optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images of the airway lumen without the use of ionizing radiation. In this chapter we describe the methods behind endoscopic OCT imaging and processing to generate full three dimensional anatomical models of the human airway which can be used in conjunction with numerical simulation methods to assess areas of airway obstruction. Combining this structural information with flow dynamic simulations, we can better estimate the site and causes of airway obstruction and better select and design surgery for patients with obstructive sleep apnea.

A Computational Study of the Respiratory Airflow Characteristics in Normal and Obstructed Human Airways

DTIC Science & Technology

2014-01-01

normal and three different obstructed airway geometries, consisting of symmetric, asym- metric, and random obstructions. Fig. 2 shows the geometric ...normal and obstructed airways Airway resistance is a measure of the opposition to the airflow caused by geometric properties, such as airway obstruction...pressure drops. Resistance values were dependent on the degree and geometric distribution of the obstruction sites. In the symmetric obstruction model

Naringin Protects Ovalbumin-Induced Airway Inflammation in a Mouse Model of Asthma.

PubMed

Guihua, Xiong; Shuyin, Liu; Jinliang, Gao; Wang, Shumin

2016-04-01

Many plant species containing flavonoids have been widely used in traditional Chinese medicine. Naringin, a well-known flavanone glycoside of citrus fruits, possesses antioxidant, anti-inflammatory, anti-apoptotic, anti-ulcer, anti-osteoporosis, and anti-carcinogenic properties. The aim of the study was to investigate the anti-asthmatic effects of naringin and the possible mechanisms. Asthma model was established by ovalbumin. A total of 50 mice were randomly assigned to five experimental groups: control, model, and dexamethasone (2 mg/kg, orally) and naringin (5 mg/kg, 10 mg/kg, orally). Airway resistance (Raw) were measured, histological studies were evaluated by the hematoxylin and eosin (HE) staining, OVA-specific serum and BALF IgE levels and Th1/Th2 cytokines were evaluated by enzyme-linked immunosorbent assay (ELISA), and Th1/Th2 cells was evaluated by flow cytometry (FCM). T-bet and GABA3 in the lung were evaluated by Western blot. Our study demonstrated that naringin inhibited OVA-induced increases in Raw and eosinophil count; OVA-induced effects on interleukin (IL)-4 and INF-gamma levels were blunted with naringin administration. Histological studies demonstrated that naringin substantially inhibited OVA-induced eosinophilia in lung tissue and airway tissue. Flow cytometry studies demonstrated that naringin substantially inhibited Th2 cells and enhanced Th1 cells. Naringin substantially inhibited GABA3 and increased T-bet. These findings suggest that naringin may effectively ameliorate the progression of asthma and could be used as a therapy for patients with allergic asthma.

Noninvasive estimation of pharyngeal airway resistance and compliance in children based on volume-gated dynamic MRI and computational fluid dynamics.

PubMed

Persak, Steven C; Sin, Sanghun; McDonough, Joseph M; Arens, Raanan; Wootton, David M

2011-12-01

Computational fluid dynamics (CFD) analysis was used to model the effect of collapsing airway geometry on internal pressure and velocity in the pharyngeal airway of three sedated children with obstructive sleep apnea syndrome (OSAS) and three control subjects. Model geometry was reconstructed from volume-gated magnetic resonance images during normal tidal breathing at 10 increments of tidal volume through the respiratory cycle. Each geometry was meshed with an unstructured grid and solved using a low-Reynolds number k-ω turbulence model driven by flow data averaged over 12 consecutive breathing cycles. Combining gated imaging with CFD modeling created a dynamic three-dimensional view of airway anatomy and mechanics, including the evolution of airway collapse and flow resistance and estimates of the local effective compliance. The upper airways of subjects with OSAS were generally much more compliant during tidal breathing. Compliance curves (pressure vs. cross-section area), derived for different locations along the airway, quantified local differences along the pharynx and between OSAS subjects. In one subject, the distal oropharynx was more compliant than the nasopharynx (1.028 vs. 0.450 mm(2)/Pa) and had a lower theoretical limiting flow rate, confirming the distal oropharynx as the flow-limiting segment of the airway in this subject. Another subject had a more compliant nasopharynx (0.053 mm(2)/Pa) during inspiration and apparent stiffening of the distal oropharynx (C = 0.0058 mm(2)/Pa), and the theoretical limiting flow rate indicated the nasopharynx as the flow-limiting segment. This new method may help to differentiate anatomical and functional factors in airway collapse.

Innate Immune Signaling Activated by MDR Bacteria in the Airway

PubMed Central

Parker, Dane; Ahn, Danielle; Cohen, Taylor; Prince, Alice

2015-01-01

Health care-associated bacterial pneumonias due to multiple-drug resistant (MDR) pathogens are an important public health problem and are major causes of morbidity and mortality worldwide. In addition to antimicrobial resistance, these organisms have adapted to the milieu of the human airway and have acquired resistance to the innate immune clearance mechanisms that normally prevent pneumonia. Given the limited efficacy of antibiotics, bacterial clearance from the airway requires an effective immune response. Understanding how specific airway pathogens initiate and regulate innate immune signaling, and whether this response is excessive, leading to host-induced pathology may guide future immunomodulatory therapy. We will focus on three of the most important causes of health care-associated pneumonia, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, and review the mechanisms through which an inappropriate or damaging innate immune response is stimulated, as well as describe how airway pathogens cause persistent infection by evading immune activation. PMID:26582515

Allergic Sensitization through the Airway Primes Th17-dependent Neutrophilia and Airway Hyperresponsiveness

PubMed Central

Wilson, Rhonda H.; Whitehead, Gregory S.; Nakano, Hideki; Free, Meghan E.; Kolls, Jay K.; Cook, Donald N.

2009-01-01

Rationale: In humans, immune responses to inhaled aeroallergens develop in the lung and draining lymph nodes. Many animal models of asthma bypass this route and instead use intraperitoneal injections of allergen using aluminum hydroxide as an adjuvant. Objectives: We investigated whether allergic sensitization through the airway elicits immune responses qualitatively different than those arising in the peritoneum. Methods: Mice were sensitized to allergen through the airway using low-dose LPS as an adjuvant, or through the peritoneum using aluminum hydroxide as an adjuvant. After a single allergen challenge, ELISA and flow cytometry were used to measure cytokines and leukocyte subsets. Invasive measurements of airway resistance were used to measure allergen-induced airway hyperreactivity (AHR). Measurements and Main Results: Sensitization through the peritoneum primed strong Th2 responses and eosinophilia, but not AHR, after a single allergen challenge. By contrast, allergic sensitization through the airway primed only modest Th2 responses, but strong Th17 responses. Th17 cells homed to the lung and released IL-17 into the airway on subsequent encounter with inhaled allergen. As a result, these mice developed IL-17–dependent airway neutrophilia and AHR. This AHR was neutrophil-dependent because it was abrogated in CXCR2-deficient mice and also in wild-type mice receiving a neutrophil-depleting antibody. Individually, neither IL-17 nor ongoing Th2 responses were sufficient to confer AHR, but together they acted synergistically to promote neutrophil recruitment, eosinophil recruitment and AHR. Conclusions: Allergic sensitization through the airway primes modest Th2 responses but strong Th17 responses that promote airway neutrophilia and acute AHR. These findings support a causal role for neutrophils in severe asthma. PMID:19661246

Expression of nitric oxide synthase-2 in the lungs decreases airway resistance and responsiveness.

PubMed

Hjoberg, Josephine; Shore, Stephanie; Kobzik, Lester; Okinaga, Shoji; Hallock, Arlene; Vallone, Joseph; Subramaniam, Venkat; De Sanctis, George T; Elias, Jack A; Drazen, Jeffrey M; Silverman, Eric S

2004-07-01

Individuals with asthma have increased levels of nitric oxide in their exhaled air. To explore its role, we have developed a regulatable transgenic mouse capable of overexpressing inducible nitric oxide synthase in a lung-specific fashion. The CC10-rtTA-NOS-2 mouse contains two transgenes, a reverse tetracycline transactivator under the control of the Clara cell protein promoter and the mouse nitric oxide synthase-2 (NOS-2) coding region under control of a tetracycline operator. Addition of doxycycline to the drinking water of CC10-rtTA-NOS-2 mice causes an increase in nitric oxide synthase-2 that is largely confined to the airway epithelium. The fraction of expired nitric oxide increases over the first 24 h from approximately 10 parts per billion to a plateau of approximately 20 parts per billion. There were no obvious differences between CC10-rtTA-NOS-2 mice, with or without doxycycline, and wild-type mice in lung histology, bronchoalveolar protein, total cell count, or count differentials. However, airway resistance was lower in CC10-rtTA-NOS-2 mice with doxycycline than in CC10-rtTA-NOS-2 mice without doxycycline or wild-type mice with doxycycline. Moreover, doxycycline-treated CC10-rtTA-NOS-2 mice were hyporesponsive to methacholine compared with other groups. These data suggest that increased nitric oxide in the airways has no proinflammatory effects per se and may have beneficial effects on pulmonary function.

Prevalence and Antimicrobial Resistance of Campylobacter Isolated from Dressed Beef Carcasses and Raw Milk in Tanzania

PubMed Central

Kashoma, Isaac P.; Kassem, Issmat I.; John, Julius; Kessy, Beda M.; Gebreyes, Wondwossen; Kazwala, Rudovick R.

2016-01-01

Campylobacter species are commonly transmitted to humans through consumption of contaminated foods such as milk and meat. The aim of this study was to investigate the prevalence, antimicrobial resistance, and genetic determinants of resistance of Campylobacter isolated from raw milk and beef carcasses in Tanzania. The antimicrobial resistance genes tested included blaOXA-61 (ampicillin), aph-3-1 (aminoglycoside), tet(O) (tetracycline), and cmeB (multi-drug efflux pump). The prevalence of Campylobacter was 9.5% in beef carcasses and 13.4% in raw milk, respectively. Using multiplex-polymerase chain reaction (PCR), we identified 58.1% of the isolates as Campylobacter jejuni, 30.7% as Campylobacter coli, and 9.7% as other Campylobacter spp. One isolate (1.6%) was positive for both C. jejuni and C. coli specific PCR. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method showed resistance to: ampicillin (63% and 94.1%), ciprofloxacin (9.3% and 11.8%), erythromycin (53.7% and 70.6%), gentamicin (0% and 15.7%), streptomycin (35.2% and 84.3%), and tetracycline (18.5% and 17.7%), respectively. Resistance to azithromycin (42.6%), nalidixic acid (64.8%), and chloramphenicol (13%) was determined using the disk diffusion assay only, while resistance to tylosin (90.2%) was quantified using the broth microdilution method. The blaOXA-61 (52.6% and 28.1%), cmeB (26.3% and 31.3%), tet(O) (26.3% and 31.3%), and aph-3-1 (5.3% and 3.0%) were detected in C. coli and C. jejuni. These findings highlight the extent of antimicrobial resistance in Campylobacter occurring in important foods in Tanzania. The potential risks to consumers emphasize the need for adequate control approaches, including the prudent use of antimicrobials to minimize the spread of antimicrobial-resistant Campylobacter. PMID:26153978

Prevalence and Antimicrobial Resistance of Campylobacter Isolated from Dressed Beef Carcasses and Raw Milk in Tanzania.

PubMed

Kashoma, Isaac P; Kassem, Issmat I; John, Julius; Kessy, Beda M; Gebreyes, Wondwossen; Kazwala, Rudovick R; Rajashekara, Gireesh

2016-01-01

Campylobacter species are commonly transmitted to humans through consumption of contaminated foods such as milk and meat. The aim of this study was to investigate the prevalence, antimicrobial resistance, and genetic determinants of resistance of Campylobacter isolated from raw milk and beef carcasses in Tanzania. The antimicrobial resistance genes tested included blaOXA-61 (ampicillin), aph-3-1 (aminoglycoside), tet(O) (tetracycline), and cmeB (multi-drug efflux pump). The prevalence of Campylobacter was 9.5% in beef carcasses and 13.4% in raw milk, respectively. Using multiplex-polymerase chain reaction (PCR), we identified 58.1% of the isolates as Campylobacter jejuni, 30.7% as Campylobacter coli, and 9.7% as other Campylobacter spp. One isolate (1.6%) was positive for both C. jejuni and C. coli specific PCR. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method showed resistance to: ampicillin (63% and 94.1%), ciprofloxacin (9.3% and 11.8%), erythromycin (53.7% and 70.6%), gentamicin (0% and 15.7%), streptomycin (35.2% and 84.3%), and tetracycline (18.5% and 17.7%), respectively. Resistance to azithromycin (42.6%), nalidixic acid (64.8%), and chloramphenicol (13%) was determined using the disk diffusion assay only, while resistance to tylosin (90.2%) was quantified using the broth microdilution method. The blaOXA-61 (52.6% and 28.1%), cmeB (26.3% and 31.3%), tet(O) (26.3% and 31.3%), and aph-3-1 (5.3% and 3.0%) were detected in C. coli and C. jejuni. These findings highlight the extent of antimicrobial resistance in Campylobacter occurring in important foods in Tanzania. The potential risks to consumers emphasize the need for adequate control approaches, including the prudent use of antimicrobials to minimize the spread of antimicrobial-resistant Campylobacter.

Assessment of upper airway mechanics during sleep.

PubMed

Farré, Ramon; Montserrat, Josep M; Navajas, Daniel

2008-11-30

Obstructive sleep apnea, which is the most prevalent sleep breathing disorder, is characterized by recurrent episodes of upper airway collapse and reopening. However, the mechanical properties of the upper airway are not directly measured in routine polysomnography because only qualitative sensors (thermistors for flow and thoraco-abdominal bands for pressure) are used. This review focuses on two techniques that quantify upper airway obstruction during sleep. A Starling model of collapsible conduit allows us to interpret the mechanics of the upper airway by means of two parameters: the critical pressure (Pcrit) and the upstream resistance (Rup). A simple technique to measure Pcrit and Rup involves the application of different levels of continuous positive airway pressure (CPAP) during sleep. The forced oscillation technique is another non-invasive procedure for quantifying upper airway impedance during the breathing cycle in sleep studies. The latest developments in these two methods allow them to be easily applied on a routine basis in order to more fully characterize upper airway mechanics in patients with sleep breathing disorders.

Small Airway Obstruction in COPD

PubMed Central

McDonough, John E.; Suzuki, Masaru

2013-01-01

The increase in total cross-sectional area in the distal airways of the human lung enhances the mixing of each tidal breath with end-expiratory gas volume by slowing bulk flow and increasing gas diffusion. However, this transition also favors the deposition of airborne particulates in this region because they diffuse 600 times slower than gases. Furthermore, the persistent deposition of toxic airborne particulates stimulates a chronic inflammatory immune cell infiltration and tissue repair and remodeling process that increases the resistance in airways <2 mm in diameter four to 40-fold in COPD. This increase was originally attributed to lumen narrowing because it increases resistance in proportion to the change in lumen radius raised to the fourth power. In contrast, removal of one-half the number of tubes arranged in parallel is required to double their resistance, and approximately 90% need to be removed to explain the increase in resistance measured in COPD. However, recent reexamination of this problem based on micro-CT imaging indicates that terminal bronchioles are both narrowed and reduced to 10% of the control values in the centrilobular and 25% in the panlobular emphysematous phenotype of very severe (GOLD [Global Initiative for Chronic Obstructive Lung Disease] grade IV) COPD. These new data indicate that both narrowing and reduction in numbers of terminal bronchioles contribute to the rapid decline in FEV1 that leads to severe airway obstruction in COPD. Moreover, the observation that terminal bronchiolar loss precedes the onset of emphysematous destruction suggests this destruction begins in the very early stages of COPD. PMID:23648907

Thermal resistance of Salmonella serovars isolated from raw, frozen chicken nuggets/strips, nugget meat and pelleted broiler feed.

PubMed

Bucher, Oliver; D'Aoust, J-Y; Holley, Richard A

2008-05-31

Raw, frozen chicken nuggets/strips available at retail and prepared at home before consumption have been identified as a significant risk factor in contracting food-borne salmonellosis. Cases of salmonellosis from consumption of these products may be due, in part, to Salmonella strains originating in broiler feed. In this study the thermal resistances of Salmonella strains isolated from chicken nuggets and strips, chicken nugget/strip meat and broiler feed were determined to assess whether they exhibited enhanced thermal resistance. Thermal resistances (D- and z- values) of 7 cocktails (25 isolates, 4 serovars) were determined in commercially prepared irradiation-treated chicken nugget/strip meat blend, and heated in a constant temperature waterbath. The thermal resistances found were lower than those reported for similar strains in the literature. D-values ranged from 6.93 to 0.12 min at 55 and 62 degrees C respectively, with z-values from 4.10 to 5.17 degrees C. Two strains of S. Enteritidis separately isolated from pelleted feed and chicken nugget meat blend, with indistinguishable geno- and phenotypes, had lower (and probably identical) thermal resistances than the other isolates. Results indicated that the strains of Salmonella isolated from raw, frozen chicken nuggets/strips and pelleted broiler feed did not exhibit unusually high thermal resistance, and that normal heating (71 degrees C) prior to consumption should eliminate these organisms from chicken nuggets/strips.

Prevalence, assessment, and antimicrobial resistance patterns of Salmonella from raw chicken eggs in Haramaya, Ethiopia.

PubMed

Kemal, Jelalu; Sibhat, Berhanu; Menkir, Sissay; Beyene, Desta

2016-11-24

The presence of antimicrobial-resistant Salmonella in poultry and poultry products, including eggs, is a global public health concern. This study aimed to estimate the levels and patterns of antimicrobial resistance of Salmonella from chicken eggs and assess consumers' raw egg consumption and farmers' handling practices. A total of 300 egg samples were collected from Haramaya open market (n = 150) and Haramaya University poultry farm (n = 150) in Ethiopia. Questionnaires were administered to egg sellers and buyers. A sterile cotton swab was used to sample the surface of eggs. The shells were sterilized and the egg content sampled. Isolation was done using the conventional methods for the detection of Salmonella, following the standard guidelines from ISO 6579. Sensitivity to 12 selected antibiotics was tested following the procedure of the Clinical and Laboratory Standards Institute. A level of 5.3% was observed among eggs shells from the open market and 0% among egg shells from the poultry farm, for an overall level of 2.7%. There was a significant difference (p = 0.004) between the prevalence of Salmonella spp. in sample site and sample type. Of the antimicrobials tested, Salmonella isolates were all resistant to erythromycin and clindamycin. Isolates were sensitive to ciprofloxacin (100%) and chloramphenicol (87.5%). All isolates were resistant to multiple antibiotics. One-third of the consumers were found to have eaten raw eggs for perceived medicinal values. To minimize the potential contamination of eggs by pathogens, the eggs should be properly handled, transported, and stored.

Prevalence, characterization, and antimicrobial resistance of Yersinia species and Yersinia enterocolitica isolated from raw milk in farm bulk tanks.

PubMed

Jamali, Hossein; Paydar, Mohammadjavad; Radmehr, Behrad; Ismail, Salmah

2015-02-01

The aims of this study were to investigate the prevalence and to characterize and determine the antibiotic resistance of Yersinia spp. isolates from raw milk. From September 2008 to August 2010, 446 raw milk samples were obtained from farm bulk milk tanks in Varamin, Iran. Yersinia spp. were detected in 29 (6.5%) samples, out of which 23 (79.3%), 5 (17.2%), and 1 (3.4%) were isolated from cow, sheep, and goat raw milk, respectively. The most common species isolated was Yersinia enterocolitica (65.5%), followed by Yersinia frederiksenii (31%), and Yersinia kristensenii (3.4%). Of the 19 Y. enterocolitica isolates, 14 (73.7%) were grouped into bioserotype 1A/O:9, 4 (21.1%) belonged to bioserotype 1B:O8, 1 (5.3%) belonged to bioserotype 4/O:3, and 1 isolate (biotype 1A) was not typable. All the isolates of biotypes 1B and 4harbored both the ystA and ail genes. However, all the isolates of biotype 1A were only positive for the ystB gene. The tested Yersinia spp. showed the highest percentages of resistance to tetracycline (48.3%), followed by ciprofloxacin and cephalothin (each 17.2%), ampicillin (13.8%), streptomycin (6.9%), and amoxicillin and nalidixic acid (each 3.4%). All of the tested isolates demonstrated significant sensitivity to gentamicin and chloramphenicol. Recovery of potentially pathogenic Y. enterocolitica from raw milk indicates high risks of yersiniosis associated with consumption of raw milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Prevalence and antibiotic resistance of Enterococcus spp. isolated from retail cheese, ready-to-eat salads, ham, and raw meat.

PubMed

Pesavento, G; Calonico, C; Ducci, B; Magnanini, A; Lo Nostro, A

2014-08-01

Food specimens were analyzed in order to research Enterococcus spp.: 636 samples of raw meat (227 beef, 238 poultry, and 171 pork), 278 samples of cheese (110 fresh soft cheese and 168 mozzarella cheese), 214 samples of ready-to-eat salads, and 187 samples of ham. 312 strains of Enterococcus spp samples were isolated, then identified and submitted to susceptibility tests against 11 antimicrobial agents. The predominant species were Enterococcus faecalis in raw meat and Enterococcus faecium in retail products. Low percentages of microorganisms were resistant to vancomycin (3.53%), teicoplanin (2.24%), linezolid (0.32%), and amoxicillin in combination with clavulanic acid (0.32%). A high percentage of resistance was noted in E. faecalis at high level gentamicin (21.9%) and tetracycline (60.6%). In general, strains of E. faecalis were more resistant than E. faecium. Enterococci should be considered not only potential pathogens, but also a reservoir of genes encoding antibiotic resistance which can be transferred to other microorganisms. Continuous monitoring of their incidence and emerging resistance is important in order to identify foods which potentially represent a real risk to the population, and to ensure effective treatment of human enterococcal infections. Copyright © 2014 Elsevier Ltd. All rights reserved.

Administration of SIN-1 induces guinea pig airway hyperresponsiveness through inactivation of airway neutral endopeptidase.

PubMed

Kanazawa, H; Hirata, K; Yoshikawa, J

1999-12-01

Peroxynitrite plays an important role in the pathogenesis of airway inflammation. We have already found that peroxynitrite may contribute to decreased beta(2)-adrenoceptor responses in airway smooth muscle. However, it is not known whether peroxynitrite can alter neutral endopeptidase (EC 3.4.24.11; NEP) activity in the airways. This study was designed to determine whether peroxynitrite induces airway hyperresponsiveness to substance P (SP) and endothelin-1 (ET-1) through the inactivation of airway NEP. We examined whether the administration of S-morpholinosydnonimine (SIN-1), a compound that releases peroxynitrite, increased bronchoconstrictor responses to SP and ET-1 in anesthetized guinea pigs. In addition, we assayed NEP activity in the airways of SIN-1-exposed guinea pigs. Though SIN-1 (10(-7) M) alone had no effect on pulmonary resistance, pretreatment with SIN-1 significantly enhanced SP- and ET-1-induced bronchoconstriction. Pretreatment with phosphoramidon, an NEP inhibitor, also enhanced SP- and ET-1-induced bronchoconstriction. However, simultaneous administration of phosphoramidon and SIN-1 had no additive effect on SP- and ET-1-induced bronchoconstriction. Peroxynitrite formation by SIN-1 was completely inhibited by N-acetylcysteine (NAC) and glutathione (GSH) in vitro, and pretreatment with NAC and GSH significantly reversed the potentiation by SIN-1 of SP-induced bronchoconstriction. In addition, the NEP activity of the trachea after SIN-1 exposure was significantly reduced compared to the level in control guinea pigs (solvent for SIN-1: 30.0+/-4.2 fmol.min(-1).mg tissue(-1); 10(-7) M SIN-1; 15.5+/-4.5 fmol.min(-1).mg tissue(-1), p<0.05). These findings suggest that peroxynitrite induces airway hyperresponsiveness to SP and ET-1 through the inactivation of airway NEP, and that peroxynitrite is an important mediator of the alterations in airway functions.

The effect of body weight on distal airway function and airway inflammation.

PubMed

van de Kant, Kim D G; Paredi, Paolo; Meah, Sally; Kalsi, Harpal S; Barnes, Peter J; Usmani, Omar S

Obesity is a global health problem that adversely influences the respiratory system. We assessed the effects of body mass index (BMI) on distal airway function and airway inflammation. Impulse oscillometry (IOS) as a measure of distal airway function, together with spirometry, were assessed in adults with a range of different BMIs. Airway inflammation was assessed with the fraction of exhaled nitric oxide (FeNO) and participants exhaled at various exhalation flows to determine alveolar and bronchial NO. In total 34 subjects were enrolled in the study; 19 subjects had a normal BMI (18.50-24.99), whilst 15 subjects were overweight (BMI 25.00-29.99), or obese (BMI ≥30). All subjects had normal spirometry. However, IOS measures of airway resistance (R) at 5Hz, 20Hz and frequency dependence (R 5-20 ) were elevated in overweight/obese individuals, compared to subjects with a normal BMI (median (interquartile range)); 5Hz: 0.41 (0.37, 0.45) vs. 0.32 (0.30, 0.37)kPa/l/s; 20Hz: 0.34 (0.30, 0.37) vs. 0.30 (0.26, 0.33)kPa/l/s; R 5-20 : 0.06 (0.04, 0.11) vs. 0.03 (0.01, 0.05)kPa/l/s; p<0.05), whereas airway reactance at 20Hz was decreased in overweight/obese individuals (20Hz: 0.07 (0.03, 0.09) vs. 0.10 (0.07, 0.13)kPa/l/s, p=0.009; 5Hz: -0.12 (-0.15, -0.10) vs. -0.10 (-0.13, -0.09)kPa/l/s, p=0.07). In contrast, within-breath IOS measures (a sign of expiratory flow limitation) and FeNO inflammatory measures, did not differ between groups (p>0.05). Being overweight has significant effects on distal and central airway function as determined by IOS, which is not detected by spirometry. Obesity does not influence airway inflammation as measured by FeNO. IOS is a reliable technique to identify airway abnormalities in the presence of normal spirometry in overweight people. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

The effects of thiopental and generic and nongeneric propofol on respiratory resistance during anesthetic induction in patients with reactive airways.

PubMed

Arain, Shahbaz R; Navani, Annu; Ebert, Thomas J

2002-06-01

To demonstrate a favorable effect of propofol on respiratory system resistance during anesthetic induction, and to determine if generic propofol causes adverse effects on respiratory resistance. Randomized pilot study. Anesthetic induction for elective surgery. 27 consenting ASA physical status II and III patients with reactive airways (positive smoking history or chronic obstructive pulmonary disease), but not receiving bronchodilator therapy. Patients were randomized equally to one of three anesthetic induction (and maintenance) drugs: sodium thiopental, 5 mg/kg (25 microg/kg/min), generic or nongeneric propofol, 1.25 mg/kg (50 microg/kg/min). They received preinduction midazolam and fentanyl (2 mg and 150 microg) and intravenous lidocaine (0.5 mg/kg). After anesthetic induction, tracheal intubation was established, and predetermined settings for mechanical ventilation were initiated. Immediately after intubation, a sensor was placed on the 8-mm endotracheal tube to detect baseline airway pressure and flow. During maintenance, repeat measurements of pressure and flow were obtained at 2.5-minute intervals for 10 minutes. Respiratory system resistance was derived off-line using the isovolumetric technique. Patients were similar across groups. The respiratory resistance measured after anesthetic induction did not differ among groups. During the maintenance infusion of thiopental or propofol, respiratory resistance increased gradually across all groups. There was no difference in the response of respiratory resistance either at induction or during the 10-minute maintenance between the generic and the nongeneric propofol groups. In contrast to earlier reports, this pilot study was unable to document a difference in the respiratory resistance in patients induced with thiopental or propofol. In addition, we were unable to demonstrate any different respiratory responses between generic propofol, containing sodium metabisulfite preservative, and nongeneric propofol.

Prevalence and antimicrobial resistance of Campylobacter species isolated from raw camel, beef, lamb, and goat meat in Iran.

PubMed

Rahimi, Ebrahim; Ameri, Mehrdad; Kazemeini, Hamid Reza

2010-04-01

Campylobacter spp. are one of the most common causes of acute bacterial gastroenteritis in human beings which are transmitted mostly via food originating from animals. This study was conducted to determine the prevalence and antimicrobial resistance of Campylobacter spp. isolated from retail raw meats in Iran. From June 2008 to June 2009, a total of 722 raw meat samples from camel (n = 107), beef (n = 190), lamb (n = 225), and goat (n = 180) were purchased from randomly selected retail outlets in Isfahan and Yazd, Iran, and were evaluated for the presence of Campylobacter spp. In this study, 50 of the 722 meat samples (6.9%) were contaminated with Campylobacter spp. The highest prevalence of Campylobacter spp. was found in lamb meat (12.0%), followed by goat meat (9.4%), beef meat (2.4%), and camel meat (0.9%). The most prevalent Campylobacter spp. isolated from the meat samples was Campylobacter jejuni (84.0%); the remaining isolates were Campylobacter coli (16.0%). Susceptibilities of 50 Campylobacter isolates were determined for 10 antimicrobial drugs using the disk-diffusion assay. Resistance to tetracycline was the most common finding (68.0%), followed by resistance to ciprofloxacin (46.0%) and nalidixic acid (40.0%). All of the isolates were susceptible to erythromycin, gentamicin, and chloramphenicol. Significantly higher prevalence rates of Campylobacter spp. (p < 0.05) were found in the lamb meat samples taken in spring (20.0%) and summer (18.9%). To our knowledge, this study is the first report of the isolation of Campylobacter spp. from raw camel, lamb, and goat meat in Iran.

Investigating the effects of laryngotracheal stenosis on upper airway aerodynamics.

PubMed

Cheng, Tracy; Carpenter, David; Cohen, Seth; Witsell, David; Frank-Ito, Dennis O

2018-04-01

Very little is known about the impact of laryngotracheal stenosis (LTS) on inspiratory airflow and resistance, especially in air hunger states. This study investigates the effect of LTS on airway resistance and volumetric flow across three different inspiratory pressures. Head-and-neck computed tomography scans of 11 subjects from 2010 to 2016 were collected. Three-dimensional reconstructions of the upper airway from the nostrils to carina, including the oral cavity, were created for one subject with a normal airway and for 10 patients with LTS. Airflow simulations were conducted using computational fluid dynamics modeling at three different inspiratory pressures (10, 25, 40 pascals [Pa]) for all subjects under two scenarios: 1) inspiration through nostrils only (MC), and 2) through both nostrils and mouth (MO). Volumetric flows in the normal subject at the three inspiratory pressures were considerably higher (MC: 11.8-26.1 L/min; MO: 17.2-36.9 L/min) compared to those in LTS (MC: 2.86-6.75 L/min; MO: 4.11-9.00 L/min). Airway resistances in the normal subject were 0.051 to 0.092 pascal seconds per milliliter (Pa.s)/mL (MC) and 0.035-0.065 Pa.s/mL (MO), which were approximately tenfold lower than those of subjects with LTS: 0.39 to 0.89 Pa.s/mL (MC) and 0.45 to 0.84 Pa.s/mL (MO). Furthermore, subjects with glottic stenosis had the greatest resistance, whereas subjects with subglottic stenosis had the greatest variability in resistance. Subjects with tracheal stenosis had the lowest resistance. This pilot study demonstrates that LTS increases resistance and decreases airflow. Mouth breathing significantly improved airflow and resistance but cannot completely compensate for the effects of stenosis. Furthermore, location of stenosis appears to modulate the effect of the stenosis on resistance differentially. NA. Laryngoscope, 128:E141-E149, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Effects of the tripeptide substance P antagonist, FR113680, on airway constriction and airway edema induced by neurokinins in guinea-pigs.

PubMed

Murai, M; Morimoto, H; Maeda, Y; Fujii, T

1992-06-24

FR113680 is a newly developed tripeptide substance P (SP) receptor antagonist. The effects of FR113680 on airway constriction and airway edema induced by neurokinins were investigated in guinea-pigs. In in vitro experiments, FR113680 inhibited the contraction of isolated guinea-pig trachea induced by SP and neurokinin A (NKA) in a dose-dependent manner with IC50 values of 2.3 x 10(-6) and 1.5 x 10(-5) M, respectively. The tracheal contraction induced by histamine and acetylcholine was not affected by FR113680. FR113680 (5 x 10(-5) M) also significantly inhibited the atropine-resistant contraction of isolated guinea-pig bronchi induced by electrical field stimulation. In in vivo experiments, FR113680 given i.v. inhibited SP-induced airway constriction in guinea-pigs at doses of 1 and 10 mg kg-1. However, FR113680 only inhibited NKA- and capsaicin-induced airway constriction by 40-50% even at a dose of 10 mg kg-1. FR113680 also inhibited SP-induced airway edema in guinea-pigs with the same potency as it inhibited SP-induced airway constriction. Histamine-induced airway constriction and airway edema were not affected at a dose of 10 mg kg-1. These results suggest that FR113680 preferentially inhibits responses induced by NK1 receptor activation (SP-induced airway constriction and airway edema), but is less effective on a NK2 receptor-induced response (airway constriction by NKA and neurogenic stimulation).

Characterization of Extended Spectrum Β-Lactamase Producing Enterobacteria and Methicillin-Resistant Staphylococcus aureus Isolated from Raw Pork and Cooked Pork Products in South China.

PubMed

Li, Lili; Ye, Lei; Yu, Li; Zhou, Chenqing; Meng, Hecheng

2016-07-01

In this study, we assessed the co-colonization with extended spectrum β-lactamase producing Enterobacteria (ESBL-E) and methicillin-resistant Staphylococcus aureus (MRSA) in raw pork and cooked pork products in south China. In total, 240 raw pork and 240 cooked pork samples collected from supermarkets (n = 20) and local butcher shops (n = 20) in the city of Guangzhou (China) were investigated. Raw pork and cooked pork was more frequent colonization with ESBL-E (7.5% in raw pork and 0.4% in cooked pork products) than with MRSA (4.2% in raw pork). Two of samples were contaminated with both tested types of multidrug-resistant bacteria. High antibiotic-resistance rate with wide spectrums of both ESBL-E and MRSA isolated were observed. In ESBL-E isolates, TEM (n = 15), CTX-M-1 (n = 3), CTX-M-9 (n = 1), and SHV (n = 1) genes were detected. TEM and SHV genes were associated with CTX-M-1 in 2 isolates, respectively. The CTX-M-9 gene of 1 isolate from cooked pork samples was found to be transferred to Escherichia coli J53 by conjugation. Detected MLST-types of MRSA were livestock-associated ST7 (n = 5) and ST9 (n = 4), as well as hospital-acquired ST239 (n = 1), suggesting contamination from human source(s) during meat processing. These findings confirmed a contamination of raw pork and cooked pork with ESBL-E and MRSA and emphasized the necessity of enforcing hygienic practices and specific detection of MRSA and ESBL-producing bacteria in meat processing and storage. © 2016 Institute of Food Technologists®

Impulse oscillometry in the evaluation of diseases of the airways in children

PubMed Central

Komarow, Hirsh D.; Myles, Ian A.; Uzzaman, Ashraf; Metcalfe, Dean D.

2012-01-01

Objective To provide an overview of impulse oscillometry and its application to the evaluation of children with diseases of the airways. Data Sources Medline and PubMed search, limited to English language and human disease, with keywords forced oscillation, impulse oscillometry, and asthma. Study Selections The opinions of the authors were used to select studies for inclusion in this review. Results Impulse oscillometry is a noninvasive and rapid technique requiring only passive cooperation by the patient. Pressure oscillations are applied at the mouth to measure pulmonary resistance and reactance. It is employed by health care professionals to help diagnose pediatric pulmonary diseases such asthma and cystic fibrosis; assess therapeutic responses; and measure airway resistance during provocation testing. Conclusions Impulse oscillometry provides a rapid, noninvasive measure of airway impedance. It may be easily employed in the diagnosis and management of diseases of the airways in children. PMID:21354020

Modulating airway defenses against microbes.

PubMed

Reynolds, Herbert Y

2002-05-01

Prevention and treatment of respiratory infections remain an important health care challenge as the US population ages, contains more susceptible or high-risk people, and encounters new pathogens or antibiotic resistant bacteria. Reasonably protective vaccines against very common microbes are available for childhood and adult immunization, but, generally, these are underutilized. A broader definition of higher risk individuals is evolving, which will include more for immunization. Different approaches to vaccine development through design of new component vaccines are necessary. This review has updated host defense mechanisms at three levels in the human respiratory tract: naso-oropharynx (upper airways), conducting airways, and alveolar space. Examples of representative pathogenic microbes have been inserted at the respective airway segment where they may colonize or create infection (influenza, measles virus, Porphyromonas gingivalis causing periodontitis, Bordetella pertussis, Chlamydia pneumoniae, Streptococcus pneumoniae, and Bacillus anthracis ). Hopefully, microbe-host interactions will suggest new approaches for preventing these kinds of infections.

Antibiotic resistance assessment in S. aureus strains isolated from raw sheep's milk cheese.

PubMed

Spanu, V; Virdis, S; Scarano, C; Cossu, F; De Santis, E P L; Cosseddu, A M

2010-06-01

In vitro activities of 16 antibiotics were tested against 36 Staphylococcus aureus (SA) strains isolated from raw sheep's milk cheese from six dairies. The minimum inhibitory concentration (MIC) was determined using a broth microdilution method (CLSI). All 36 isolates were analyzed for the presence of the accessory gene regulator gene, agr (I-IV), and genes encoding resistance to methicillin (mecA), erythromycin (ermA), penicillin (blaZ), and vancomycin (vanA-B). The isolates were also analyzed for similarities in pulsed-field gel electrophoresis (PFGE) patterns. SA strains showed resistance to ampicillin (36.1%), penicillin (33.3%), tetracycline (11.1%), and cloxacillin (2.8%) but were susceptible (>or=94.4%) to 12 out of 16 tested antimicrobials. The overall susceptibility of the strains to oxacillin, vancomycin, and erythromycin was confirmed by the absence of the mecA, vanA-B, and ermA genes. The PFGE results showed that 32 strains belonged to 10 different clusters (P1-P10) while four strains were untypeable.

Impact of airway morphological changes on pulmonary flows in scoliosis

NASA Astrophysics Data System (ADS)

Farrell, James; Garrido, Enrique; Valluri, Prashant

2016-11-01

The relationship between thoracic deformity in scoliosis and lung function is poorly understood. In a pilot study, we reviewed computed tomography (CT) routine scans of patients undergoing scoliosis surgery. The CT scans were processed to segment the anatomy of the airways, lung and spine. A three-dimensional model was created to study the anatomical relationship. Preliminary analysis showed significant airway morphological differences depending on the anterior position of the spine. A computational fluid dynamics (CFD) study was also conducted on the airway geometry using the inspiratory scans. The CFD model assuming non-compliant airway walls was capable of showing pressure drops in areas of high airway resistance, but was unable to predict regional ventilation differences. Our results indicate a dependence between the dynamic deformation of the airway during breathing and lung function. Dynamic structural deformation must therefore be incorporated within any modelling approaches to guide clinicians on the decision to perform surgical correction of the scoliosis.

Control of nasal vasculature and airflow resistance in the dog.

PubMed Central

Lung, M A; Phipps, R J; Wang, J C; Widdicombe, J G

1984-01-01

Nasal vascular and airflow resistances have been measured in dogs, simultaneously on both sides separately. Vascular resistance was measured either by constant flow perfusion of the terminal branch of the maxillary artery (which supplies, via the sphenopalatine artery, the nasal septum, most of the turbinates and the nasal sinuses) or by measuring blood flow through this artery, maintained by the dog's own blood pressure. Airflow resistance was assessed by inserting balloon-tipped endotracheal catheters into the back of each nasal cavity via the nasopharynx, and measuring transnasal pressure at constant airflow through each side of the nose simultaneously. Preliminary experiments indicated that there was 5-10% collateral anastomosis between the two sides. Close-arterial injection of drugs showed different patterns of response. Adrenaline, phenylephrine, chlorpheniramine and low doses of prostaglandin F2 alpha increased vascular resistance and lowered airway resistance. Salbutamol, methacholine and histamine lowered vascular resistance and increased airway resistance. Dobutamine decreased airway resistance with a small increase in vascular resistance. Prostaglandins E1, E2 and F2 alpha (high dose) decreased both vascular and airway resistances. Substance P, eledoisin-related peptide and vasoactive intestinal polypeptide lowered vascular resistance with little change in airway resistance. The results are interpreted in terms of possible drug actions on precapillary resistance vessels, sinusoids and venules, and arteriovenous anastomoses. It is concluded that nasal airway resistance cannot be correlated with vascular resistance or blood flow, since the latter has a complex and ill-defined relationship with nasal vascular blood volume. PMID:6204040

Control of nasal vasculature and airflow resistance in the dog.

PubMed

Lung, M A; Phipps, R J; Wang, J C; Widdicombe, J G

1984-04-01

Nasal vascular and airflow resistances have been measured in dogs, simultaneously on both sides separately. Vascular resistance was measured either by constant flow perfusion of the terminal branch of the maxillary artery (which supplies, via the sphenopalatine artery, the nasal septum, most of the turbinates and the nasal sinuses) or by measuring blood flow through this artery, maintained by the dog's own blood pressure. Airflow resistance was assessed by inserting balloon-tipped endotracheal catheters into the back of each nasal cavity via the nasopharynx, and measuring transnasal pressure at constant airflow through each side of the nose simultaneously. Preliminary experiments indicated that there was 5-10% collateral anastomosis between the two sides. Close-arterial injection of drugs showed different patterns of response. Adrenaline, phenylephrine, chlorpheniramine and low doses of prostaglandin F2 alpha increased vascular resistance and lowered airway resistance. Salbutamol, methacholine and histamine lowered vascular resistance and increased airway resistance. Dobutamine decreased airway resistance with a small increase in vascular resistance. Prostaglandins E1, E2 and F2 alpha (high dose) decreased both vascular and airway resistances. Substance P, eledoisin-related peptide and vasoactive intestinal polypeptide lowered vascular resistance with little change in airway resistance. The results are interpreted in terms of possible drug actions on precapillary resistance vessels, sinusoids and venules, and arteriovenous anastomoses. It is concluded that nasal airway resistance cannot be correlated with vascular resistance or blood flow, since the latter has a complex and ill-defined relationship with nasal vascular blood volume.

The Contribution of Small Airway Obstruction to the Pathogenesis of Chronic Obstructive Pulmonary Disease.

PubMed

Hogg, James C; Paré, Peter D; Hackett, Tillie-Louise

2017-04-01

The hypothesis that the small conducting airways were the major site of obstruction to airflow in normal lungs was introduced by Rohrer in 1915 and prevailed until Weibel introduced a quantitative method of studying lung anatomy in 1963. Green repeated Rohrer's calculations using Weibels new data in 1965 and found that the smaller conducting airways offered very little resistance to airflow. This conflict was resolved by seminal experiments conducted by Macklem and Mead in 1967, which confirmed that a small proportion of the total lower airways resistance is attributable to small airways <2 mm in diameter. Shortly thereafter, Hogg, Macklem, and Thurlbeck used this technique to show that small airways become the major site of obstruction in lungs affected by emphysema. These and other observations led Mead to write a seminal editorial in 1970 that postulated the small airways are a silent zone within normal lungs where disease can accumulate over many years without being noticed. This review provides a progress report since the 1970s on methods for detecting chronic obstructive pulmonary disease, the structural nature of small airways' disease, and the cellular and molecular mechanisms that are thought to underlie its pathogenesis. Copyright © 2017 the American Physiological Society.

Neutrophil Extracellular Trap (NET)-Mediated Killing of Pseudomonas aeruginosa: Evidence of Acquired Resistance within the CF Airway, Independent of CFTR

PubMed Central

Young, Robert L.; Malcolm, Kenneth C.; Kret, Jennifer E.; Caceres, Silvia M.; Poch, Katie R.; Nichols, David P.; Taylor-Cousar, Jennifer L.; Saavedra, Milene T.; Randell, Scott H.; Vasil, Michael L.; Burns, Jane L.; Moskowitz, Samuel M.; Nick, Jerry A.

2011-01-01

The inability of neutrophils to eradicate Pseudomonas aeruginosa within the cystic fibrosis (CF) airway eventually results in chronic infection by the bacteria in nearly 80 percent of patients. Phagocytic killing of P. aeruginosa by CF neutrophils is impaired due to decreased cystic fibrosis transmembrane conductance regulator (CFTR) function and virulence factors acquired by the bacteria. Recently, neutrophil extracellular traps (NETs), extracellular structures composed of neutrophil chromatin complexed with granule contents, were identified as an alternative mechanism of pathogen killing. The hypothesis that NET-mediated killing of P. aeruginosa is impaired in the context of the CF airway was tested. P. aeruginosa induced NET formation by neutrophils from healthy donors in a bacterial density dependent fashion. When maintained in suspension through continuous rotation, P. aeruginosa became physically associated with NETs. Under these conditions, NETs were the predominant mechanism of killing, across a wide range of bacterial densities. Peripheral blood neutrophils isolated from CF patients demonstrated no impairment in NET formation or function against P. aeruginosa. However, isogenic clinical isolates of P. aeruginosa obtained from CF patients early and later in the course of infection demonstrated an acquired capacity to withstand NET-mediated killing in 8 of 9 isolates tested. This resistance correlated with development of the mucoid phenotype, but was not a direct result of the excess alginate production that is characteristic of mucoidy. Together, these results demonstrate that neutrophils can kill P. aeruginosa via NETs, and in vitro this response is most effective under non-stationary conditions with a low ratio of bacteria to neutrophils. NET-mediated killing is independent of CFTR function or bacterial opsonization. Failure of this response in the context of the CF airway may occur, in part, due to an acquired resistance against NET-mediated killing by

The Effect of Lung Stretch during Sleep on Airway Mechanics in Overweight and Obese Asthma

PubMed Central

Campana, L.M.; Malhotra, A.; Suki, B.; Hess, L.; Israel, E.; Smales, E.; DeYoung, P.; Owens, R.L.

2012-01-01

Both obesity and sleep reduce lung volume and limit deep breaths, possibly contributing to asthma. We hypothesize that increasing lung volume dynamically during sleep would reduce airway resistance in asthma. Asthma (n=10) and control (n=10) subjects were studied during sleep at baseline and with increased lung volume via bi-level positive airway pressure (BPAP). Using forced oscillations, respiratory system resistance (Rrs) and reactance (Xrs) were measured during sleep and Rrs was partitioned to upper and lower airway resistance (Rup, Rlow) using an epiglottic pressure catheter. Rrs and Rup increased with sleep (p<0.01) and Xrs was decreased in REM (p=0.02) as compared to wake. Rrs, Rup, and Rlow, were larger (p<0.01) and Xrs was decreased (p<0.02) in asthma. On BPAP, Rrs and Rup were decreased (p<0.001) and Xrs increased (p<0.01), but Rlow was unchanged. High Rup was observed in asthma, which reduced with BPAP. We conclude that the upper airway is a major component of Rrs and larger lung volume changes may be required to alter Rlow. PMID:23041446

Antibiotic Resistance Patterns of Enterococci and Occurrence of Vancomycin-Resistant Enterococci in Raw Minced Beef and Pork in Germany

PubMed Central

Klein, Günter; Pack, Alexander; Reuter, Gerhard

1998-01-01

The food chain, especially raw minced meat, is thought to be responsible for an increase in the incidence of vancomycin-resistant enterococci (VRE) in human nosocomial infections. Therefore, 555 samples from 115 batches of minced beef and pork from a European Union-licensed meat-processing plant were screened for the occurrence of VRE. The processed meat came from 45 different slaughterhouses in Germany. Enterococci were isolated directly from Enterococcosel selective agar plates and also from Enterococcosel selective agar plates supplemented with 32 mg of vancomycin per liter. In addition, peptone broth was used in a preenrichment procedure, and samples were subsequently plated onto Enterococcosel agar containing vancomycin. To determine resistance, 209 isolates from 275 samples were tested with the glycopeptides vancomycin, teicoplanin, and avoparcin and 19 other antimicrobial substances by using a broth microdilution test. When the direct method was used, VRE were found in 3 of 555 samples (0.5%) at a concentration of 1.0 log CFU/g of minced meat. When the preenrichment procedure was used, 8% of the samples were VRE positive. Our findings indicate that there is a low incidence of VRE in minced meat in Germany. In addition, the resistance patterns of the VRE isolates obtained were different from the resistance patterns of clinical isolates. A connection between the occurrence of VRE in minced meat and nosocomial infections could not be demonstrated on the basis of our findings. PMID:9572958

Airway and Pulmonary β2-Adrenergic Vasodilatory Function in Current Smokers and Never Smokers.

PubMed

Hurwitz, Barry E; Mendes, Eliana S; Schmid, Andreas; Parker, Meela; Arana, Johana; Gonzalez, Alex; Wanner, Adam

2017-03-01

Cigarette smoking has been associated with diminished vasodilatory function in the airway circulation. It is possible that cigarette smoking similarly affects the pulmonary circulation before resting pulmonary circulatory abnormalities become manifested. The aim of this study was to compare the acute effect of inhaled albuterol on airway and pulmonary hemodynamic function as an index of β 2 -adrenoceptor-mediated vasodilation in smokers and never smokers. In 30 adults, airway and pulmonary vascular function was assessed before and 15 min after albuterol inhalation (270 μg). From mean systemic arterial pressure, cardiac output, airway blood flow, and mean pulmonary arterial pressure, airway vascular resistance (AVR) and pulmonary vascular resistance (PVR) were derived. Albuterol induced a substantial drop in mean (± SE) PVR (-67.2% ± 5%), with no difference between groups. In contrast, the albuterol-induced decrease in AVR was significantly greater in never smokers than in smokers (-28.6% ± 3% vs -3.1% ± 6%; P < .02). These results are consistent with a dysfunction in a β 2 -adrenergic signaling pathway mediating vasorelaxation in the airway circulation of current smokers. The vasodilatory deficit in the airway circulation but not in the pulmonary circulation could be related to local differences in the impact of cigarette smoke on the vascular endothelium. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Airways in smooth muscle α-actin null mice experience a compensatory mechanism that modulates their contractile response.

PubMed

Shardonofsky, Felix R; Moore, Joan; Schwartz, Robert J; Boriek, Aladin M

2012-03-01

We hypothesized that ablation of smooth muscle α-actin (SM α-A), a contractile-cytoskeletal protein expressed in airway smooth muscle (ASM) cells, abolishes ASM shortening capacity and decreases lung stiffness. In both SM α-A knockout and wild-type (WT) mice, airway resistance (Raw) determined by the forced oscillation technique rose in response to intravenous methacholine (Mch). However, the slope of Raw (cmH(2)O·ml(-1)·s) vs. log(2) Mch dose (μg·kg(-1)·min(-1)) was lower (P = 0.007) in mutant (0.54 ± 0.14) than in WT mice (1.23 ± 0.19). RT-PCR analysis performed on lung tissues confirmed that mutant mice lacked SM α-A mRNA and showed that these mice had robust expressions of both SM γ-A mRNA and skeletal muscle (SKM) α-A mRNA, which were not expressed in WT mice, and an enhanced SM22 mRNA expression relative to that in WT mice. Compared with corresponding spontaneously breathing mice, mechanical ventilation-induced lung mechanical strain increased the expression of SM α-A mRNA in WT lungs; in mutant mice, it augmented the expressions of SM γ-A mRNA and SM22 mRNA and did not alter that of SKM α-A mRNA. In mutant mice, the expression of SM γ-A mRNA in the lung during spontaneous breathing and its enhanced expression following mechanical ventilation are consistent with the likely possibility that in the absence of SM α-A, SM γ-A underwent polymerization and interacted with smooth muscle myosin to produce ASM shortening during cholinergic stimulation. Thus our data are consistent with ASM in mutant mice experiencing compensatory mechanisms that modulated its contractile muscle capacity.

Theoretical and experimental evaluation of the effects of an argon gas mixture on the pressure drop through adult tracheobronchial airway replicas.

PubMed

Litwin, Patrick D; Reis Dib, Anna Luisa; Chen, John; Noga, Michelle; Finlay, Warren H; Martin, Andrew R

2017-06-14

Argon has the potential to be a novel inhaled therapeutic agent, owing to the neuroprotective and organoprotective properties demonstrated in preclinical studies. Before human trials are performed, an understanding of varying gas properties on airway resistance during inhalation is essential. This study predicts the effect of an 80% argon/20% oxygen gas mixture on the pressure drop through conducting airways, and by extension the airway resistance, and then verifies these predictions experimentally using 3-D printed adult tracheobronchial airway replicas. The predicted pressure drop was calculated using established analytical models of airway resistance, incorporating the change in viscosity and density of the 80% argon/20% oxygen mixture versus that of air. Predicted pressure drop for the argon mixture increased by approximately 29% compared to that for air. The experimental results were consistent with this prediction for inspiratory flows ranging from 15 to 90slpm. These results indicate that established analytical models may be used to predict increases in conducting airway resistance for argon/oxygen mixtures, compared with air. Such predictions are valuable in predicting average patient response to breathing argon/oxygen mixtures, and in selecting or designing delivery systems for use in administration of argon/oxygen mixtures to critically ill or injured patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Detection of the airway obstruction stage in asthma using impulse oscillometry system.

PubMed

Qi, Guang-Sheng; Zhou, Zhi-Cai; Gu, Wen-Chao; Xi, Feng; Wu, Hao; Yang, Wen-Lan; Liu, Jin-Ming

2013-02-01

Although spirometry is the most common method for evaluating the airway obstruction stage in asthma patients, it is difficult to perform in some patients. The aim of this study was to evaluate whether impulse oscillometry, an easy-to-perform technique, can detect asthmatic airway obstruction stage. A total of 80 subjects, including healthy volunteers and patients with asthma, were enrolled in this study. The asthma patients were classified into three groups according to American Thoracic Society (ATS)/European Respiratory Society (ERS)-2005: the mild group (forced expiratory volume in 1 second (FEV(1)) ≥ 70% predicted (Pred), n = 20), the moderate group (50% Pred ≤ FEV(1) <70% Pred, n = 20), and the severe group (FEV(1) < 50% Pred, n = 20). Spirometry and impulse oscillometry (IOS) parameters were obtained from every subject. Correlation analysis was used to compare spirometry measurements and IOS parameters. One-way analysis of variance (ANOVA) was performed to compare IOS parameters among different groups. The potential of using all individual IOS parameters to detect the different stages of asthmatic airway obstruction was evaluated by the receiver operating characteristic (ROC) curve analysis. The correlation analysis showed that IOS parameters, such as respiratory resistance at 5 Hz (R(5)), respiratory resistance at 10 Hz (R(10)), respiratory resistance at 20 Hz (R(20)), difference in resistance between 5 Hz and 20 Hz (R(5-20)), impedance at 5 Hz (Z(5)), resonant frequency (Fres), and area of reactance (AX) were negatively correlated with FEV(1) and peak expiratory flow (PEF), while reactance at 5 Hz (X(5)) was positively correlated with FEV(1) and PEF. The increase in R(5), R(10), R(20), Z(5), R(5-20), Fres, (-X(5)), and AX parameters corresponded significantly with an increase in the airway obstruction stage, as determined by one-way ANOVA . ROC curve analysis revealed that all the IOS parameters studied, except for Fres, were capable of classifying

The Effects of Airway Microbiome on Corticosteroid Responsiveness in Asthma

PubMed Central

Goleva, Elena; Jackson, Leisa P.; Harris, J. Kirk; Robertson, Charles E.; Sutherland, E. Rand; Hall, Clifton F.; Good, James T.; Gelfand, Erwin W.; Martin, Richard J.

2013-01-01

Rationale: The role of airway microbiome in corticosteroid response in asthma is unknown. Objectives: To examine airway microbiome composition in patients with corticosteroid-resistant (CR) asthma and compare it with patients with corticosteroid-sensitive (CS) asthma and normal control subjects and explore whether bacteria in the airways of subjects with asthma may direct alterations in cellular responses to corticosteroids. Methods: 16S rRNA gene sequencing was performed on bronchoalveolar lavage (BAL) samples of 39 subjects with asthma and 12 healthy control subjects. In subjects with asthma, corticosteroid responsiveness was characterized, BAL macrophages were stimulated with pathogenic versus commensal microorganisms, and analyzed by real-time polymerase chain reaction for the expression of corticosteroid-regulated genes and cellular p38 mitogen-activated protein kinase (MAPK) activation. Measurements and Main Results: Of the 39 subjects with asthma, 29 were CR and 10 were CS. BAL microbiome from subjects with CR and CS asthma did not differ in richness, evenness, diversity, and community composition at the phylum level, but did differ at the genus level, with distinct genus expansions in 14 subjects with CR asthma. Preincubation of asthmatic airway macrophages with Haemophilus parainfluenzae, a uniquely expanded potential pathogen found only in CR asthma airways, resulted in p38 MAPK activation, increased IL-8 (P < 0.01), mitogen-activated kinase phosphatase 1 mRNA (P < 0.01) expression, and inhibition of corticosteroid responses (P < 0.05). This was not observed after exposure to commensal bacterium Prevotella melaninogenica. Inhibition of transforming growth factor-β–associated kinase-1 (TAK1), upstream activator of MAPK, but not p38 MAPK restored cellular sensitivity to corticosteroids. Conclusions: A subset of subjects with CR asthma demonstrates airway expansion of specific gram-negative bacteria, which trigger TAK1/MAPK activation and induce

BLOCKADE OF TRKA OR P75 NEUROTROPHIN RECEPTORS ATTENUATES DIESEL PARTICULATE-INDUCED ENHANCEMENT OF ALLERGIC AIRWAYS RESPONSES IN BALB/C MICE

EPA Science Inventory

Neurotrophins, including nerve growth factor (NGF) partially mediate many features of allergic airways disease including airway resistance. Exposure to diesel exhaust particles (DEP) associated with the combustion of diesel fuel exacerbates allergic airways responses. We tested t...

The contribution of airway smooth muscle to airway narrowing and airway hyperresponsiveness in disease.

PubMed

Martin, J G; Duguet, A; Eidelman, D H

2000-08-01

Airway hyperresponsiveness (AHR), the exaggerated response to constrictor agonists in asthmatic subjects, is incompletely understood. Changes in either the quantity or properties of airway smooth muscle (ASM) are possible explanations for AHR. Morphometric analyses demonstrate structural changes in asthmatic airways, including subepithelial fibrosis, gland hyperplasia/hypertrophy, neovascularization and an increase in ASM mass. Mathematical modelling of airway narrowing suggests that, of all the changes in structure, the increase in ASM mass is the most probable cause of AHR. An increase in ASM mass in the large airways is more closely associated with a greater likelihood of dying from asthma than increases in ASM mass in other locations within the airway tree. ASM contraction is opposed by the elastic recoil of the lungs and airways, which appears to limit the degree of bronchoconstriction in vivo. The cyclical nature of tidal breathing applies stresses to the airway wall that enhance the bronchodilating influence of the lung tissues on the contracting ASM, in all probability by disrupting cross-bridges. However, the increase in ASM mass in asthma may overcome the limitation resulting from the impedances to ASM shortening imposed by the lung parenchyma and airway wall tissues. Additionally, ASM with the capacity to shorten rapidly may achieve shorter lengths and cause a greater degree of bronchoconstriction when stimulated to contract than slower ASM. Changes in ASM properties are induced by the process of sensitization and allergen-exposure such as enhancement of phospholipase C activity and inositol phosphate turnover, and increases in myosin light chain kinase activity. Whether changes in ASM mass or biochemical/biomechanical properties form the basis for asthma remains to be determined.

Role of upper airway in ventilatory control in awake and sleeping dogs.

PubMed

Stradling, J R; England, S J; Harding, R; Kozar, L F; Andrey, S; Phillipson, E A

1987-03-01

We examined the role of the upper airway in the regulation of the pattern of breathing in six adult dogs during wakefulness and sleep. The dogs breathed through a fenestrated endotracheal tube inserted through a tracheostomy. The tube was modified to allow airflow to be directed either through the nose or through the tracheostomy. When airflow was diverted from nose to tracheostomy there was an abrupt increase in the rate of expiratory airflow, resulting in prolongation of the end-expiratory pause but no change in overall expiratory duration or respiratory frequency. Furthermore, electromyogram recordings from implanted diaphragmatic and laryngeal muscle electrodes did not show any changes that could be interpreted as an attempt to delay expiratory airflow or increase end-expiratory lung volume. The effects of switching from nose to tracheostomy breathing could be reversed by adding a resistance to the endotracheal tube so as to approximate upper airway resistance. The findings indicate that under normal conditions in the adult dog upper airway receptors play little role in regulation of respiratory pattern and that the upper airway exerts little influence on the maintenance of end-expiratory lung volume.

First study on characterization of virulence and antibiotic resistance genes in verotoxigenic and enterotoxigenic E. coli isolated from raw milk and unpasteurized traditional cheeses in Romania.

PubMed

Tabaran, Alexandra; Mihaiu, Marian; Tăbăran, Flaviu; Colobatiu, Liora; Reget, Oana; Borzan, Mihai Marian; Dan, Sorin Daniel

2017-03-01

The study focused on the incidence of enterotoxigenic Escherichia coli (ETEC) and verotoxigenic E. coli (VTEC) in raw milk and traditional dairy cheeses marketed in Romania, characterizing the virulence and antibiotic resistance genes of these isolates. One hundred and twenty samples of raw milk and 80 samples of unpasteurized telemy cheese were collected and cultured according to the international standard protocol. All the characteristic E. coli cultures were analyzed for the presence of STa, STb, LT, stx1, and stx2 toxicity genes. The ETEC/VTEC strains were tested for the presence of antibiotic resistance genes, such as aadA1, tetA, tetB, tetC, tetG, dfrA1, qnrA, aaC, sul1, bla SHV , bla CMY , bla TEM , and ere(A), using PCR. The results showed that 27 samples (18.62%) were positive for one of the virulence genes investigated. 48.1% (n = 13) tested positive at the genes encoding for tetracycline resistance, tetA being the most prevalent one (61.5%; n = 8). A high percent (33.3%; n = 9) revealed the beta-lactamase (bla TEM ) resistance gene, and none of the samples tested positive for bla CMY and bla SHV genes. The genes responsible for resistance to sulfonamides (sul1) and trimethoprim (dfrA1) were detected in rates of 14.8% (n = 4) and 7.4% (n = 2), respectively. E. coli is highly prevalent in raw milk and unpasteurized cheeses marketed in Romania. These strains might represent an important reservoir of resistance genes which can easily spread into other European countries, given the unique market.

Airway-parenchymal interdependence

PubMed Central

Paré, Peter D; Mitzner, Wayne

2015-01-01

In this manuscript we discuss the interaction of the lung parenchyma and the airways as well as the physiological and pathophysiological significance of this interaction. These two components of the respiratory organ can be thought of as two independent elastic structures but in fact the mechanical properties of one influence the behavior of the other. Traditionally the interaction has focused on the effects of the lung on the airways but there is good evidence that the opposite is also true, i.e., that the mechanical properties of the airways influence the elastic properties of the parenchyma. The interplay between components of the respiratory system including the airways, parenchyma and vasculature is often referred to as “interdependence.” This interdependence transmits the elastic recoil of the lung to create an effective pressure that dilates the airways as transpulmonary pressure and lung volume increase. By using a continuum mechanics analysis of the lung parenchyma, it is possible to predict the effective pressure between the airways and parenchyma, and these predictions can be empirically evaluated. Normal airway caliber is maintained by this pressure in the adventitial interstitium of the airway, and it counteracts airway compression during forced expiration as well as the ability of airway smooth muscle to narrow airways. Interdependence has physiological and pathophysiological significance. Weakening of the forces of interdependence contributes to airway dysfunction and gas exchange impairment in acute and chronic airway diseases including asthma and emphysema. PMID:23723029

Airway disease: anatomopathologic patterns and functional correlations.

PubMed

Mormile, F; Ciappi, G

1997-01-01

Airways represent a serial and parallel branched system, through which the alveoli are connected with the external air. They participate in the mechanical and immune defense against noxious agents, regional flow regulation to optimize the perfusion/ventilation ratio and provide lung mechanical support. Functional exploration of central airways is based on resistance measurement, flow-volume curve or spirometry, while peripheral airways influence parameters as the upstream resistance, the slope of phase III nitrogen washout and the residual volume. Bronchodynamic tests supply important information on airway reversibility and nonspecific reactivity. Anatomopathologic alterations of obstructive chronic bronchitis, pulmonary emphysema and bronchial asthma account for their specific functional and bronchodynamic alterations. There is a growing interest for bronchiolitis in the clinical, radiologic and functional field. This type of lesion, always present in COPD, asthma and interstitial disease, becomes relevant when isolated or predominant. The most useful anatomofunctional classification separates the "constrictive" forms, the cause of obstruction and hyperinflation, from "proliferative" forms where an intraluminal proliferation more or less extended to alveolar air spaces as in BOOP (bronchiolitis obliterans organizing pneumonia) results in restrictive dysfunction. Constrictive bronchiolitis obliterans represents a severe and frequent complication of lung and bone marrow transplantation. Idiopathic BOOP may occur with cough or flue-like symptoms. In other cases, constrictive and proliferative forms may have a toxic (gases or drugs), postinfective or immune etiology (rheumatoid arthritis, LES, etc). Respiratory bronchiolitis or smokers' bronchiolitis, an often asymptomatic lesion, rarely associated to an interstitial lung disease, should be considered separately. The relationships between respiratory bronchiolitis, COPD and initial centriacinar emphysema is still to

Trefoil factor-2 reverses airway remodeling changes in allergic airways disease.

PubMed

Royce, Simon G; Lim, Clarice; Muljadi, Ruth C; Samuel, Chrishan S; Ververis, Katherine; Karagiannis, Tom C; Giraud, Andrew S; Tang, Mimi L K

2013-01-01

Trefoil factor 2 (TFF2) is a small peptide with an important role in mucosal repair. TFF2 is up-regulated in asthma, suggesting a role in asthma pathogenesis. Given its known biological role in promoting epithelial repair, TFF2 might be expected to exert a protective function in limiting the progression of airway remodeling in asthma. The contribution of TFF2 to airway remodeling in asthma was investigated by examining the expression of TFF2 in the airway and lung, and evaluating the effects of recombinant TFF2 treatment on established airway remodeling in a murine model of chronic allergic airways disease (AAD). BALB/c mice were sensitized and challenged with ovalbumin (OVA) or saline for 9 weeks, whereas mice with established OVA-induced AAD were treated with TFF2 or vehicle control (intranasally for 14 d). Effects on airway remodeling, airway inflammation, and airway hyperresponsiveness were then assessed, whereas TFF2 expression was determined by immunohistochemistry. TFF2 expression was significantly increased in the airways of mice with AAD, compared with expression levels in control mice. TFF2 treatment resulted in reduced epithelial thickening, subepithelial collagen deposition, goblet-cell metaplasia, bronchial epithelium apoptosis, and airway hyperresponsiveness (all P < 0.05, versus vehicle control), but TFF2 treatment did not influence airway inflammation. The increased expression of endogenous TFF2 in response to chronic allergic inflammation is insufficient to prevent the progression of airway inflammation and remodeling in a murine model of chronic AAD. However, exogenous TFF2 treatment is effective in reversing aspects of established airway remodeling. TFF2 has potential as a novel treatment for airway remodeling in asthma.

Occurrence and antimicrobial resistance of pathogenic Escherichia coli and Salmonella spp. in retail raw table eggs sold for human consumption in Enugu state, Nigeria

PubMed Central

Okorie-Kanu, O. Josephine; Ezenduka, E. Vivienne; Okorie-Kanu, C. Onwuchokwe; Ugwu, L. Chinweokwu; Nnamani, U. John

2016-01-01

Aim: This study was conducted to investigate the occurrence of pathogenic Escherichia coli and Salmonella species in retail raw table eggs sold for human consumption in Enugu State and to determine the resistance of these pathogens to antimicrobials commonly used in human and veterinary practices in Nigeria. Materials and Methods: A total of 340 raw table eggs comprising 68 composite samples (5 eggs per composite sample) were collected from five selected farms (13 composite samples from the farms) and 10 retail outlets (55 composite samples from the retail outlets) in the study area over a period of 4-month (March-June, 2014). The eggs were screened for pathogenic E. coli and Salmonella species following standard procedures within 24 h of sample collection. Isolates obtained were subjected to in-vitro antimicrobial susceptibility test with 15 commonly used antimicrobials using the disk diffusion method. Results: About 37 (54.4%) and 7 (10.3%) of the 68 composite samples were positive for pathogenic E. coli and Salmonella species, respectively. The shells showed significantly higher (p<0.05) contaminations than the contents for both microorganisms. The eggs from the farms showed higher contamination with pathogenic E. coli than eggs from the retail outlets while the reverse was the case for Salmonella species even though they were not significant (p>0.05). The organisms obtained showed a multiple drug resistance. They were completely resistant to nitrofurantoin, sulfamethoxazole/trimethoprim, penicillin G and oxacillin. In addition to these, Salmonella spp. also showed 100% resistance to tetracycline. The pathogenic E. coli isolates obtained were 100% susceptible to gentamicin, neomycin, ciprofloxacin, and amoxicillin-clavulanic acid while Salmonella spp. showed 100% susceptibility to erythromycin, neomycin, and rifampicin. Both organisms showed varying degrees of resistance to streptomycin, amoxicillin, vancomycin, and doxycycline. Conclusion: From the results of

Occurrence and antimicrobial resistance of pathogenic Escherichia coli and Salmonella spp. in retail raw table eggs sold for human consumption in Enugu state, Nigeria.

PubMed

Okorie-Kanu, O Josephine; Ezenduka, E Vivienne; Okorie-Kanu, C Onwuchokwe; Ugwu, L Chinweokwu; Nnamani, U John

2016-11-01

This study was conducted to investigate the occurrence of pathogenic Escherichia coli and Salmonella species in retail raw table eggs sold for human consumption in Enugu State and to determine the resistance of these pathogens to antimicrobials commonly used in human and veterinary practices in Nigeria. A total of 340 raw table eggs comprising 68 composite samples (5 eggs per composite sample) were collected from five selected farms (13 composite samples from the farms) and 10 retail outlets (55 composite samples from the retail outlets) in the study area over a period of 4-month (March-June, 2014). The eggs were screened for pathogenic E. coli and Salmonella species following standard procedures within 24 h of sample collection. Isolates obtained were subjected to in-vitro antimicrobial susceptibility test with 15 commonly used antimicrobials using the disk diffusion method. About 37 (54.4%) and 7 (10.3%) of the 68 composite samples were positive for pathogenic E. coli and Salmonella species, respectively. The shells showed significantly higher (p<0.05) contaminations than the contents for both microorganisms. The eggs from the farms showed higher contamination with pathogenic E. coli than eggs from the retail outlets while the reverse was the case for Salmonella species even though they were not significant (p>0.05). The organisms obtained showed a multiple drug resistance. They were completely resistant to nitrofurantoin, sulfamethoxazole/trimethoprim, penicillin G and oxacillin. In addition to these, Salmonella spp. also showed 100% resistance to tetracycline. The pathogenic E. coli isolates obtained were 100% susceptible to gentamicin, neomycin, ciprofloxacin, and amoxicillin-clavulanic acid while Salmonella spp. showed 100% susceptibility to erythromycin, neomycin, and rifampicin. Both organisms showed varying degrees of resistance to streptomycin, amoxicillin, vancomycin, and doxycycline. From the results of the study, it can be concluded that the raw table

Airway and alveolar nitric oxide production, lung function, and pulmonary blood flow in sickle cell disease.

PubMed

Lunt, Alan; Ahmed, Na'eem; Rafferty, Gerrard F; Dick, Moira; Rees, David; Height, Sue; Thein, Swee Lay; Greenough, Anne

2016-02-01

Children with sickle cell disease (SCD) often have obstructive lung function abnormalities which could be due to asthma or increased pulmonary blood volume; it is important to determine the underlying mechanism to direct appropriate treatment. In asthmatics, exhaled nitric oxide (FeNO) is elevated. FeNO, however, can also be raised due to increased alveolar production. Our aim, therefore, was to determine if airway or alveolar NO production differed between SCD children and ethnic and age-matched controls. Lung function, airway NO flux and alveolar NO production, and effective pulmonary blood flow were assessed in 18 SCD children and 18 ethnic and age-matched controls. The SCD children compared to the controls had a higher respiratory system resistance (P = 0.0008), alveolar NO production (P = 0.0224), and pulmonary blood flow (P < 0.0001), but not airway NO flux. There was no significant correlation between FeNO and respiratory system resistance in either group, but in the SCD children, there were correlations between alveolar NO production (P = 0.0006) and concentration (P < 0.0001) and pulmonary blood flow. Airway NO flux was not elevated in the SCD children nor correlated with airways obstruction, suggesting that airways obstruction, at least in some SCD children, is not due to asthma.

Exercise-induced airway obstruction in young asthmatics measured by impulse oscillometry.

PubMed

Lee, J H; Lee, Y W; Shin, Y S; Jung, Y H; Hong, C S; Park, J W

2010-01-01

Impulse oscillometry (IOS) is a good method for measuring airway resistance. It does not require special breathing skills and it can reflect different aspects of airway obstruction to those revealed by spirometry, which is an effort-dependent maneuver. To evaluate the characteristics of airway obstruction in young asthmatics after an exercise bronchial provocation test (EBPT) using IOS. Forty-seven young adults were enrolled in the study. All the participants underwent a methacholine bronchial provocation test (MBPT) and an EBPT for the evaluation of their asthma. IOS and spirometric parameters were collected at baseline and at 0, 5, 10, 20, and 30 minutes post-EBPT.The participants were divided into 2 groups according to MBPT positivity: an airway hyperresponsiveness (AHR) group and a no-AHR group. There were differences in the percent decrease in forced expiratory volume in the first second (FEV1) between the 2 groups at 5, 10, and 20 minutes after exercise. Resistance at 5 Hz (R5) increased in the AHR group but not in the no-AHR group at 5 and 10 minutes after exercise. Integration of reactance from 5 Hz to resonance frequency (area of reactance, AX) was also increased in the AHR group at only 5 and 10 minutes post-EBPT. Delta R5 and delta AX at 5 and 10 minutes post-exercise were well correlated with the percent decrease in FEV1. IOS parameters, especially delta R5 and delta AX, may be useful for performing objective evaluations and improving our understanding of exercise-induced airway obstruction in young asthmatics.

Fate of acid-resistant and non-acid resistant Shiga toxin-producing Escherichia coli strains in experimentally contaminated French fermented raw meat sausages.

PubMed

Montet, M P; Christieans, S; Thevenot, D; Coppet, V; Ganet, S; Muller, M L Delignette; Dunière, L; Miszczycha, S; Vernozy-Rozand, C

2009-02-28

Both pathogenic and nonpathogenic E. coli exhibit a stress response to sublethal environmental stresses. Several studies have reported acid tolerance and survival characteristics of E. coli O157:H7 in foodstuffs, but there are few reports about the tolerance of non-O157 serogroups (STEC) to organic acids in foods. The purpose of this study was to examine the effect of the manufacturing process of French fermented raw meat sausages on the growth and survival of acid-resistant (AR) and non-acid resistant (NAR) STEC strains. The six strains, 3 AR and 3 NAR, were inoculated separately into raw sausage mixture at a level of 10(4)-10(5) CFU/g. A total of 19 batches of sausages were manufactured. A rapid and similar decrease in the number of both AR and NAR STEC strains, from less than 1 to 1.5 log(10) CFU/g, was observed during the first 5 days of fermentation at 20-24 degrees C. This rapid decrease was followed by a more gradual but continuous decrease in STEC counts after drying at 13-14 degrees C, up to day 35. The STEC counts were <10 CFU/g after 35 days for the NAR strains and the same concentration for the AR strains on the best before date (day 60). It was not possible to detect any NAR STEC after 60 days. The present study shows that the process used in the manufacture of French sausages results in a complete destruction of NAR STEC strains after 60 days, but it does not have the same effect on the AR STEC strains.

Antimicrobial Resistance and Virulence-Associated Genes of Campylobacter spp. Isolated from Raw Milk, Fish, Poultry, and Red Meat.

PubMed

Raeisi, Mojtaba; Khoshbakht, Rahem; Ghaemi, Ezzat Allah; Bayani, Mahsan; Hashemi, Mohammad; Seyedghasemi, Navisa Sadat; Shirzad-Aski, Hesamaddin

2017-10-01

This study was designed and conducted to evaluate the frequency, antimicrobial resistance, and presence of six virulence-associated genes among thermophilic Campylobacters isolated from raw milk, poultry (chicken, turkey, and duck), fish, cattle, and sheep meat. Out of 590 samples, which were recovered from different origins, 141 (23.9%) samples were positive for Campylobacters. Campylobacter spp. was isolated in 40.8% (106/260), 14% (28/200), and 8.7% (7/80) of poultry meat, red meat, and milk samples, respectively. Antimicrobial susceptibility test indicated a high frequency of resistance to ciprofloxacin, tetracycline, and nalidixic acid among the isolates. Furthermore, prevalence of waaC, ciaB, and pldA genes were 91.7%, 86.7%, and 80.8%, respectively; and, none of the isolates harbored both wlaN and cgtB genes, simultaneously. Moreover, there was a weak correlation between antibiotics resistance and presence of the pathogen genes. However, the existence of Campylobacter spp. isolates in food animal products, with high resistance to antibiotics and several virulence gene possessions, is alarming and increases the attention to the widespread use of antibiotics.

Relationship between gastro-oesophageal reflux and airway diseases: the airway reflux paradigm.

PubMed

Pacheco-Galván, Adalberto; Hart, Simon P; Morice, Alyn H

2011-04-01

Our understanding of the relationship between gastro-oesophageal reflux and respiratory disease has recently undergone important changes. The previous paradigm of airway reflux as synonymous with the classic gastro-oesophageal reflux disease (GORD) causing heartburn has been overturned. Numerous epidemiological studies have shown a highly significant association of the acid, liquid, and gaseous reflux of GORD with conditions such as laryngeal diseases, chronic rhinosinusitis, treatment resistant asthma, COPD and even idiopathic pulmonary fibrosis. However, it has become clear from studies on cough hypersensitivity syndrome that much reflux of importance in the airways has been missed, since it is either non- or weakly acid and gaseous in composition. The evidence for such a relationship relies on the clinical history pointing to symptom associations with known precipitants of reflux. The tools for the diagnosis of extra-oesophageal reflux, in contrast to the oesophageal reflux of GORD, lack sensitivity and reproducibility. Unfortunately, methodology for detecting such reflux is only just becoming available and much additional work is required to properly delineate its role. Copyright © 2011 SEPAR. Published by Elsevier Espana. All rights reserved.

Eicosanoids modulate hyperpnea-induced late phase airway obstruction and hyperreactivity in dogs.

PubMed

Davis, Michael S; McCulloch, Sharron; Myers, Teresa; Freed, Arthur N

2002-01-01

A canine model of exercise-induced asthma was used to test the hypothesis that the development of a late phase response to hyperventilation depends on the acute production of pro-inflammatory mediators. Peripheral airway resistance, reactivity to hypocapnia and aerosol histamine, and bronchoalveolar lavage fluid (BALF) cell and eicosanoid content were measured in dogs approximately 5 h after dry air challenge (DAC). DAC resulted in late phase obstruction, hyperreactivity to histamine, and neutrophilic inflammation. Both cyclooxygenase and lipoxygenase inhibitors administered in separate experiments attenuated the late phase airway obstruction and hyperreactivity to histamine. Neither drug affected the late phase inflammation nor the concentrations of eicosanoids in the BALF obtained 5 h after DAC. This study confirms that hyperventilation of peripheral airways with unconditioned air causes late phase neutrophilia, airway obstruction, and hyperreactivity. The late phase changes in airway mechanics are related to the hyperventilation-induced release of both prostaglandins and leukotrienes, and appear to be independent of the late phase infiltration of inflammatory cells.

Effect of fenspiride on pulmonary function in the rat and guinea pig.

PubMed

Bee, D; Laude, E A; Emery, C J; Howard, P

1995-03-01

1. Fenspiride is an anti-inflammatory agent that may have a role in reversible obstructive airways disease. Small, but significant, improvements have been seen in airways function and arterial oxygen tension in patients with mild chronic obstructive pulmonary disease. These changes have been attributed to the anti-inflammatory properties of the drug. However, airways function can be improved by other means, e.g. improved ventilation/perfusion ratio or reduced airways resistance. The possibility that fenspiride may have actions other than anti-inflammatory was investigated in two animal species. 2. In the rat, actions on the pulmonary circulation were investigated in the isolated perfused lung, but fenspiride proved to be a poor pulmonary vasodilator, showing only a small reversal of the raised pulmonary artery pressure induced by hypoxia. 3. Ventilation was measured in the anaesthetized rat using whole-body plethysmography. Fenspiride caused no increase in ventilation or changes in arterial blood gases. However, a profound hypotensive action was observed with high doses. 4. The possibility that a decrease in airways resistance (R(aw)) might occur with fenspiride was investigated in anaesthetized guinea pigs. Capsaicin (30 mumol/l) was used to increase baseline R(aw) through bronchoconstriction. Fenspiride gave a dose-dependent partial reversal of the raised R(aw), and its administration by aerosol proved as efficacious as the intravenous route. In addition, the hypotensive side-effect found with intravenous injection was alleviated by aerosolized fenspiride.(ABSTRACT TRUNCATED AT 250 WORDS)

Presence of Multidrug-Resistant Shiga Toxin-Producing Escherichia coli, Enteropathogenic E. coli and Enterotoxigenic E. coli, on Raw Nopalitos (Opuntia ficus-indica L.) and in Nopalitos Salads from Local Retail Markets in Mexico.

PubMed

Gómez-Aldapa, Carlos A; Cerna-Cortes, Jorge F; Rangel-Vargas, Esmeralda; Torres-Vitela, Mdel Refugio; Villarruel-López, Angelica; Gutiérrez-Alcántara, Eduardo J; Castro-Rosas, Javier

2016-05-01

The presence of multidrug-resistant pathogenic bacteria in food is a significant public health concern. Diarrheagenic Escherichia coli pathotypes (DEPs) are foodborne bacteria. In Mexico, DEPs have been associated with diarrheal illness. There is no information about the presence of multidrug-resistant DEPs on fresh vegetables and in cooked vegetable salads in Mexico. "Nopalitos" (Opuntia ficus-indica L.) is a Cactacea extensively used as a fresh green vegetable throughout Mexico. The presence of generic E. coli and multidrug-resistant DEPs on raw whole and cut nopalitos and in nopalitos salad samples was determined. One hundred raw whole nopalitos (without prickles) samples, 100 raw nopalitos cut into small square samples, and 100 cooked nopalitos salad samples were collected from markets. Generic E. coli was determined using the most probable number procedures. DEPs were identified using two multiplex polymerase chain reaction procedures. Susceptibility to 16 antibiotics was tested for the isolated DEP strains by standard test. Of the 100 whole nopalitos samples, 100 cut nopalitos samples, and 100 nopalitos salad samples, generic E. coli and DEPs were identified, respectively, in 80% and 10%, 74% and 10%, and 64% and 8%. Eighty-two DEP strains were isolated from positive nopalitos samples. The identified DEPs included Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC). All isolated strains exhibited resistance to at least six antibiotics. To the best of our knowledge, this is the first report of the presence of multidrug-resistant and antibiotic resistance profiles of STEC, ETEC, and EPEC on raw nopalitos and in nopalitos salads in Mexico.

Adam8 Limits the Development of Allergic Airway Inflammation in Mice

PubMed Central

Knolle, Martin D.; Nakajima, Takahiro; Hergrueter, Anja; Gupta, Kushagra; Polverino, Francesca; Craig, Vanessa J.; Fyfe, Susanne E.; Zahid, Muhammad; Permaul, Perdita; Cernadas, Manuela; Montano, Gilbert; Tesfaigzi, Yohannes; Sholl, Lynette; Kobzik, Lester; Israel, Elliot; Owen, Caroline A.

2013-01-01

To determine whether a disintegrin and a metalloproteinase-8 (Adam8) regulates allergic airway inflammation (AAI) and airway hyper-responsiveness (AHR), we compared AAI and AHR in wild type (WT) versus Adam8−/− mice in different genetic backgrounds sensitized and challenged with ovalbumin (OVA) or house dust mite protein extract (HDM). OVA- and HDM-treated Adam8−/− mice had higher lung leukocyte counts, more airway mucus metaplasia, greater lung levels of some TH2 cytokines, and higher methacholine-induced increases in central airway resistance than allergen-treated WT mice. Studies of OVA-treated Adam8 bone marrow chimeric mice confirmed that leukocyte-derived Adam8 predominantly mediated Adam8’s anti-inflammatory activities in murine airways. Airway eosinophils and macrophages both expressed Adam8 in WT mice with AAI. Adam8 limited AAI and AHR in mice by reducing leukocyte survival because: 1) Adam8−/− mice with AAI had fewer apoptotic eosinophils and macrophages in their airways than WT mice with AAI; and 2) Adam8−/− macrophages and eosinophils had reduced rates of apoptosis compared with WT leukocytes when the intrinsic (but not the extrinsic) apoptosis pathway was triggered in the cells in vitro. ADAM8 was robustly expressed by airway granulocytes in lung sections from human asthma patients but, surprisingly, airway macrophages had less ADAM8 staining than airway eosinophils. Thus, ADAM8 has anti-inflammatory activities during AAI in mice by activating the intrinsic apoptosis pathway in myeloid leukocytes. Strategies that increase ADAM8 levels in myeloid leukocytes may have therapeutic efficacy in asthma. PMID:23670189

Antibiotic Resistance-Susceptibility Profiles of Streptococcus thermophilus Isolated from Raw Milk and Genome Analysis of the Genetic Basis of Acquired Resistances

PubMed Central

Flórez, Ana B.; Mayo, Baltasar

2017-01-01

The food chain is thought to play an important role in the transmission of antibiotic resistances from commensal and beneficial bacteria to pathogens. Streptococcus thermophilus is a lactic acid bacterium of major importance as a starter for the dairy industry. This study reports the minimum inhibitory concentration (MIC) of 16 representative antimicrobial agents to 41 isolates of S. thermophilus derived from raw milk. Strains showing resistance to tetracycline (seven), erythromycin and clindamycin (two), and streptomycin and neomycin (one) were found. PCR amplification identified tet(S) in all the tetracycline-resistant strains, and ermB in the two erythromycin/clindamycin-resistant strains. Hybridisation experiments suggested each resistance gene to be located in the chromosome with a similar genetic organization. Five antibiotic-resistant strains -two resistant to tetracycline (St-2 and St-9), two resistant to erythromycin/clindamycin (St-5 and St-6), and one resistant to streptomycin/neomycin (St-10)- were subjected to genome sequencing and analysis. The tet(S) gene was identified in small contigs of 3.2 and 3.7 kbp in St-2 and St-9, respectively, flanked by truncated copies of insertion sequence (IS) elements. Similarly, ermB in St-6 and St-5 was found in contigs of 1.6 and 28.1 kbp, respectively. Sequence analysis and comparison of the largest contig showed it to contain three segments (21.9, 3.7, and 1.4 kbp long) highly homologous to non-collinear sequences of pRE25 from Enterococcus faecalis. These segments contained the ermB gene, a transference module with an origin of transfer (oriT) plus 15 open reading frames encoding proteins involved in conjugation, and modules for plasmid replication and segregation. Homologous stretches were separated by short, IS-related sequences, resembling the genetic organization of the integrative and conjugative elements (ICEs) found in Streptococcus species. No gene known to provide aminoglycoside resistance was seen in St

Computed tomography-guided tissue engineering of upper airway cartilage.

PubMed

Brown, Bryan N; Siebenlist, Nicholas J; Cheetham, Jonathan; Ducharme, Norm G; Rawlinson, Jeremy J; Bonassar, Lawrence J

2014-06-01

Normal laryngeal function has a large impact on quality of life, and dysfunction can be life threatening. In general, airway obstructions arise from a reduction in neuromuscular function or a decrease in mechanical stiffness of the structures of the upper airway. These reductions decrease the ability of the airway to resist inspiratory or expiratory pressures, causing laryngeal collapse. We propose to restore airway patency through methods that replace damaged tissue and improve the stiffness of airway structures. A number of recent studies have utilized image-guided approaches to create cell-seeded constructs that reproduce the shape and size of the tissue of interest with high geometric fidelity. The objective of the present study was to establish a tissue engineering approach to the creation of viable constructs that approximate the shape and size of equine airway structures, in particular the epiglottis. Computed tomography images were used to create three-dimensional computer models of the cartilaginous structures of the larynx. Anatomically shaped injection molds were created from the three-dimensional models and were seeded with bovine auricular chondrocytes that were suspended within alginate before static culture. Constructs were then cultured for approximately 4 weeks post-seeding and evaluated for biochemical content, biomechanical properties, and histologic architecture. Results showed that the three-dimensional molded constructs had the approximate size and shape of the equine epiglottis and that it is possible to seed such constructs while maintaining 75%+ cell viability. Extracellular matrix content was observed to increase with time in culture and was accompanied by an increase in the mechanical stiffness of the construct. If successful, such an approach may represent a significant improvement on the currently available treatments for damaged airway cartilage and may provide clinical options for replacement of damaged tissue during treatment of

Prevalence of Methicillin-Resistant Staphylococcus aureus and Other Staphylococcus Species in Raw Meat Samples Intended for Human Consumption in Benin City, Nigeria: Implications for Public Health.

PubMed

Igbinosa, Etinosa O; Beshiru, Abeni; Akporehe, Lucy U; Oviasogie, Faith E; Igbinosa, Owen O

2016-09-24

The present study was designed to characterize methicillin-resistant staphylococci from raw meat. A total of 126 meat samples were obtained from open markets between February and April, 2015. Antimicrobial susceptibility testing was carried out using the disc diffusion method. Molecular profiling was conducted using 16S rRNA, mecA, nuc, and PVL gene signatures were detected by polymerase chain reaction assay. Fifty isolates of methicillin-resistant Staphylococcus spp. were detected in 26 (52%) pork, 14 (28%) beef and 10 (20%) chicken samples. The staphylococcal isolates were identified through partial 16S ribosomal ribonucleic acid (16S rRNA) nucleotide sequencing, and BLAST analysis of the gene sequence revealed 98%-100% staphylococcal similarity. All isolates from beef and chicken samples amplified the mecA gene, while 100% of the MRSA isolates amplified the PVL gene. The multidrug resistance profile (resistant to ≥1 antimicrobial agent in ≥3 classes of antimicrobial agents) of the staphylococcal isolates showed that 7 isolates were resistant to methicillin, penicillin, clindamycin, chloramphenicol, trimethoprim-sulfamethoxazole, kanamycin, amoxicillin, cloxacillin, erythromycin, vancomycin, and gentamycin. There was a significant regression effect from the multidrug-resistant profile on the number of isolates (p < 0.05) suggesting a consequence of the dissemination of resistant strains within bacterial populations. The findings of the present study indicate that raw meats in the Benin metropolis were possibly contaminated with pathogenic and multi-drug resistant staphylococci strains and therefore could constitute a risk to public health communities.

Automated airway evaluation system for multi-slice computed tomography using airway lumen diameter, airway wall thickness and broncho-arterial ratio

NASA Astrophysics Data System (ADS)

Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

2006-03-01

Pulmonary diseases such as bronchiectasis, asthma, and emphysema are characterized by abnormalities in airway dimensions. Multi-slice computed tomography (MSCT) has become one of the primary means to depict these abnormalities, as the availability of high-resolution near-isotropic data makes it possible to evaluate airways at oblique angles to the scanner plane. However, currently, clinical evaluation of airways is typically limited to subjective visual inspection only: systematic evaluation of the airways to take advantage of high-resolution data has not proved practical without automation. We present an automated method to quantitatively evaluate airway lumen diameter, wall thickness and broncho-arterial ratios. In addition, our method provides 3D visualization of these values, graphically illustrating the location and extent of disease. Our algorithm begins by automatic airway segmentation to extract paths to the distal airways, and to create a map of airway diameters. Normally, airway diameters decrease as paths progress distally; failure to taper indicates abnormal dilatation. Our approach monitors airway lumen diameters along each airway path in order to detect abnormal profiles, allowing even subtle degrees of pathologic dilatation to be identified. Our method also systematically computes the broncho-arterial ratio at every terminal branch of the tree model, as a ratio above 1 indicates potentially abnormal bronchial dilatation. Finally, the airway wall thickness is computed at corresponding locations. These measurements are used to highlight abnormal branches for closer inspection, and can be summed to compute a quantitative global score for the entire airway tree, allowing reproducible longitudinal assessment of disease severity. Preliminary tests on patients diagnosed with bronchiectasis demonstrated rapid identification of lack of tapering, which also was confirmed by corresponding demonstration of elevated broncho-arterial ratios.

Airway Surface Dehydration Aggravates Cigarette Smoke-Induced Hallmarks of COPD in Mice.

PubMed

Seys, Leen J M; Verhamme, Fien M; Dupont, Lisa L; Desauter, Elke; Duerr, Julia; Seyhan Agircan, Ayca; Conickx, Griet; Joos, Guy F; Brusselle, Guy G; Mall, Marcus A; Bracke, Ken R

2015-01-01

Airway surface dehydration, caused by an imbalance between secretion and absorption of ions and fluid across the epithelium and/or increased epithelial mucin secretion, impairs mucociliary clearance. Recent evidence suggests that this mechanism may be implicated in chronic obstructive pulmonary disease (COPD). However, the role of airway surface dehydration in the pathogenesis of cigarette smoke (CS)-induced COPD remains unknown. We aimed to investigate in vivo the effect of airway surface dehydration on several CS-induced hallmarks of COPD in mice with airway-specific overexpression of the β-subunit of the epithelial Na⁺ channel (βENaC). βENaC-Tg mice and wild-type (WT) littermates were exposed to air or CS for 4 or 8 weeks. Pathological hallmarks of COPD, including goblet cell metaplasia, mucin expression, pulmonary inflammation, lymphoid follicles, emphysema and airway wall remodelling were determined and lung function was measured. Airway surface dehydration in βENaC-Tg mice aggravated CS-induced airway inflammation, mucin expression and destruction of alveolar walls and accelerated the formation of pulmonary lymphoid follicles. Moreover, lung function measurements demonstrated an increased compliance and total lung capacity and a lower resistance and hysteresis in βENaC-Tg mice, compared to WT mice. CS exposure further altered lung function measurements. We conclude that airway surface dehydration is a risk factor that aggravates CS-induced hallmarks of COPD.

Azithromycin ameliorates airway remodeling via inhibiting airway epithelium apoptosis.

PubMed

Liu, Yuanqi; Pu, Yue; Li, Diandian; Zhou, Liming; Wan, Lihong

2017-02-01

Azithromycin can benefit treating allergic airway inflammation and remodeling. In the present study, we hypothesized that azithromycin alleviated airway epithelium injury through inhibiting airway epithelium apoptosis via down regulation of caspase-3 and Bax/Bcl2 ratio in vivo and in vitro. Ovalbumin induced rat asthma model and TGF-β1-induced BEAS-2B cell apoptosis model were established, respectively. In vivo experiments, airway epithelium was stained with hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) to histologically evaluate the airway inflammation and remodeling. Airway epithelium apoptotic index (AI) was further analyzed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), while expression of apoptosis related gene (Bax, Bcl2, Caspase-3) in lungs were measured by qRT-PCR and western blotting, respectively. In vitro experiments, apoptosis were evaluated by Flow cytometry (FCM) and TUNEL. Above apoptosis related gene were also measured by qRT-PCR and western blotting. Compared with the OVA group, azithromycin significantly reduced the inflammation score, peribronchial smooth muscle layer thickness, epithelial thickening and goblet cell metaplasia (P<0.05), and effectively suppressed AI of airway epithelium (P<0.05). Moreover, the increasing mRNA and protein expressions of Caspase-3 and Bax/Bcl-2 ratio in lung tissue were all significantly decreased in azithromycin-treated rats (P<0.05). In vitro, azithromycin significantly suppressed TGF-β1-induced BEAS-2B cells apoptosis (P<0.05) and reversed TGF-β1 elevated Caspase-3 mRNA level and Bax/Bcl-2 ratio (P<0.05). Azithromycin is an attractive treatment option for reducing airway epithelial cell apoptosis by improving the imbalance of Bax/Bcl-2 ratio and inhibiting Caspase-3 level in airway epithelium. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of hypercapnia and hypoxia on nasal vasculature and airflow resistance in the anaesthetized dog.

PubMed Central

Lung, M A; Wang, J C

1986-01-01

The experiments were performed on anaesthetized dogs which breathed spontaneously or were artificially ventilated and paralysed. The spontaneous nasal arterial blood flow was measured on one side of the nose while nasal vascular resistance was determined on the other side simultaneously. Nasal arterial blood flow was measured by means of an electromagnetic flow sensor placed around the terminal branch of the internal maxillary artery, the main arterial supply to the nasal mucosa. Nasal vascular resistance was measured by constant-flow perfusion of the terminal branch of the internal maxillary artery. Nasal airway resistance was assessed by monitoring the transnasal pressure at constant airflow through each side of the nose simultaneously. Hypercapnic gas challenge (8% CO2, 30% O2 in N2) to the lungs increased nasal vascular resistance and decreased nasal airway resistance. Similar gas challenge to the nose did not affect nasal vascular resistance but decreased nasal airway resistance. Hypoxic gas challenge (6% O2 in N2) to the lungs did not affect the nasal vascular resistance but decreased nasal airway resistance only when the nasal vascular bed was under controlled perfusion. Similar gas challenge to the nose did not affect either nasal vascular or airway resistance. Arterial chemoreceptor stimulation by intracarotid injection of sodium cyanide increased nasal vascular resistance and decreased nasal airway resistance. The nasal vascular response to hypercapnia and arterial chemoreceptor stimulation was reflex in nature, being abolished by nasal sympathectomy. The nasal airway response to hypercapnia, hypoxia and arterial chemoreceptor stimulation was reflex in nature, being partially or completely abolished by nasal sympathectomy. Hypercapnia probably induced a local vasodilatatory effect on the capacitance vessels whereas hypoxia had no direct action on the vasculature. PMID:3091811

Airway responsiveness and airway remodeling after chronic exposure to procaterol and fenoterol in guinea pigs in vivo.

PubMed

Nishimura, Hideko; Tokuyama, Kenichi; Arakawa, Hirokazu; Ohki, Yasushi; Sato, Akira; Kato, Masahiko; Mochizuki, Hiroyuki; Morikawa, Akihiro

2002-12-01

Chronic exposure to fenoterol (FEN), a beta(2)-adrenergic receptor (beta(2)-AR) agonist, was shown to induce both airway hyperresponsiveness and airway remodeling in experimental animals. We wanted to know the effects of chronic exposure to procaterol (PRO), a beta(2)-AR agonist, on airway function and structure, because this agent is widely used as a bronchodilator in Japan. For comparison, the effects of FEN were also examined. Aerosolized PRO (0.1 or 1 mg/ml), FEN (1 mg/ml) or vehicle (0.9% NaCl) was given to guinea pigs 3 times a day for 6 weeks. Sublaryngeal deposition of these agents was calculated using radioisotopes. At 72 h after the last inhalation of PRO, FEN or vehicle, the dose-response relationship between lung resistance (R(L)) and intravenously administered acetylcholine (ACh) was measured. After measuring R(L), histological changes in noncartilaginous airway dimensions were evaluated. The amount of sublaryngeal deposition of 0.1 mg/ml PRO in the present study was speculated to be 100 times larger than that of therapeutic dose. ACh concentrations causing 2-fold, 10-fold and maximal increases in R(L) were not different in 4 groups tested. In the smaller membranous airways (<0.4 mm in diameter), but not the larger ones, thickening of adventitial areas was significantly greater in animals treated with beta(2)-AR agonists than in control animals (23 and 25, and 96% higher in animals treated with 0.1 and 1 mg/ml PRO or 1 mg/ml FEN, respectively). The degree of the increase was significantly less in PRO-treated animals than in FEN-treated animals (p < 0.01). Our results did not provide any evidence that regular inhalation of PRO at the therapeutic dose might induce bronchial hyperresponsiveness. In addition, huge amounts of PRO only caused a mild thickening of the adventitial areas, suggesting that PRO may be a weak inducer of airway remodeling compared with FEN. Copyright 2002 S. Karger AG, Basel

Antibiotic resistance and growth of the emergent pathogen Escherichia albertii on raw ground beef stored under refrigeration, abuse, and physiological temperature.

PubMed

Perez, Keila L; Alam, M Jahangir; Castillo, Alejandro; Taylor, T Matthew

2013-01-01

Escherichia albertii is an emerging gram-negative facultative rod that has been implicated in multiple cases of human diarrheal disease, particularly in young children. When biochemical and other typing methods have been used, this organism has often been misidentified due to similarities with other members of the family Enterobacteriaceae. Isolates have been reported to be capable of producing attachment and effacement lesions via the synthesis of intimin, cytolethal distending toxin, and a variant form of Shiga toxin. The purposes of this study were to characterize the antibiotic resistance characteristics and the growth of individual strains of E. albertii on raw ground beef at different storage temperatures. Nalidixic acid-resistant strains of E. albertii were inoculated onto raw ground beef to a target of 4.0 log CFU/g, and samples were then aerobically incubated at 5, 22, or 35°C for various time periods prior to microbiological enumeration of the pathogen on lactose-free MacConkey agar containing 50 mg of nalidixic acid per liter and 0.5% L-rhamnose. Antibiotic resistance was determined using a broth microdilution assay. E. albertii did not grow at 5°C, with populations declining slowly over 14 days of refrigerated storage. Strains of the organism grew well under abusive storage, increasing by 2.5 to 3.1 log CFU/g and 4.1 to 4.3 log CFU/g after 24 h at 22 and 35°C, respectively. All strains were resistant to tetracycline but were sensitive to tested cephalosporins and chloramphenicol. Resistance to penicillin was observed, but susceptibility to other members of the b -lactam group, including ampicillin, amoxicillin, and clavulanic acid, was recorded. E. albertii represents an emerging pathogen with a probable foodborne transmission route. Future research should focus on verifying food process measures able to inactivate the pathogen.

Airway stents

PubMed Central

Keyes, Colleen

2018-01-01

Stents and tubes to maintain the patency of the airways are commonly used for malignant obstruction and are occasionally employed in benign disease. Malignant airway obstruction usually results from direct involvement of bronchogenic carcinoma, or by extension of carcinomas occurring in the esophagus or the thyroid. External compression from lymph nodes or metastatic disease from other organs can also cause central airway obstruction. Most malignant airway lesions are surgically inoperable due to advanced disease stage and require multimodality palliation, including stent placement. As with any other medical device, stents have significantly evolved over the last 50 years and deserve an in-depth understanding of their true capabilities and complications. Not every silicone stent is created equal and the same holds for metallic stents. Herein, we present an overview of the topic as well as some of the more practical and controversial issues surrounding airway stents. We also try to dispel the myths surrounding stent removal and their supposed use only in central airways. At the end, we come to the long-held conclusion that stents should not be used as first line treatment of choice, but after ruling out the possibility of curative surgical resection or repair. PMID:29707506

Assessment of central airway obstruction using impulse oscillometry before and after interventional bronchoscopy.

PubMed

Handa, Hiroshi; Huang, Jyongsu; Murgu, Septimiu D; Mineshita, Masamichi; Kurimoto, Noriaki; Colt, Henri G; Miyazawa, Teruomi

2014-02-01

Spirometry is used to physiologically assess patients with central airway obstruction (CAO) before and after interventional bronchoscopy, but is not always feasible in these patients, does not localize the anatomic site of obstruction, and may not correlate with the patient's functional impairment. Impulse oscillometry may overcome these limitations. We assessed the correlations between impulse oscillometry measurements, symptoms, and type of airway narrowing, before and after interventional bronchoscopy, and whether impulse oscillometry parameters can discriminate between fixed and dynamic CAO. Twenty consecutive patients with CAO underwent spirometry, impulse oscillometry, computed tomography, dyspnea assessment, and bronchoscopy, before and after interventional bronchoscopy. The collapsibility index (the percent difference in airway lumen diameter during expiration versus during inspiration) was calculated using morphometric bronchoscopic images during quiet breathing. Variable CAO was defined as a collapsibility index of > 50%. Fixed CAO was defined as a collapsibility index of < 50%. The degree of obstruction was analyzed with computed tomography measurements. After interventional bronchoscopy, all impulse oscillometry measurements significantly improved, especially resistance at 5 Hz, which decreased from 0.67 ± 0.29kPa/L/s to 0.38 ± 0.17kPa/L/s (P < .001), and reactance at 20 Hz, which increased from -0.09 ± 0.11 to 0.03 ± 0.08 (P < .001). Changes in dyspnea score correlated with resistance at 5 Hz, the difference between the resistance at 5 Hz and the resistance at 20 Hz, and the reactance at 5 Hz, but not with spirometry measurements. The type of obstruction also correlated with dyspnea score, and showed distinct impulse oscillometry measurements. Impulse oscillometry measurements correlate with symptom improvements after interventional bronchoscopy. Impulse oscillometry might be useful to discriminate variable from fixed central airway obstruction

Local small airway epithelial injury induces global smooth muscle contraction and airway constriction.

PubMed

Zhou, Jian; Alvarez-Elizondo, Martha B; Botvinick, Elliot; George, Steven C

2012-02-01

Small airway epithelial cells form a continuous sheet lining the conducting airways, which serves many functions including a physical barrier to protect the underlying tissue. In asthma, injury to epithelial cells can occur during bronchoconstriction, which may exacerbate airway hyperreactivity. To investigate the role of epithelial cell rupture in airway constriction, laser ablation was used to precisely rupture individual airway epithelial cells of small airways (<300-μm diameter) in rat lung slices (∼250-μm thick). Laser ablation of single epithelial cells using a femtosecond laser reproducibly induced airway contraction to ∼70% of the original cross-sectional area within several seconds, and the contraction lasted for up to 40 s. The airway constriction could be mimicked by mechanical rupture of a single epithelial cell using a sharp glass micropipette but not with a blunt glass pipette. These results suggest that soluble mediators released from the wounded epithelial cell induce global airway contraction. To confirm this hypothesis, the lysate of primary human small airway epithelial cells stimulated a similar airway contraction. Laser ablation of single epithelial cells triggered a single instantaneous Ca(2+) wave in the epithelium, and multiple Ca(2+) waves in smooth muscle cells, which were delayed by several seconds. Removal of extracellular Ca(2+) or decreasing intracellular Ca(2+) both blocked laser-induced airway contraction. We conclude that local epithelial cell rupture induces rapid and global airway constriction through release of soluble mediators and subsequent Ca(2+)-dependent smooth muscle shortening.

Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products.

PubMed

Zycka-Krzesinska, Joanna; Boguslawska, Joanna; Aleksandrzak-Piekarczyk, Tamara; Jopek, Jakub; Bardowski, Jacek K

2015-10-15

To assess the occurrence of antibiotic-resistant Lactic Acid Bacteria (LAB) in Polish raw milk and fermented artisanal products, a collection comprising 500 isolates from these products was screened. Among these isolates, six strains (IBB28, IBB160, IBB161, IBB224, IBB477 and IBB487) resistant to tetracycline were identified. The strains showing atypical tetracycline resistance were classified as Lactococcus lactis: three of them were identified as L. lactis subsp. cremoris (IBB224, IBB477 and IBB487) and the other three (IBB28, IBB160, IBB161) were identified as L. lactis subsp. lactis. The mechanism involving Ribosomal Protection Proteins (RPP) was identified as responsible for tetracycline resistance. Three of the tested strains (IBB28, IBB160 and IBB224) had genes encoding the TetS protein, whereas the remaining three (IBB161, IBB477 and IBB487) expressed TetM. The results also demonstrated that the genes encoding these proteins were located on genetic mobile elements. The tet(S) gene was found to be located on plasmids, whereas tet(M) was found within the Tn916 transposon. Copyright © 2015 Elsevier B.V. All rights reserved.

Inhibitory effects of Pycnogenol® (French maritime pine bark extract) on airway inflammation in ovalbumin-induced allergic asthma.

PubMed

Shin, In-Sik; Shin, Na-Rae; Jeon, Chan-Mi; Hong, Ju-Mi; Kwon, Ok-Kyoung; Kim, Jong-Choon; Oh, Sei-Ryang; Hahn, Kyu-Woung; Ahn, Kyung-Seop

2013-12-01

Pycnogenol® (PYC) is a standardized extracts from the bark of the French maritime pine (Pinus maritime) and used as a herbal remedy for various diseases. In this study, we evaluated the effects of PYC on airway inflammation using a model of ovalbumin (OVA)-induced allergic asthma and RAW264.7 cells. PYC decreased nitric oxide production and reduced the interleukine (IL)-1β and IL-6 levels in LPS-stimulated RAW264.7 cells. PYC also reduced the expression of inducible nitric oxide synthase (iNOS) and matrix metalloproteinase (MMP)-9 and enhanced the expression of hemeoxygenase (HO)-1. In the in vivo experiment, PYC decreased the inflammatory cell count and the levels of IL-4, IL-5, IL-13, and immunoglobulin (Ig) E in BALF or serum. These results are consistent with the histological analysis findings, which showed that PYC attenuated the airway inflammation and mucus hypersecretion induced by OVA challenge. In addition, PYC enhanced the expression of HO-1. In contrast, PYC inhibited the elevated expression of iNOS and MMP-9 proteins induced by OVA challenge. In conclusion, PYC exhibits protective effects against OVA-induced asthma and LPS-stimulated RAW264.7 cells. These results suggest that PYC has potential as a therapeutic agent for the treatment of allergic asthma. Copyright © 2013 Elsevier Ltd. All rights reserved.

Atopic asthmatic immune phenotypes associated with airway microbiota and airway obstruction.

PubMed

Turturice, Benjamin A; McGee, Halvor S; Oliver, Brian; Baraket, Melissa; Nguyen, Brian T; Ascoli, Christian; Ranjan, Ravi; Rani, Asha; Perkins, David L; Finn, Patricia W

2017-01-01

Differences in asthma severity may be related to inflammation in the airways. The lower airway microbiota has been associated with clinical features such as airway obstruction, symptom control, and response to corticosteroids. To assess the relationship between local airway inflammation, severity of disease, and the lower airway microbiota in atopic asthmatics. A cohort of young adult, atopic asthmatics with intermittent or mild/moderate persistent symptoms (n = 13) were assessed via bronchoscopy, lavage, and spirometry. These individuals were compared to age matched non-asthmatic controls (n = 6) and to themselves after six weeks of treatment with fluticasone propionate (FP). Inflammation of the airways was assessed via a cytokine and chemokine panel. Lower airway microbiota composition was determined by metagenomic shotgun sequencing. Unsupervised clustering of cytokines and chemokines prior to treatment with FP identified two asthmatic phenotypes (AP), termed AP1 and AP2, with distinct bronchoalveolar lavage inflammatory profiles. AP2 was associated with more obstruction, compared to AP1. After treatment with FP reduced MIP-1β and TNF-α and increased IL-2 was observed. A module of highly correlated cytokines that include MIP-1β and TNF-α was identified that negatively correlated with pulmonary function. Independently, IL-2 was positively correlated with pulmonary function. The airway microbiome composition correlated with asthmatic phenotypes. AP2, prior to FP treatment, was enriched with Streptococcus pneumoniae. Unique associations between IL-2 or the cytokine module and the microbiota composition of the airways were observed in asthmatics subjects prior to treatment but not after or in controls. The underlying inflammation in atopic asthma is related to the composition of microbiota and is associated with severity of airway obstruction. Treatment with inhaled corticosteroids was associated with changes in the airway inflammatory response to microbiota.

Degrees of reality: airway anatomy of high-fidelity human patient simulators and airway trainers.

PubMed

Schebesta, Karl; Hüpfl, Michael; Rössler, Bernhard; Ringl, Helmut; Müller, Michael P; Kimberger, Oliver

2012-06-01

Human patient simulators and airway training manikins are widely used to train airway management skills to medical professionals. Furthermore, these patient simulators are employed as standardized "patients" to evaluate airway devices. However, little is known about how realistic these patient simulators and airway-training manikins really are. This trial aimed to evaluate the upper airway anatomy of four high-fidelity patient simulators and two airway trainers in comparison with actual patients by means of radiographic measurements. The volume of the pharyngeal airspace was the primary outcome parameter. Computed tomography scans of 20 adult trauma patients without head or neck injuries were compared with computed tomography scans of four high-fidelity patient simulators and two airway trainers. By using 14 predefined distances, two cross-sectional areas and three volume parameters of the upper airway, the manikins' similarity to a human patient was assessed. The pharyngeal airspace of all manikins differed significantly from the patients' pharyngeal airspace. The HPS Human Patient Simulator (METI®, Sarasota, FL) was the most realistic high-fidelity patient simulator (6/19 [32%] of all parameters were within the 95% CI of human airway measurements). The airway anatomy of four high-fidelity patient simulators and two airway trainers does not reflect the upper airway anatomy of actual patients. This finding may impact airway training and confound comparative airway device studies.

Local small airway epithelial injury induces global smooth muscle contraction and airway constriction

PubMed Central

Zhou, Jian; Alvarez-Elizondo, Martha B.; Botvinick, Elliot

2012-01-01

Small airway epithelial cells form a continuous sheet lining the conducting airways, which serves many functions including a physical barrier to protect the underlying tissue. In asthma, injury to epithelial cells can occur during bronchoconstriction, which may exacerbate airway hyperreactivity. To investigate the role of epithelial cell rupture in airway constriction, laser ablation was used to precisely rupture individual airway epithelial cells of small airways (<300-μm diameter) in rat lung slices (∼250-μm thick). Laser ablation of single epithelial cells using a femtosecond laser reproducibly induced airway contraction to ∼70% of the original cross-sectional area within several seconds, and the contraction lasted for up to 40 s. The airway constriction could be mimicked by mechanical rupture of a single epithelial cell using a sharp glass micropipette but not with a blunt glass pipette. These results suggest that soluble mediators released from the wounded epithelial cell induce global airway contraction. To confirm this hypothesis, the lysate of primary human small airway epithelial cells stimulated a similar airway contraction. Laser ablation of single epithelial cells triggered a single instantaneous Ca2+ wave in the epithelium, and multiple Ca2+ waves in smooth muscle cells, which were delayed by several seconds. Removal of extracellular Ca2+ or decreasing intracellular Ca2+ both blocked laser-induced airway contraction. We conclude that local epithelial cell rupture induces rapid and global airway constriction through release of soluble mediators and subsequent Ca2+-dependent smooth muscle shortening. PMID:22114176

Evaluation of Endotracheal Tube Scraping on Airway Resistance.

PubMed

Scott, J Brady; Dubosky, Meagan N; Vines, David L; Sulaiman, Adewunmi S; Jendral, Kyle R; Singh, Gagan; Patel, Ankeet; Kaplan, Carl A; Gurka, David P; Balk, Robert A

2017-11-01

Spontaneous breathing trials (SBTs) are used to assess the readiness for discontinuation of mechanical ventilation. When airway resistance (R aw ) is elevated, the imposed work of breathing can lead to prolongation of mechanical ventilation. Biofilm and mucus build-up within the endotracheal tube (ETT) can increase R aw . Scraping the ETT can remove the biofilm build-up and decrease mechanical R aw . The primary aim of this study was to evaluate the impact of ETT scraping on R aw . The secondary aim was to determine whether decreasing R aw would impact subsequent SBT success. Intubated, mechanically ventilated subjects were enrolled if they failed an SBT and had an R aw of > 10 cm H 2 O/L/s. SBT failure was based on institutional guidelines, and R aw was calculated by subtracting the difference between the measured peak and plateau pressures using a square flow waveform with an inspiratory flow set at 60 L/min. The endOclear device was inserted into the ETT and withdrawn per manufacturer's guidelines. Scraping was repeated until the ETT was cleared. Change in R aw was compared pre- and post-ETT scraping using a paired t test. A Mann-Whitney U test evaluated the difference in percentage change in R aw between SBT groups. Twenty-nine subjects completed the study. The mean pre- and post-ETT scraping R aw values were 15.17 ± 3.83 and 12.05 ± 3.19 cm H 2 O/L/s, respectively ( P < .001). Subsequent SBT success was 48%; however, there was no difference in percentage change in R aw between subsequent passed SBT (18.61% [interquartile range 8.90-33.93%]) and failed SBT (23.88% [interquartile range 0.00-34.80%]), U = 78.5, z = -0.284, P = .78. No adverse events were noted with ETT scraping. This study demonstrated that ETT scraping can reduce R aw . The decrease in R aw post-ETT scraping did not affect subsequent SBT success. Copyright © 2017 by Daedalus Enterprises.

Anaerobic bacteria colonizing the lower airways in lung cancer patients.

PubMed

Rybojad, Pawel; Los, Renata; Sawicki, Marek; Tabarkiewicz, Jacek; Malm, Anna

2011-01-01

Anaerobes comprise most of the endogenous oropharyngeal microflora, and can cause infections of airways in lung cancer patients who are at high risk for respiratory tract infections. The aim of this study was to determine the frequency and species diversity of anaerobes in specimens from the lower airways of lung cancer patients. Sensitivity of the isolates to conventional antimicrobial agents used in anaerobe therapy was assessed. Respiratory secretions obtained by bronchoscopy from 30 lung cancer patients were cultured onto Wilkins-Chalgren agar in anaerobic conditions at 37°C for 72-96 hours. The isolates were identified using microtest Api 20A. The minimal inhibitory concentrations for penicillin G, amoxicillin/clavulanate, piperacillin/tazobactam, cefoxitin, imipenem, clindamycin, and metronidazole were determined by E-test. A total of 47 isolates of anaerobic bacteria were detected in 22 (73.3%) specimens. More than one species of anaerobe was found in 16 (53.3%) samples. The most frequently isolated were Actinomyces spp. and Peptostreptococcus spp., followed by Eubacterium lentum, Veillonella parvula, Prevotella spp., Bacteroides spp., Lactobacillus jensenii. Among antibiotics used in the study amoxicillin/clavulanate and imipenem were the most active in vitro (0% and 2% resistant strains, respectively). The highest resistance rate was found for penicillin G and metronidazole (36% and 38% resistant strains, respectively). The results obtained confirm the need to conduct analyses of anaerobic microflora colonizing the lower respiratory tract in patients with lung cancer to monitor potential etiologic factors of airways infections, as well as to propose efficient, empirical therapy.

Parasympathetic Control of Airway Submucosal Glands: Central Reflexes and the Airway Intrinsic Nervous System

PubMed Central

Wine, Jeffrey J.

2007-01-01

Airway submucosal glands produce the mucus that lines the upper airways to protect them against insults. This review summarizes evidence for two forms of gland secretion, and hypothesizes that each is mediated by different but partially overlapping neural pathways. Airway innate defense comprises low level gland secretion, mucociliary clearance and surveillance by airway-resident phagocytes to keep the airways sterile in spite of nearly continuous inhalation of low levels of pathogens. Gland secretion serving innate defense is hypothesized to be under the control of intrinsic (peripheral) airway neurons and local reflexes, and these may depend disproportionately on non-cholinergic mechanisms, with most secretion being produced by VIP and tachykinins. In the genetic disease cystic fibrosis, airway glands no longer secrete in response to VIP alone and fail to show the synergy between VIP, tachykinins and ACh that is observed in normal glands. The consequent crippling of the submucosal gland contribution to innate defense may be one reason that cystic fibrosis airways are infected by mucus-resident bacteria and fungi that are routinely cleared from normal airways. By contrast, the acute (emergency) airway defense reflex is centrally mediated by vagal pathways, is primarily cholinergic, and stimulates copious volumes of gland mucus in response to acute, intense challenges to the airways, such as those produced by very vigorous exercise or aspiration of foreign material. In cystic fibrosis, the acute airway defense reflex can still stimulate the glands to secrete large amounts of mucus, although its properties are altered. Importantly, treatments that recruit components of the acute reflex, such as inhalation of hypertonic saline, are beneficial in treating cystic fibrosis airway disease. The situation for recipients of lung transplants is the reverse; transplanted airways retain the airway intrinsic nervous system but lose centrally mediated reflexes. The consequences

Upper airway resistance syndrome. Central electroencephalographic power and changes in breathing effort.

PubMed

Black, J E; Guilleminault, C; Colrain, I M; Carrillo, O

2000-08-01

Upper airway resistance syndrome (UARS) is defined by excessive daytime sleepiness and tiredness, and is associated with increased breathing effort. Its polygraphic features involve progressive increases in esophageal pressure (Pes), terminated by arousal (AR) as defined by the American Sleep Disorders Association (ASDA). With the arousal there is an abrupt decrease in Pes, called Pes reversal. However, Pes reversal can be seen without the presence of an AR. We performed spectral analysis on electroencephalographic data from a central lead for both AR and nonarousal (N-AR) events obtained from 15 UARS patients (eight men and seven women). Delta band activity was increased before and surrounding Pes reversal regardless of the presence or absence of AR. In the period after Pes reversal, alpha, sigma, and beta activity showed a greater increase in AR events than in N-AR events. The Pes measures were identical leading up to the point of reversal, but showed a longer-lasting and significantly greater decrease in respiratory effort after an AR. The data indicate that substantial electroencephalographic changes can be identified in association with Pes events, even when ARs cannot be detected according to standard criteria; however, visually identifiable electroencephalographic arousals clearly have a greater impact on ongoing inspiratory effort.

Ventilation heterogeneity is a major determinant of airway hyperresponsiveness in asthma, independent of airway inflammation

PubMed Central

Downie, Sue R; Salome, Cheryl M; Verbanck, Sylvia; Thompson, Bruce; Berend, Norbert; King, Gregory G

2007-01-01

Background Airway hyperresponsiveness is the ability of airways to narrow excessively in response to inhaled stimuli and is a key feature of asthma. Airway inflammation and ventilation heterogeneity have been separately shown to be associated with airway hyperresponsiveness. A study was undertaken to establish whether ventilation heterogeneity is associated with airway hyperresponsiveness independently of airway inflammation in subjects with asthma and to determine the effect of inhaled corticosteroids on this relationship. Methods Airway inflammation was measured in 40 subjects with asthma by exhaled nitric oxide, ventilation heterogeneity by multiple breath nitrogen washout and airway hyperresponsiveness by methacholine challenge. In 18 of these subjects with uncontrolled symptoms, measurements were repeated after 3 months of treatment with inhaled beclomethasone dipropionate. Results At baseline, airway hyperresponsiveness was independently predicted by airway inflammation (partial r2 = 0.20, p<0.001) and ventilation heterogeneity (partial r2 = 0.39, p<0.001). Inhaled corticosteroid treatment decreased airway inflammation (p = 0.002), ventilation heterogeneity (p = 0.009) and airway hyperresponsiveness (p<0.001). After treatment, ventilation heterogeneity was the sole predictor of airway hyperresponsiveness (r2 = 0.64, p<0.001). Conclusions Baseline ventilation heterogeneity is a strong predictor of airway hyperresponsiveness, independent of airway inflammation in subjects with asthma. Its persistent relationship with airway hyperresponsiveness following anti‐inflammatory treatment suggests that it is an important independent determinant of airway hyperresponsiveness. Normalisation of ventilation heterogeneity is therefore a potential goal of treatment that may lead to improved long‐term outcomes. PMID:17311839

Short communication: Characterization of methicillin-resistant Staphylococcus aureus isolated from raw milk fresh cheese in Colombia.

PubMed

Herrera, Fanny C; García-López, María-Luisa; Santos, Jesús A

2016-10-01

The aim of this study was the characterization of a collection of 8 methicillin-resistant Staphylococcus aureus (MRSA) isolates, obtained from samples of fresh cheese (Doble Crema) produced from raw cow milk in small dairies in Colombia. All the isolates harbored the mecA and Panton-Valentine leukocidin (PVL) genes, presented with SCCmec type IV, and belonged to multilocus sequence type 8 and spa type 024. Seven isolates presented 3 closely related pulsed-field gel electrophoresis profiles. Three of them carried the staphylococcal enterotoxin B gene. The isolates were resistant to cefoxitin, oxacillin, penicillin, and ampicillin and susceptible to all non-β-lactams antibiotics tested, with minimum inhibitory concentration values for oxacillin of 4 to 8mg/L. The isolates belonged to the community-acquired MRSA group, suggesting a human source of contamination. The risk of human infection by MRSA via contaminated foods is considered low, but contaminated food commodities can contribute to the worldwide dissemination of clones of community-acquired MRSA. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Myosin Light Chain Kinase Is Necessary for Tonic Airway Smooth Muscle Contraction*

PubMed Central

Zhang, Wen-Cheng; Peng, Ya-Jing; Zhang, Gen-Sheng; He, Wei-Qi; Qiao, Yan-Ning; Dong, Ying-Ying; Gao, Yun-Qian; Chen, Chen; Zhang, Cheng-Hai; Li, Wen; Shen, Hua-Hao; Ning, Wen; Kamm, Kristine E.; Stull, James T.; Gao, Xiang; Zhu, Min-Sheng

2010-01-01

Different interacting signaling modules involving Ca2+/calmodulin-dependent myosin light chain kinase, Ca2+-independent regulatory light chain phosphorylation, myosin phosphatase inhibition, and actin filament-based proteins are proposed as specific cellular mechanisms involved in the regulation of smooth muscle contraction. However, the relative importance of specific modules is not well defined. By using tamoxifen-activated and smooth muscle-specific knock-out of myosin light chain kinase in mice, we analyzed its role in tonic airway smooth muscle contraction. Knock-out of the kinase in both tracheal and bronchial smooth muscle significantly reduced contraction and myosin phosphorylation responses to K+-depolarization and acetylcholine. Kinase-deficient mice lacked bronchial constrictions in normal and asthmatic airways, whereas the asthmatic inflammation response was not affected. These results indicate that myosin light chain kinase acts as a central participant in the contractile signaling module of tonic smooth muscle. Importantly, contractile airway smooth muscles are necessary for physiological and asthmatic airway resistance. PMID:20018858

The effect of inhaled K+ channel openers on bronchoconstriction and airway microvascular leakage in anaesthetised guinea pigs.

PubMed

Kidney, J C; Lotvall, J O; Lei, Y; Chung, K F; Barnes, P J

1996-01-18

Since orally administered K+ channel openers may have cardiovascular side effects, it is possible that inhaled administration would be preferred for the treatment of asthma. We have investigated whether inhaled levcromakalim and HOE 234 inhibit histamine-induced bronchoconstriction and airway plasma exudation in anaesthetised guinea pigs. We have also investigated whether inhaled HOE 234 inhibits the bronchoconstriction and plasma exudation induced by vagus nerve stimulation, which is due to the release of tachykinins from sensory nerves. Lung resistance was measured by airway resistance (RL) computed from airway and transpulmonary pressures and plasma exudation by measurement of Evans blue dye extravasation. Inhaled levcromakalim (25 mu g/ml) had a short duration of action, being effective against histamine-induced bronchoconstriction 2 min after pretreatment, but not at 10 min. Inhaled HOE 234 (25 mu g/ml) was similarly effective against histamine-induced bronchoconstriction but had a longer duration of action. Inhaled levcromakalim partially attenuated histamine-induced plasma extravasation in small airways, but not in the trachea or main bronchi, whereas inhaled HOE 234 had no effect. HOE 234 protected against non-adrenergic non-cholinergic nerve-induced bronchoconstriction, but had no effect on neurogenic- or substance P-induced plasma extravasation in the airway. Inhaled K+ channel openers protect against induced bronchoconstriction, but provide little or no protection against plasma exudation, possibly because of an increase in airway blood flow. In addition, inhaled HOE 234 had no effect on neurogenic leakage, suggesting that its vagal inhibitory effect on bronchoconstriction was on airway smooth muscle, rather than on release of neuropeptides from sensory nerves.

Parasympathetic control of airway submucosal glands: central reflexes and the airway intrinsic nervous system.

PubMed

Wine, Jeffrey J

2007-04-30

Airway submucosal glands produce the mucus that lines the upper airways to protect them against insults. This review summarizes evidence for two forms of gland secretion, and hypothesizes that each is mediated by different but partially overlapping neural pathways. Airway innate defense comprises low level gland secretion, mucociliary clearance and surveillance by airway-resident phagocytes to keep the airways sterile in spite of nearly continuous inhalation of low levels of pathogens. Gland secretion serving innate defense is hypothesized to be under the control of intrinsic (peripheral) airway neurons and local reflexes, and these may depend disproportionately on non-cholinergic mechanisms, with most secretion being produced by VIP and tachykinins. In the genetic disease cystic fibrosis, airway glands no longer secrete in response to VIP alone and fail to show the synergy between VIP, tachykinins and ACh that is observed in normal glands. The consequent crippling of the submucosal gland contribution to innate defense may be one reason that cystic fibrosis airways are infected by mucus-resident bacteria and fungi that are routinely cleared from normal airways. By contrast, the acute (emergency) airway defense reflex is centrally mediated by vagal pathways, is primarily cholinergic, and stimulates copious volumes of gland mucus in response to acute, intense challenges to the airways, such as those produced by very vigorous exercise or aspiration of foreign material. In cystic fibrosis, the acute airway defense reflex can still stimulate the glands to secrete large amounts of mucus, although its properties are altered. Importantly, treatments that recruit components of the acute reflex, such as inhalation of hypertonic saline, are beneficial in treating cystic fibrosis airway disease. The situation for recipients of lung transplants is the reverse; transplanted airways retain the airway intrinsic nervous system but lose centrally mediated reflexes. The consequences

Hyaluronan mediates airway hyperresponsiveness in oxidative lung injury

PubMed Central

Lazrak, Ahmed; Creighton, Judy; Yu, Zhihong; Komarova, Svetlana; Doran, Stephen F.; Aggarwal, Saurabh; Emala, Charles W.; Stober, Vandy P.; Trempus, Carol S.; Garantziotis, Stavros

2015-01-01

Chlorine (Cl2) inhalation induces severe oxidative lung injury and airway hyperresponsiveness (AHR) that lead to asthmalike symptoms. When inhaled, Cl2 reacts with epithelial lining fluid, forming by-products that damage hyaluronan, a constituent of the extracellular matrix, causing the release of low-molecular-weight fragments (L-HA, <300 kDa), which initiate a series of proinflammatory events. Cl2 (400 ppm, 30 min) exposure to mice caused an increase of L-HA and its binding partner, inter-α-trypsin-inhibitor (IαI), in the bronchoalveolar lavage fluid. Airway resistance following methacholine challenge was increased 24 h post-Cl2 exposure. Intratracheal administration of high-molecular-weight hyaluronan (H-HA) or an antibody against IαI post-Cl2 exposure decreased AHR. Exposure of human airway smooth muscle (HASM) cells to Cl2 (100 ppm, 10 min) or incubation with Cl2-exposed H-HA (which fragments it to L-HA) increased membrane potential depolarization, intracellular Ca2+, and RhoA activation. Inhibition of RhoA, chelation of intracellular Ca2+, blockade of cation channels, as well as postexposure addition of H-HA, reversed membrane depolarization in HASM cells. We propose a paradigm in which oxidative lung injury generates reactive species and L-HA that activates RhoA and Ca2+ channels of airway smooth muscle cells, increasing their contractility and thus causing AHR. PMID:25747964

Toluene diisocyanate increases airway responsiveness to substance P and decreases airway neutral endopeptidase.

PubMed

Sheppard, D; Thompson, J E; Scypinski, L; Dusser, D; Nadel, J A; Borson, D B

1988-04-01

Substance P and related tachykinins contribute to the airway hyperresponsiveness caused by toluene diisocyanate (TDI) in guinea pigs. Neutral endopeptidase (NEP) is an important modulator of substance P-induced responses. To test the hypothesis that exposure to TDI would increase responsiveness to substance P by inhibiting activity of this enzyme, we determined the dose of substance P required to increase pulmonary resistance by 200% above baseline (PD200) before and after administration of the pharmacologic inhibitor phosphoramidon in guinea pigs studied 1 h after a 1-h exposure to air or 3 ppm TDI. TDI exposure increased responsiveness to substance P significantly. However, phosphoramidon caused a significantly greater leftward shift of the substance P dose-response curve in air-exposed animals than it did in TDI-exposed animals, so that after phosphoramidon, mean values of PD200 in animals exposed to air or TDI did not differ. Tracheal NEP activity was significantly less after exposure to TDI than after exposure to air, whereas activity in the esophagus was the same in both groups. These results suggest that TDI exposure increases the bronchoconstrictor responsiveness of guinea pigs to substance P, in large part through inhibition of airway NEP.

Toluene diisocyanate increases airway responsiveness to substance P and decreases airway neutral endopeptidase.

PubMed Central

Sheppard, D; Thompson, J E; Scypinski, L; Dusser, D; Nadel, J A; Borson, D B

1988-01-01

Substance P and related tachykinins contribute to the airway hyperresponsiveness caused by toluene diisocyanate (TDI) in guinea pigs. Neutral endopeptidase (NEP) is an important modulator of substance P-induced responses. To test the hypothesis that exposure to TDI would increase responsiveness to substance P by inhibiting activity of this enzyme, we determined the dose of substance P required to increase pulmonary resistance by 200% above baseline (PD200) before and after administration of the pharmacologic inhibitor phosphoramidon in guinea pigs studied 1 h after a 1-h exposure to air or 3 ppm TDI. TDI exposure increased responsiveness to substance P significantly. However, phosphoramidon caused a significantly greater leftward shift of the substance P dose-response curve in air-exposed animals than it did in TDI-exposed animals, so that after phosphoramidon, mean values of PD200 in animals exposed to air or TDI did not differ. Tracheal NEP activity was significantly less after exposure to TDI than after exposure to air, whereas activity in the esophagus was the same in both groups. These results suggest that TDI exposure increases the bronchoconstrictor responsiveness of guinea pigs to substance P, in large part through inhibition of airway NEP. PMID:2450892

Inspiratory High Frequency Airway Oscillation Attenuates Resistive Loaded Dyspnea and Modulates Respiratory Function in Young Healthy Individuals

PubMed Central

Morris, Theresa; Sumners, David Paul; Green, David Andrew

2014-01-01

Direct chest-wall percussion can reduce breathlessness in Chronic Obstructive Pulmonary Disease and respiratory function may be improved, in health and disease, by respiratory muscle training (RMT). We tested whether high-frequency airway oscillation (HFAO), a novel form of airflow oscillation generation can modulate induced dyspnoea and respiratory strength and/or patterns following 5 weeks of HFAO training (n = 20) compared to a SHAM-RMT (conventional flow-resistive RMT) device (n = 15) in healthy volunteers (13 males; aged 20–36 yrs). HFAO causes oscillations with peak-to-peak amplitude of 1 cm H2O, whereas the SHAM-RMT device was identical but created no pressure oscillation. Respiratory function, dyspnoea and ventilation during 3 minutes of spontaneous resting ventilation, 1 minute of maximal voluntary hyperventilation and 1 minute breathing against a moderate inspiratory resistance, were compared PRE and POST 5-weeks of training (2×30 breaths at 70% peak flow, 5 days a week). Training significantly reduced NRS dyspnoea scores during resistive loaded ventilation, both in the HFAO (p = 0.003) and SHAM-RMT (p = 0.005) groups. Maximum inspiratory static pressure (cm H2O) was significantly increased by HFAO training (vs. PRE; p<0.001). Maximum inspiratory dynamic pressure was increased by training in both the HFAO (vs. PRE; p<0.001) and SHAM-RMT (vs. PRE; p = 0.021) groups. Peak inspiratory flow rate (L.s−1) achieved during the maximum inspiratory dynamic pressure manoeuvre increased significantly POST (vs. PRE; p = 0.001) in the HFAO group only. HFAO reduced inspiratory resistive loading–induced dyspnoea and augments static and dynamic maximal respiratory manoeuvre performance in excess of flow-resistive IMT (SHAM-RMT) in healthy individuals without the respiratory discomfort associated with RMT. PMID:24651392

Allergic inflammation induces a persistent mechanistic switch in thromboxane-mediated airway constriction in the mouse

PubMed Central

Cyphert, Jaime M.; Allen, Irving C.; Church, Rachel J.; Latour, Anne M.; Snouwaert, John N.; Coffman, Thomas M.

2012-01-01

Actions of thromboxane (TXA2) to alter airway resistance were first identified over 25 years ago. However, the mechanism underlying this physiological response has remained largely undefined. Here we address this question using a novel panel of mice in which expression of the thromboxane receptor (TP) has been genetically manipulated. We show that the response of the airways to TXA2 is complex: it depends on expression of other G protein-coupled receptors but also on the physiological context of the signal. In the healthy airway, TXA2-mediated airway constriction depends on expression of TP receptors by smooth muscle cells. In contrast, in the inflamed lung, the direct actions of TXA2 on smooth muscle cell TP receptors no longer contribute to bronchoconstriction. Instead, in allergic lung disease, TXA2-mediated airway constriction depends on neuronal TP receptors. Furthermore, this mechanistic switch persists long after resolution of pulmonary inflammation. Our findings demonstrate the powerful ability of lung inflammation to modify pathways leading to airway constriction, resulting in persistent changes in mechanisms of airway reactivity to key bronchoconstrictors. Such alterations are likely to shape the pathogenesis of asthmatic lung disease. PMID:21984570

Insights on persistent airway infection by non-typeable Haemophilus influenzae in chronic obstructive pulmonary disease

PubMed Central

Ahearn, Christian P.; Gallo, Mary C.

2017-01-01

Abstract Non-typeable Haemophilus influenzae (NTHi) is the most common bacterial cause of infection of the lower airways in adults with chronic obstructive pulmonary disease (COPD). Infection of the COPD airways causes acute exacerbations, resulting in substantial morbidity and mortality. NTHi has evolved multiple mechanisms to establish infection in the hostile environment of the COPD airways, allowing the pathogen to persist in the airways for months to years. Persistent infection of the COPD airways contributes to chronic airway inflammation that increases symptoms and accelerates the progressive loss of pulmonary function, which is a hallmark of the disease. Persistence mechanisms of NTHi include the expression of multiple redundant adhesins that mediate binding to host cellular and extracellular matrix components. NTHi evades host immune recognition and clearance by invading host epithelial cells, forming biofilms, altering gene expression and displaying surface antigenic variation. NTHi also binds host serum factors that confer serum resistance. Here we discuss the burden of COPD and the role of NTHi infections in the course of the disease. We provide an overview of NTHi mechanisms of persistence that allow the pathogen to establish a niche in the hostile COPD airways. PMID:28449098

Host-microbe interactions in distal airways: relevance to chronic airway diseases.

PubMed

Martin, Clémence; Burgel, Pierre-Régis; Lepage, Patricia; Andréjak, Claire; de Blic, Jacques; Bourdin, Arnaud; Brouard, Jacques; Chanez, Pascal; Dalphin, Jean-Charles; Deslée, Gaetan; Deschildre, Antoine; Gosset, Philippe; Touqui, Lhousseine; Dusser, Daniel

2015-03-01

This article is the summary of a workshop, which took place in November 2013, on the roles of microorganisms in chronic respiratory diseases. Until recently, it was assumed that lower airways were sterile in healthy individuals. However, it has long been acknowledged that microorganisms could be identified in distal airway secretions from patients with various respiratory diseases, including cystic fibrosis (CF) and non-CF bronchiectasis, chronic obstructive pulmonary disease, asthma and other chronic airway diseases (e.g. post-transplantation bronchiolitis obliterans). These microorganisms were sometimes considered as infectious agents that triggered host immune responses and contributed to disease onset and/or progression; alternatively, microorganisms were often considered as colonisers, which were considered unlikely to play roles in disease pathophysiology. These concepts were developed at a time when the identification of microorganisms relied on culture-based methods. Importantly, the majority of microorganisms cannot be cultured using conventional methods, and the use of novel culture-independent methods that rely on the identification of microorganism genomes has revealed that healthy distal airways display a complex flora called the airway microbiota. The present article reviews some aspects of current literature on host-microbe (mostly bacteria and viruses) interactions in healthy and diseased airways, with a special focus on distal airways. Copyright ©ERS 2015.

The New Perilaryngeal Airway (CobraPLA™)1 Is as Efficient as the Laryngeal Mask Airway (LMA™)2, But Provides Better Airway Sealing Pressures

PubMed Central

Akça, Ozan; Wadhwa, Anupama; Sengupta, Papiya; Durrani, Jaleel; Hanni, Keith; Wenke, Mary; Yücel, Yüksel; Lenhardt, Rainer; Doufas, Anthony G.; Sessler, Daniel I.

2006-01-01

The Laryngeal Mask Airway (LMA) is a frequently-used efficient airway device, yet it sometimes seals poorly, thus reducing the efficacy of positive-pressure ventilation. The Perilaryngeal Airway (CobraPLA) is a novel airway device with a larger pharyngeal cuff (when inflated). We tested the hypothesis that the CobraPLA was superior to LMA with regard to insertion time and airway sealing pressure and comparable to LMA in airway adequacy and recovery characteristics. After midazolam and fentanyl, 81 ASA I-II outpatients having elective surgery were randomized to receive an LMA or CobraPLA. Anesthesia was induced with propofol (2.5 mg/kg, IV), and the airway inserted. We measured 1) insertion time; 2) adequacy of the airway (no leak at 15-cm-H2O peak pressure or tidal volume of 5 ml/kg); 3) airway sealing pressure; 4) number of repositioning attempts; and 5) sealing quality (no leak at tidal volume of 8 ml/kg). At the end of surgery, gastric insufflation, postoperative sore throat, dysphonia, and dysphagia were evaluated. Data were compared with unpaired t-tests, chi-square tests, or Fisher’s Exact tests; P<0.05 was significant. Patient characteristics, insertion times, airway adequacy, number of repositioning attempts, and recovery were similar in each group. Airway sealing pressure was significantly greater with CobraPLA (23±6 cm H2O) than LMA (18±5 cm H2O, P<0.001). The CobraPLA has insertion characteristics similar to LMA, but better airway sealing capabilities. PMID:15281543

Airway surface mycosis in chronic TH2-associated airway disease.

PubMed

Porter, Paul C; Lim, Dae Jun; Maskatia, Zahida Khan; Mak, Garbo; Tsai, Chu-Lin; Citardi, Martin J; Fakhri, Samer; Shaw, Joanne L; Fothergil, Annette; Kheradmand, Farrah; Corry, David B; Luong, Amber

2014-08-01

Environmental fungi have been linked to TH2 cell-related airway inflammation and the TH2-associated chronic airway diseases asthma, chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), and allergic fungal rhinosinusitis (AFRS), but whether these organisms participate directly or indirectly in disease pathology remains unknown. To determine the frequency of fungus isolation and fungus-specific immunity in patients with TH2-associated and non-TH2-associated airway disease. Sinus lavage fluid and blood were collected from sinus surgery patients (n = 118) including patients with CRSwNP, patients with CRS without nasal polyps, patients with AFRS, and non-CRS/nonasthmatic control patients. Asthma status was determined from medical history. Sinus lavage fluids were cultured and directly examined for evidence of viable fungi. PBMCs were restimulated with fungal antigens in an enzyme-linked immunocell spot assay to determine total memory fungus-specific IL-4-secreting cells. These data were compared with fungus-specific IgE levels measured from plasma by ELISA. Filamentous fungi were significantly more commonly cultured in patients with TH2-associated airway disease (asthma, CRSwNP, or AFRS: n = 68) than in control patients with non-TH2-associated disease (n = 31): 74% vs 16%, respectively (P < .001). Both fungus-specific IL-4 enzyme-linked immunocell spot (n = 48) and specific IgE (n = 70) data correlated with TH2-associated diseases (sensitivity 73% and specificity 100% vs 50% and 77%, respectively). The frequent isolation of fungi growing directly within the airways accompanied by specific immunity to these organisms only in patients with TH2-associated chronic airway diseases suggests that fungi participate directly in the pathogenesis of these conditions. Efforts to eradicate airway fungi from the airways should be considered in selected patients. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Cystic Fibrosis Transmembrane Conductance Regulator in Sarcoplasmic Reticulum of Airway Smooth Muscle. Implications for Airway Contractility

PubMed Central

Cook, Daniel P.; Rector, Michael V.; Bouzek, Drake C.; Michalski, Andrew S.; Gansemer, Nicholas D.; Reznikov, Leah R.; Li, Xiaopeng; Stroik, Mallory R.; Ostedgaard, Lynda S.; Abou Alaiwa, Mahmoud H.; Thompson, Michael A.; Prakash, Y. S.; Krishnan, Ramaswamy; Meyerholz, David K.; Seow, Chun Y.

2016-01-01

Rationale: An asthma-like airway phenotype has been described in people with cystic fibrosis (CF). Whether these findings are directly caused by loss of CF transmembrane conductance regulator (CFTR) function or secondary to chronic airway infection and/or inflammation has been difficult to determine. Objectives: Airway contractility is primarily determined by airway smooth muscle. We tested the hypothesis that CFTR is expressed in airway smooth muscle and directly affects airway smooth muscle contractility. Methods: Newborn pigs, both wild type and with CF (before the onset of airway infection and inflammation), were used in this study. High-resolution immunofluorescence was used to identify the subcellular localization of CFTR in airway smooth muscle. Airway smooth muscle function was determined with tissue myography, intracellular calcium measurements, and regulatory myosin light chain phosphorylation status. Precision-cut lung slices were used to investigate the therapeutic potential of CFTR modulation on airway reactivity. Measurements and Main Results: We found that CFTR localizes to the sarcoplasmic reticulum compartment of airway smooth muscle and regulates airway smooth muscle tone. Loss of CFTR function led to delayed calcium reuptake following cholinergic stimulation and increased myosin light chain phosphorylation. CFTR potentiation with ivacaftor decreased airway reactivity in precision-cut lung slices following cholinergic stimulation. Conclusions: Loss of CFTR alters porcine airway smooth muscle function and may contribute to the airflow obstruction phenotype observed in human CF. Airway smooth muscle CFTR may represent a therapeutic target in CF and other diseases of airway narrowing. PMID:26488271

Viscoelastic behavior of lung and chest wall in dogs determined by flow interruption.

PubMed

Similowski, T; Levy, P; Corbeil, C; Albala, M; Pariente, R; Derenne, J P; Bates, J H; Jonson, B; Milic-Emili, J

1989-12-01

Pulmonary and chest wall mechanics were studied in six anesthetized paralyzed dogs, by use of the technique of rapid airway occlusion during constant flow inflation. Analysis of the pressure changes after flow interruption allowed us to partition the overall resistance of the lung (Rl) and chest wall (Rw) and total respiratory system (Rrs) into two components, one (Rinit) reflecting in the lung airway resistance (Raw), the other (delta R) reflecting primarily the viscoelastic properties of the pulmonary and chest wall tissues. The effects of varying inspiratory flow and inflation volume were interpreted in terms of frequency dependence of resistance, by using a spring-and-dashpot model previously proposed and substantiated by Bates et al. (Proc. 9th Annu. Conf. IEEE Med. Biol. Soc., 1987, vol. 3, p. 1802-1803). We observed that 1) Raw and Rw,init were nearly equal and small relative to Rl and Rw (both were unaffected by flow); 2) Rrs,init decreased slightly with increasing volume; 3) both delta Rl and delta Rw decreased with increasing flow and increased with increasing lung volume. These changes were manifestations of frequency dependence of delta R, as it is predicted by the model; 4) Rrs, Rl, and Rw followed the same trends as delta R. These results corroborate data previously reported in the literature with the use of different techniques to measure airways and pulmonary tissue resistances and confirm that the use of Rl to assess bronchial reactivity is problematic. The interrupter techniques provides a convenient way to obtain Raw values, as well as analogs of lung and chest wall tissue resistances in intact dogs.

Airway smooth muscle in airway reactivity and remodeling: what have we learned?

PubMed Central

2013-01-01

It is now established that airway smooth muscle (ASM) has roles in determining airway structure and function, well beyond that as the major contractile element. Indeed, changes in ASM function are central to the manifestation of allergic, inflammatory, and fibrotic airway diseases in both children and adults, as well as to airway responses to local and environmental exposures. Emerging evidence points to novel signaling mechanisms within ASM cells of different species that serve to control diverse features, including 1) [Ca2+]i contractility and relaxation, 2) cell proliferation and apoptosis, 3) production and modulation of extracellular components, and 4) release of pro- vs. anti-inflammatory mediators and factors that regulate immunity as well as the function of other airway cell types, such as epithelium, fibroblasts, and nerves. These diverse effects of ASM “activity” result in modulation of bronchoconstriction vs. bronchodilation relevant to airway hyperresponsiveness, airway thickening, and fibrosis that influence compliance. This perspective highlights recent discoveries that reveal the central role of ASM in this regard and helps set the stage for future research toward understanding the pathways regulating ASM and, in turn, the influence of ASM on airway structure and function. Such exploration is key to development of novel therapeutic strategies that influence the pathophysiology of diseases such as asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. PMID:24142517

Difficult airway response team: a novel quality improvement program for managing hospital-wide airway emergencies.

PubMed

Mark, Lynette J; Herzer, Kurt R; Cover, Renee; Pandian, Vinciya; Bhatti, Nasir I; Berkow, Lauren C; Haut, Elliott R; Hillel, Alexander T; Miller, Christina R; Feller-Kopman, David J; Schiavi, Adam J; Xie, Yanjun J; Lim, Christine; Holzmueller, Christine; Ahmad, Mueen; Thomas, Pradeep; Flint, Paul W; Mirski, Marek A

2015-07-01

Difficult airway cases can quickly become emergencies, increasing the risk of life-threatening complications or death. Emergency airway management outside the operating room is particularly challenging. We developed a quality improvement program-the Difficult Airway Response Team (DART)-to improve emergency airway management outside the operating room. DART was implemented by a team of anesthesiologists, otolaryngologists, trauma surgeons, emergency medicine physicians, and risk managers in 2005 at The Johns Hopkins Hospital in Baltimore, Maryland. The DART program had 3 core components: operations, safety, and education. The operations component focused on developing a multidisciplinary difficult airway response team, standardizing the emergency response process, and deploying difficult airway equipment carts throughout the hospital. The safety component focused on real-time monitoring of DART activations and learning from past DART events to continuously improve system-level performance. This objective entailed monitoring the paging system, reporting difficult airway events and DART activations to a Web-based registry, and using in situ simulations to identify and mitigate defects in the emergency airway management process. The educational component included development of a multispecialty difficult airway curriculum encompassing case-based lectures, simulation, and team building/communication to ensure consistency of care. Educational materials were also developed for non-DART staff and patients to inform them about the needs of patients with difficult airways and ensure continuity of care with other providers after discharge. Between July 2008 and June 2013, DART managed 360 adult difficult airway events comprising 8% of all code activations. Predisposing patient factors included body mass index >40, history of head and neck tumor, prior difficult intubation, cervical spine injury, airway edema, airway bleeding, and previous or current tracheostomy. Twenty

Difficult Airway Response Team: A Novel Quality Improvement Program for Managing Hospital-Wide Airway Emergencies

PubMed Central

Mark, Lynette J.; Herzer, Kurt R.; Cover, Renee; Pandian, Vinciya; Bhatti, Nasir I.; Berkow, Lauren C.; Haut, Elliott R.; Hillel, Alexander T.; Miller, Christina R.; Feller-Kopman, David J.; Schiavi, Adam J.; Xie, Yanjun J.; Lim, Christine; Holzmueller, Christine; Ahmad, Mueen; Thomas, Pradeep; Flint, Paul W.; Mirski, Marek A.

2015-01-01

Background Difficult airway cases can quickly become emergencies, increasing the risk of life-threatening complications or death. Emergency airway management outside the operating room is particularly challenging. Methods We developed a quality improvement program—the Difficult Airway Response Team (DART)—to improve emergency airway management outside the operating room. DART was implemented by a team of anesthesiologists, otolaryngologists, trauma surgeons, emergency medicine physicians, and risk managers in 2005 at The Johns Hopkins Hospital in Baltimore, Maryland. The DART program had three core components: operations, safety, and education. The operations component focused on developing a multidisciplinary difficult airway response team, standardizing the emergency response process, and deploying difficult airway equipment carts throughout the hospital. The safety component focused on real-time monitoring of DART activations and learning from past DART events to continuously improve system-level performance. This objective entailed monitoring the paging system, reporting difficult airway events and DART activations to a web-based registry, and using in situ simulations to identify and mitigate defects in the emergency airway management process. The educational component included development of a multispecialty difficult airway curriculum encompassing case-based lectures, simulation, and team building/communication to ensure consistency of care. Educational materials were also developed for non-DART staff and patients to inform them about the needs of patients with difficult airways and ensure continuity of care with other providers after discharge. Results Between July 2008 and June 2013, DART managed 360 adult difficult airway events comprising 8% of all code activations. Predisposing patient factors included body mass index > 40, history of head and neck tumor, prior difficult intubation, cervical spine injury, airway edema, airway bleeding, and previous

The Supraglottic Effect of a Reduction in Expiratory Mask Pressure During Continuous Positive Airway Pressure

PubMed Central

Masdeu, Maria J.; Patel, Amit V.; Seelall, Vijay; Rapoport, David M.; Ayappa, Indu

2012-01-01

Study Objectives: Patients with obstructive sleep apnea may have difficulty exhaling against positive pressure, hence limiting their acceptance of continuous positive airway pressure (CPAP). C-Flex is designed to improve comfort by reducing pressure in the mask during expiration proportionally to expiratory airflow (3 settings correspond to increasing pressure changes). When patients use CPAP, nasal resistance determines how much higher supraglottic pressure is than mask pressure. We hypothesized that increased nasal resistance results in increased expiratory supraglottic pressure swings that could be mitigated by the effects of C-Flex on mask pressure. Design: Cohort study. Setting: Sleep center. Participants: Seventeen patients with obstructive sleep apnea/hypopnea syndrome and a mechanical model of the upper airway. Interventions: In patients on fixed CPAP, CPAP with different C-Flex levels was applied multiple times during the night. In the model, 2 different respiratory patterns and resistances were tested. Measurements and Results: Airflow, expiratory mask, and supraglottic pressures were measured on CPAP and on C-Flex. Swings in pressure during expiration were determined. On CPAP, higher nasal resistance produced greater expiratory pressure swings in the supraglottis in the patients and in the model, as expected. C-Flex 3 produced expiratory drops in mask pressure (range −0.03 to −2.49 cm H2O) but mitigated the expira-tory pressure rise in the supraglottis only during a sinusoidal respiratory pattern in the model. Conclusions: Expiratory changes in mask pressure induced by C-Flex did not uniformly transmit to the supraglottis in either patients with obstructive sleep apnea on CPAP or in a mechanical model of the upper airway with fixed resistance. Data suggest that the observed lack of expiratory drop in supraglottic pressure swings is related to dynamics of the C-Flex algorithm. Citation: Masdeu MJ; Patel AV; Seelall V; Rapoport DM; Ayappa I. The

Laryngeal mask airway for airway control during percutaneous dilatational tracheostomy.

PubMed

Pratt, T; Bromilow, J

2011-11-01

Percutaneous dilatational tracheostomy is a common bedside procedure in critical care for patients requiring prolonged mechanical ventilation. The traditional technique requires withdrawal of the endotracheal tube to a proximal position to facilitate tracheostomy insertion, but this carries the risk of inadvertent extubation and does not prevent cuff rupture. Use of a supraglottic airway such as the laryngeal mask airway may avoid these risks and could provide a safe alternative to the endotracheal tube. We present an appraisal of the literature to date. We found reasonable evidence to show improved ventilation and bronchoscopic visualisation with the laryngeal mask airway, but this has not been translated into improved outcome. There is currently insufficient evidence to draw conclusions about the safety of the laryngeal mask airway during percutaneous dilatational tracheostomy.

Experimental evidence of age-related adaptive changes in human acinar airways

PubMed Central

Quirk, James D.; Sukstanskii, Alexander L.; Woods, Jason C.; Lutey, Barbara A.; Conradi, Mark S.; Gierada, David S.; Yusen, Roger D.; Castro, Mario

2015-01-01

The progressive decline of lung function with aging is associated with changes in lung structure at all levels, from conducting airways to acinar airways (alveolar ducts and sacs). While information on conducting airways is becoming available from computed tomography, in vivo information on the acinar airways is not conventionally available, even though acini occupy 95% of lung volume and serve as major gas exchange units of the lung. The objectives of this study are to measure morphometric parameters of lung acinar airways in living adult humans over a broad range of ages by using an innovative MRI-based technique, in vivo lung morphometry with hyperpolarized 3He gas, and to determine the influence of age-related differences in acinar airway morphometry on lung function. Pulmonary function tests and MRI with hyperpolarized 3He gas were performed on 24 healthy nonsmokers aged 19-71 years. The most significant age-related difference across this population was a 27% loss of alveolar depth, h, leading to a 46% increased acinar airway lumen radius, hence, decreased resistance to acinar air transport. Importantly, the data show a negative correlation between h and the pulmonary function measures forced expiratory volume in 1 s and forced vital capacity. In vivo lung morphometry provides unique information on age-related changes in lung microstructure and their influence on lung function. We hypothesize that the observed reduction of alveolar depth in subjects with advanced aging represents a remodeling process that might be a compensatory mechanism, without which the pulmonary functional decline due to other biological factors with advancing age would be significantly larger. PMID:26542518

Mass loading of the upper airway extraluminal tissue space in rabbits: effects on tissue pressure and pharyngeal airway lumen geometry.

PubMed

Kairaitis, Kristina; Howitt, Lauren; Wheatley, John R; Amis, Terence C

2009-03-01

Lateral pharyngeal fat pad compression of the upper airway (UA) wall is thought to influence UA size in patients with obstructive sleep apnea. We examined interactions between acute mass/volume loading of the UA extra-luminal tissue space and UA patency. We studied 12 supine, anesthetized, spontaneously breathing, head position-controlled (50 degrees ), New Zealand White rabbits. Submucosal extraluminal tissue pressures (ETP) in the anterolateral (ETPlat) and anterior (ETPant) pharyngeal wall were monitored with surgically inserted pressure transducer-tipped catheters (Millar). Tracheal pressure (Ptr) and airflow (V) were measured via a pneumotachograph and pressure transducer inserted in series into the intact trachea, with hypopharyngeal cross-sectional area (CSA) measured via computed tomography, while graded saline inflation (0-1.5ml) of a compliant tissue expander balloon in the anterolateral subcutaneous tissue was performed. Inspiratory UA resistance (Rua) at 20 ml/s was calculated from a power function fitted to Ptr vs. V data. Graded expansion of the anterolateral balloon increased ETPlat from 2.3 +/- 0.5 cmH(2)O (n = 11, mean +/- SEM) to 5.0 +/- 1.1 cmH(2)O at 1.5-ml inflation (P < 0.05; ANOVA). However, ETPant was unchanged from 0.5 +/- 0.5 cmH(2)O (n = 9; P = 0.17). Concurrently, Rua increased to 119 +/- 4.2% of baseline value (n = 12; P < 0.001) associated with a significant reduction in CSA between 10 and 70% of airway length to a minimum of 82.2 +/- 4.4% of baseline CSA at 40% of airway length (P < 0.05). We conclude that anterolateral loading of the upper airway extraluminal tissue space decreases upper airway patency via an increase in ETPlat, but not ETPant. Lateral pharyngeal fat pad size may influence UA patency via increased tissue volume and pressure causing UA wall compression.

Use of a Novel Airway Kit and Simulation in Resident Training on Emergent Pediatric Airways.

PubMed

Melzer, Jonathan M; Hamersley, Erin R S; Gallagher, Thomas Q

2017-06-01

Objective Development of a novel pediatric airway kit and implementation with simulation to improve resident response to emergencies with the goal of improving patient safety. Methods Prospective study with 9 otolaryngology residents (postgraduate years 1-5) from our tertiary care institution. Nine simulated pediatric emergency airway drills were carried out with the existing system and a novel portable airway kit. Response times and time to successful airway control were noted with both the extant airway system and the new handheld kit. Results were analyzed to ensure parametric data and compared with t tests. A Bonferroni adjustment indicated that an alpha of 0.025 was needed for significance. Results Use of the airway kit significantly reduced the mean time of resident arrival by 47% ( P = .013) and mean time of successful intubation by 50% ( P = .007). Survey data indicated 100% improved resident comfort with emergent airway scenarios with use of the kit. Discussion Times to response and meaningful intervention were significantly reduced with implementation of the handheld airway kit. Use of simulation training to implement the new kit improved residents' comfort and airway skills. This study describes an affordable novel mobile airway kit and demonstrates its ability to improve response times. Implications for Practice The low cost of this airway kit makes it a tenable option even for smaller hospitals. Simulation provides a safe and effective way to familiarize oneself with novel equipment, and, when possible, realistic emergent airway simulations should be used to improve provider performance.

INHIBITION OF PAN NEUROTROPHIN RECEPTOR P75 ATTENUATES DIESEL PARTICULATE-INDUCED ENHANCEMENT OF ALLERGIC AIRWAY RESPONSES IN C57/BL6J MICE

EPA Science Inventory

Recent investigations have linked neurotrophins including nerve growth factor (NGF), neurotrophin-3 (NT-3), and brain-derived neurotrophic factor (BDNF) to allergic airways diseases. Antibody blockade of NGF attenuates airway resistance in allergic mice. Diesel exhaust particle...

Characterization of airway and vascular responses in murine lungs

PubMed Central

Held, Heinz-Dieter; Martin, Christian; Uhlig, Stefan

1999-01-01

We characterized the responses of murine airways and pulmonary vessels to a variety of endogenous mediators in the isolated perfused and ventilated mouse lung (IPL) and compared them with those in precision-cut lung slices. Airways: The EC50 (μM) for contractions of airways in IPL/slices was methacholine (Mch), 6.1/1.5>serotonin, 0.7/2.0>U46619 (TP-receptor agonist), 0.1/0.06>endothelin-1, 0.1/0.05. In the IPL, maximum increase in airway resistance (RL) was 0.6, 0.4, 0.8 and 11 cmH2O s ml−1, respectively. Adenosine (⩽1 mM), bombesin (⩽100 μM), histamine (⩽10 mM), LTC4 (⩽1 μM), PAF (0.25 μM) and substance P (⩽100 μM) had only weak effects (<5% of Mch) on RL. Vessels: The EC50 (μM) for vasoconstriction in the IPL was LTC4, 0.06>U46619, 0.05airway response to Mch 5 fold and the maximum PAF-induced vasoconstriction 4 fold. Conclusion: Murine precision-cut lung slices maintain important characteristics of the whole organ. The maximum reagibility of murine airways to endogenous mediators is serotoninairway and vessel hyperreactivity induced by U46619 raises the possibility that thromboxane contributes directly to airway hyperresponsiveness in various experimental and clinical settings. PMID:10205008

Crosstalk between beta-2-adrenoceptor and muscarinic acetylcholine receptors in the airway.

PubMed

Pera, Tonio; Penn, Raymond B

2014-06-01

The M3 and M2 muscarinic acetylcholine receptors (mAChRs) and beta-2-adrenoceptors (β2ARs) are important regulators of airway cell function, and drugs targeting these receptors are among the first line drugs in the treatment of the obstructive lung diseases asthma and chronic obstructive lung disease (COPD). Cross-regulation or crosstalk between mAChRs and β2ARs in airway smooth muscle (ASM) helps determine the contractile state of the muscle, thus airway diameter and resistance to airflow. In this review we will detail mAChR and β2AR-signaling and crosstalk, focusing on events in the ASM cell but also addressing the function of these receptors in other cell types that impact airway physiology. We conclude by discussing how recent advances in GPCR pharmacology offer a unique opportunity to fine tune mAChR and β2AR signaling and their crosstalk, and thereby produce superior therapeutics for obstructive lung and other diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Efficacy of Surgical Airway Plasty for Benign Airway Stenosis.

PubMed

Tsukioka, Takuma; Takahama, Makoto; Nakajima, Ryu; Kimura, Michitaka; Inoue, Hidetoshi; Yamamoto, Ryoji

2016-01-01

Long-term patency is required during treatment for benign airway stenosis. This study investigated the effectiveness of surgical airway plasty for benign airway stenosis. Clinical courses of 20 patients, who were treated with surgical plasty for their benign airway stenosis, were retrospectively investigated. Causes of stenosis were tracheobronchial tuberculosis in 12 patients, post-intubation stenosis in five patients, malacia in two patients, and others in one patient. 28 interventional pulmonology procedures and 20 surgical plasty were performed. Five patients with post-intubation stenosis and four patients with tuberculous stenosis were treated with tracheoplasty. Eight patients with tuberculous stenosis were treated with bronchoplasty, and two patients with malacia were treated with stabilization of the membranous portion. Anastomotic stenosis was observed in four patients, and one to four additional treatments were required. Performance status, Hugh-Jones classification, and ventilatory functions were improved after surgical plasty. Outcomes were fair in patients with tuberculous stenosis and malacia. However, efficacy of surgical plasty for post-intubation stenosis was not observed. Surgical airway plasty may be an acceptable treatment for tuberculous stenosis. Patients with malacia recover well after surgical plasty. There may be untreated patients with malacia who have the potential to benefit from surgical plasty.

Efficacy of Surgical Airway Plasty for Benign Airway Stenosis

PubMed Central

Takahama, Makoto; Nakajima, Ryu; Kimura, Michitaka; Inoue, Hidetoshi; Yamamoto, Ryoji

2015-01-01

Background: Long-term patency is required during treatment for benign airway stenosis. This study investigated the effectiveness of surgical airway plasty for benign airway stenosis. Methods: Clinical courses of 20 patients, who were treated with surgical plasty for their benign airway stenosis, were retrospectively investigated. Results: Causes of stenosis were tracheobronchial tuberculosis in 12 patients, post-intubation stenosis in five patients, malacia in two patients, and others in one patient. 28 interventional pulmonology procedures and 20 surgical plasty were performed. Five patients with post-intubation stenosis and four patients with tuberculous stenosis were treated with tracheoplasty. Eight patients with tuberculous stenosis were treated with bronchoplasty, and two patients with malacia were treated with stabilization of the membranous portion. Anastomotic stenosis was observed in four patients, and one to four additional treatments were required. Performance status, Hugh–Jones classification, and ventilatory functions were improved after surgical plasty. Outcomes were fair in patients with tuberculous stenosis and malacia. However, efficacy of surgical plasty for post-intubation stenosis was not observed. Conclusion: Surgical airway plasty may be an acceptable treatment for tuberculous stenosis. Patients with malacia recover well after surgical plasty. There may be untreated patients with malacia who have the potential to benefit from surgical plasty. PMID:26567879

Attenuation of tachykinin-induced airflow obstruction and microvascular leakage in immature airways.

PubMed Central

Tokuyama, K.; Yokoyama, T.; Morikawa, A.; Mochizuki, H.; Kuroume, T.; Barnes, P. J.

1993-01-01

1. To study the effect of maturation on substance P (SP)- and neurokinin A (NKA)-induced airflow obstruction and airway microvascular leakage (MVL), we have measured changes in both lung resistance (RL) and extravasation of Evans blue dye in anaesthetized immature (aged 14 +/- 1 days) and adult guinea-pigs (aged 80 +/- 3 days). 2. RL and its recovery after hyperinflation at 5 min were measured for 6 min after i.v. SP (0.2, 1 and 30 nmol kg-1), NKA (1 and 10 nmol kg-1) or vehicle (0.9% NaCl). After measurement of RL, MVL in trachea, main bronchi and intrapulmonary airways was also examined. 3. The order of potency in inducing airflow obstruction did not change with age (NKA > SP) but immature animals required a larger dose of SP or NKA than adults to cause a significant increase in RL. 4. The order of potency in inducing airway microvascular leakage was SP > NKA in both immature and adult animals. The amount of extravasated dye after SP was significantly less in immature airways, especially in central airways. 5. Phosphoramidon (2.5 mg kg-1), a neutral endopeptidase (NEP) inhibitor, significantly increased RL after 0.2 nmol kg-1 SP only in adult airways. Phosphoramidon enhanced the dye extravasation after 0.2 nmol kg-1 SP in both immature and adult airways with a significantly greater amount of dye in adult animals, suggesting that mechanisms other than changes in NEP activity may be responsible for this age-related difference.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7679033

FABP4 induces asthmatic airway epithelial barrier dysfunction via ROS-activated FoxM1.

PubMed

Wu, Gaohui; Yang, Liteng; Xu, Yi; Jiang, Xiaohong; Jiang, Xiaomin; Huang, Lisha; Mao, Ling; Cai, Shaoxi

2018-01-01

Functional abnormal airway epithelial cells, along with activated inflammatory cells, resulting in chronic airway inflammation, are considered as the characteristic of asthma. Fatty Acid Binding Protein 4 (FABP4) takes part in glucose and lipid homeostasis, and also have an important role in allergic airway inflammation. However, whether FABP4 influence barrier function of airway epithelial cells is unknown. In vivo, a HDM-induced murine model of asthma was obtained to assessed airway inflammation and protein expression of E-cadherin and Forkhead Box M1 (FoxM1). In vitro, 16-HBE was cultured and was treated with hrFABP4, siFABP4, FABPF4 inhibitor BMS, or FoxM1 inhibitor RCM-1. IL-4, IL-5, and IL-13 level was determined by ELISA. Transepithelial electrical resistance (TER), paracellular permeability and E-cadherin-special immunofluorescence were measured to value airway epithelial barrier function. Intracellular ROS production was determined by DCF-DA fluorescence. FABP4 inhibitor BMS alleviate airway inflammation and destruction of E-cad in allergic mouse. Treatment with HDM or hrFABP4 aggravated inflammatory response, damaged airway epithelial barrier, which could be inhibited by siFABP4 and BMS. Treatment with HDM or hrFABP4 also enhanced levels of FoxM1, and Inhibited FoxM1 suppressed HDM- and hrFABP4-induced inflammation and airway epithelial barrier dysfunction. In addition, H 2 O 2 promoted FoxM1 expression, HDM and hrFABP4 induced-FoxM1 could be inhibited by NAC, leading to decreased inflammation and improved airway epithelial barrier. Upregulated ROS induced by FABP4 was of significance in activating FoxM1 leading to airway inflammation and epithelial barrier dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

Respiratory impedance is correlated with airway narrowing in asthma using three-dimensional computed tomography.

PubMed

Karayama, M; Inui, N; Mori, K; Kono, M; Hozumi, H; Suzuki, Y; Furuhashi, K; Hashimoto, D; Enomoto, N; Fujisawa, T; Nakamura, Y; Watanabe, H; Suda, T

2018-03-01

Respiratory impedance comprises the resistance and reactance of the respiratory system and can provide detailed information on respiratory function. However, details of the relationship between impedance and morphological airway changes in asthma are unknown. We aimed to evaluate the correlation between imaging-based airway changes and respiratory impedance in patients with asthma. Respiratory impedance and spirometric data were evaluated in 72 patients with asthma and 29 reference subjects. We measured the intraluminal area (Ai) and wall thickness (WT) of third- to sixth-generation bronchi using three-dimensional computed tomographic analyses, and values were adjusted by body surface area (BSA, Ai/BSA, and WT/the square root (√) of BSA). Asthma patients had significantly increased respiratory impedance, decreased Ai/BSA, and increased WT/√BSA, as was the case in those without airflow limitation as assessed by spirometry. Ai/BSA was inversely correlated with respiratory resistance at 5 Hz (R5) and 20 Hz (R20). R20 had a stronger correlation with Ai/BSA than did R5. Ai/BSA was positively correlated with forced expiratory volume in 1 second/forced vital capacity ratio, percentage predicted forced expiratory volume in 1 second, and percentage predicted mid-expiratory flow. WT/√BSA had no significant correlation with spirometry or respiratory impedance. Respiratory resistance is associated with airway narrowing. © 2018 John Wiley & Sons Ltd.

Site of Allergic Airway Narrowing and the Influence of Exogenous Surfactant in the Brown Norway Rat

PubMed Central

Risse, Paul-André; Bullimore, Sharon R.; Benedetti, Andrea; Martin, James G.

2012-01-01

Background The parameters RN (Newtonian resistance), G (tissue damping), and H (tissue elastance) of the constant phase model of respiratory mechanics provide information concerning the site of altered mechanical properties of the lung. The aims of this study were to compare the site of allergic airway narrowing implied from respiratory mechanics to a direct assessment by morphometry and to evaluate the effects of exogenous surfactant administration on the site and magnitude of airway narrowing. Methods We induced airway narrowing by ovalbumin sensitization and challenge and we tested the effects of a natural surfactant lacking surfactant proteins A and D (Infasurf®) on airway responses. Sensitized, mechanically ventilated Brown Norway rats underwent an aerosol challenge with 5% ovalbumin or vehicle. Other animals received nebulized surfactant prior to challenge. Three or 20 minutes after ovalbumin challenge, airway luminal areas were assessed on snap-frozen lungs by morphometry. Results At 3 minutes, RN and G detected large airway narrowing whereas at 20 minutes G and H detected small airway narrowing. Surfactant inhibited RN at the peak of the early allergic response and ovalbumin-induced increase in bronchoalveolar lavage fluid cysteinyl leukotrienes and amphiregulin but not IgE-induced mast cell activation in vitro. Conclusion Allergen challenge triggers the rapid onset of large airway narrowing, detected by RN and G, and subsequent peripheral airway narrowing detected by G and H. Surfactant inhibits airway narrowing and reduces mast cell-derived mediators. PMID:22276110

Sensory neuropeptides modulate cigarette smoke-induced decrease in neutral endopeptidase activity in guinea pig airways.

PubMed

Kuo, H P; Lu, L C

1995-01-01

Cigarette smoke (CS) inhalation stimulates C-fibers to release sensory neuropeptides which mediate airway reflex responses to prevent irritants from entering the lower airways. When CS is inhaled via the upper airways, these airway defense responses may modulate the effect of CS on airway NEP activity and related airway hyperresponsiveness. To examine this possibility, we exposed guinea pigs to 1:10 diluted mid-tar cigarette smoke 100 puffs per day for 7 days and recorded pulmonary resistance of cumulative doses of neurokinin A (NKA, 10(-12)-10(-8) mol/kg, i.v.) or methacholine (Mch, 1-50 micrograms/kg, i.v.). NEP activity in the tracheobronchi was measured using fluorometric assay. Exposure of CS alone failed to alter the dose-response to NKA or Mch compared with air control. NEP activity in the airways after CS exposure was slightly but significantly lower than that of air control. Capsaicin pretreatment 1 week before CS exposure significantly shifted the dose-response curves of NKA, but not Mch, to the left and decreased NEP activity in the airways to a greater extent compared with CS exposure alone group. Capsaicin pretreatment alone failed to alter the responsiveness to NKA or NEP activity. CS also induced a significant increase in neutrophil counts in airways. Capsaicin pretreatment enhanced the effect of CS on neutrophil recruitment. We conclude that sensory neuropeptides may have a protective role in modulation of airways NEP activity downregulation induced by CS, probably by preventing CS from entering the lower airways or the chronic release of sensory neuropeptides induced by CS providing increased amount of substrata for NEP upregulation, and therefore modify the direct effect of CS on NEP activity and related airway hyperresponsiveness.

Pro-inflammatory mediators disrupt glucose homeostasis in airway surface liquid ‡

PubMed Central

Garnett, James P.; Nguyen, Trang T.; Moffatt, James D.; Pelham, Elizabeth R.; Kalsi, Kameljit K.; Baker, Emma H.; Baines, Deborah L.

2012-01-01

The glucose concentration of the airway surface liquid (ASL) is much lower than blood and is tightly regulated by the airway epithelium. ASL glucose is elevated in patients with viral colds, cystic fibrosis, chronic obstructive pulmonary disease (COPD) and asthma. Elevated ASL glucose is also associated with increased incidence of respiratory infection. However, the mechanism by which ASL glucose increases under inflammatory conditions is unknown. The aim of this study was to investigate the effect of pro-inflammatory mediators (PIMs) on the mechanisms governing airway glucose homeostasis in polarised monolayers of human airway (H441) and primary human bronchial epithelial (HBE) cells. Monolayers were treated with TNF-α, IFN-γ and LPS over 72 hours. PIM treatment led to increase in ASL glucose concentration and significantly reduced H441 and HBE transepithelial resistance (RT). This decline in RT was associated with an increase in paracellular permeability of glucose. Similar enhanced rates of paracellular glucose flux were also observed across excised trachea from LPS-treated mice. Interestingly, PIMs enhanced glucose uptake across the apical, but not the basolateral, membrane of H441 and HBE monolayers. This increase was predominantly via phloretin-sensitive GLUT-mediated uptake, which coincided with an increase in GLUT2 and GLUT10 abundance. In conclusion, exposure of airway epithelial monolayers to PIMs results in increased paracellular glucose flux, and apical GLUT-mediated glucose uptake. However uptake was insufficient to limit glucose accumulation in ASL. These data provide for the first time, a mechanism to support clinical findings that ASL glucose concentration is increased in patients with airway inflammation. PMID:22623330

Sleep and pulmonary outcomes for clinical trials of airway plexiform neurofibromas in NF1.

PubMed

Plotkin, Scott R; Davis, Stephanie D; Robertson, Kent A; Akshintala, Srivandana; Allen, Julian; Fisher, Michael J; Blakeley, Jaishri O; Widemann, Brigitte C; Ferner, Rosalie E; Marcus, Carole L

2016-08-16

Plexiform neurofibromas (PNs) are complex, benign nerve sheath tumors that occur in approximately 25%-50% of individuals with neurofibromatosis type 1 (NF1). PNs that cause airway compromise or pulmonary dysfunction are uncommon but clinically important. Because improvement in sleep quality or airway function represents direct clinical benefit, measures of sleep and pulmonary function may be more meaningful than tumor size as endpoints in therapeutic clinical trials targeting airway PN. The Response Evaluation in Neurofibromatosis and Schwannomatosis functional outcomes group reviewed currently available endpoints for sleep and pulmonary outcomes and developed consensus recommendations for response evaluation in NF clinical trials. For patients with airway PNs, polysomnography, impulse oscillometry, and spirometry should be performed to identify abnormal function that will be targeted by the agent under clinical investigation. The functional group endorsed the use of the apnea hypopnea index (AHI) as the primary sleep endpoint, and pulmonary resistance at 10 Hz (R10) or forced expiratory volume in 1 or 0.75 seconds (FEV1 or FEV0.75) as primary pulmonary endpoints. The group defined minimum changes in AHI, R10, and FEV1 or FEV0.75 for response criteria. Secondary sleep outcomes include desaturation and hypercapnia during sleep and arousal index. Secondary pulmonary outcomes include pulmonary resistance and reactance measurements at 5, 10, and 20 Hz; forced vital capacity; peak expiratory flow; and forced expiratory flows. These recommended sleep and pulmonary evaluations are intended to provide researchers with a standardized set of clinically meaningful endpoints for response evaluation in trials of NF1-related airway PNs. © 2016 American Academy of Neurology.

Peripheral airway impairment measured by oscillometry predicts loss of asthma control in children.

PubMed

Shi, Yixin; Aledia, Anna S; Galant, Stanley P; George, Steven C

2013-03-01

We previously showed that impulse oscillometry (IOS) indices of peripheral airway function are associated with asthma control in children. However, little data exist on whether dysfunction in the peripheral airways can predict loss of asthma control. We sought to determine the utility of peripheral airway impairment, as measured by IOS, in predicting loss of asthma control in children. Fifty-four children (age, 7-17 years) with controlled asthma were enrolled in the study. Spirometric and IOS indices of airway function were obtained at baseline and at a follow-up visit 8 to 12 weeks later. Physicians who were blinded to the IOS measurements assessed asthma control (National Asthma Education and Prevention Program guidelines) on both visits and prescribed no medication change between visits. Thirty-eight (70%) patients maintained asthma control between 2 visits (group C-C), and 16 patients had asthma that became uncontrolled on the follow-up visit (group C-UC). There was no difference in baseline spirometric results between the C-C and C-UC groups, except for FEV1/forced vital capacity ratio (86% vs 82%, respectively; P < .01). Baseline IOS results, including resistance of the respiratory system at 5 Hz (R5; 6.4 vs 4.3 cm H2O · L(-1) · s), frequency dependence of resistance (difference of R5 and resistance of the respiratory system at 20 Hz [R5-20]; 2.0 vs 0.7 cm H2O · L(-1) · s), and reactance area (13.1 vs 4.1 cm H2O · L(-1)), of group C-UC were significantly higher than those of group C-C (P < .01). Receiver operating characteristic analysis showed baseline R5-20 and reactance area effectively predicted asthma control status at the follow-up visit (area under the curve, 0.91 and 0.90). Children with controlled asthma who have increased peripheral airway IOS indices are at risk of losing asthma control. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Airway management in neuroanesthesiology.

PubMed

Aziz, Michael

2012-06-01

Airway management for neuroanesthesiology brings together some key principles that are shared throughout neuroanesthesiology. This article appropriately targets the cervical spine with associated injury and the challenges surrounding airway management. The primary focus of this article is on the unique airway management obstacles encountered with cervical spine injury or cervical spine surgery, and unique considerations regarding functional neurosurgery are addressed. Furthermore, topics related to difficult airway management for those with rheumatoid arthritis or pituitary surgery are reviewed. Copyright © 2012 Elsevier Inc. All rights reserved.

[Difficult Ventilation Requiring Emergency Endotracheal Intubation during Awake Craniotomy Managed by Laryngeal Mask Airway].

PubMed

Matsuda, Asako; Mizota, Toshiyuki; Tanaka, Tomoharu; Segawa, Hajime; Fukuda, Kazuhiko

2016-04-01

We report a case of difficult ventilation requiring emergency endotracheal intubation during awake craniotomy managed by laryngeal mask airway (LMA). A 45-year-old woman was scheduled to receive awake craniotomy for brain tumor in the frontal lobe. After anesthetic induction, airway was secured using ProSeal LMA and patient was mechanically ventilated in pressure-control mode. Patient's head was fixed with head-pins at anteflex position, and the operation started. About one hour after the start of the operation, tidal volume suddenly decreased. We immediately started manual ventilation, but the airway resistance was extremely high and we could not adequately ventilate the patient. We administered muscle relaxant for suspected laryngospasm, but ventilatory status did not improve; so we decided to conduct emergency endotracheal intubation. We tried to intubate using Airwayscope or LMA-Fastrach, but they were not effective in our case. Finally trachea was intubated using transnasal fiberoptic bronchoscopy. We discuss airway management during awake craniotomy, focusing on emergency endotracheal intubation during surgery.

Emergency airway puncture

MedlinePlus

... support for only a very short period of time. Alternative Names Needle cricothyrotomy Images Emergency airway puncture Cricoid cartilage Emergency airway puncture - series References Hebert RB, Bose S, Mace SE. Cricothyrotomy and ...

Influence of pharyngeal airway respiration pressure on Class II mandibular retrusion in children: A computational fluid dynamics study of inspiration and expiration.

PubMed

Iwasaki, T; Sato, H; Suga, H; Takemoto, Y; Inada, E; Saitoh, I; Kakuno, K; Kanomi, R; Yamasaki, Y

2017-05-01

To examine the influence of negative pressure of the pharyngeal airway on mandibular retraction during inspiration in children with nasal obstruction using the computational fluid dynamics (CFD) method. Sixty-two children were divided into Classes I, II (mandibular retrusion) and III (mandibular protrusion) malocclusion groups. Cone-beam computed tomography data were used to reconstruct three-dimensional shapes of the nasal and pharyngeal airways. Airflow pressure was simulated using CFD to calculate nasal resistance and pharyngeal airway pressure during inspiration and expiration. Nasal resistance of the Class II group was significantly higher than that of the other two groups, and oropharyngeal airway inspiration pressure in the Class II (-247.64 Pa) group was larger than that in the Class I (-43.51 Pa) and Class III (-31.81 Pa) groups (P<.001). The oropharyngeal airway inspiration-expiration pressure difference in the Class II (-27.38 Pa) group was larger than that in the Class I (-5.17 Pa) and Class III (0.68 Pa) groups (P=.006). Large negative inspiratory pharyngeal airway pressure due to nasal obstruction in children with Class II malocclusion may be related to their retrognathia. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Careers in Airway Science.

ERIC Educational Resources Information Center

Federal Aviation Administration (DOT), Washington, DC.

The Federal Aviation Administration (FAA) has initiated the Airway Science curriculum as a method of preparing the next generation of aviation technicians and managers. This document: (1) discusses the FAA's role in the Airway Science program; (2) describes some of the career fields that FAA offers to Airway Science graduates (air traffic control…

Hygiene quality and presence of ESBL-producing Escherichia coli in raw food diets for dogs

PubMed Central

Nilsson, Oskar

2015-01-01

Background Raw food diets are popular among some dog owners, even though there are concerns regarding the infectious disease risk and public health implications. Hence, the two aims of this study were to investigate the hygiene quality of raw food diets for dogs in the Swedish market and if Escherichia coli with transferable resistance to extended spectrum cephalosporins (ESC) was present in such products. Methods Samples of raw food diets were suspended and further diluted in 0.9% saline. Appropriate dilutions were 1) cultured on Petrifilm™SEC to quantify the amount of E. coli in the samples and 2) mixed with cefotaxime to a final concentration of 1 mg/L and cultured on Petrifilm™SEC to quantify the amount of ESC-resistant E. coli in the samples. Furthermore, undiluted suspensions were mixed 1:1 with double strength MacConkey broth with cefotaxime, enriched overnight and finally cultured on MacConkey agar with cefotaxime (1 mg/L). Suspected ESC-resistant E. coli were screened by PCR for genes encoding extended spectrum beta lactamases and plasmid-mediated AmpC and their susceptibility to a panel of antimicrobials was performed by broth microdilution using VetMIC GN-mo. Results Escherichia coli was isolated from all samples (n=39) and ESC-resistant E. coli was isolated from nine samples (23%). All ESC-resistant E. coli were PCR-positive for the bla CMY-2 group and only one of them was also resistant to a non-beta-lactam antibiotic. Conclusion The results of this study indicate that raw food diets could be a source of ESC-resistant E. coli to dogs and highlight the need for maintaining good hygiene when handling these products to prevent infection. PMID:26490763

Post-Exposure Antioxidant Treatment in Rats Decreases Airway Hyperplasia and Hyperreactivity Due to Chlorine Inhalation

PubMed Central

Bracher, Andreas; Doran, Stephen F.; Squadrito, Giuseppe L.; Fernandez, Solana; Postlethwait, Edward M.; Bowen, Larry; Matalon, Sadis

2012-01-01

We assessed the safety and efficacy of combined intravenous and aerosolized antioxidant administration to attenuate chlorine gas–induced airway alterations when administered after exposure. Adult male Sprague-Dawley rats were exposed to air or 400 parts per million (ppm) chlorine (a concentration likely to be encountered in the vicinity of industrial accidents) in environmental chambers for 30 minutes, and returned to room air, and they then received a single intravenous injection of ascorbic acid and deferoxamine or saline. At 1 hour and 15 hours after chlorine exposure, the rats were treated with aerosolized ascorbate and deferoxamine or vehicle. Lung antioxidant profiles, plasma ascorbate concentrations, airway morphology, and airway reactivity were evaluated at 24 hours and 7 days after chlorine exposure. At 24 hours after exposure, chlorine-exposed rats had significantly lower pulmonary ascorbate and reduced glutathione concentrations. Treatment with antioxidants restored depleted ascorbate in lungs and plasma. At 7 days after exposure, in chlorine-exposed, vehicle-treated rats, the thickness of the proximal airways was 60% greater than in control rats, with twice the amount of mucosubstances. Airway resistance in response to methacholine challenge was also significantly elevated. Combined treatment with intravenous and aerosolized antioxidants restored airway morphology, the amount of airway mucosubstances, and airway reactivity to control levels by 7 days after chlorine exposure. Our results demonstrate for the first time, to the best of our knowledge, that severe injury to major airways in rats exposed to chlorine, as characterized by epithelial hyperplasia, mucus accumulation, and airway hyperreactivity, can be reversed in a safe and efficacious manner by the post-exposure administration of ascorbate and deferoxamine. PMID:22162906

Prevalence and antibiotic resistance of Salmonella Enteritidis and Salmonella Typhimurium in raw chicken meat at retail markets in Malaysia.

PubMed

Thung, T Y; Mahyudin, N A; Basri, D F; Wan Mohamed Radzi, C W J; Nakaguchi, Y; Nishibuchi, M; Radu, S

2016-08-01

Salmonellosis is one of the major food-borne diseases in many countries. This study was carried out to determine the occurrence of Salmonella spp., Salmonella Enteritidis, and Salmonella Typhimurium in raw chicken meat from wet markets and hypermarkets in Selangor, as well as to determine the antibiotic susceptibility profile of S. Enteritidis and S. Typhimurium. The most probable number (MPN) in combination with multiplex polymerase chain reaction (mPCR) method was used to quantify the Salmonella spp., S. Enteritidis, and S. Typhimurium in the samples. The occurrence of Salmonella spp., S. Enteritidis, and S. Typhimurium in 120 chicken meat samples were 20.80%, 6.70%, and 2.50%, respectively with estimated quantity varying from <3 to 15 MPN/g. The antibiogram testing revealed differential multi-drug resistance among S. Enteritidis and S. Typhimurium isolates. All the isolates were resistance to erythromycin, penicillin, and vancomycin whereas sensitivity was recorded for Amoxicillin/Clavulanic acid, Gentamicin, Tetracycline, and Trimethoprim. Our findings demonstrated that the retail chicken meat could be a source of multiple antimicrobial-resistance Salmonella and may constitute a public health concern in Malaysia. © 2016 Poultry Science Association Inc.

Identification of genes differentially regulated by vitamin D deficiency that alter lung pathophysiology and inflammation in allergic airways disease.

PubMed

Foong, Rachel E; Bosco, Anthony; Troy, Niamh M; Gorman, Shelley; Hart, Prue H; Kicic, Anthony; Zosky, Graeme R

2016-09-01

Vitamin D deficiency is associated with asthma risk. Vitamin D deficiency may enhance the inflammatory response, and we have previously shown that airway remodeling and airway hyperresponsiveness is increased in vitamin D-deficient mice. In this study, we hypothesize that vitamin D deficiency would exacerbate house dust mite (HDM)-induced inflammation and alterations in lung structure and function. A BALB/c mouse model of vitamin D deficiency was established by dietary manipulation. Responsiveness to methacholine, airway smooth muscle (ASM) mass, mucus cell metaplasia, lung and airway inflammation, and cytokines in bronchoalveolar lavage (BAL) fluid were assessed. Gene expression patterns in mouse lung samples were profiled by RNA-Seq. HDM exposure increased inflammation and inflammatory cytokines in BAL, baseline airway resistance, tissue elastance, and ASM mass. Vitamin D deficiency enhanced the HDM-induced influx of lymphocytes into BAL, ameliorated the HDM-induced increase in ASM mass, and protected against the HDM-induced increase in baseline airway resistance. RNA-Seq identified nine genes that were differentially regulated by vitamin D deficiency in the lungs of HDM-treated mice. Immunohistochemical staining confirmed that protein expression of midline 1 (MID1) and adrenomedullin was differentially regulated such that they promoted inflammation, while hypoxia-inducible lipid droplet-associated, which is associated with ASM remodeling, was downregulated. Protein expression studies in human bronchial epithelial cells also showed that addition of vitamin D decreased MID1 expression. Differential regulation of these genes by vitamin D deficiency could determine lung inflammation and pathophysiology and suggest that the effect of vitamin D deficiency on HDM-induced allergic airways disease is complex. Copyright © 2016 the American Physiological Society.

Small airway obstruction in COPD: new insights based on micro-CT imaging and MRI imaging.

PubMed

Hogg, James C; McDonough, John E; Suzuki, Masaru

2013-05-01

The increase in total cross-sectional area in the distal airways of the human lung enhances the mixing of each tidal breath with end-expiratory gas volume by slowing bulk flow and increasing gas diffusion. However, this transition also favors the deposition of airborne particulates in this region because they diffuse 600 times slower than gases. Furthermore, the persistent deposition of toxic airborne particulates stimulates a chronic inflammatory immune cell infiltration and tissue repair and remodeling process that increases the resistance in airways <2 mm in diameter four to 40-fold in COPD. This increase was originally attributed to lumen narrowing because it increases resistance in proportion to the change in lumen radius raised to the fourth power. In contrast, removal of one-half the number of tubes arranged in parallel is required to double their resistance, and approximately 90% need to be removed to explain the increase in resistance measured in COPD. However, recent reexamination of this problem based on micro-CT imaging indicates that terminal bronchioles are both narrowed and reduced to 10% of the control values in the centrilobular and 25% in the panlobular emphysematous phenotype of very severe (GOLD [Global Initiative for Chronic Obstructive Lung Disease] grade IV) COPD. These new data indicate that both narrowing and reduction in numbers of terminal bronchioles contribute to the rapid decline in FEV₁ that leads to severe airway obstruction in COPD. Moreover, the observation that terminal bronchiolar loss precedes the onset of emphysematous destruction suggests this destruction begins in the very early stages of COPD.

Relapsing polychondritis and airway involvement.

PubMed

Ernst, Armin; Rafeq, Samaan; Boiselle, Phillip; Sung, Arthur; Reddy, Chakravarthy; Michaud, Gaetane; Majid, Adnan; Herth, Felix J F; Trentham, David

2009-04-01

To assess the prevalence and characteristics of airway involvement in relapsing polychondritis (RP). Retrospective chart review and data analysis of RP patients seen in the Rheumatology Clinic and the Complex Airway Center at Beth Israel Deaconess Medical Center from January 2004 through February 2008. RP was diagnosed in 145 patients. Thirty-one patients had airway involvement, a prevalence of 21%. Twenty-two patients were women (70%), and they were between 11 and 61 years of age (median age, 42 years) at the time of first symptoms. Airway symptoms were the first manifestation of disease in 17 patients (54%). Dyspnea was the most common symptom in 20 patients (64%), followed by cough, stridor, and hoarseness. Airway problems included the following: subglottic stenosis (n = 8; 26%); focal and diffuse malacia (n = 15; 48%); and focal stenosis in different areas of the bronchial tree in the rest of the patients. Twelve patients (40%) required and underwent intervention including balloon dilatation, stent placement, tracheotomy, or a combination of the above with good success. The majority of patients experienced improvement in airway symptoms after intervention. One patient died during the follow-up period from the progression of airway disease. The rest of the patients continue to undergo periodic evaluation and intervention. In this largest cohort described in the English language literature, we found symptomatic airway involvement in RP to be common and at times severe. The nature of airway problems is diverse, with tracheomalacia being the most common. Airway intervention is frequently required and in experienced hands results in symptom improvement.

Airway recovery after face transplantation.

PubMed

Fischer, Sebastian; Wallins, Joe S; Bueno, Ericka M; Kueckelhaus, Maximilian; Chandawarkar, Akash; Diaz-Siso, J Rodrigo; Larson, Allison; Murphy, George F; Annino, Donald J; Caterson, Edward J; Pomahac, Bohdan

2014-12-01

Severe facial injuries can compromise the upper airway by reducing airway volume, obstructing or obliterating the nasal passage, and interfering with oral airflow. Besides the significant impact on quality of life, upper airway impairments can have life-threatening or life-altering consequences. The authors evaluated improvements in functional airway after face transplantation. Between 2009 and 2011, four patients underwent face transplantation at the authors' institution, the Brigham and Women's Hospital. Patients were examined preoperatively and postoperatively and their records reviewed for upper airway infections and sleeping disorders. The nasal mucosa was biopsied after face transplantation and analyzed using scanning electron microscopy. Volumetric imaging software was used to evaluate computed tomographic scans of the upper airway and assess airway volume changes before and after transplantation. Before transplantation, two patients presented an exposed naked nasal cavity and two suffered from occlusion of the nasal passage. Two patients required tracheostomy tubes and one had a prosthetic nose. Sleeping disorders were seen in three patients, and chronic cough was diagnosed in one. After transplantation, there was no significant improvement in sleeping disorders. The incidence of sinusitis increased because of mechanical interference of the donor septum and disappeared after surgical correction. All patients were decannulated after transplantation and were capable of nose breathing. Scanning electron micrographs of the respiratory mucosa revealed viable tissue capable of mucin production. Airway volume significantly increased in all patients. Face transplantation successfully restored the upper airway in four patients. Unhindered nasal breathing, viable respiratory mucosa, and a significant increase in airway volume contributed to tracheostomy decannulation.

Nicotine impairs cyclooxygenase-2-dependent kinin-receptor-mediated murine airway relaxations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yuan, E-mail: yuan.xu@ki.se; Cardell, Lars-Olaf

Introduction: Cigarette smoke induces local inflammation and airway hyperreactivity. In asthmatics, it worsens the symptoms and increases the risk for exacerbation. The present study investigates the effects of nicotine on airway relaxations in isolated murine tracheal segments. Methods: Segments were cultured for 24 h in the presence of vehicle, nicotine (10 μM) and/or dexamethasone (1 μM). Airway relaxations were assessed in myographs after pre-contraction with carbachol (1 μM). Kinin receptors, cyclooxygenase (COX) and inflammatory mediator expressions were assessed by real-time PCR and confocal-microscopy-based immunohistochemistry. Results: The organ culture procedure markedly increased bradykinin- (selective B{sub 2} receptor agonist) and des-Arg{sup 9}-bradykinin-more » (selective B{sub 1} receptor agonist) induced relaxations, and slightly increased relaxation induced by isoprenaline, but not that induced by PGE{sub 2}. The kinin receptor mediated relaxations were epithelium-, COX-2- and EP2-receptor-dependent and accompanied by drastically enhanced mRNA levels of kinin receptors, as well as inflammatory mediators MCP-1 and iNOS. Increase in COX-2 and mPGES-1 was verified both at mRNA and protein levels. Nicotine selectively suppressed the organ-culture-enhanced relaxations induced by des-Arg{sup 9}-bradykinin and bradykinin, at the same time reducing mPGES-1 mRNA and protein expressions. α7-nicotinic acetylcholine receptor inhibitors α-bungarotoxin and MG624 both blocked the nicotine effects on kinin B{sub 2} receptors, but not those on B{sub 1}. Dexamethasone completely abolished kinin-induced relaxations. Conclusion: It is tempting to conclude that a local inflammatory process per se could have a bronchoprotective component by increasing COX-2 mediated airway relaxations and that nicotine could impede this safety mechanism. Dexamethasone further reduced airway inflammation together with relaxations. This might contribute to the steroid resistance

Effect of thromboxane antagonists on ozone-induced airway responses in dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, G.L.; Lane, C.G.; O'Byrne, P.M.

1990-09-01

Airway hyperresponsiveness after inhaled ozone in dogs may occur as a result of thromboxane release in the airway. In this study, two thromboxane receptor antagonists, L-655,240 and L-670,596, were used in doses that inhibit the response to an inhaled thromboxane mimetic, U-46619, to determine further the role of thromboxane in ozone-induced airway hyperresponsiveness. Dogs were studied on 2 days separated by 1 wk. On each day, the dogs inhaled ozone (3 ppm) for 30 min. On one randomly assigned day, 10 dogs received an infusion of L-655,240 (5 mg.kg-1.h-1) and 5 dogs received an infusion of L-670,596 (1 mg.kg-1.h-1); onmore » the other day dogs received a control infusion. Airway responses to doubling doses of acetylcholine were measured before and after inhalation of ozone and were expressed as the concentration of acetylcholine giving a rise in resistance of 5 cmH2O.l-1.s from baseline (acetylcholine provocation concentration). The development of airway hyperresponsiveness after ozone was not inhibited by the thromboxane antagonists. The mean log difference in the acetylcholine provocative concentration before and after ozone on the L-655,240 treatment day was 0.62 +/- 0.12 (SE) and on the control day was 0.71 +/- 0.12 (P = 0.48); on the L-670,596 treatment day the mean log difference was 0.68 +/- 0.15 (SE) and on the control day it was 0.75 +/- 0.19 (P = 0.45). These results do not support an important role for thromboxane in causing ozone-induced airway hyperresponsiveness.« less

[Quality assurance in airway management: education and training for difficult airway management].

PubMed

Kaminoh, Yoshiroh

2006-01-01

Respiratory problem is one of the main causes of death or severe brain damage in perioperative period. Three major factors of respiratory problem are esophageal intubation, inadequate ventilation, and difficult airway. The wide spread of pulse oximeter and capnograph reduced the incidences of esophageal intubation and inadequate ventilation, but the difficult airway still occupies the large portion in the causes of adverse events during anesthesia. "Practice guideline for management of the difficult airway" was proposed by American Society of Anesthesiologists (ASA) in 1992 and 2002. Improvement of knowledge, technical skills, and cognitive skills are necessary for the education and training of the difficult airway management. "The practical seminar of difficult airway management (DAM practical seminar)" has been cosponsored by the Japanese Association of Medical Simulation (JAMS) in the 51 st and 52 nd annual meetings of Japanese Society of Anesthesiologists and the 24th annual meeting of Japanese Society for Clinical Anesthesia. The DAM practical seminar is composed of the lecture session for ASA difficult airway algorithm, the hands-on training session for technical skills, and the scenario-based training session for cognitive skills. Ninty six Japanese anesthesiologists have completed the DAM practical seminar in one year. "The DAM instructor course" should be immediately prepared to organize the seminar more frequently.

Sphingosine-1-phosphate induces pro-remodelling response in airway smooth muscle cells

PubMed Central

Fuerst, E; Foster, H R; Ward, J P T; Corrigan, C J; Cousins, D J; Woszczek, G

2014-01-01

Background Increased proliferation of airway smooth muscle (ASM) cells leading to hyperplasia and increased ASM mass is one of the most characteristic features of airway remodelling in asthma. A bioactive lipid, sphingosine-1-phosphate (S1P), has been suggested to affect airway remodelling by stimulation of human ASM cell proliferation. Objective To investigate the effect of S1P on signalling and regulation of gene expression in ASM cells from healthy and asthmatic individuals. Methods Airway smooth muscle cells grown from bronchial biopsies of healthy and asthmatic individuals were exposed to S1P. Gene expression was analysed using microarray, real-time PCR and Western blotting. Receptor signalling and function were determined by mRNA knockdown and intracellular calcium mobilization experiments. Results S1P potently regulated the expression of more than 80 genes in human ASM cells, including several genes known to be involved in the regulation of cell proliferation and airway remodelling (HBEGF, TGFB3, TXNIP, PLAUR, SERPINE1, RGS4). S1P acting through S1P2 and S1P3 receptors activated intracellular calcium mobilization and extracellular signal-regulated and Rho-associated kinases to regulate gene expression. S1P-induced responses were not inhibited by corticosteroids and did not differ significantly between ASM cells from healthy and asthmatic individuals. Conclusion S1P induces a steroid-resistant, pro-remodelling pathway in ASM cells. Targeting S1P or its receptors could be a novel treatment strategy for inhibiting airway remodelling in asthma. PMID:25041788

Airway malacia in children with achondroplasia.

PubMed

Dessoffy, Kimberly E; Modaff, Peggy; Pauli, Richard M

2014-02-01

This study was undertaken to assess the frequency of airway malacia in infants and young children with achondroplasia, a population well known to be at risk for a variety of respiratory problems. We also wished to evaluate what, if any, contribution airway malacia makes to the complex respiratory issues that may be present in those with achondroplasia. Retrospective chart review of all infants and young children with achondroplasia who were assessed through the Midwest Regional Bone Dysplasia Clinics from 1985 through 2012 (n = 236) was completed. Records of comprehensive clinical examinations, polysomnographic assessments, and airway visualization were reviewed and abstracted using a data collection form. Analyses were completed comparing the group with and those without evidence for airway malacia. Thirteen of 236 patients (5.5%) were found to have airway malacia. Most of those affected had lower airway involvement (9/13). The presence of airway malacia was correlated with an increased occurrence of obstructive sleep apnea as well as need for oxygen supplementation, airway surgeries and tracheostomy placement. Although estimates of the frequency of airway malacia in the general population are limited, its frequency in children with achondroplasia appears to be much higher than any published general population estimate. The presence of airway malacia appears to confound other breathing abnormalities in this population and results in the need for more invasive airway treatments. © 2013 Wiley Periodicals, Inc.

Extraglottic airway devices: technology update.

PubMed

Sharma, Bimla; Sahai, Chand; Sood, Jayashree

2017-01-01

Extraglottic airway devices (EADs) have revolutionized the field of airway management. The invention of the laryngeal mask airway was a game changer, and since then, there have been several innovations to improve the EADs in design, functionality, safety and construction material. These have ranged from changes in the shape of the mask, number of cuffs and material used, like rubber, polyvinylchloride and latex. Phthalates, which were added to the construction material in order to increase device flexibility, were later omitted when this chemical was found to have serious adverse reproductive outcomes. The various designs brought out by numerous companies manufacturing EADs resulted in the addition of several devices to the airway market. These airway devices were put to use, many of them with inadequate or no evidence base regarding their efficacy and safety. To reduce the possibility of compromising the safety of the patient, the Difficult Airway Society (DAS) formed the Airway Device Evaluation Project Team (ADEPT) to strengthen the evidence base for airway equipment and vet the new extraglottic devices. A preuse careful analysis of the design and structure may help in better understanding of the functionality of a particular device. In the meantime, the search for the ideal EAD continues.

Airway Protective Mechanisms

PubMed Central

Pitts, Teresa

2014-01-01

Cough and swallow are highly coordinated reflex behaviors whose common purpose is to protect the airway. The pharynx is the common tube for air and food/liquid movement from the mouth into the thorax, has been largely overlooked, and is potentially seen as just a passive space. The thyropharyngeus muscle responds to cough inducing stimuli to prepare a transient holding area for material that has been removed from the subglottic airway. The cricopharyngeus muscle participates with the larynx to ensure regulation of pressure when a bolus/air is moving from the upper airway through to the thorax (i.e inspiration or swallow) or the reverse (i.e expiration reflex or vomiting).These vital mechanisms have not been evaluated in clinical conditions, but could be impaired in many neurodegenerative diseases leading to aspiration pneumonia. These newly described airway protective mechanisms need further study, especially in healthy and pathologic human populations. PMID:24297325

Definitive airway management after pre-hospital supraglottic airway insertion: Outcomes and a management algorithm for trauma patients.

PubMed

Hernandez, Matthew C; Aho, Johnathon M; Zielinski, Martin D; Zietlow, Scott P; Kim, Brian D; Morris, David S

2018-01-01

Prehospital airway management increasingly involves supraglottic airway insertion and a paucity of data evaluates outcomes in trauma populations. We aim to describe definitive airway management in traumatically injured patients who necessitated prehospital supraglottic airway insertion. We performed a single institution retrospective review of multisystem injured patients (≥15years) that received prehospital supraglottic airway insertion during 2009 to 2016. Baseline demographics, number and type of: supraglottic airway insertion attempts, definitive airway and complications were recorded. Primary outcome was need for tracheostomy. Univariate and multivariable statistics were performed. 56 patients met inclusion criteria and were reviewed, 78% were male. Median age [IQR] was 36 [24-56] years. Injuries comprised blunt (94%), penetrating (4%) and burns (2%). Median ISS was 26 [22-41]. Median number of prehospital endotracheal intubation (PETI) attempts was 2 [1-3]. Definitive airway management included: (n=20, 36%, tracheostomy), (n=10, 18%, direct laryngoscopy), (n=6, 11%, bougie), (n=9, 15%, Glidescope), (n=11, 20%, bronchoscopic assistance). 24-hour mortality was 41%. Increasing number of PETI was associated with increasing facial injury. On regression, increasing cervical and facial injury patterns as well as number of PETI were associated with definitive airway control via surgical tracheostomy. After supraglottic airway insertion, operative or non-operative approaches can be utilized to obtain a definitive airway. Patients with increased craniofacial injuries have an increased risk for airway complications and need for tracheostomy. We used these factors to generate an evidence based algorithm that requires prospective validation. Level IV - Retrospective study. Retrospective single institution study. Copyright © 2017 Elsevier Inc. All rights reserved.

Airway compliance and dynamics explain the apparent discrepancy in length adaptation between intact airways and smooth muscle strips.

PubMed

Dowie, Jackson; Ansell, Thomas K; Noble, Peter B; Donovan, Graham M

2016-01-01

Length adaptation is a phenomenon observed in airway smooth muscle (ASM) wherein over time there is a shift in the length-tension curve. There is potential for length adaptation to play an important role in airway constriction and airway hyper-responsiveness in asthma. Recent results by Ansell et al., 2015 (JAP 2014 10.1152/japplphysiol.00724.2014) have cast doubt on this role by testing for length adaptation using an intact airway preparation, rather than strips of ASM. Using this technique they found no evidence for length adaptation in intact airways. Here we attempt to resolve this apparent discrepancy by constructing a minimal mathematical model of the intact airway, including ASM which follows the classic length-tension curve and undergoes length adaptation. This allows us to show that (1) no evidence of length adaptation should be expected in large, cartilaginous, intact airways; (2) even in highly compliant peripheral airways, or at more compliant regions of the pressure-volume curve of large airways, the effect of length adaptation would be modest and at best marginally detectable in intact airways; (3) the key parameters which control the appearance of length adaptation in intact airways are airway compliance and the relaxation timescale. The results of this mathematical simulation suggest that length adaptation observed at the level of the isolated ASM may not clearly manifest in the normal intact airway. Copyright © 2015 Elsevier B.V. All rights reserved.

Progesterone attenuates airway remodeling and glucocorticoid resistance in a murine model of exposing to ozone.

PubMed

Zhang, Xue; Bao, Wuping; Fei, Xia; Zhang, Yingying; Zhang, Guoqing; Zhou, Xin; Zhang, Min

2018-04-01

Airway remodeling is a vital component of chronic obstructive pulmonary disease (COPD). Despite the broad anti-inflammation effects of glucocorticoids, they exhibit relatively little therapeutic benefit in COPD, indicating the accelerating demands of new agents for COPD. We aim to explore the effect of progesterone on airway remodeling in a murine modeling of exposing to ozone and to further examine the potential effect of progesterone on glucocorticoid insensitivity. C57/BL6 mice were exposed to ozone for 12 times over 6 weeks, and were administered with progesterone alone or combined with budesonide (BUD) after each exposure until the 10th week. The peribronchial collagen deposition was measured. The protein levels of MMP8 and MMP9 in bronchoalveolar lavage fluid (BALF) and lungs were assessed. Western blot analysis was used to detect the levels of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), a-smooth muscle actin (α-SMA), glycogen synthase kinase-3β (GSK-3β). The expression of VEGF and histone deacetylase 2 (HDAC2) in the lung were determined by Immunohistochemical analyses. We observe that progesterone attenuates the peribronchial collagen deposition, as well as the expression of MMP8, MMP9, HIF-1α, VEGF, α-SMA, and GSK-3β in BALF or lung tissues. Progesterone or BUD monotherapy has no effect on HDAC2 production. Progesterone combines with BUD induce dramatically enhanced effects. Thus, these results demonstrate novel roles of progesterone for the pathogenesis and airway remodeling in COPD. Progesterone plus BUD administration exerts more significant inhibition on airway remodeling with dose-independent. Additionally, progesterone may, to some extent, improve the glucocorticoid insensitivity. Copyright © 2018. Published by Elsevier Ltd.

Investigation of mucus transport in an idealized lung airway model using multiphase CFD analysis

NASA Astrophysics Data System (ADS)

Rajendran, Rahul; Banerjee, Arindam

2015-11-01

Mucus, a Bingham fluid is transported in the pulmonary airways by consistent beating of the cilia and exhibits a wide range of physical properties in response to the core air flow and various pathological conditions. A better understanding of the interfacial instability is required as it plays a crucial role in gas transport, mixing, mucus clearance and drug delivery. In the current study, mucus is modelled as a Newtonian fluid and the two phase gas-liquid flow in the airways is investigated using an inhomogeneous Eulerian-Eulerian approach. The complex interface between the phases is tracked using the conventional VOF (Volume of Fluid) method. Results from our CFD simulations which are performed in idealized single and double bifurcation geometries will be presented and the influence of airflow rate, mucus layer thickness, mucus viscosity, airway geometry (branching & diameter) and surface tension on mucus flow behavior will be discussed. Mean mucus layer thickness, pressure drop due to momentum transfer & increased airway resistance, mucus transport speed and the flow morphology will be compared to existing experimental and theoretical data.

Listeria monocytogenes Prevalence and Characteristics in Retail Raw Foods in China

PubMed Central

Wu, Shi; Wu, Qingping; Zhang, Jumei; Chen, Moutong; Yan, Ze′an; Hu, Huijuan

2015-01-01

The prevalence and levels of Listeria monocytogenes in retail raw foods covering most provincial capitals in China were studied with testing of 1036 samples of vegetables, edible mushrooms, raw meat, aquatic products and quick-frozen products from September 2012 to January 2014. The total prevalence of Listeria monocytogenes was 20.0% (207/1036), and the most probable number (MPN) values of 65.7% of the positive samples ranged from 0.3 to 110 MPN/g. Geographical differences were observed in this survey, and the results of both qualitative and quantitative methods indicated that the levels in the samples from North China were higher than those in the samples from South China. A total of 248 isolates were analyzed, of which approximately half belonged to molecular serogroup 1/2a-3a (45.2%), followed by 1/2b-3b-7 (30.6%), 1/2c-3c (16.1%), 4b-4d-4e (5.2%) and 4a-4c (2.8%). Most of the isolates carried hly (100%), inlB (98.8%), inlA (99.6%), inlC (98.0%) and inlJ (99.2%), and 44.8% of the isolates were llsX-positive. Seventeen epidemic clones (ECs) were detected, with 7 strains belonging to ECI (2.8%) and 10 belonging to ECIII (4.03%). Resistance to clindamycin (46.8%) was commonly observed, and 59 strains (23.8%) were susceptible to all 14 tested antibiotics, whereas 84 (33.9%) showed an intermediate level of resistance or were resistant to two or more antibiotics, including 7 multi-resistant strains that exhibited resistance to more than 10 antibiotics. The data obtained in the present study provides useful information for assessment of the possible risk posed to Chinese consumers, and this information will have a significant public health impact in China. Furthermore, the presence of virulence markers, epidemic clones, as well as the antibiotic resistance amongst the isolates strongly implies that many of these strains might be capable of causing listeriosis, and more accurate treatment of human listeriosis with effective antibiotics should be considered. This

A computational study of the respiratory airflow characteristics in normal and obstructed human airways.

PubMed

Sul, Bora; Wallqvist, Anders; Morris, Michael J; Reifman, Jaques; Rakesh, Vineet

2014-09-01

Obstructive lung diseases in the lower airways are a leading health concern worldwide. To improve our understanding of the pathophysiology of lower airways, we studied airflow characteristics in the lung between the 8th and the 14th generations using a three-dimensional computational fluid dynamics model, where we compared normal and obstructed airways for a range of breathing conditions. We employed a novel technique based on computing the Pearson׳s correlation coefficient to quantitatively characterize the differences in airflow patterns between the normal and obstructed airways. We found that the airflow patterns demonstrated clear differences between normal and diseased conditions for high expiratory flow rates (>2300ml/s), but not for inspiratory flow rates. Moreover, airflow patterns subjected to filtering demonstrated higher sensitivity than airway resistance for differentiating normal and diseased conditions. Further, we showed that wall shear stresses were not only dependent on breathing rates, but also on the distribution of the obstructed sites in the lung: for the same degree of obstruction and breathing rate, we observed as much as two-fold differences in shear stresses. In contrast to previous studies that suggest increased wall shear stress due to obstructions as a possible damage mechanism for small airways, our model demonstrated that for flow rates corresponding to heavy activities, the wall shear stress in both normal and obstructed airways was <0.3Pa, which is within the physiological limit needed to promote respiratory defense mechanisms. In summary, our model enables the study of airflow characteristics that may be impractical to assess experimentally. Published by Elsevier Ltd.

Microbial loads and antibiotic resistance patterns of Staphylococcus aureus in different types of raw poultry-based meat preparations.

PubMed

Buzón-Durán, Laura; Capita, Rosa; Alonso-Calleja, Carlos

2017-09-01

The hygiene status of raw chicken-meat preparations from retail outlets in North-Western Spain was investigated. Microbial counts (aerobic plate counts (APCs), psychrotrophs, Enterobacteriaceae, fecal coliforms, enterococci, pseudomonads, fluorescent pseudomonads, yeasts and molds, and Staphylococcus aureus) were determined for minced meat, hamburgers, nuggets, white sausages, red sausages, escalope, and roll-ups. S. aureus isolates were tested for susceptibility to twenty antimicrobials of veterinary and human clinical significance (disc diffusion method, CLSI). Average microbial loads (log10 cfu/g) ranged from 2.63 ± 0.80 (enterococci) to 6.66 ± 1.09 (psychrotrophs). Average APCs (6.44 ± 1.16 log10 cfu/g) were regarded as acceptable according to EU microbiological criteria. The type of product had an influence (P < 0.05) on microbial loads, samples of escalope showing the highest counts for most microbial groups. Two-thirds (66.7%) of the samples tested harbored S. aureus. All the S. aureus isolates were multi-resistant (to between three and fifteen antibiotics). The greatest prevalence of resistance was shown for ampicillin, oxacillin, penicillin G, ceftazidime, and nalidixic acid. The results of this study show that poultry-based meat preparations present high microbial loads and are a major reservoir of antibiotic-resistant S. aureus strains. This highlights the need for correct handling of such foodstuffs with a view to reducing risks to consumers. © 2017 Poultry Science Association Inc.

Critical Airway Team: A Retrospective Study of an Airway Response System in a Pediatric Hospital.

PubMed

Sterrett, Emily C; Myer, Charles M; Oehler, Jennifer; Das, Bobby; Kerrey, Benjamin T

2017-12-01

Objective Study the performance of a pediatric critical airway response team. Study Design Case series with chart review. Setting Freestanding academic children's hospital. Subjects and Methods A structured review of the electronic medical record was conducted for all activations of the critical airway team. Characteristics of the activations and patients are reported using descriptive statistics. Activation of the critical airway team occurred 196 times in 46 months (March 2012 to December 2015); complete data were available for 162 activations (83%). For 49 activations (30%), patients had diagnoses associated with difficult intubation; 45 (28%) had a history of difficult laryngoscopy. Results Activation occurred at least 4 times per month on average (vs 3 per month for hospital-wide codes). The most common reasons for team activation were anticipated difficult intubation (45%) or failed intubation attempt (20%). For 79% of activations, the team performed an airway procedure, most commonly direct laryngoscopy and tracheal intubation. Bronchoscopy was performed in 47% of activations. Surgical airway rescue was attempted 4 times. Cardiopulmonary resuscitation occurred in 41 activations (25%). Twenty-nine patients died during or following team activation (18%), including 10 deaths associated with the critical airway event. Conclusion Critical airway team activation occurred at least once per week on average. Direct laryngoscopy, tracheal intubation, and bronchoscopic procedures were performed frequently; surgical airway rescue was rare. Most patients had existing risk factors for difficult intubation. Given our rate of serious morbidity and mortality, primary prevention of critical airway events will be a focus of future efforts.

A 4-Week Model of House Dust Mite (HDM) Induced Allergic Airways Inflammation with Airway Remodeling.

PubMed

Woo, L N; Guo, W Y; Wang, X; Young, A; Salehi, S; Hin, A; Zhang, Y; Scott, J A; Chow, C W

2018-05-02

Animal models of allergic airways inflammation are useful tools in studying the pathogenesis of asthma and potential therapeutic interventions. The different allergic airways inflammation models available to date employ varying doses, frequency, duration and types of allergen, which lead to the development of different features of asthma; showing varying degrees of airways inflammation and hyper-responsiveness (AHR) and airways remodeling. Models that also exhibit airway remodeling, a key feature of asthma, in addition to AHR and airway inflammation typically require 5-12 weeks to develop. In this report, we describe a 4-week mouse model of house dust mite (HDM)-induced allergic airways inflammation, and compare the phenotypic features of two different doses of HDM exposures (10 µg and 25 µg) for 5 days/week with a well-characterized 8-week chronic HDM model. We found that 4 weeks of intranasal HDM (25 µg in 35 µl saline; 5 days/week) resulted in AHR, airway inflammation and airway remodeling that were comparable to the 8-week model. We conclude that this new 4-week HDM model is another useful tool in studies of human asthma that offers advantages of shorter duration for development and decreased costs when compared to other models that require longer durations of exposure (5-12 weeks) to develop.

Operative endoscopy of the airway

PubMed Central

Walters, Dustin M.

2016-01-01

Airway endoscopy has long been an important and useful tool in the management of thoracic diseases. As thoracic specialists have gained experience with both flexible and rigid bronchoscopic techniques, the technology has continued to evolve so that bronchoscopy is currently the foundation for diagnosis and treatment of many thoracic ailments. Airway endoscopy plays a significant role in the biopsy of tumors within the airways, mediastinum, and lung parenchyma. Endoscopic methods have been developed to treat benign and malignant airway stenoses and tracheomalacia. And more recently, techniques have been conceived to treat end-stage emphysema and prolonged air leaks in select patients. This review describes the abundant uses of airway endoscopy, as well as technical considerations and limitations of the current technologies. PMID:26981263

The effects of IL-5 on airway physiology and inflammation in rats.

PubMed

Nag, Sammy S; Xu, Li Jing; Hamid, Qutayba; Renzi, Paolo M

2003-03-01

There is evidence that the cytokine IL-5 is a prominent feature of airway inflammation in asthma. The aim of this study was to determine whether exogenous IL-5 could cause changes in lung physiology, the early and late airway response after antigen challenge, and airway inflammation in rats that do not have a propensity to develop these changes after sensitization and challenge. Intratracheal administration of IL-5 to ovalbumin sensitized Brown Norway SSN rats increased the airway responsiveness to methacholine (AHR) 20 hours after administration of IL-5 at the same time as an increase in neutrophils occurred in the lung lavage. This effect was dose dependent and was not caused by endotoxin. Concurrent intratracheal administration of 50 ng of anti-IL-5 monoclonal antibody with 10 microg of recombinant human IL-5 decreased the AHR and neutrophil influx. Pretreatment with 3 microg of IL-5 had no effect on the early and late airway response or on AHR after ovalbumin challenge. However, IL-5 increased lung re-sistance 20 hours after antigen challenge. Although total lung cells and differential counts did not differ significantly 8 hours after antigen challenge, the blood lymphocyte CD4/CD8 ratio decreased in IL-5 pretreated rats (P <.05). In addition, in situ hybridization showed a significant increase in cells within the airway wall expressing IL-4 and IL-5 mRNA in IL-5 treated/challenged rats compared to controls (P <.05). The intratracheal administration of IL-5 causes only part of the physiologic changes that are associated with asthma. Other factors are necessary to obtain the complete asthma phenotype.

Respiratory gas conditioning in infants with an artificial airway.

PubMed

Schulze, Andreas

2002-10-01

There is a strong physiological rationale for delivering the inspiratory gas at or close to core body temperature and saturated with water vapour to infants with an artificial airway undergoing long-term mechanical ventilatory assistance. Cascade humidifiers with heated wire ventilatory circuitry may achieve this goal safely. Whenever saturated air leaves the humidifier chamber at 37 degrees C and condensate accumulates in the circuit, the gas loses humidity and acquires the potential to dry airway secretions near the tip of the endotracheal tube. Heat and moisture exchangers and hygroscopic condenser humidifiers with or without bacterial filters have become available for neonates. They can provide sufficient moisture output for short-term ventilation without excessive additional dead space or flow-resistive load for term infants. Their safety and efficacy for very low birthweight infants and for long-term mechanical ventilation has not been established conclusively. A broader application of these inexpensive and simple devices is likely to occur with further design improvements. When heated humidifiers are appropriately applied, water or normal saline aerosol application offers no additional significant advantage in terms of inspiratory gas conditioning and may impose a water overload on the airway or even systemically. Although airway irrigation by periodic bolus instillation of normal saline solution prior to suctioning procedures is widely practised in neonatology, virtually no data exist on its safety and efficacy when used with appropriately humidified inspired gas. There is no evidence that conditioning of inspired gas to core body temperature and full water vapour saturation may promote nosocomial respiratory infections.

Neural control of airway to deep inhalation in rabbits.

PubMed

Schweitzer, Cyril; Demoulin, Bruno; Varechova, Silvia; Poussel, Mathias; Marchal, François

2011-07-31

Bronchodilation induced by a deep inhalation (DI) is usually attributed to the mechanical interdependence between airways and parenchyma. The aim of the study was to evaluate the contribution of neural control of the airway in the response to DI. In mechanically ventilated rabbits, cervical vagi were cooled using 2 Peltier elements. Lung resistance was measured before and up to 2 min after a DI at vagus nerve temperature = 37 °C (R(L37 °C)), 8 °C (R(L8 °C)) and 4 °C (R(L4 °C)). Measurements were performed in control conditions (Ctrl) and during infusion of methacholine (Mch). At Ctrl, R(L8 °C) and R(L4 °C) were significantly lower than R(L37 °C). After Mch, however, R(L4 °C) was not different from R(L37 °C), both being significantly higher than R(L8 °C). Vagal cold block (VCB) abolished the bronchodilation observed after the control DI and reduced its magnitude after Mch. The magnitude of bronchodilation immediately after the DI was significantly related to baseline R(L) at any vagal temperature (p < 0.001), but the renarrowing was more strongly related to baseline R(L) after VCB than at baseline. The data indicate a significant contribution of respiratory reflexes to the airway response after DI, highlight the influence of vagal control of airway wall visco-elasticity and suggests the occurrence of a moderate reflex bronchodilation in response to Mch. Copyright © 2011 Elsevier B.V. All rights reserved.

Endogenous gamma-aminobutyric acid modulates tonic guinea pig airway tone and propofol-induced airway smooth muscle relaxation.

PubMed

Gallos, George; Gleason, Neil R; Virag, Laszlo; Zhang, Yi; Mizuta, Kentaro; Whittington, Robert A; Emala, Charles W

2009-04-01

Emerging evidence indicates that an endogenous autocrine/paracrine system involving gamma-aminobutyric acid (GABA) is present in airways. GABAA channels, GABAB receptors, and the enzyme that synthesizes GABA have been identified in airway epithelium and smooth muscle. However, the endogenous ligand itself, GABA, has not been measured in airway tissues. The authors sought to demonstrate that GABA is released in response to contractile agonists and tonically contributes a prorelaxant component to contracted airway smooth muscle. The amount and cellular localization of GABA in upper guinea pig airways under resting and contracted tone was determined by high pressure liquid chromatography and immunohistochemistry, respectively. The contribution that endogenous GABA imparts on the maintenance of airway smooth muscle acetylcholine-induced contraction was assessed in intact guinea pig airway tracheal rings using selective GABAA antagonism (gabazine) under resting or acetylcholine-contracted conditions. The ability of an allosteric agent (propofol) to relax a substance P-induced relaxation in an endogenous GABA-dependent manner was assessed. GABA levels increased and localized to airway smooth muscle after contractile stimuli in guinea pig upper airways. Acetylcholine-contracted guinea pig tracheal rings exhibited an increase in contracted force upon addition of the GABAA antagonist gabazine that was subsequently reversed by the addition of the GABAA agonist muscimol. Propofol dose-dependently relaxed a substance P contraction that was blocked by gabazine. These studies demonstrate that GABA is endogenously present and increases after contractile stimuli in guinea pig upper airways and that endogenous GABA contributes a tonic prorelaxant component in the maintenance of airway smooth muscle tone.

Endogenous γ-aminobutyric Acid Modulates Tonic Guinea Pig Airway Tone and Propofol-induced Airway Smooth Muscle Relaxation

PubMed Central

Gallos, George; Gleason, Neil R.; Virag, Laszlo; Zhang, Yi; Mizuta, Kentauro; Whittington, Robert A.; Emala, Charles W.

2009-01-01

Background Emerging evidence indicates that an endogenous autocrine/paracrine system involving γ-aminobutyric acid (GABA) is present in airways. GABAA channels, GABAB receptors and the enzyme that synthesizes GABA have been identified in airway epithelium and smooth muscle. However, the endogenous ligand itself, GABA, has not been measured in airway tissues. We sought to demonstrate that GABA is released in response to contractile agonists and tonically contributes a pro-relaxant component to contracted airway smooth muscle. Methods The amount and cellular localization of GABA in upper guinea pig airways under resting and contracted tone was determined by high pressure liquid chromatography and immunohistochemistry, respectively. The contribution that endogenous GABA imparts on the maintenance of airway smooth muscle acetylcholine-induced contraction was assessed in intact guinea pig airway tracheal rings using selective GABAA antagonism (gabazine) under resting or acetylcholine-contracted conditions. The ability of an allosteric agent (propofol) to relax a substance P-induced relaxation in an endogenous GABA-dependent manner was assessed. Results GABA levels increased and localized to airway smooth muscle following contractile stimuli in guinea pig upper airways. Acetylcholine-contracted guinea pig tracheal rings exhibited an increase in contracted force upon addition of the GABAA antagonist gabazine which was subsequently reversed by the addition of the GABAA agonist muscimol. Propofol dose-dependently relaxed a substance P contraction that was blocked by gabazine. Conclusion These studies demonstrate that GABA is endogenously present and increases following contractile stimuli in guinea pig upper airways and that endogenous GABA contributes a tonic pro-relaxant component in the maintenance of airway smooth muscle tone. PMID:19322939

Neurokinin-1 receptor mediates stress-exacerbated allergic airway inflammation and airway hyperresponsiveness in mice.

PubMed

Joachim, Ricarda A; Sagach, Viktoriya; Quarcoo, David; Dinh, Q Thai; Arck, Petra C; Klapp, Burghard F

2004-01-01

A wealth of clinical observation has suggested that stress and asthma morbidity are associated. We have previously established a mouse model of stress-exacerbated allergic airway inflammation, which reflects major clinical findings. The aim of the current study was to investigate the role of the neurokinin- (NK-)1 receptor in the mediation of stress effects in allergic airway inflammation. BALB/c mice were systemically sensitized with ovalbumin (OVA) on assay days 1, 14, and 21 and repeatedly challenged with OVA aerosol on days 26 and 27. Sound stress was applied to the animals for 24 hours, starting with the first airway challenge. Additionally, one group of stressed and one group of nonstressed mice received the highly specific NK-1 receptor antagonist RP 67580. Bronchoalveolar lavage fluid was obtained, and cell numbers and differentiation were determined. Airway hyperreactivity was measured in vitro by electrical field stimulation of tracheal smooth-muscle elements. Application of stress in sensitized and challenged animals resulted in a significant increase in leukocyte number in the bronchoalveolar lavage fluid. Furthermore, stressed animals showed enhanced airway reactivity. The increase of inflammatory cells and airway reactivity was blocked by treatment of animals with the NK-1 receptor antagonist. These data indicate that the NK-1 receptor plays an important role in mediating stress effects in allergen-induced airway inflammation.

The Human Airway Epithelial Basal Cell Transcriptome

PubMed Central

Wang, Rui; Zwick, Rachel K.; Ferris, Barbara; Witover, Bradley; Salit, Jacqueline; Crystal, Ronald G.

2011-01-01

Background The human airway epithelium consists of 4 major cell types: ciliated, secretory, columnar and basal cells. During natural turnover and in response to injury, the airway basal cells function as stem/progenitor cells for the other airway cell types. The objective of this study is to better understand human airway epithelial basal cell biology by defining the gene expression signature of this cell population. Methodology/Principal Findings Bronchial brushing was used to obtain airway epithelium from healthy nonsmokers. Microarrays were used to assess the transcriptome of basal cells purified from the airway epithelium in comparison to the transcriptome of the differentiated airway epithelium. This analysis identified the “human airway basal cell signature” as 1,161 unique genes with >5-fold higher expression level in basal cells compared to differentiated epithelium. The basal cell signature was suppressed when the basal cells differentiated into a ciliated airway epithelium in vitro. The basal cell signature displayed overlap with genes expressed in basal-like cells from other human tissues and with that of murine airway basal cells. Consistent with self-modulation as well as signaling to other airway cell types, the human airway basal cell signature was characterized by genes encoding extracellular matrix components, growth factors and growth factor receptors, including genes related to the EGF and VEGF pathways. Interestingly, while the basal cell signature overlaps that of basal-like cells of other organs, the human airway basal cell signature has features not previously associated with this cell type, including a unique pattern of genes encoding extracellular matrix components, G protein-coupled receptors, neuroactive ligands and receptors, and ion channels. Conclusion/Significance The human airway epithelial basal cell signature identified in the present study provides novel insights into the molecular phenotype and biology of the stem

Vitamin D deficiency causes airway hyperresponsiveness, increases airway smooth muscle mass, and reduces TGF‐β expression in the lungs of female BALB/c mice

PubMed Central

Foong, Rachel E.; Shaw, Nicole C.; Berry, Luke J.; Hart, Prue H.; Gorman, Shelley; Zosky, Graeme R.

2014-01-01

Abstract Vitamin D deficiency is associated with disease severity in asthma. We tested whether there is a causal association between vitamin D deficiency, airway smooth muscle (ASM) mass, and the development of airway hyperresponsiveness (AHR). A physiologically relevant mouse model of vitamin D deficiency was developed by raising BALB/c mice on vitamin D‐deficient or ‐replete diets. AHR was assessed by measuring lung function responses to increasing doses of inhaled methacholine. Five‐micron sections from formalin‐fixed lungs were used for ASM measurement and assessment of lung structure using stereological methods. Transforming growth factor (TGF)‐β levels were measured in bronchoalveolar lavage fluid (BALF). Lungs were dissected from embryonic day (E) 17.5 vitamin D‐deficient and ‐replete fetal mice for quantification of ASM density and relative gene expression of TGF‐β signaling pathway molecules. Eight‐week‐old adult vitamin D‐deficient female mice had significantly increased airway resistance and ASM in the large airways compared with controls. Vitamin D‐deficient female mice had a smaller lung volume, volume of parenchyma, and alveolar septa. Both vitamin D‐deficient male and female mice had reduced TGF‐β levels in BALF. Vitamin D deficiency did not have an effect on ASM density in E17.5 mice, however, expression of TGF‐β1 and TGF‐β receptor I was downregulated in vitamin D‐deficient female fetal mice. Decreased expression of TGF‐β1 and TGF‐β receptor I during early lung development in vitamin D‐deficient mice may contribute to airway remodeling and AHR in vitamin D‐deficient adult female mice. This study provides a link between vitamin D deficiency and respiratory symptoms in chronic lung disease. PMID:24760528

Antitussive activity of Althaea officinalis L. polysaccharide rhamnogalacturonan and its changes in guinea pigs with ovalbumine-induced airways inflammation.

PubMed

Sutovska, M; Capek, P; Franova, S; Joskova, M; Sutovsky, J; Marcinek, J; Kalman, M

2011-01-01

The presented studies were aimed on experimental confirmation of Althaea officinalis polysaccharide rhamnogalacturonan antitussive effect and its changes in conditions of allergic inflammation. We have tested whether rhamnogalacturonan inhibits cough reflex and modulates airways reactivity of guinea pigs in vivo. The cough in guinea pigs was induced by 0.3 M citric acid (CA) aerosol for 3 min interval, in which total number of cough efforts (sudden enhancement of expiratory flow accompanied by cough movement and sound) was counted. Specific airway resistance and its changes induced by citric acid aerosol were considered as an indicator of the in vivo reactivity changes. 1) Althaea officinalis polysaccharide rhamnogalacturonan dose- dependently inhibits cough reflex in unsensitized guinea pigs. Simultaneously, plant polysaccharide shortened the duration of antitussive effect when it was been tested in inflammatory conditions. 2) Rhamnogalacturonan did not influence airways reactivity in vivo conditions expressed as specific resistance values neither sensitized nor unsensitized groups of animals. 3) The antitussive activity of codeine (dose 10 mg.kg(-1) b.w. orally) tested under the same condition was comparable to higher dose of rhamnogalacturonan in unsensitized animals. 4) The characteristic cellular pattern of allergic airways inflammation was confirmed by histopathological investigations. Rhamnogalacturonan isolated from Althaea officinalis mucilage possesses very high cough suppressive effect in guinea pigs test system, which is shortened in conditions of experimentally induced airways allergic inflammation (Tab. 1, Fig. 4, Ref. 25). Full Text in free PDF www.bmj.sk.

Determinants of peripheral airway function in adults with and without asthma.

PubMed

Robinson, Paul D; King, Gregory G; Sears, Malcolm R; Hong, Chuen Y; Hancox, Robert J

2017-08-01

Peripheral airway involvement in asthma remains poorly understood. We investigated impulse oscillometry (IOS) measures of peripheral airway function in a population-based birth cohort. Pre- and post-bronchodilator spirometry and IOS measures of respiratory resistance and reactance were measured in 915 participants at age 38 years. Current asthma was associated with impairments in both spirometry and IOS parameters. These impairments were greater in men and in those with childhood persistent asthma. Spirometry and IOS values for those whose asthma was in remission were not different to non-asthmatic participants. There were significant changes in IOS in both asthmatic and non-asthmatic participants after bronchodilator, but between-group differences persisted. Higher BMIs were associated with impairments in IOS but not spirometry. Cumulative tobacco use was associated with spirometric airflow obstruction in both sexes, whereas cannabis use was associated with impairments in IOS in women. Despite higher lifetime exposure, there were few associations between cannabis and IOS in men. Asthma is associated with abnormalities in IOS measures of peripheral airway dysfunction. This association is stronger in men and in those with asthma persisting since childhood. Tobacco and cannabis use are associated with different patterns of spirometry and IOS abnormalities and may affect the bronchial tree at different airway generations with differences in susceptibility between sexes. © 2017 Asian Pacific Society of Respirology.

Physical principle of airway design in human lungs

NASA Astrophysics Data System (ADS)

Park, Keunhwan; Son, Taeho; Kim, Wonjung; Kim, Ho-Young

2014-11-01

From an engineering perspective, lungs are natural microfluidic devices that extract oxygen from air. In the bronchial tree, airways branch by dichotomy with a systematic reduction of their diameters. It is generally accepted that in conducting airways, which air passes on the way to the acinar airways from the atmosphere, the reduction ratio of diameter is closely related to the minimization of viscous dissipation. Such a principle is formulated as the Hess-Murray law. However, in acinar airways, where oxygen transfer to alveolae occurs, the diameter reduction with progressive generations is more moderate than in conducting airways. Noting that the dominant transfer mechanism in acinar airways is diffusion rather than advection, unlike conducting airways, we construct a mathematical model for oxygen transfer through a series of acinar airways. Our model allows us to predict the optimal airway reduction ratio that maximizes the oxygen transfer in a finite airway volume, thereby rationalizing the observed airway reduction ratio in acinar airways.

Airway management in cervical spine injury

PubMed Central

Austin, Naola; Krishnamoorthy, Vijay; Dagal, Arman

2014-01-01

To minimize risk of spinal cord injury, airway management providers must understand the anatomic and functional relationship between the airway, cervical column, and spinal cord. Patients with known or suspected cervical spine injury may require emergent intubation for airway protection and ventilatory support or elective intubation for surgery with or without rigid neck stabilization (i.e., halo). To provide safe and efficient care in these patients, practitioners must identify high-risk patients, be comfortable with available methods of airway adjuncts, and know how airway maneuvers, neck stabilization, and positioning affect the cervical spine. This review discusses the risks and benefits of various airway management strategies as well as specific concerns that affect patients with known or suspected cervical spine injury. PMID:24741498

Small-airway obstruction and emphysema in chronic obstructive pulmonary disease.

PubMed

McDonough, John E; Yuan, Ren; Suzuki, Masaru; Seyednejad, Nazgol; Elliott, W Mark; Sanchez, Pablo G; Wright, Alexander C; Gefter, Warren B; Litzky, Leslie; Coxson, Harvey O; Paré, Peter D; Sin, Don D; Pierce, Richard A; Woods, Jason C; McWilliams, Annette M; Mayo, John R; Lam, Stephen C; Cooper, Joel D; Hogg, James C

2011-10-27

The major sites of obstruction in chronic obstructive pulmonary disease (COPD) are small airways (<2 mm in diameter). We wanted to determine whether there was a relationship between small-airway obstruction and emphysematous destruction in COPD. We used multidetector computed tomography (CT) to compare the number of airways measuring 2.0 to 2.5 mm in 78 patients who had various stages of COPD, as judged by scoring on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) scale, in isolated lungs removed from patients with COPD who underwent lung transplantation, and in donor (control) lungs. MicroCT was used to measure the extent of emphysema (mean linear intercept), the number of terminal bronchioles per milliliter of lung volume, and the minimum diameters and cross-sectional areas of terminal bronchioles. On multidetector CT, in samples from patients with COPD, as compared with control samples, the number of airways measuring 2.0 to 2.5 mm in diameter was reduced in patients with GOLD stage 1 disease (P=0.001), GOLD stage 2 disease (P=0.02), and GOLD stage 3 or 4 disease (P<0.001). MicroCT of isolated samples of lungs removed from patients with GOLD stage 4 disease showed a reduction of 81 to 99.7% in the total cross-sectional area of terminal bronchioles and a reduction of 72 to 89% in the number of terminal bronchioles (P<0.001). A comparison of the number of terminal bronchioles and dimensions at different levels of emphysematous destruction (i.e., an increasing value for the mean linear intercept) showed that the narrowing and loss of terminal bronchioles preceded emphysematous destruction in COPD (P<0.001). These results show that narrowing and disappearance of small conducting airways before the onset of emphysematous destruction can explain the increased peripheral airway resistance reported in COPD. (Funded by the National Heart, Lung, and Blood Institute and others.).

Relationships between equine airway reactivity measured by flowmetric plethysmography and specific indicators of airway inflammation in horses with suspected inflammatory airway disease.

PubMed

Wichtel, M; Gomez, D; Burton, S; Wichtel, J; Hoffman, A

2016-07-01

Agreement between airway reactivity measured by flowmetric plethysmography and histamine bronchoprovocation, and lower airway inflammation measured by bronchoalveolar lavage (BAL) cytology, has not been studied in horses with suspected inflammatory airway disease (IAD). We tested the hypothesis that airway reactivity is associated with BAL cytology in horses presenting for unexplained poor performance and/or chronic cough. Prospective clinical study. Forty-five horses, predominantly young Standardbred racehorses, presenting for unexplained poor performance or chronic cough, underwent endoscopic evaluation, tracheal wash, flowmetric plethysmography with histamine bronchoprovocation and BAL. Histamine response was measured by calculating PC35, the concentration of nebulised histamine eliciting an increase in Δflow of 35%. In this population, there was no significant correlation between histamine response and cell populations in BAL cytology. When airway hyperreactivity (AHR) was defined as ≥35% increase in Δflow at a histamine concentration of <6 mg/ml, 24 of the 45 horses (53%) were determined to have AHR. Thirty-three (73%) had either abnormal BAL cytology or AHR, and were diagnosed with IAD on this basis. Of horses diagnosed with IAD, 9 (27%) had an abnormal BAL, 11 (33%) had AHR and 13 (39%) had both. Airway reactivity and BAL cytology did not show concordance in this population of horses presenting for unexplained poor performance and/or chronic cough. Failure to include tests of airway reactivity may lead to underdiagnosis of IAD in young Standardbred racehorses that present with clinical signs suggestive of IAD. © 2015 EVJ Ltd.

Radiology-guided forceps biopsy and airway stenting in severe airway stenosis.

PubMed

Li, Zong Ming; Wu, Gang; Han, Xin Wei; Ren, Ke Wei; Zhu, Ming

2014-01-01

We aimed to determine the feasibility, safety, and effectiveness of radiology-guided forceps biopsy and airway stenting in patients with severe airway stenosis. This study involved 28 patients with severe airway stenosis who underwent forceps biopsy between October 2006 and September 2011. Chest multislice computed tomography was used to determine the location and extent of stenosis. Sixteen patients had tracheal stenosis, two patients had stenosis of the tracheal carina, six patients had stenosis of the left main bronchus, and four patients had stenosis of the right main bronchus. Forceps biopsy and stenting of the stenosed area were performed under fluoroscopic guidance in digital subtraction angiography and the biopsy specimens were analyzed histopathologically. We contacted the patients via phone call and utilized a standardized questionnaire to determine their medical condition during a postoperative three-month follow-up. The technical success rate of radiology-guided forceps biopsy was 100%. Biopsy specimens were obtained in all patients. Dyspnea was relieved immediately after stent placement. No serious complications, such as tracheal hemorrhage or perforation, mediastinal emphysema, or asphyxia, occurred. Radiology-guided forceps biopsy and airway stenting can be used for the emergency treatment of severe airway stenosis. This method appears to be safe and effective, and it may be an alternative therapeutic option in patients who cannot tolerate fiberoptic bronchoscopy.

Radiology-guided forceps biopsy and airway stenting in severe airway stenosis

PubMed Central

Li, Zong-Ming; Wu, Gang; Han, Xin-Wei; Ren, Ke-Wei; Zhu, Ming

2014-01-01

PURPOSE We aimed to determine the feasibility, safety, and effectiveness of radiology-guided forceps biopsy and airway stenting in patients with severe airway stenosis. MATERIALS AND METHODS This study involved 28 patients with severe airway stenosis who underwent forceps biopsy between October 2006 and September 2011. Chest multislice computed tomography was used to determine the location and extent of stenosis. Sixteen patients had tracheal stenosis, two patients had stenosis of the tracheal carina, six patients had stenosis of the left main bronchus, and four patients had stenosis of the right main bronchus. Forceps biopsy and stenting of the stenosed area were performed under fluoroscopic guidance in digital subtraction angiography and the biopsy specimens were analyzed histopathologically. We contacted the patients via phone call and utilized a standardized questionnaire to determine their medical condition during a postoperative three-month follow-up. RESULTS The technical success rate of radiology-guided forceps biopsy was 100%. Biopsy specimens were obtained in all patients. Dyspnea was relieved immediately after stent placement. No serious complications, such as tracheal hemorrhage or perforation, mediastinal emphysema, or asphyxia, occurred. CONCLUSION Radiology-guided forceps biopsy and airway stenting can be used for the emergency treatment of severe airway stenosis. This method appears to be safe and effective, and it may be an alternative therapeutic option in patients who cannot tolerate fiberoptic bronchoscopy. PMID:24808434

Inflammatory bowel disease and airway diseases.

PubMed

Vutcovici, Maria; Brassard, Paul; Bitton, Alain

2016-09-14

Airway diseases are the most commonly described lung manifestations of inflammatory bowel disease (IBD). However, the similarities in disease pathogenesis and the sharing of important environmental risk factors and genetic susceptibility suggest that there is a complex interplay between IBD and airway diseases. Recent evidence of IBD occurrence among patients with airway diseases and the higher than estimated prevalence of subclinical airway injuries among IBD patients support the hypothesis of a two-way association. Future research efforts should be directed toward further exploration of this association, as airway diseases are highly prevalent conditions with a substantial public health impact.

Airway response to emotion- and disease-specific films in asthma, blood phobia, and health.

PubMed

Ritz, Thomas; Wilhelm, Frank H; Meuret, Alicia E; Gerlach, Alexander L; Roth, Walton T

2011-01-01

Earlier research found autonomic and airway reactivity in asthma patients when they were exposed to blood-injection-injury (BII) stimuli. We studied oscillatory resistance (R(os)) in asthma and BII phobia during emotional and disease-relevant films and examined whether muscle tension counteracts emotion-induced airway constriction. Fifteen asthma patients, 12 BII phobia patients, and 14 healthy controls viewed one set of negative, positive, neutral, BII-related, and asthma-related films with leg muscle tension and a second set without. R(os), ventilation, cardiovascular activity, and skin conductance were measured continuously. R(os) was higher during emotional compared to neutral films, particularly during BII material, and responses increased from healthy over asthmatic to BII phobia participants. Leg muscle tension did not abolish R(os) increases. Thus, the airways are particularly responsive to BII-relevant stimuli, which could become risk factors for asthma patients. Copyright © 2010 Society for Psychophysiological Research.

Continuous positive airway pressure intolerance associated with elevated nasal resistance is possible mechanism of complex sleep apnea syndrome.

PubMed

Nakazaki, Chie; Noda, Akiko; Yasuda, Yoshinari; Nakata, Seiichi; Koike, Yasuo; Yasuma, Fumihiko; Murohara, Toyoaki; Nakashima, Tsutomu

2012-09-01

Complex sleep apnea syndrome (CompSAS) is diagnosed after an elimination of obstructive events with continuous positive airway pressure (CPAP), when a central apnea index ≥5/h or Cheyne-Stokes respiration pattern emerges in patients with obstructive sleep apnea syndrome (OSAS). However, the pathophysiology of CompSAS remains controversial. Of the 281 patients with suspected OSAS, all of whom underwent polysomnography conducted at Nagoya University Hospital, we enrolled 52 patients with apnea-hypopnea index ≥15/h (age 51.4 ± 13.3 years). The polysomnographic findings, left ventricular ejection fraction (LVEF), and nasal resistance were compared between the CompSAS patients and OSAS patients. Forty-three patients were diagnosed with OSAS and nine patients with central sleep apnea syndrome by natural sleep PSG. Furthermore, 43 OSAS patients were classified into the OSAS patients (OSAS group, n = 38) and the CompSAS patients (CompSAS group, n = 5) by the night on CPAP PSG. The nasal resistance was significantly higher in CompSAS group than in OSAS group (0.30 ± 0.10 vs. 0.19 ± 0.07 Pa/cm(3)/s, P = 0.004). The arousal index, percentage of stage 1 sleep, and oxygen desaturation index were significantly decreased, and the percentage of stage REM sleep was significantly increased in the OSAS group with the initial CPAP treatment, but not in the CompSAS group. In addition, the patients with CompSAS showed normal LVEF. CPAP intolerance secondary to an elevated nasal resistance might relate to frequent arousals, which could presumably contribute to an increase in central sleep apnea. Further evaluation in a large study is needed to clarify the mechanism of CompSAS.

Airway extravasation induced by increasing airway temperature in ovalbumin-sensitized rats

PubMed Central

Hsu, Chun-Chun; Tapia, Reyno J.; Lee, Lu-Yuan

2015-01-01

This study was carried out to determine whether hyperventilation of humidified warm air (HWA) induced airway extravasation in ovalbumin (Ova)-sensitized rats. Our results showed: 1) After isocapnic hyperventilation with HWA for 2 min, tracheal temperature (Ttr) was increased to 40.3°C, and the Evans blue contents in major airways and lung tissue were elevated to 651% and 707%, respectively, of that after hyperventilation with humidified room air in Ova-sensitized rats; this striking effect of HWA was absent in control rats. 2) The HWA-induced increase in Evans blue content in sensitized rats was completely prevented by a pretreatment with either L-732138, a selective antagonist of neurokinin type 1 (NK-1) receptor, or formoterol, a selective agonist of β2 adrenoceptor. This study demonstrated that an increase in airway temperature induced protein extravasation in the major airways and lung tissue of sensitized rats, and an activation of the NK-1 receptor by tachykinins released from bronchopulmonary C-fiber nerve endings was primarily responsible. PMID:25864799

Nebulized perflubron and carbon dioxide rapidly dilate constricted airways in an ovine model of allergic asthma.

PubMed

El Mays, Tamer Y; Choudhury, Parichita; Leigh, Richard; Koumoundouros, Emmanuel; Van der Velden, Joanne; Shrestha, Grishma; Pieron, Cora A; Dennis, John H; Green, Francis Hy; Snibson, Ken J

2014-09-16

The low toxicity of perfluorocarbons (PFCs), their high affinity for respiratory gases and their compatibility with lung surfactant have made them useful candidates for treating respiratory diseases such as adult respiratory distress syndrome. We report results for treating acute allergic and non-allergic bronchoconstriction in sheep using S-1226 (a gas mixture containing carbon dioxide and small volumes of nebulized perflubron). The carbon dioxide, which is highly soluble in perflubron, was used to relax airway smooth muscle. Sheep previously sensitized to house dust mite (HDM) were challenged with HDM aerosols to induce early asthmatic responses. At the maximal responses (characterised by an increase in lung resistance), the sheep were either not treated or treated with one of the following; nebulized S-1226 (perflubron + 12% CO2), nebulized perflubron + medical air, 12% CO2, salbutamol or medical air. Lung resistance was monitored for up to 20 minutes after cessation of treatment. Treatment with S-1226 for 2 minutes following HDM challenge resulted in a more rapid, more profound and more prolonged decline in lung resistance compared with the other treatment interventions. Video bronchoscopy showed an immediate and complete (within 5 seconds) re-opening of MCh-constricted airways following treatment with S-1226. S-1226 is a potent and rapid formulation for re-opening constricted airways. Its mechanism(s) of action are unknown. The formulation has potential as a rescue treatment for acute severe asthma.

Bronchoconstriction induced by increasing airway temperature in ovalbumin-sensitized rats: role of tachykinins.

PubMed

Hsu, Chun-Chun; Lin, Ruei-Lung; Lin, You Shuei; Lee, Lu-Yuan

2013-09-01

This study was carried out to determine the effect of allergic inflammation on the airway response to increasing airway temperature. Our results showed the following: 1) In Brown-Norway rats actively sensitized by ovalbumin (Ova), isocapnic hyperventilation with humidified warm air (HWA) for 2 min raised tracheal temperature (Ttr) from 33.4 ± 0.6°C to 40.6 ± 0.1°C, which induced an immediate and sustained (>10 min) increase in total pulmonary resistance (Rl) from 0.128 ± 0.004 to 0.212 ± 0.013 cmH2O·ml(-1)·s (n = 6, P < 0.01). In sharp contrast, the HWA challenge caused the same increase in Ttr but did not generate any increase in Rl in control rats. 2) The increase in Rl in sensitized rats was reproducible when the same HWA challenge was repeated 60-90 min later. 3) This bronchoconstrictive effect was temperature dependent: a slightly smaller increase in peak Ttr (39.6 ± 0.2°C) generated a significant but smaller increase in Rl in sensitized rats. 4) The HWA-induced bronchoconstriction was not generated by the humidity delivered by the HWA challenge alone, because the same water content delivered by saline aerosol at room temperature had no effect. 5) The HWA-evoked increase in Rl in sensitized rats was not blocked by atropine but was completely prevented by pretreatment either with a combination of neurokinin (NK)-1 and NK-2 antagonists or with formoterol, a β2 agonist, before the HWA challenge. This study showed that increasing airway temperature evoked a pronounced and reversible increase in airway resistance in sensitized rats and that tachykinins released from the vagal bronchopulmonary C-fiber endings were primarily responsible.

Airway reactivity in response to repeated emotional film clip presentation in asthma.

PubMed

Janssens, Thomas; Steele, Ashton M; Rosenfield, David; Ritz, Thomas

2017-02-01

Emotional stimuli elicit airway constriction in individuals with asthma and in healthy individuals, but little is known about effects of repeated stimulation. We therefore explored the effect of repeated emotion induction on respiratory resistance (R rs ) using unpleasant, high-arousal surgery films and investigated effects of respiration and emotional reactivity. Twenty-six participants (13 with asthma) watched a series of 12 short, 45-s surgery films followed by 2-min recovery periods. R rs assessed with impulse oscillometry was significantly elevated during films in both groups compared to baseline and recovered quickly after that. No habituation of airway responses occurred. R rs was higher in participants who felt more aroused and less in control when watching the films. Changes in R rs remained significant when controlling for changes in respiration or emotional experience. Thus, although unpleasant stimuli lead to elevated R rs , airway obstruction is not exacerbated with repeated stimulation due to a fast return to baseline after stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Interleukin-1beta-induced airway hyperresponsiveness enhances substance P in intrinsic neurons of ferret airway.

PubMed

Wu, Z-X; Satterfield, B E; Fedan, J S; Dey, R D

2002-11-01

Interleukin (IL)-1beta causes airway inflammation, enhances airway smooth muscle responsiveness, and alters neurotransmitter expression in sensory, sympathetic, and myenteric neurons. This study examines the role of intrinsic airway neurons in airway hyperresponsiveness (AHR) induced by IL-1beta. Ferrets were instilled intratracheally with IL-1beta (0.3 microg/0.3 ml) or saline (0.3 ml) once daily for 5 days. Tracheal smooth muscle contractility in vitro and substance P (SP) expression in tracheal neurons were assessed. Tracheal smooth muscle reactivity to acetylcholine (ACh) and methacholine (MCh) and smooth muscle contractions to electric field stimulation (EFS) both increased after IL-1beta. The IL-1beta-induced AHR was maintained in tracheal segments cultured for 24 h, a procedure that depletes SP from sensory nerves while maintaining viability of intrinsic airway neurons. Pretreatment with CP-99994, an antagonist of neurokinin 1 receptor, attenuated the IL-1beta-induced hyperreactivity to ACh and MCh and to EFS in cultured tracheal segments. SP-containing neurons in longitudinal trunk, SP innervation of superficial muscular plexus neurons, and SP nerve fiber density in tracheal smooth muscle all increased after treatment with IL-1beta. These results show that IL-1beta-enhanced cholinergic airway smooth muscle contractile responses are mediated by the actions of SP released from intrinsic airway neurons.

Critical role of actin-associated proteins in smooth muscle contraction, cell proliferation, airway hyperresponsiveness and airway remodeling.

PubMed

Tang, Dale D

2015-10-30

Asthma is characterized by airway hyperresponsiveness and airway remodeling, which are largely attributed to increased airway smooth muscle contractility and cell proliferation. It is known that both chemical and mechanical stimulation regulates smooth muscle contraction. Recent studies suggest that contractile activation and mechanical stretch induce actin cytoskeletal remodeling in smooth muscle. However, the mechanisms that control actin cytoskeletal reorganization are not completely elucidated. This review summarizes our current understanding regarding how actin-associated proteins may regulate remodeling of the actin cytoskeleton in airway smooth muscle. In particular, there is accumulating evidence to suggest that Abelson tyrosine kinase (Abl) plays a critical role in regulating airway smooth muscle contraction and cell proliferation in vitro, and airway hyperresponsiveness and remodeling in vivo. These studies indicate that Abl may be a novel target for the development of new therapy to treat asthma.

Airway Management in a Patient With Tracheal Disruption due to Penetrating Neck Trauma With Hollow Point Ammunition: A Case Report.

PubMed

Johnson, Angela M; Hill, James L; Zagorski, Dave J; McClain, Joseph M; Maronian, Nicole C

2017-11-27

Rapid sequence induction and intubation was performed for a patient in respiratory distress after a gunshot wound to the neck. Resistance was noted distal to vocal cords. With a bronchoscope unavailable, the endotracheal tube was advanced with a corkscrew maneuver. Subcutaneous emphysema had developed. The endotracheal tube was advanced into the right mainstem with adequate ventilation. Imaging illustrated tracheoesophageal injury. The patient was emergently explored. An intraluminal bullet was removed, lateral wall tracheal defect was repaired, and a tracheostomy was placed. The intubating provider should secure the airway by the method they are most comfortable, have high suspicion of airway injury, and prepare to manage airway disruption.

Airway Management in a Patient With Tracheal Disruption due to Penetrating Neck Trauma With Hollow Point Ammunition: A Case Report.

PubMed

Johnson, Angela M; Hill, James L; Zagorski, Dave J; McClain, Joseph M; Maronian, Nicole C

2018-05-01

Rapid sequence induction and intubation was performed for a patient in respiratory distress after a gunshot wound to the neck. Resistance was noted distal to vocal cords. With a bronchoscope unavailable, the endotracheal tube was advanced with a corkscrew maneuver. Subcutaneous emphysema had developed. The endotracheal tube was advanced into the right mainstem with adequate ventilation. Imaging illustrated tracheoesophageal injury. The patient was emergently explored. An intraluminal bullet was removed, lateral wall tracheal defect was repaired, and a tracheostomy was placed. The intubating provider should secure the airway by the method they are most comfortable, have high suspicion of airway injury, and prepare to manage airway disruption.

A 'Good' muscle in a 'Bad' environment: the importance of airway smooth muscle force adaptation to airway hyperresponsiveness.

PubMed

Bossé, Ynuk; Chapman, David G; Paré, Peter D; King, Gregory G; Salome, Cheryl M

2011-12-15

Asthma is characterized by airway inflammation, with a consequent increase in spasmogens, and exaggerated airway narrowing in response to stimuli, termed airway hyperresponsiveness (AHR). The nature of any relationship between inflammation and AHR is less clear. Recent ex vivo data has suggested a novel mechanism by which inflammation may lead to AHR, in which increased basal ASM-tone, due to the presence of spasmogens in the airways, may "strengthen" the ASM and ultimately lead to exaggerated airway narrowing. This phenomenon was termed "force adaptation" [Bossé, Y., Chin, L.Y., Paré, P.D., Seow, C.Y., 2009. Adaptation of airway smooth muscle to basal tone: relevance to airway hyperresponsiveness. Am. J. Respir. Cell Mol. Biol. 40, 13-18]. However, it is unknown whether the magnitude of the effect of force adaptation ex vivo could contribute to exaggerated airway narrowing in vivo. Our aim was to utilize a computational model of ASM shortening in order to quantify the potential effect of force adaptation on airway narrowing when all other mechanical factors were kept constant. The shortening in the model is dictated by a balance between physiological loads and ASM force-generating capacity at different lengths. The results suggest that the magnitude of the effect of force adaptation on ASM shortening would lead to substantially more airway narrowing during bronchial challenge at any given airway generation. We speculate that the increased basal ASM-tone in asthma, due to the presence of inflammation-derived spasmogens, produces an increase in the force-generating capacity of ASM, predisposing to AHR during subsequent challenge. Copyright © 2011 Elsevier B.V. All rights reserved.

Mechanotransduction, asthma, and airway smooth muscle

PubMed Central

Fabry, Ben; Fredberg, Jeffrey J.

2008-01-01

Excessive force generation by airway smooth muscle is the main culprit in excessive airway narrowing during an asthma attack. The maximum force the airway smooth muscle can generate is exquisitely sensitive to muscle length fluctuations during breathing, and is governed by complex mechanotransduction events that can best be studied by a hybrid approach in which the airway wall is modeled in silico so as to set a dynamic muscle load comparable to that experienced in vivo. PMID:18836522

Cardiovascular causes of airway compression.

PubMed

Kussman, Barry D; Geva, Tal; McGowan, Francis X

2004-01-01

Compression of the paediatric airway is a relatively common and often unrecognized complication of congenital cardiac and aortic arch anomalies. Airway obstruction may be the result of an anomalous relationship between the tracheobronchial tree and vascular structures (producing a vascular ring) or the result of extrinsic compression caused by dilated pulmonary arteries, left atrial enlargement, massive cardiomegaly, or intraluminal bronchial obstruction. A high index of suspicion of mechanical airway compression should be maintained in infants and children with recurrent respiratory difficulties, stridor, wheezing, dysphagia, or apnoea unexplained by other causes. Prompt diagnosis is required to avoid death and minimize airway damage. In addition to plain chest radiography and echocardiography, diagnostic investigations may consist of barium oesophagography, magnetic resonance imaging (MRI), computed tomography, cardiac catheterization and bronchoscopy. The most important recent advance is MRI, which can produce high quality three-dimensional reconstruction of all anatomic elements allowing for precise anatomic delineation and improved surgical planning. Anaesthetic technique will depend on the type of vascular ring and the presence of any congenital heart disease or intrinsic lesions of the tracheobronchial tree. Vascular rings may be repaired through a conventional posterolateral thoracotomy, or utilizing video-assisted thoracoscopic surgery (VATS) or robotic endoscopic surgery. Persistent airway obstruction following surgical repair may be due to residual compression, secondary airway wall instability (malacia), or intrinsic lesions of the airway. Simultaneous repair of cardiac defects and vascular tracheobronchial compression carries a higher risk of morbidity and mortality.

Role for NLRP3 Inflammasome-mediated, IL-1β-Dependent Responses in Severe, Steroid-Resistant Asthma.

PubMed

Kim, Richard Y; Pinkerton, James W; Essilfie, Ama T; Robertson, Avril A B; Baines, Katherine J; Brown, Alexandra C; Mayall, Jemma R; Ali, M Khadem; Starkey, Malcolm R; Hansbro, Nicole G; Hirota, Jeremy A; Wood, Lisa G; Simpson, Jodie L; Knight, Darryl A; Wark, Peter A; Gibson, Peter G; O'Neill, Luke A J; Cooper, Matthew A; Horvat, Jay C; Hansbro, Philip M

2017-08-01

Severe, steroid-resistant asthma is the major unmet need in asthma therapy. Disease heterogeneity and poor understanding of pathogenic mechanisms hampers the identification of therapeutic targets. Excessive nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome and concomitant IL-1β responses occur in chronic obstructive pulmonary disease, respiratory infections, and neutrophilic asthma. However, the direct contributions to pathogenesis, mechanisms involved, and potential for therapeutic targeting remain poorly understood, and are unknown in severe, steroid-resistant asthma. To investigate the roles and therapeutic targeting of the NLRP3 inflammasome and IL-1β in severe, steroid-resistant asthma. We developed mouse models of Chlamydia and Haemophilus respiratory infection-mediated, ovalbumin-induced severe, steroid-resistant allergic airway disease. These models share the hallmark features of human disease, including elevated airway neutrophils, and NLRP3 inflammasome and IL-1β responses. The roles and potential for targeting of NLRP3 inflammasome, caspase-1, and IL-1β responses in experimental severe, steroid-resistant asthma were examined using a highly selective NLRP3 inhibitor, MCC950; the specific caspase-1 inhibitor Ac-YVAD-cho; and neutralizing anti-IL-1β antibody. Roles for IL-1β-induced neutrophilic inflammation were examined using IL-1β and anti-Ly6G. Chlamydia and Haemophilus infections increase NLRP3, caspase-1, IL-1β responses that drive steroid-resistant neutrophilic inflammation and airway hyperresponsiveness. Neutrophilic airway inflammation, disease severity, and steroid resistance in human asthma correlate with NLRP3 and IL-1β expression. Treatment with anti-IL-1β, Ac-YVAD-cho, and MCC950 suppressed IL-1β responses and the important steroid-resistant features of disease in mice, whereas IL-1β administration recapitulated these features. Neutrophil depletion suppressed IL-1�

21 CFR 868.2600 - Airway pressure monitor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper airway...

Awake Craniotomy: A New Airway Approach.

PubMed

Sivasankar, Chitra; Schlichter, Rolf A; Baranov, Dimitry; Kofke, W Andrew

2016-02-01

Awake craniotomies have been performed regularly at the University of Pennsylvania since 2004. Varying approaches to airway management are described for this procedure, including intubation with an endotracheal tube and use of a laryngeal mask airway, simple facemask, or nasal cannula. In this case series, we describe the successful use (i.e., no need for endotracheal intubation related to inadequate gas exchange) of bilateral nasopharyngeal airways in 90 patients undergoing awake craniotomies. The use of nasopharyngeal airways can ease the transition between the asleep and awake phases of the craniotomy without the need to stimulate the airway. Our purpose was to describe our experience and report adverse events related to this technique.

Airway structure and function in Eisenmenger's syndrome.

PubMed

McKay, K O; Johnson, P R; Black, J L; Glanville, A R; Armour, C L

1998-10-01

The responsiveness of airways from patients with Eisenmenger's syndrome (n = 5) was compared with that in airways from organ donors (n = 10). Enhanced contractile responses to cholinergic stimulation were found in airways from patients with Eisenmenger's syndrome. The maximal responses to acetylcholine, carbachol, and parasympathetic nerve stimulation in airway tissue from these patients were 221%, 139%, and 152%, respectively, of the maximal responses obtained in donor tissue. Further, relaxation responses to isoproterenol and levocromakalim were absent (n = 2) or markedly impaired (n = 3) in airways from patients with Eisenmenger's syndrome. This attenuated relaxation response was nonspecific in that it was also absent after vasoactive intestinal peptide, sodium nitroprusside, papaverine, and electrical field application. These observations can most likely be explained by a decrease in intrinsic smooth muscle tone, as precontraction of airways revealed relaxation responses that were equivalent to those obtained in donor tissues. Morphometric analysis of tissues used for the functional studies revealed no differences in the airway dimensions (internal perimeter) or airway wall components (e.g., smooth muscle, cartilage) or total area to explain these observations. Although the mechanism for this observed decrease in intrinsic airway smooth muscle tone is not certain, it may be due to alteration in the substructure of the airway wall or, alternatively, may result from the continued release of depressant factors in the vicinity of the smooth muscle which permanently alters smooth muscle responsiveness.

A meta-analysis of prehospital airway control techniques part II: alternative airway devices and cricothyrotomy success rates.

PubMed

Hubble, Michael W; Wilfong, Denise A; Brown, Lawrence H; Hertelendy, Attila; Benner, Randall W

2010-01-01

Airway management is a key component of prehospital care for seriously ill and injured patients. Oral endotracheal intubation (OETI) is the definitive airway of choice in most emergency medical services (EMS) systems. However, OETI may not be an approved skill for some clinicians or may prove problematic in certain patients because of anatomic abnormalities, trauma, or inadequate relaxation. In these situations alternative airways are frequently employed. However, the reported success rates for these devices vary widely, and established benchmarks are lacking. We sought to determine pooled estimates of the success rates of alternative airway devices (AADs) and needle cricothyrotomy (NCRIC) and surgical cricothyrotomy (SCRIC) placement through a meta-analysis of the literature. We performed a systematic literature search for all English-language articles reporting success rates for AADs, SCRIC, and NCRIC. Studies of field procedures performed by prehospital personnel from any nation were included. All titles were reviewed independently by two authors using prespecified inclusion criteria. Pooled estimates of success rates for each airway technique were calculated using a random-effects meta-analysis model. Of 2,005 prehospital airway titles identified, 35 unique studies were retained for analysis of AAD success rates, encompassing a total of 10,172 prehospital patients. The success rates for SCRIC and NCRIC were analyzed across an additional 21 studies totaling 512 patients. The pooled estimates (and 95% confidence intervals [CIs]) for intervention success across all clinicians and patients were as follows: esophageal obturator airway-esophageal gastric tube airway (EOA-EGTA) 92.6% (90.1%-94.5%); pharyngeotracheal lumen airway (PTLA) 82.1% (74.0%-88.0%); esophageal-tracheal Combitube (ETC) 85.4% (77.3%-91.0%); laryngeal mask airway (LMA) 87.4% (79.0%-92.8%); King Laryngeal Tube airway (King LT) 96.5% (71.2%-99.7%); NCRIC 65.8% (42.3%-83.59%); and SCRIC 90.5% (84

Neutralizing inhibitors in the airways of naïve ferrets do not play a major role in modulating the virulence of H3 subtype influenza A viruses.

PubMed

Job, Emma R; Pizzolla, Angela; Nebl, Thomas; Short, Kirsty R; Deng, Yi-Mo; Carolan, Louise; Laurie, Karen L; Brooks, Andrew G; Reading, Patrick C

2016-07-01

Many insights regarding the pathogenesis of human influenza A virus (IAV) infections have come from studies in mice and ferrets. Surfactant protein (SP)-D is the major neutralizing inhibitor of IAV in mouse airway fluids and SP-D-resistant IAV mutants show enhanced virus replication and virulence in mice. Herein, we demonstrate that sialylated glycoproteins, rather than SP-D, represent the major neutralizing inhibitors against H3 subtype viruses in airway fluids from naïve ferrets. Moreover, while resistance to neutralizing inhibitors is a critical factor in modulating virus replication and disease in the mouse model, it does not appear to be so in the ferret model, as H3 mutants resistant to either SP-D or sialylated glycoproteins in ferret airway fluids did not show enhanced virulence in ferrets. These data have important implications for our understanding of pathogenesis and immunity to human IAV infections in these two widely used animal models of infection. Copyright © 2016. Published by Elsevier Inc.

Investigating the geometry of pig airways using computed tomography

NASA Astrophysics Data System (ADS)

Mansy, Hansen A.; Azad, Md Khurshidul; McMurray, Brandon; Henry, Brian; Royston, Thomas J.; Sandler, Richard H.

2015-03-01

Numerical modeling of sound propagation in the airways requires accurate knowledge of the airway geometry. These models are often validated using human and animal experiments. While many studies documented the geometric details of the human airways, information about the geometry of pig airways is scarcer. In addition, the morphology of animal airways can be significantly different from that of humans. The objective of this study is to measure the airway diameter, length and bifurcation angles in domestic pigs using computed tomography. After imaging the lungs of 3 pigs, segmentation software tools were used to extract the geometry of the airway lumen. The airway dimensions were then measured from the resulting 3 D models for the first 10 airway generations. Results showed that the size and morphology of the airways of different animals were similar. The measured airway dimensions were compared with those of the human airways. While the trachea diameter was found to be comparable to the adult human, the diameter, length and branching angles of other airways were noticeably different from that of humans. For example, pigs consistently had an early airway branching from the trachea that feeds the superior (top) right lung lobe proximal to the carina. This branch is absent in the human airways. These results suggested that the human geometry may not be a good approximation of the pig airways and may contribute to increasing the errors when the human airway geometric values are used in computational models of the pig chest.

Effect of airway acidosis and alkalosis on airway vascular smooth muscle responsiveness to albuterol.

PubMed

Cancado, Jose E; Mendes, Eliana S; Arana, Johana; Horvath, Gabor; Monzon, Maria E; Salathe, Matthias; Wanner, Adam

2015-04-02

In vitro and animal experiments have shown that the transport and signaling of β2-adrenergic agonists are pH-sensitive. Inhaled albuterol, a hydrophilic β2-adrenergic agonist, is widely used for the treatment of obstructive airway diseases. Acute exacerbations of obstructive airway diseases can be associated with changes in ventilation leading to either respiratory acidosis or alkalosis thereby affecting albuterol responsiveness in the airway. The purpose of this study was to determine if airway pH has an effect on albuterol-induced vasodilation in the airway. Ten healthy volunteers performed the following respiratory maneuvers: quiet breathing, hypocapnic hyperventilation, hypercapnic hyperventilation, and eucapnic hyperventilation (to dissociate the effect of pH from the effect of ventilation). During these breathing maneuvers, exhaled breath condensate (EBC) pH and airway blood flow response to inhaled albuterol (ΔQ̇aw) were assessed. Mean ± SE EBC pH (units) and ΔQ̇aw (μl.min(-1).mL(-1)) were 6.4 ± 0.1 and 16.8 ± 1.9 during quiet breathing, 6.3 ± 0.1 and 14.5 ± 2.4 during eucapnic hyperventilation, 6.6 ± 0.2 and -0.2 ± 1.8 during hypocapnic hyperventilation (p = 0.02 and <0.01 vs. quiet breathing), and 5.9 ± 0.1 and 2.0 ± 1.5 during hypercapnic hyperventilation (p = 0.02 and <0.02 vs quiet breathing). Albuterol responsiveness in the airway as assessed by ΔQ̇aw is pH sensitive. The breathing maneuver associated with decreased and increased EBC pH both resulted in a decreased responsiveness independent of the level of ventilation. These findings suggest an attenuated response to hydrophilic β2-adrenergic agonists during airway disease exacerbations associated with changes in pH. Registered at clinicaltrials.gov: NCT01216748 .

Motorcycle exhaust particles induce airway inflammation and airway hyperresponsiveness in BALB/C mice.

PubMed

Lee, Chen-Chen; Liao, Jiunn-Wang; Kang, Jaw-Jou

2004-06-01

A number of large studies have reported that environmental pollutants from fossil fuel combustion can cause deleterious effects to the immune system, resulting in an allergic reaction leading to respiratory tract damage. In this study, we investigated the effect of motorcycle exhaust particles (MEP), a major pollutant in the Taiwan urban area, on airway inflammation and airway hyperresponsiveness in laboratory animals. BALB/c mice were instilled intratracheally (i.t.) with 1.2 mg/kg and 12 mg/kg of MEP, which was collected from two-stroke motorcycle engines. The mice were exposed 3 times i.t. with MEP, and various parameters for airway inflammation and hyperresponsiveness were sequentially analyzed. We found that MEP would induce airway and pulmonary inflammation characterized by infiltration of eosinophils, neutrophils, lymphocytes, and macrophages in bronchoalveolar lavage fluid (BALF) and inflammatory cell infiltration in lung. In addition, MEP treatment enhanced BALF interleukin-4 (IL-4), IL-5, and interferon-gamma (IFN-gamma) cytokine levels and serum IgE production. Bronchial response measured by unrestrained plethysmography with methacholine challenge showed that MEP treatment induced airway hyperresponsiveness (AHR) in BALB/c mice. The chemical components in MEP were further fractionated with organic solvents, and we found that the benzene-extracted fraction exerts a similar biological effect as seen with MEP, including airway inflammation, increased BALF IL-4, serum IgE production, and induction of AHR. In conclusion, we present evidence showing that the filter-trapped particles emitted from the unleaded-gasoline-fueled two-stroke motorcycle engine may induce proinflammatory and proallergic response profiles in the absence of exposure to allergen.

ISMRM Raw data format: A proposed standard for MRI raw datasets.

PubMed

Inati, Souheil J; Naegele, Joseph D; Zwart, Nicholas R; Roopchansingh, Vinai; Lizak, Martin J; Hansen, David C; Liu, Chia-Ying; Atkinson, David; Kellman, Peter; Kozerke, Sebastian; Xue, Hui; Campbell-Washburn, Adrienne E; Sørensen, Thomas S; Hansen, Michael S

2017-01-01

This work proposes the ISMRM Raw Data format as a common MR raw data format, which promotes algorithm and data sharing. A file format consisting of a flexible header and tagged frames of k-space data was designed. Application Programming Interfaces were implemented in C/C++, MATLAB, and Python. Converters for Bruker, General Electric, Philips, and Siemens proprietary file formats were implemented in C++. Raw data were collected using magnetic resonance imaging scanners from four vendors, converted to ISMRM Raw Data format, and reconstructed using software implemented in three programming languages (C++, MATLAB, Python). Images were obtained by reconstructing the raw data from all vendors. The source code, raw data, and images comprising this work are shared online, serving as an example of an image reconstruction project following a paradigm of reproducible research. The proposed raw data format solves a practical problem for the magnetic resonance imaging community. It may serve as a foundation for reproducible research and collaborations. The ISMRM Raw Data format is a completely open and community-driven format, and the scientific community is invited (including commercial vendors) to participate either as users or developers. Magn Reson Med 77:411-421, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Brain-Derived Neurotrophic Factor in the Airways

PubMed Central

Prakash, Y.S.; Martin, Richard J.

2014-01-01

In addition to their well-known roles in the nervous system, there is increasing recognition that neurotrophins such as brain derived neurotrophic factor (BDNF) as well as their receptors are expressed in peripheral tissues including the lung, and can thus potentially contribute to both normal physiology and pathophysiology of several diseases. The relevance of this family of growth factors lies in emerging clinical data indicating altered neurotrophin levels and function in a range of diseases including neonatal and adult asthma, sinusitis, influenza, and lung cancer. The current review focuses on 1) the importance of BDNF expression and signaling mechanisms in early airway and lung development, critical to both normal neonatal lung function and also its disruption in prematurity and insults such as inflammation and infection; 2) how BDNF, potentially derived from airway nerves modulate neurogenic control of airway tone, a key aspect of airway reflexes as well as dysfunctional responses to allergic inflammation; 3) the emerging idea that local BDNF production by resident airway cells such as epithelium and airway smooth muscle can contribute to normal airway structure and function, and to airway hyperreactivity and remodeling in diseases such as asthma. Furthermore, given its pleiotropic effects in the airway, BDNF may be a novel and appealing therapeutic target. PMID:24560686

Sequential Stenting for Extensive Malignant Airway Stenosis

PubMed Central

Takahama, Makoto; Nakajima, Ryu; Kimura, Michitaka; Tei, Keiko; Yamamoto, Ryoji

2014-01-01

Purpose: Malignant airway stenosis extending from the bronchial bifurcation to the lower lobar orifice was treated with airway stenting. We herein examine the effectiveness of airway stenting for extensive malignant airway stenosis. Methods: Twelve patients with extensive malignant airway stenosis underwent placement of a silicone Dumon Y stent (Novatech, La Ciotat, France) at the tracheal bifurcation and a metallic Spiral Z-stent (Medico’s Hirata, Osaka, Japan) at either distal side of the Y stent. We retrospectively analyzed the therapeutic efficacy of the sequential placement of these silicone and metallic stents in these 12 patients. Results: The primary disease was lung cancer in eight patients, breast cancer in two patients, tracheal cancer in one patient, and thyroid cancer in one patient. The median survival period after airway stent placement was 46 days. The Hugh–Jones classification and performance status improved in nine patients after airway stenting. One patient had prolonged hemoptysis and died of respiratory tract hemorrhage 15 days after the treatment. Conclusion: Because the initial disease was advanced and aggressive, the prognosis after sequential airway stent placement was significantly poor. However, because respiratory distress decreased after the treatment in most patients, this treatment may be acceptable for selected patients with extensive malignant airway stenosis. PMID:25273272

Differential roles of endothelin-1 ETA and ETB receptors and vasoactive intestinal polypeptide in regulation of the airways and the pulmonary vasculature in isolated rat lung.

PubMed

Janosi, Tibor; Peták, Ferenc; Fontao, Fabienne; Morel, Denis R; Beghetti, Maurice; Habre, Walid

2008-11-01

The available treatment strategies against pulmonary hypertension include the administration of endothelin-1 (ET-1) receptor subtype blockers (ET(A) and ET(B) antagonists); vasoactive intestinal polypeptide (VIP) has recently been suggested as a potential new therapeutic agent. We set out to investigate the ability of these agents to protect against the vasoconstriction and impairment of lung function commonly observed in patients with pulmonary hypertension. An ET(A) blocker (BQ123), ET(B) blocker (BQ788), a combination of these selective blockers (ET(A) + ET(B) blockers) or VIP (V6130) was administered into the pulmonary circulation in four groups of perfused normal rat lungs. Pulmonary vascular resistance (PVR) and forced oscillatory lung input impedance (Z(L)) were measured in all groups under baseline conditions and at 1 min intervals following ET-1 administrations. The airway resistance, inertance, tissue damping and elastance were extracted from the Z(L) spectra. While VIP, ET(A) blocker and combined ET(A) and ET(B) blockers significantly prevented the pulmonary vasoconstriction induced by ET-1, ET(B) blockade enhanced the ET-1-induced increases in PVR. In contrast, the ET(A) and ET(B) blockers markedly elevated the ET-1-induced increases in airway resistance, while VIP blunted this constrictor response. Our results suggest that VIP potently acts against the airway and pulmonary vascular constriction mediated by endothelin-1, while the ET(A) and ET(B) blockers exert a differential effect between airway resistance and PVR.

Malignant central airway obstruction

PubMed Central

Mudambi, Lakshmi; Miller, Russell

2017-01-01

This review comprehensively describes recent advances in the management of malignant central airway obstruction (CAO). Malignant CAO can be a dramatic and devastating manifestation of primary lung cancer or metastatic disease. A variety of diagnostic modalities are available to provide valuable information to plan a therapeutic intervention. Clinical heterogeneity in the presentation of malignant CAO provides opportunities to adapt and utilize endoscopic technology and tools in many ways. Mechanical debulking, thermal tools, cryotherapy and airway stents are methods and instruments used to rapidly restore airway patency. Delayed bronchoscopic methods, such as photodynamic therapy (PDT) and brachytherapy can also be utilized in specific non-emergent situations to establish airway patency. Although data regarding the success and complications of therapeutic interventions are retrospective and characterized by clinical and outcome measure variability, the symptoms of malignant CAO can often be successfully palliated. Assessment of risks and benefits of interventions in each individual patient during the decision-making process forms the critical foundation of the management of malignant CAO. PMID:29214067

Regulation of human airway surface liquid.

PubMed

Widdicombe, J H; Widdicombe, J G

1995-01-01

Human airways are lined with a film of liquid from 5-100 microns in depth, consisting of a periciliary sol around and a mucous gel above the cilia. Microscopical studies have shown the sol to be invariably the same depth as the length of the cilia, and we discuss possible reasons for this. The composition and sources of the airway surface liquid are also described. In addition the forces regulating its volume are analyzed. Several airway diseases are characterised by dramatic changes in the volume and composition of airway liquid. We review recent research suggesting that the accumulation of airway mucous secretions in cystic fibrosis is caused by alterations in active transport of ions and water across both the surface and gland epithelia.

Repeated episodes of ozone inhalation amplifies the effects of allergen sensitization and inhalation on airway immune and structural development in Rhesus monkeys.

PubMed

Schelegle, Edward S; Miller, Lisa A; Gershwin, Laurel J; Fanucchi, Michelle V; Van Winkle, Laura S; Gerriets, Joan E; Walby, William F; Mitchell, Valerie; Tarkington, Brian K; Wong, Viviana J; Baker, Gregory L; Pantle, Lorraine M; Joad, Jesse P; Pinkerton, Kent E; Wu, Reen; Evans, Michael J; Hyde, Dallas M; Plopper, Charles G

2003-08-15

Twenty-four infant rhesus monkeys (30 days old) were exposed to 11 episodes of filtered air (FA), house dust mite allergen aerosol (HDMA), ozone (O3), or HDMA + O3 (5 days each followed by 9 days of FA). Ozone was delivered for 8 h/day at 0.5 ppm. Twelve of the monkeys were sensitized to house dust mite allergen (Dermatophagoides farinae) at ages 14 and 28 days by subcutaneous inoculation (SQ) of HDMA in alum and intraperitoneal injection of heat-killed Bordetella pertussis cells. Sensitized monkeys were exposed to HDMA aerosol for 2 h/day on days 3-5 of either FA (n = 6) or O3 (n = 6) exposure. Nonsensitized monkeys were exposed to either FA (n = 6) or O3 (n = 6). During the exposure regimen, parameters of allergy (i.e., serum IgE, histamine, and eosinophilia), airways resistance, reactivity, and structural remodeling were evaluated. Eleven repeated 5-day cycles of inhaling 0.5 ppm ozone over a 6-month period had only mild effects on the airways of nonsensitized infant rhesus monkeys. Similarly, the repeated inhalation of HDMA by HDMA-sensitized infant monkeys resulted in only mild airway effects, with the exception of a marked increase in proximal airway and terminal bronchiole content of eosinophils. In contrast, the combined cyclic inhalation of ozone and HDMA by HDMA sensitized infants monkeys resulted in a marked increase in serum IgE, serum histamine, and airways eosinophilia. Furthermore, combined cyclic inhalation of ozone and HDMA resulted in even greater alterations in airway structure and content that were associated with a significant elevation in baseline airways resistance and reactivity. These results suggest that ozone can amplify the allergic and structural remodeling effects of HDMA sensitization and inhalation.

Continuous positive airway pressure for the treatment of obstructive sleep apnea.

PubMed

Nurwidya, Fariz; Susanto, Agus Dwi; Juzar, Dafsah A; Kobayashi, Isao; Yunus, Faisal

2016-01-01

Obstructive sleep apnea (OSA) is a recurrent episode of partial or complete upper airway obstruction during sleep despite ongoing respiratory efforts and is implicated as the risk factor of cardiovascular disease. The OSA syndrome is typified by recurring partial or total occlusion of the pharynx, sleep fragmentation, episodes of gasping, and, eventually, daytime sleepiness. If it is left untreated, OSA syndrome can cause hypertension, coronary artery disease congestive heart disease, insulin resistance and death. In this review, we describe the pathogenesis and diagnosis of OSA. We also focused on the continuous positive airway pressure (CPAP) as the main therapy for OSA. CPAP has been shown to provide benefit for not only respiratory system, but also for cardiovascular system and metabolic system. Finally, we discussed briefly about the issue of adherence of using CPAP that could contribute to lower compliant in patient with OSA.

Postnatal airway growth in cystic fibrosis piglets.

PubMed

Adam, Ryan J; Abou Alaiwa, Mahmoud H; Bouzek, Drake C; Cook, Daniel P; Gansemer, Nicholas D; Taft, Peter J; Powers, Linda S; Stroik, Mallory R; Hoegger, Mark J; McMenimen, James D; Hoffman, Eric A; Zabner, Joseph; Welsh, Michael J; Meyerholz, David K; Stoltz, David A

2017-09-01

Mutations in the gene encoding the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) anion channel cause CF. The leading cause of death in the CF population is lung disease. Increasing evidence suggests that in utero airway development is CFTR-dependent and that developmental abnormalities may contribute to CF lung disease. However, relatively little is known about postnatal CF airway growth, largely because such studies are limited in humans. Therefore, we examined airway growth and lung volume in a porcine model of CF. We hypothesized that CF pigs would have abnormal postnatal airway growth. To test this hypothesis, we performed CT-based airway and lung volume measurements in 3-wk-old non-CF and CF pigs. We found that 3-wk-old CF pigs had tracheas of reduced caliber and irregular shape. Their bronchial lumens were reduced in size proximally but not distally, were irregularly shaped, and had reduced distensibility. Our data suggest that lack of CFTR results in aberrant postnatal airway growth and development, which could contribute to CF lung disease pathogenesis. NEW & NOTEWORTHY This CT scan-based study of airway morphometry in the cystic fibrosis (CF) postnatal period is unique, as analogous studies in humans are greatly limited for ethical and technical reasons. Findings such as reduced airway lumen area and irregular caliber suggest that airway growth and development are CF transmembrane conductance regulator-dependent and that airway growth defects may contribute to CF lung disease pathogenesis. Copyright © 2017 the American Physiological Society.

Relating small airways to asthma control using impulse oscillometry in children

PubMed Central

Shi, Yixin; Aledia, Anna S.; Tatavoosian, Ahramahzd V.; Vijayalakshmi, Shruthi; Galant, Stanley P.; George, Steven C.

2012-01-01

Background Previous reports suggest that peripheral airways are associated with asthma control. Patient history, although subjective is used largely to assess asthma control in children because spirometry is many times normal. Impulse oscillometry (IOS) is an objective non-invasive measurement of lung function, which has the potential to examine independently both small and large airway obstruction. Objective To determine the utility of IOS in assessing asthma control in children. Methods Asthmatic and healthy children (6–17 yrs) were enrolled in the study. Spirometry and IOS (resistance at 5 and 20 Hz, R5 and R20, respectively, reactance at 5 Hz, X5, resonant frequency, Fres, and area under the reactance curve between 5 Hz and Fres, AX) were collected in triplicate before and after a bronchodilator was administered. The physicians were blinded to the IOS measurements and assessed asthma control using ATS guidelines. Results Small airway IOS measurements, including R5-20, X5, Fres and AX, of children with uncontrolled asthma (n=44) were significantly different from those of controlled asthmatic (n=57) and healthy (n=14) children, especially prior to the administration of a bronchodilator. However, there was no difference in large airway IOS (R20). No differences were found between controlled asthmatic and healthy children in any of the endpoints. ROC analysis showed cut-points for baseline R5-20 (1.5 cmH2O·L−1·s) and AX (9.5 cmH2O·L−1) that effectively discriminated controlled versus uncontrolled asthma (AUC=0.86 and 0.84), and correctly classified more than 80% of the population. Conclusion Uncontrolled asthma is associated with small airways dysfunction, and IOS may be a reliable non-invasive method to assess asthma control in children. PMID:22178635

Intrathoracic airway measurement: ex-vivo validation

NASA Astrophysics Data System (ADS)

Reinhardt, Joseph M.; Raab, Stephen A.; D'Souza, Neil D.; Hoffman, Eric A.

1997-05-01

High-resolution x-ray CT (HRCT) provides detailed images of the lungs and bronchial tree. HRCT-based imaging and quantitation of peripheral bronchial airway geometry provides a valuable tool for assessing regional airway physiology. Such measurements have been sued to address physiological questions related to the mechanics of airway collapse in sleep apnea, the measurement of airway response to broncho-constriction agents, and to evaluate and track the progression of disease affecting the airways, such as asthma and cystic fibrosis. Significant attention has been paid to the measurements of extra- and intra-thoracic airways in 2D sections from volumetric x-ray CT. A variety of manual and semi-automatic techniques have been proposed for airway geometry measurement, including the use of standardized display window and level settings for caliper measurements, methods based on manual or semi-automatic border tracing, and more objective, quantitative approaches such as the use of the 'half-max' criteria. A recently proposed measurements technique uses a model-based deconvolution to estimate the location of the inner and outer airway walls. Validation using a plexiglass phantom indicates that the model-based method is more accurate than the half-max approach for thin-walled structures. In vivo validation of these airway measurement techniques is difficult because of the problems in identifying a reliable measurement 'gold standard.' In this paper we report on ex vivo validation of the half-max and model-based methods using an excised pig lung. The lung is sliced into thin sections of tissue and scanned using an electron beam CT scanner. Airways of interest are measured from the CT images, and also measured with using a microscope and micrometer to obtain a measurement gold standard. The result show no significant difference between the model-based measurements and the gold standard; while the half-max estimates exhibited a measurement bias and were significantly

The Development and Application of Airway Devices in China

PubMed Central

Chen, Xiangdong; Ma, Wuhua; Liu, Renyu; Yao, Shanglong

2017-01-01

Airway management is one of the most important tasks for anesthesiologists. Anesthesiologists are experts in airway management and have made tremendous contribution to the development of the airway devices. Chinese anesthesiologists have made significant contribution in introducing advanced airway management and developing innovative techniques and devices for airway management in China. This article overviews the development and application of airway devices in China as well as the dedication and contribution of Chinese experts in the development of novel airway devices. With the development of science and technology accompanied by the advanced knowledge in airway management, more effective and safe artificial airways will be developed for clinical practice. The authors believe that Chinese experts will continue their outstanding contribution to the development of innovative airway devices, systems and knowledge. PMID:28191485

Airway smooth muscle responsiveness from dogs with airway hyperresponsiveness after O/sub 3/ inhalation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, G.L.; O'Byrne, P.M.; Pashley, M.

1988-07-01

Airway hyperresponsiveness occurs after inhalation of O3 in dogs. The purpose of this study was to examine the responsiveness of trachealis smooth muscle in vitro to electrical field stimulation, exogenous acetylcholine, and potassium chloride from dogs with airway hyperresponsiveness after inhaled O3 in vivo and to compare this with the responsiveness of trachealis muscle from control dogs. In addition, excitatory junction potentials were measured with the use of single and double sucrose gap techniques in both groups of dogs to determine whether inhaled O3 affects the release of acetylcholine from parasympathetic nerves in trachealis muscle. Airway hyperresponsiveness developed in allmore » dogs after inhaled O3 (3 ppm for 30 min). The acetylcholine provocative concentration decreased from 4.11 mg/ml before O3 inhalation to 0.66 mg/ml after O3 (P less than 0.0001). The acetylcholine provocative concentration increased slightly after control inhalation of dry room air. Airway smooth muscle showed increased responses to both electrical field stimulation and exogenous acetylcholine but not to potassium chloride in preparations from dogs with airway hyperresponsiveness in vivo. The increased response to electrical field stimulation was not associated with a change in excitatory junctional potentials. These results suggest that a postjunctional alteration in trachealis muscle function occurs after inhaled O3 in dogs, which may account for airway hyperresponsiveness after O3 in vivo.« less

Alcohol and Airways Function in Health and Disease

PubMed Central

Sisson, Joseph H.

2007-01-01

The volatility of alcohol promotes the movement of alcohol from the bronchial circulation across the airway epithelium and into the conducting airways of the lung. The exposure of the airways through this route likely accounts for many of the biologic effects of alcohol on lung airway functions. The impact of alcohol on lung airway functions is dependent on the concentration, duration and route of exposure. Brief exposure to mild concentrations of alcohol may enhance mucociliary clearance, stimulates bronchodilation and probably attenuates the airway inflammation and injury observed in asthma and COPD. Prolonged and heavy exposure to alcohol impairs mucociliary clearance, may complicate asthma management and likely worsens outcomes including lung function and mortality in COPD patients. Non-alcohol congeners and alcohol metabolites act as triggers for airway disease exacerbations especially in atopic asthmatics and in Asian populations who have a reduced capacity to metabolize alcohol. Research focused on the mechanisms of alcohol-mediated changes in airway functions has identified specific mechanisms that mediate alcohol effects within the lung airways. These include prominent roles for the second messengers calcium and nitric oxide, regulatory kinases including PKG and PKA, alcohol and acetaldehyde-metabolizing enzymes such as aldehyde dehydrogenase type 2 (ALDH2). The role alcohol may play in the pathobiology of airway mucus, bronchial blood flow, airway smooth muscle regulation and the interaction with other airway exposure agents, such as cigarette smoke, represent opportunities for future investigation. PMID:17764883

Alcohol and airways function in health and disease.

PubMed

Sisson, Joseph H

2007-08-01

The volatility of alcohol promotes the movement of alcohol from the bronchial circulation across the airway epithelium and into the conducting airways of the lung. The exposure of the airways through this route likely accounts for many of the biologic effects of alcohol on lung airway functions. The effect of alcohol on lung airway functions is dependent on the concentration, duration, and route of exposure. Brief exposure to mild concentrations of alcohol may enhance mucociliary clearance, stimulates bronchodilation, and probably attenuates the airway inflammation and injury observed in asthma and chronic obstructive pulmonary disease (COPD). Prolonged and heavy exposure to alcohol impairs mucociliary clearance, may complicate asthma management, and likely worsens outcomes including lung function and mortality in COPD patients. Nonalcohol congeners and alcohol metabolites act as triggers for airway disease exacerbations especially in atopic asthmatics and in Asian populations who have a reduced capacity to metabolize alcohol. Research focused on the mechanisms of alcohol-mediated changes in airway functions has identified specific mechanisms that mediate alcohol effects within the lung airways. These include prominent roles for the second messengers calcium and nitric oxide, regulatory kinases including PKG and PKA, alcohol- and acetaldehyde-metabolizing enzymes such as aldehyde dehydrogenase 2. The role alcohol may play in the pathobiology of airway mucus, bronchial blood flow, airway smooth muscle regulation, and the interaction with other airway exposure agents, such as cigarette smoke, represents opportunities for future investigation.

Manipulation of Cell Physiology Enables Gene Silencing in Well-differentiated Airway Epithelia

PubMed Central

Krishnamurthy, Sateesh; Behlke, Mark A; Ramachandran, Shyam; Salem, Aliasger K; McCray Jr, Paul B; Davidson, Beverly L

2012-01-01

The application of RNA interference-based gene silencing to the airway surface epithelium holds great promise to manipulate host and pathogen gene expression for therapeutic purposes. However, well-differentiated airway epithelia display significant barriers to double-stranded small-interfering RNA (siRNA) delivery despite testing varied classes of nonviral reagents. In well-differentiated primary pig airway epithelia (PAE) or human airway epithelia (HAE) grown at the air–liquid interface (ALI), the delivery of a Dicer-substrate small-interfering RNA (DsiRNA) duplex against hypoxanthine–guanine phosphoribosyltransferase (HPRT) with several nonviral reagents showed minimal uptake and no knockdown of the target. In contrast, poorly differentiated cells (2–5-day post-seeding) exhibited significant oligonucleotide internalization and target knockdown. This finding suggested that during differentiation, the barrier properties of the epithelium are modified to an extent that impedes oligonucleotide uptake. We used two methods to overcome this inefficiency. First, we tested the impact of epidermal growth factor (EGF), a known enhancer of macropinocytosis. Treatment of the cells with EGF improved oligonucleotide uptake resulting in significant but modest levels of target knockdown. Secondly, we used the connectivity map (Cmap) database to correlate gene expression changes during small molecule treatments on various cells types with genes that change upon mucociliary differentiation. Several different drug classes were identified from this correlative assessment. Well-differentiated epithelia treated with DsiRNAs and LY294002, a PI3K inhibitor, significantly improved gene silencing and concomitantly reduced target protein levels. These novel findings reveal that well-differentiated airway epithelia, normally resistant to siRNA delivery, can be pretreated with small molecules to improve uptake of synthetic oligonucleotide and RNA interference (RNAi) responses. PMID

Popcorn flavoring effects on reactivity of rat airways in vivo and in vitro.

PubMed

Zaccone, Eric J; Thompson, Janet A; Ponnoth, Dovenia S; Cumpston, Amy M; Goldsmith, W Travis; Jackson, Mark C; Kashon, Michael L; Frazer, David G; Hubbs, Ann F; Shimko, Michael J; Fedan, Jeffrey S

2013-01-01

"Popcorn workers' lung" is an obstructive pulmonary disease produced by inhalation of volatile artificial butter flavorings. In rats, inhalation of diacetyl, a major component of butter flavoring, and inhalation of a diacetyl substitute, 2,3-pentanedione, produce similar damage to airway epithelium. The effects of diacetyl and 2,3-pentanedione and mixtures of diacetyl, acetic acid, and acetoin, all components of butter flavoring, on pulmonary function and airway reactivity to methacholine (MCh) were investigated. Lung resistance (RL) and dynamic compliance (Cdyn) were negligibly changed 18 h after a 6-h inhalation exposure to diacetyl or 2,3-pentanedione (100-360 ppm). Reactivity to MCh was not markedly changed after diacetyl, but was modestly decreased after 2,3-pentanedione inhalation. Inhaled diacetyl exerted essentially no effect on reactivity to mucosally applied MCh, but 2,3-pentanedione (320 and 360 ppm) increased reactivity to MCh in the isolated, perfused trachea preparation (IPT). In IPT, diacetyl and 2,3-pentanedione (≥3 mM) applied to the serosal and mucosal surfaces of intact and epithelium-denuded tracheas initiated transient contractions followed by relaxations. Inhaled acetoin (150 ppm) exerted no effect on pulmonary function and airway reactivity in vivo; acetic acid (27 ppm) produced hyperreactivity to MCh; and exposure to diacetyl + acetoin + acetic acid (250 + 150 + 27 ppm) led to a diacetyl-like reduction in reactivity. Data suggest that the effects of 2,3-pentanedione on airway reactivity are greater than those of diacetyl, and that flavorings are airway smooth muscle relaxants and constrictors, thus indicating a complex mechanism.

POPCORN FLAVORING EFFECTS ON REACTIVITY OF RAT AIRWAYS IN VIVO AND IN VITRO

PubMed Central

Zaccone, Eric J.; Thompson, Janet A.; Ponnoth, Dovenia S.; Cumpston, Amy M.; Goldsmith, W. Travis; Jackson, Mark C.; Kashon, Michael L.; Frazer, David G.; Hubbs, Ann F.; Shimko, Michael J.; Fedan, Jeffrey S.

2015-01-01

“Popcorn workers’ lung” is an obstructive pulmonary disease produced by inhalation of volatile artificial butter flavorings. In rats, inhalation of diacetyl, a major component of butter flavoring, and inhalation of a diacetyl substitute, 2,3-pentanedione, produce similar damage to airway epithelium. The effects of diacetyl and 2,3-pentanedione and mixtures of diacetyl, acetic acid, and acetoin, all components of butter flavoring, on pulmonary function and airway reactivity to methacholine (MCh) were investigated. Lung resistance (RL) and dynamic compliance (Cdyn) were negligibly changed 18 h after a 6-h inhalation exposure to diacetyl or 2,3-pentanedione (100–360 ppm). Reactivity to MCh was not markedly changed after diacetyl, but was modestly decreased after 2,3-pentanedione inhalation. Inhaled diacetyl exerted essentially no effect on reactivity to mucosally applied MCh, but 2,3-pentanedione (320 and 360 ppm) increased reactivity to MCh in the isolated, perfused trachea preparation (IPT). In IPT, diacetyl and 2,3-pentanedione (≥3 mM) applied to the serosal and mucosal surfaces of intact and epithelium-denuded tracheas initiated transient contractions followed by relaxations. Inhaled acetoin (150 ppm) exerted no effect on pulmonary function and airway reactivity in vivo; acetic acid (27 ppm) produced hyperreactivity to MCh; and exposure to diacetyl + acetoin + acetic acid (250 + 150 + 27 ppm) led to a diacetyl-like reduction in reactivity. Data suggest that the effects of 2,3-pentanedione on airway reactivity are greater than those of diacetyl, and that flavorings are airway smooth muscle relaxants and constrictors, thus indicating a complex mechanism. PMID:23941636

Neither raw nor retrograded resistant starch lowers fasting serum cholesterol concentrations in healthy normolipidemic subjects.

PubMed

Heijnen, M L; van Amelsvoort, J M; Deurenberg, P; Beynen, A C

1996-09-01

The question addressed was whether dietary resistant starch would lower serum cholesterol and triacylglycerol concentrations in healthy normolipidemic subjects. In a randomized single-blind 3 x 3 Latin-square study with corrections for any carryover effects, 27 males and 30 females consumed supplements containing glucose or resistant starch (RS) from raw high-amylose cornstarch (RS2) or from retrograded high-amylose cornstarch (RS3). The RS2 and RS3 supplements provided 30 g RS/d. Each type of supplement was consumed in addition to the habitual diet for 3 wk. At the end of each 3-wk period, fasting blood samples and a 24-h food-consumption recall were obtained from each subject. The subjects collected 24-h urine samples for lithium determination, which was added to the supplements to check compliance. Mean lithium recovery was 97% and did not differ between supplements. The mean composition of the background diet was similar when the three supplements were taken. Body weight remained constant throughout the study. There were no significant differences in the fasting concentrations of serum total, high-density-lipoprotein (HDL), and low-density-lipoprotein (LDL) cholesterol; triacylglycerols, or 3 alpha-hydroxy bile acids after consumption of glucose, RS2, or RS3. Evidence is presented that the lack of effect of RS2 and RS3 on serum lipid concentrations cannot be explained by insufficient statistical power, a low dose, or a short duration of treatment. The subjects reported softer stools and more gastrointestinal symptoms after supplementation with RS than after glucose. Neither the RS2 nor the RS3 supplements lowered serum lipid concentrations in healthy, normolipidemic men and women.

Elevated Airway Purines in COPD

PubMed Central

Lazaar, Aili L.; Bordonali, Elena; Qaqish, Bahjat; Boucher, Richard C.

2011-01-01

Background: Adenosine and related purines have established roles in inflammation, and elevated airway concentrations are predicted in patients with COPD. However, accurate airway surface purine measurements can be confounded by stimulation of purine release during collection of typical respiratory samples. Methods: Airway samples were collected noninvasively as exhaled breath condensate (EBC) from 36 healthy nonsmokers (NS group), 28 healthy smokers (S group), and 89 subjects with COPD (29 with GOLD [Global Initiative for Chronic Obstructive Lung Disease] stage II, 29 with GOLD stage III, and 31 with GOLD stage IV) and analyzed with mass spectrometry for adenosine, adenosine monophosphate (AMP), and phenylalanine, plus urea as a dilution marker. Variable dilution of airway secretions in EBC was controlled using ratios to urea, and airway surface concentrations were calculated using EBC to serum urea-based dilution factors. Results: EBC adenosine to urea ratios were similar in NS (0.20 ± 0.21) and S (0.22 ± 0.20) groups but elevated in those with COPD (0.32 ± 0.30, P < .01 vs NS). Adenosine to urea ratios were highest in the most severely affected cohort (GOLD IV, 0.35 ± 0.34, P < .01 vs NS) and negatively correlated with FEV1 (r = −0.27, P < .01). Elevated AMP to urea ratios were also observed in the COPD group (0.58 ± 0.97 COPD, 0.29 ± 0.35 NS, P < .02), but phenylalanine to urea ratios were similar in all groups. Airway surface adenosine concentrations calculated in a subset of subjects were 3.2 ± 2.7 μM in those with COPD (n = 28) relative to 1.7 ± 1.5 μM in the NS group (n = 16, P < .05). Conclusions: Airway purines are present on airway surfaces at physiologically significant concentrations, are elevated in COPD, and correlate with markers of COPD severity. Purinergic signaling pathways are potential therapeutic targets in COPD, and EBC purines are potential noninvasive biomarkers. PMID:21454402

Anatomic and physiopathologic changes affecting the airway of the elderly patient: implications for geriatric-focused airway management

PubMed Central

Johnson, Kathleen N; Botros, Daniel B; Groban, Leanne; Bryan, Yvon F

2015-01-01

There are many anatomical, physiopathological, and cognitive changes that occur in the elderly that affect different components of airway management: intubation, ventilation, oxygenation, and risk of aspiration. Anatomical changes occur in different areas of the airway from the oral cavity to the larynx. Common changes to the airway include tooth decay, oropharyngeal tumors, and significant decreases in neck range of motion. These changes may make intubation challenging by making it difficult to visualize the vocal cords and/or place the endotracheal tube. Also, some of these changes, including but not limited to, atrophy of the muscles around the lips and an edentulous mouth, affect bag mask ventilation due to a difficult face-mask seal. Physiopathologic changes may impact airway management as well. Common pulmonary issues in the elderly (eg, obstructive sleep apnea and COPD) increase the risk of an oxygen desaturation event, while gastrointestinal issues (eg, achalasia and gastroesophageal reflux disease) increase the risk of aspiration. Finally, cognitive changes (eg, dementia) not often seen as related to airway management may affect patient cooperation, especially if an awake intubation is required. Overall, degradation of the airway along with other physiopathologic and cognitive changes makes the elderly population more prone to complications related to airway management. When deciding which airway devices and techniques to use for intubation, the clinician should also consider the difficulty associated with ventilating the patient, the patient’s risk of oxygen desaturation, and/or aspiration. For patients who may be difficult to bag mask ventilate or who have a risk of aspiration, a specialized supralaryngeal device may be preferable over bag mask for ventilation. Patients with tumors or decreased neck range of motion may require a device with more finesse and maneuverability, such as a flexible fiberoptic broncho-scope. Overall, geriatric-focused airway

The Difficult Airway Society 'ADEPT' guidance on selecting airway devices: the basis of a strategy for equipment evaluation.

PubMed

Pandit, J J; Popat, M T; Cook, T M; Wilkes, A R; Groom, P; Cooke, H; Kapila, A; O'Sullivan, E

2011-08-01

Faced with the concern that an increasing number of airway management devices were being introduced into clinical practice with little or no prior evidence of their clinical efficacy or safety, the Difficult Airway Society formed a working party (Airway Device Evaluation Project Team) to establish a process by which the airway management community within the profession could itself lead a process of formal device/equipment evaluation. Although there are several national and international regulations governing which products can come on to the market and be legitimately sold, there has hitherto been no formal professional guidance relating to how products should be selected (i.e. purchased). The Airway Device Evaluation Project Team's first task was to formulate such advice, emphasising evidence-based principles. Team discussions led to a definition of the minimum level of evidence needed to make a pragmatic decision about the purchase or selection of an airway device. The Team concluded that this definition should form the basis of a professional standard, guiding those with responsibility for selecting airway devices. We describe how widespread adoption of this professional standard can act as a driver to create an infrastructure in which the required evidence can be obtained. Essential elements are that: (i) the Difficult Airway Society facilitates a coherent national network of research-active units; and (ii) individual anaesthetists in hospital trusts play a more active role in local purchasing decisions, applying the relevant evidence and communicating their purchasing decisions to the Difficult Airway Society. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

Multi-stage surgery for airway patency after metallic stent removal in benign laryngotracheal airway disease in two adolescents.

PubMed

Coordes, Annekatrin; Todt, Ingo; Ernst, Arne; Seidl, Rainer O

2013-05-01

Laryngotracheal stents may damage the highly complex laryngeal structures, impair voice and swallowing functions and cause tissue ingrowths, thereby necessitating airway patency interventions. In benign airway disease, the number of adolescents with laryngotracheal stents is therefore limited. We present two cases of laryngeal metallic stent placement following benign airway disease. Two adolescents presented with severe dyspnea and self-expandable metallic stent placement after benign laryngotracheal stenoses. Granulation tissue ingrowths required additional surgical interventions every 6-8 weeks to recanalize the stent lumen. We performed multi-stage surgery including removal of the embedded stent, segmental resection of the stenotic area, end-to-end-anastomosis and laryngotracheal reconstruction respectively, to achieve patent airway without tracheal cannulation. Montgomery T-tubes were temporarily inserted to bridge the complex reconstructions. In both adolescents, we achieved successful removal of the embedded stent and patent airway. Bilateral vocal fold paralysis required additional surgery to improve the final airway patency and vocal rehabilitation. Stent removal, segmental resection and laryngotracheal reconstruction provide the achievement of patent airway and allow decannulation. Temporary Montgomery T-tubes bridge complex laryngotracheal reconstructions. In benign laryngeal airway disease, stent placement should be avoided, especially in adolescents. Transfer to a specialist center should be considered prior to metallic stent implantation. In general, self-expanding tracheobronchial stents can be placed in selected patients where surgical interventions are limited. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Seroprevalence and molecular epidemiology of EAST1 gene-carrying Escherichia coli from diarrheal patients and raw meats.

PubMed

Sukkua, Kannika; Manothong, Somruthai; Sukhumungoon, Pharanai

2017-03-31

Several Escherichia coli pathotypes have been reported in Thailand; however, information on enteroaggregative heat-stable enterotoxin 1 (EAST1)-carrying E. coli (EAST1-EC) is insufficient. Previous reports show that consumption of raw meats causes diarrheagenic E. coli infections. In this study, we investigated the seroprevalence and genetic relationship of EAST1-EC from clinical and raw meat samples. Diarrheal patients and raw meat samples were investigated for the presence of EAST1-EC by performing polymerase chain reaction (PCR) to detect astA. Serotyping, antimicrobial susceptibility tests, and PCR-based phylogenetic group assay were performed. Molecular epidemiology of E. coli strains from clinical and raw meat samples was determined using repetitive element-PCR typing, BOX-PCR, and ERIC2-PCR. Results showed that 11.2% (17/152) of clinical samples and 53.3% (16/30) of raw meat samples had EAST1-EC. In all, 24 and 36 EAST1-EC strains were successfully isolated from 17 clinical and 16 raw meat samples, respectively. These strains had astA but did not possess the indicative genes of other E. coli pathotypes and were therefore classified as EAST1-EC. Most of these strains were multidrug resistant and were classified into nine serogroups. Molecular genotyping showed identical DNA fingerprint among EAST1-EC serotype O15 strains from clinical and raw chicken samples, suggesting that they were derived from the same bacterial clone. Our results indicated a high prevalence of multidrug-resistant EAST1-EC strains in clinical and environmental samples in Thailand belonging to nine serogroups. Moreover, the study highlighted the close association between infections caused by EAST1-EC serotype O15 and raw meat consumption.

Integrated care pathways for airway diseases (AIRWAYS-ICPs).

PubMed

Bousquet, J; Addis, A; Adcock, I; Agache, I; Agusti, A; Alonso, A; Annesi-Maesano, I; Anto, J M; Bachert, C; Baena-Cagnani, C E; Bai, C; Baigenzhin, A; Barbara, C; Barnes, P J; Bateman, E D; Beck, L; Bedbrook, A; Bel, E H; Benezet, O; Bennoor, K S; Benson, M; Bernabeu-Wittel, M; Bewick, M; Bindslev-Jensen, C; Blain, H; Blasi, F; Bonini, M; Bonini, S; Boulet, L P; Bourdin, A; Bourret, R; Bousquet, P J; Brightling, C E; Briggs, A; Brozek, J; Buhl, R; Bush, A; Caimmi, D; Calderon, M; Calverley, P; Camargos, P A; Camuzat, T; Canonica, G W; Carlsen, K H; Casale, T B; Cazzola, M; Cepeda Sarabia, A M; Cesario, A; Chen, Y Z; Chkhartishvili, E; Chavannes, N H; Chiron, R; Chuchalin, A; Chung, K F; Cox, L; Crooks, G; Crooks, M G; Cruz, A A; Custovic, A; Dahl, R; Dahlen, S E; De Blay, F; Dedeu, T; Deleanu, D; Demoly, P; Devillier, P; Didier, A; Dinh-Xuan, A T; Djukanovic, R; Dokic, D; Douagui, H; Dubakiene, R; Eglin, S; Elliot, F; Emuzyte, R; Fabbri, L; Fink Wagner, A; Fletcher, M; Fokkens, W J; Fonseca, J; Franco, A; Frith, P; Furber, A; Gaga, M; Garcés, J; Garcia-Aymerich, J; Gamkrelidze, A; Gonzales-Diaz, S; Gouzi, F; Guzmán, M A; Haahtela, T; Harrison, D; Hayot, M; Heaney, L G; Heinrich, J; Hellings, P W; Hooper, J; Humbert, M; Hyland, M; Iaccarino, G; Jakovenko, D; Jardim, J R; Jeandel, C; Jenkins, C; Johnston, S L; Jonquet, O; Joos, G; Jung, K S; Kalayci, O; Karunanithi, S; Keil, T; Khaltaev, N; Kolek, V; Kowalski, M L; Kull, I; Kuna, P; Kvedariene, V; Le, L T; Lodrup Carlsen, K C; Louis, R; MacNee, W; Mair, A; Majer, I; Manning, P; de Manuel Keenoy, E; Masjedi, M R; Melen, E; Melo-Gomes, E; Menzies-Gow, A; Mercier, G; Mercier, J; Michel, J P; Miculinic, N; Mihaltan, F; Milenkovic, B; Molimard, M; Momas, I; Montilla-Santana, A; Morais-Almeida, M; Morgan, M; N'Diaye, M; Nafti, S; Nekam, K; Neou, A; Nicod, L; O'Hehir, R; Ohta, K; Paggiaro, P; Palkonen, S; Palmer, S; Papadopoulos, N G; Papi, A; Passalacqua, G; Pavord, I; Pigearias, B; Plavec, D; Postma, D S; Price, D; Rabe, K F; Radier Pontal, F; Redon, J; Rennard, S; Roberts, J; Robine, J M; Roca, J; Roche, N; Rodenas, F; Roggeri, A; Rolland, C; Rosado-Pinto, J; Ryan, D; Samolinski, B; Sanchez-Borges, M; Schünemann, H J; Sheikh, A; Shields, M; Siafakas, N; Sibille, Y; Similowski, T; Small, I; Sola-Morales, O; Sooronbaev, T; Stelmach, R; Sterk, P J; Stiris, T; Sud, P; Tellier, V; To, T; Todo-Bom, A; Triggiani, M; Valenta, R; Valero, A L; Valiulis, A; Valovirta, E; Van Ganse, E; Vandenplas, O; Vasankari, T; Vestbo, J; Vezzani, G; Viegi, G; Visier, L; Vogelmeier, C; Vontetsianos, T; Wagstaff, R; Wahn, U; Wallaert, B; Whalley, B; Wickman, M; Williams, D M; Wilson, N; Yawn, B P; Yiallouros, P K; Yorgancioglu, A; Yusuf, O M; Zar, H J; Zhong, N; Zidarn, M; Zuberbier, T

2014-08-01

The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers).

A Mechanism for Upper Airway Stability during Slow Wave Sleep

PubMed Central

McSharry, David G.; Saboisky, Julian P.; DeYoung, Pam; Matteis, Paul; Jordan, Amy S.; Trinder, John; Smales, Erik; Hess, Lauren; Guo, Mengshuang; Malhotra, Atul

2013-01-01

Study Objectives: The severity of obstructive sleep apnea is diminished (sometimes markedly) during slow wave sleep (SWS). We sought to understand why SWS stabilizes the upper airway. Increased single motor unit (SMU) activity of the major upper airway dilating muscle (genioglossus) should improve upper airway stability. Therefore, we hypothesized that genioglossus SMUs would increase their activity during SWS in comparison with Stage N2 sleep. Design: The activity of genioglossus SMUs was studied on both sides of the transition between Stage N2 sleep and SWS. Setting: Sleep laboratory. Participants: Twenty-nine subjects (age 38 ± 13 yr, 17 males) were studied. Intervention: SWS. Measurement and Results: Subjects slept overnight with fine-wire electrodes in their genioglossus muscles and with full polysomnographic and end tidal carbon dioxide monitors. Fifteen inspiratory phasic (IP) and 11 inspiratory tonic (IT) units were identified from seven subjects and these units exhibited significantly increased inspiratory discharge frequencies during SWS compared with Stage N2 sleep. The peak discharge frequency of the inspiratory units (IP and IT) was 22.7 ± 4.1 Hz in SWS versus 20.3 ± 4.5 Hz in Stage N2 (P < 0.001). The IP units also fired for a longer duration (expressed as a percentage of inspiratory time) during SWS (104.6 ± 39.5 %TI) versus Stage N2 sleep (82.6 ± 39.5 %TI, P < 0.001). The IT units fired faster during expiration in SWS (14.2 ± 1.8 Hz) versus Stage N2 sleep (12.6 ± 3.1 Hz, P = 0.035). There was minimal recruitment or derecruitment of units between SWS and Stage N2 sleep. Conclusion: Increased genioglossus SMU activity likely makes the airway more stable and resistant to collapse throughout the respiratory cycle during SWS. Citation: McSharry DG; Saboisky JP; DeYoung P; Matteis P; Jordan AS; Trinder J; Smales E; Hess L; Guo M; Malhotra A. A mechanism for upper airway stability during slow wave sleep. SLEEP 2013;36(4):555-563. PMID:23565001

Inactivation of the Radiation-Resistant Spoilage Bacterium Micrococcus radiodurans

PubMed Central

Duggan, D. E.; Anderson, A. W.; Elliker, P. R.

1963-01-01

A simplified technique permitting the pipetting of raw puréed meats for quantitative bacteriological study is described for use in determining survival of these non-sporing bacteria, which are exceptionally resistant to radiation. Survival curves, using gamma radiation as the sterilizing agent, were determined in raw beef with four strains of Micrococcus radiodurans. Survival curves of the R1 strain in other meat substrates showed that survival was significantly greater in raw beef and raw chicken than in raw fish or in cooked beef. Resistance was lowest in the buffer. Cells grown in broth (an artificial growth medium) and resuspended in beef did not differ in resistance from cells that had been grown and irradiated in beef. Survival rate was statistically independent of the initial cell concentration, even though there appeared to be a correlation between lower death rate and lower initial cell concentrations. The initial viable count of this culture of the domesticated R1 strain in beef was reduced by a factor of about 10-5 by 3.0 megarad, and 4.0 megarad reduced the initial count by a factor of more than 10-9. Data suggest that M. radiodurans R1 is more resistant to radiation than spore-forming spoilage bacteria for which inactivation rates have been published. PMID:14063780

Aerosolized neutral endopeptidase reverses ozone-induced airway hyperreactivity to substance P.

PubMed

Murlas, C G; Lang, Z; Williams, G J; Chodimella, V

1992-03-01

We investigated the effects of ozone exposure (3.0 ppm, 2 h) on airway neutral endopeptidase (NEP) activity and bronchial reactivity to substance P in guinea pigs. Reactivity after ozone or air exposure was determined by measuring specific airway resistance in intact unanesthetized spontaneously breathing animals in response to increasing doses of intravenous substance P boluses. The effective dose of substance P (in micrograms) that produced a doubling of baseline specific airway resistance (ED200SP) was determined by interpolation of cumulative substance P dose-response curves. NEP activity was measured in tracheal homogenates made from each animal of other groups exposed to either ozone or room air. By reverse-phase high-pressure liquid chromatography, this activity was characterized by the phosphoramidon-inhibitable cleavage of alanine-p-nitroaniline from succinyl-(Ala)3-p-nitroaniline in the presence of 100 microM amastatin. Mean values of the changes in log ED200SP were 0.27 +/- 0.07 (SE) for the ozone-exposed group and 0.08 +/- 0.04 for the air-exposed group. We found that phosphoramidon significantly increased substance P reactivity in the air-exposed animals (P less than 0.01), but it had no effect in the ozone-exposed group. This finding was associated with a significant reduction in tracheal homogenate NEP activity of ozone-exposed animals compared with controls: mean values were 18.1 +/- 1.9 nmol.min-1.mg protein-1 for the ozone-exposed group and 25.1 +/- 2.4 nmol.min-1.mg protein-1 for air-exposed animals (P less than 0.05). Inhalation of an aerosolized NEP preparation, partially purified from guinea pig kidney, reversed the substance P hyperreactivity produced by ozone exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosolized neutral endopeptidase reverses ozone-induced airway hyperreactivity to substance P

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murlas, C.G.; Lang, Z.; Williams, G.J.

1992-03-01

The authors investigated the effects of ozone exposure (3.0 ppm, 2 h) on airway neutral endopeptidase (NEP) activity and bronchial reactivity to substance P in guinea pigs. Reactivity after ozone or air exposure was determined by measuring specific airway resistance in intact unanesthetized spontaneously breathing animals in response to increasing doses of intravenous substance P boluses. The effective dose of substance P (in micrograms) that produced a doubling of baseline specific airway resistance (ED200SP) was determined by interpolation of cumulative substance P dose-response curves. NEP activity was measured in tracheal homogenates made from each animal of other groups exposed tomore » either ozone or room air. By reverse-phase high-pressure liquid chromatography, this activity was characterized by the phosphoramidon-inhibitable cleavage of alanine-p-nitroaniline from succinyl-(Ala)3-p-nitroaniline in the presence of 100 microM amastatin. Mean values of the changes in log ED200SP were 0.27 +/- 0.07 (SE) for the ozone-exposed group and 0.08 +/- 0.04 for the air-exposed group. We found that phosphoramidon significantly increased substance P reactivity in the air-exposed animals (P less than 0.01), but it had no effect in the ozone-exposed group. This finding was associated with a significant reduction in tracheal homogenate NEP activity of ozone-exposed animals compared with controls: mean values were 18.1 +/- 1.9 nmol.min-1.mg protein-1 for the ozone-exposed group and 25.1 +/- 2.4 nmol.min-1.mg protein-1 for air-exposed animals (P less than 0.05). Inhalation of an aerosolized NEP preparation, partially purified from guinea pig kidney, reversed the substance P hyperreactivity produced by ozone exposure.(ABSTRACT TRUNCATED AT 250 WORDS)« less

Genetic deletion of apolipoprotein A-I increases airway hyperresponsiveness, inflammation, and collagen deposition in the lung

PubMed Central

Wang, Weiling; Xu, Hao; Shi, Yang; Nandedkar, Sandhya; Zhang, Hao; Gao, Haiqing; Feroah, Thom; Weihrauch, Dorothee; Schulte, Marie L.; Jones, Deron W.; Jarzembowski, Jason; Sorci-Thomas, Mary; Pritchard, Kirkwood A.

2010-01-01

The relationship between high-density lipoprotein and pulmonary function is unclear. To determine mechanistic relationships we investigated the effects of genetic deletion of apolipoprotein A-I (apoA-I) on plasma lipids, paraoxonase (PON1), pro-inflammatory HDL (p-HDL), vasodilatation, airway hyperresponsiveness and pulmonary oxidative stress, and inflammation. ApoA-I null (apoA-I−/−) mice had reduced total and HDL cholesterol but increased pro-inflammatory HDL compared with C57BL/6J mice. Although PON1 protein was increased in apoA-I−/− mice, PON1 activity was decreased. ApoA-I deficiency did not alter vasodilatation of facialis arteries, but it did alter relaxation responses of pulmonary arteries. Central airway resistance was unaltered. However, airway resistance mediated by tissue dampening and elastance were increased in apoA-I−/− mice, a finding also confirmed by positive end-expiratory pressure (PEEP) studies. Inflammatory cells, collagen deposition, 3-nitrotyrosine, and 4-hydroxy-2-nonenal were increased in apoA-I−/− lungs but not oxidized phospholipids. Colocalization of 4-hydroxy-2-nonenal with transforming growth factor β-1 (TGFβ-1 was increased in apoA-I−/− lungs. Xanthine oxidase, myeloperoxidase and endothelial nitric oxide synthase were increased in apoA-I−/− lungs. Dichlorodihydrofluorescein-detectable oxidants were increased in bronchoalveolar lavage fluid (BALF) in apoA-I−/− mice. In contrast, BALF nitrite+nitrate levels were decreased in apoA-I−/− mice. These data demonstrate that apoA-I plays important roles in limiting pulmonary inflammation and oxidative stress, which if not prevented, will decrease pulmonary artery vasodilatation and increase airway hyperresponsiveness. PMID:20498409

Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

PubMed

Boopathy, Raj

2017-09-01

The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanical Properties of the Upper Airway

PubMed Central

Strohl, Kingman P.; Butler, James P.; Malhotra, Atul

2013-01-01

The importance of the upper airway (nose, pharynx, and larynx) in health and in the pathogenesis of sleep apnea, asthma, and other airway diseases, discussed elsewhere in the Comprehensive Physiology series, prompts this review of the biomechanical properties and functional aspects of the upper airway. There is a literature based on anatomic or structural descriptions in static circumstances, albeit studied in limited numbers of individuals in both health and disease. As for dynamic features, the literature is limited to studies of pressure and flow through all or parts of the upper airway and to the effects of muscle activation on such features; however, the links between structure and function through airway size, shape, and compliance remain a topic that is completely open for investigation, particularly through analyses using concepts of fluid and structural mechanics. Throughout are included both historically seminal references, as well as those serving as signposts or updated reviews. This article should be considered a resource for concepts needed for the application of biomechanical models of upper airway physiology, applicable to understanding the pathophysiology of disease and anticipated results of treatment interventions. PMID:23723026

[Small airway diseases and immune deficiency].

PubMed

Burgel, P-R; Bergeron, A; Knoop, C; Dusser, D

2016-02-01

Innate or acquired immune deficiency may show respiratory manifestations, often characterized by small airway involvement. The purpose of this article is to provide an overview of small airway disease across the major causes of immune deficiency. In patients with common variable immune deficiency, recurrent lower airway infections may lead to bronchiolitis and bronchiectasis. Follicular and/or granulomatous bronchiolitis of unknown origin may also occur. Bronchiolitis obliterans is the leading cause of death after the first year in patients with lung transplantation. Bronchiolitis obliterans also occurs in patients with allogeneic haematopoietic stem cell transplantation, especially in the context of systemic graft-versus-host disease. Small airway diseases have different clinical expression and pathophysiology across various causes of immune deficiency. A better understanding of small airways disease pathogenesis in these settings may lead to the development of novel targeted therapies. Copyright © 2015 SPLF. Published by Elsevier Masson SAS. All rights reserved.

How anaesthesiologists understand difficult airway guidelines-an interview study.

PubMed

Knudsen, Kati; Pöder, Ulrika; Nilsson, Ulrica; Högman, Marieann; Larsson, Anders; Larsson, Jan

2017-11-01

In the practice of anaesthesia, clinical guidelines that aim to improve the safety of airway procedures have been developed. The aim of this study was to explore how anaesthesiologists understand or conceive of difficult airway management algorithms. A qualitative phenomenographic design was chosen to explore anaesthesiologists' views on airway algorithms. Anaesthesiologists working in three hospitals were included. Individual face-to-face interviews were conducted. Four different ways of understanding were identified, describing airway algorithms as: (A) a law-like rule for how to act in difficult airway situations; (B) a cognitive aid, an action plan for difficult airway situations; (C) a basis for developing flexible, personal action plans for the difficult airway; and (D) the experts' consensus, a set of scientifically based guidelines for handling the difficult airway. The interviewed anaesthesiologists understood difficult airway management guidelines/algorithms very differently.

Gene Delivery to the Airway

PubMed Central

Keiser, Nicholas W.; Engelhardt, John F.

2013-01-01

This unit describes generation of and gene transfer to several commonly used airway models. Isolation and transduction of primary airway epithelial cells are first described. Next, the preparation of polarized airway epithelial monolayers is outlined. Transduction of these polarized cells is also described. Methods are presented for generation of tracheal xenografts as well as both ex vivo and in vivo gene transfer to these xenografts. Finally, a method for in vivo gene delivery to the lungs of rodents is included. Methods for evaluating transgene expression are given in the support protocols. PMID:23853081

Detection of Salmonella spp. in Retail Raw Food Samples from Vietnam and Characterization of Their Antibiotic Resistance▿

PubMed Central

Van, Thi Thu Hao; Moutafis, George; Istivan, Taghrid; Tran, Linh Thuoc; Coloe, Peter J.

2007-01-01

A study was conducted to examine the levels of Salmonella spp. contamination in raw food samples, including chicken, beef, pork, and shellfish, from Vietnam and to determine their antibiotic resistance characteristics. A total of 180 samples were collected and examined for the presence of Salmonella spp., yielding 91 Salmonella isolates. Sixty-one percent of meat and 18% of shellfish samples were contaminated with Salmonella spp. Susceptibility of all isolates to a variety of antimicrobial agents was tested, and resistance to tetracycline, ampicillin/amoxicillin, nalidixic acid, sulfafurazole, and streptomycin was found in 40.7%, 22.0%, 18.7%, 16.5%, and 14.3% of the isolates, respectively. Resistance to enrofloxacin, trimethoprim, chloramphenicol, kanamycin, and gentamicin was also detected (8.8 to 2.2%). About half (50.5%) of the isolates were resistant to at least one antibiotic, and multiresistant Salmonella isolates, resistant to at least three different classes of antibiotics, were isolated from all food types. One isolate from chicken (serovar Albany) contained a variant of the Salmonella genomic island 1 antibiotic resistance gene cluster. The results show that antibiotic resistance in Salmonella spp. in raw food samples from Vietnam is significant. PMID:17766455

CFTR rescue with VX-809 and VX-770 favors the repair of primary airway epithelial cell cultures from patients with class II mutations in the presence of Pseudomonas aeruginosa exoproducts.

PubMed

Adam, Damien; Bilodeau, Claudia; Sognigbé, Laura; Maillé, Émilie; Ruffin, Manon; Brochiero, Emmanuelle

2018-04-13

Progressive airway damage due to bacterial infections, especially with Pseudomonas aeruginosa remains the first cause of morbidity and mortality in CF patients. Our previous work revealed a repair delay in CF airway epithelia compared to non-CF. This delay was partially prevented after CFTR correction (with VRT-325) in the absence of infection. Our goals were now to evaluate the effect of the Orkambi combination (CFTR VX-809 corrector + VX-770 potentiator) on the repair of CF primary airway epithelia, in infectious conditions. Primary airway epithelial cell cultures from patients with class II mutations were mechanically injured and wound healing rates and transepithelial resistances were monitored after CFTR rescue, in the absence and presence of P. aeruginosa exoproducts. Our data revealed that combined treatment with VX-809 and VX-770 elicited a greater beneficial impact on airway epithelial repair than VX-809 alone, in the absence of infection. The treatment with Orkambi was effective not only in airway epithelial cell cultures from patients homozygous for the F508del mutation but also from heterozygous patients carrying F508del and another class II mutation (N1303 K, I507del). The stimulatory effect of the Orkambi treatment was prevented by CFTR inhibition with GlyH101. Finally, Orkambi combination elicited a slight but significant improvement in airway epithelial repair and transepithelial resistance, despite the presence of P. aeruginosa exoproducts. Our findings indicate that Orkambi may favor airway epithelial integrity in CF patients with class II mutations. Complementary approaches would however be needed to further improve CFTR rescue and airway epithelial repair. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Are new supraglottic airway devices, tracheal tubes and airway viewing devices cost-effective?

PubMed

Slinn, Simon J; Froom, Stephen R; Stacey, Mark R W; Gildersleve, Christopher D

2015-01-01

Over the past two decades, a plethora of new airway devices has become available to the pediatric anesthetist. While all have the laudable intention of improving patient care and some have proven clinical benefits, these devices are often costly and at times claims of an advantage over current equipment and techniques are marginal. Supraglottic airway devices are used in the majority of pediatric anesthetics delivered in the U.K., and airway-viewing devices provide an alternative for routine intubation as well as an option in the management of the difficult airway. Yet hidden beneath the convenience of the former and the technology of the latter, the impact on basic airway skills with a facemask and the lack of opportunities to fine-tune the core skill of intubation represent an unrecognised and unquantifiable cost. A judgement on this value must be factored into the absolute purchase cost and any potential benefits to the quality of patient care, thus blurring any judgement on cost-effectiveness that we might have. An overall value on cost-effectiveness though not in strict monetary terms can then be ascribed. In this review, we evaluate the role of these devices in the care of the pediatric patient and attempt to balance the advantages they offer against the cost they incur, both financial and environmental, and in any quality improvement they might offer in clinical care. © 2014 John Wiley & Sons Ltd.

How anaesthesiologists understand difficult airway guidelines—an interview study

PubMed Central

Knudsen, Kati; Nilsson, Ulrica; Larsson, Anders; Larsson, Jan

2017-01-01

Background In the practice of anaesthesia, clinical guidelines that aim to improve the safety of airway procedures have been developed. The aim of this study was to explore how anaesthesiologists understand or conceive of difficult airway management algorithms. Methods A qualitative phenomenographic design was chosen to explore anaesthesiologists’ views on airway algorithms. Anaesthesiologists working in three hospitals were included. Individual face-to-face interviews were conducted. Results Four different ways of understanding were identified, describing airway algorithms as: (A) a law-like rule for how to act in difficult airway situations; (B) a cognitive aid, an action plan for difficult airway situations; (C) a basis for developing flexible, personal action plans for the difficult airway; and (D) the experts’ consensus, a set of scientifically based guidelines for handling the difficult airway. Conclusions The interviewed anaesthesiologists understood difficult airway management guidelines/algorithms very differently. PMID:29299973

Role of substance P and neurokinin A in toluene diisocyanate-induced increased airway responsiveness in rabbits.

PubMed

Marek, W; Potthast, J J; Marcynski, B; Baur, X

1996-01-01

The aim of the present study was to examine the role of neuropeptides, especially substance P (SP) and neurokinin A (NKA), in toluene diisocyanate (TDI)-induced airway hyperresponsiveness (AHR) to acetylcholine aerosols. Thirty parts per billion of TDI in air administered over 4 hours caused a significant increase in the airway constrictive response to acetylcholine (ACH) aerosols in rabbits (DeltaRI: 245 +/- 30%, p < 0.005) without altering basic values of respiratory, cardiovascular or blood gas parameters. Inhalation of the aerosolized neuropeptides SP and NKA resulted in a similar increase in airway responsiveness (AR) to ACH as exposure to 30 ppb TDI. To determine whether neuropeptides contribute to TDI-induced AHR, we studied their effects after systemic treatment with capsaicin as well as after infusion of specific synthetic antagonists for SP and NK2 (NKA) receptors. CAPS treatment performed on 4 consecutive days as well as antagonists' infusion only moderately (p > 0.05) decreased airway responses to ACH. CAPS application prevented the TDI-induced increase in AR to ACH in all rabbits. The increase in airway resistance to ACH did not significantly change after TDI exposure (98 +/- 22% of the control response before TDI, p > 0.05). Simultaneous infusion of specific synthetic SP and NK2 receptor antagonists also abolished the TDI-induced increase in airway responses to ACH in all animals investigated (p > 0.05). The results of this study demonstrate that neuropeptides, especially the tachykinins SP and NKA, are important mediators in TDI-induced AHR in rabbits.

Electronic cigarette inhalation alters innate immunity and airway cytokines while increasing the virulence of colonizing bacteria.

PubMed

Hwang, John H; Lyes, Matthew; Sladewski, Katherine; Enany, Shymaa; McEachern, Elisa; Mathew, Denzil P; Das, Soumita; Moshensky, Alexander; Bapat, Sagar; Pride, David T; Ongkeko, Weg M; Crotty Alexander, Laura E

2016-06-01

Electronic (e)-cigarette use is rapidly rising, with 20 % of Americans ages 25-44 now using these drug delivery devices. E-cigarette users expose their airways, cells of host defense, and colonizing bacteria to e-cigarette vapor (EV). Here, we report that exposure of human epithelial cells at the air-liquid interface to fresh EV (vaped from an e-cigarette device) resulted in dose-dependent cell death. After exposure to EV, cells of host defense-epithelial cells, alveolar macrophages, and neutrophils-had reduced antimicrobial activity against Staphylococcus aureus (SA). Mouse inhalation of EV for 1 h daily for 4 weeks led to alterations in inflammatory markers within the airways and elevation of an acute phase reactant in serum. Upon exposure to e-cigarette vapor extract (EVE), airway colonizer SA had increased biofilm formation, adherence and invasion of epithelial cells, resistance to human antimicrobial peptide LL-37, and up-regulation of virulence genes. EVE-exposed SA were more virulent in a mouse model of pneumonia. These data suggest that e-cigarettes may be toxic to airway cells, suppress host defenses, and promote inflammation over time, while also promoting virulence of colonizing bacteria. Acute exposure to e-cigarette vapor (EV) is cytotoxic to airway cells in vitro. Acute exposure to EV decreases macrophage and neutrophil antimicrobial function. Inhalation of EV alters immunomodulating cytokines in the airways of mice. Inhalation of EV leads to increased markers of inflammation in BAL and serum. Staphylococcus aureus become more virulent when exposed to EV.

Effects of Ginger and Its Constituents on Airway Smooth Muscle Relaxation and Calcium Regulation

PubMed Central

Siviski, Matthew E.; Zhang, Yi; Xu, Carrie; Hoonjan, Bhupinder; Emala, Charles W.

2013-01-01

The prevalence of asthma has increased in recent years, and is characterized by airway hyperresponsiveness and inflammation. Many patients report using alternative therapies to self-treat asthma symptoms as adjuncts to short-acting and long-acting β-agonists and inhaled corticosteroids (ICS). As many as 40% of patients with asthma use herbal therapies to manage asthma symptoms, often without proven efficacy or known mechanisms of action. Therefore, investigations of both the therapeutic and possible detrimental effects of isolated components of herbal treatments on the airway are important. We hypothesized that ginger and its active components induce bronchodilation by modulating intracellular calcium ([Ca2+]i) in airway smooth muscle (ASM). In isolated human ASM, ginger caused significant and rapid relaxation. Four purified constituents of ginger were subsequently tested for ASM relaxant properties in both guinea pig and human tracheas: [6]-gingerol, [8]-gingerol, and [6]-shogaol induced rapid relaxation of precontracted ASM (100–300 μM), whereas [10]-gingerol failed to induce relaxation. In human ASM cells, exposure to [6]-gingerol, [8]-gingerol, and [6]-shogaol, but not [10]-gingerol (100 μM), blunted subsequent Ca2+ responses to bradykinin (10 μM) and S-(−)-Bay K 8644 (10 μM). In A/J mice, the nebulization of [8]-gingerol (100 μM), 15 minutes before methacholine challenge, significantly attenuated airway resistance, compared with vehicle. Taken together, these novel data show that ginger and its isolated active components, [6]-gingerol, [8]-gingerol, and [6]-shogaol, relax ASM, and [8]-gingerol attenuates airway hyperresponsiveness, in part by altering [Ca2+]i regulation. These purified compounds may provide a therapeutic option alone or in combination with accepted therapeutics, including β2-agonists, in airway diseases such as asthma. PMID:23065130

Parsing and Quantification of Raw Orbitrap Mass Spectrometer Data Using RawQuant.

PubMed

Kovalchik, Kevin A; Moggridge, Sophie; Chen, David D Y; Morin, Gregg B; Hughes, Christopher S

2018-06-01

Effective analysis of protein samples by mass spectrometry (MS) requires careful selection and optimization of a range of experimental parameters. As the output from the primary detection device, the "raw" MS data file can be used to gauge the success of a given sample analysis. However, the closed-source nature of the standard raw MS file can complicate effective parsing of the data contained within. To ease and increase the range of analyses possible, the RawQuant tool was developed to enable parsing of raw MS files derived from Thermo Orbitrap instruments to yield meta and scan data in an openly readable text format. RawQuant can be commanded to export user-friendly files containing MS 1 , MS 2 , and MS 3 metadata as well as matrices of quantification values based on isobaric tagging approaches. In this study, the utility of RawQuant is demonstrated in several scenarios: (1) reanalysis of shotgun proteomics data for the identification of the human proteome, (2) reanalysis of experiments utilizing isobaric tagging for whole-proteome quantification, and (3) analysis of a novel bacterial proteome and synthetic peptide mixture for assessing quantification accuracy when using isobaric tags. Together, these analyses successfully demonstrate RawQuant for the efficient parsing and quantification of data from raw Thermo Orbitrap MS files acquired in a range of common proteomics experiments. In addition, the individual analyses using RawQuant highlights parametric considerations in the different experimental sets and suggests targetable areas to improve depth of coverage in identification-focused studies and quantification accuracy when using isobaric tags.

Counts, serovars, and antimicrobial resistance phenotypes of Salmonella on raw chicken meat at retail in Colombia.

PubMed

Donado-Godoy, Pilar; Clavijo, Viviana; León, Maribel; Arevalo, Alejandra; Castellanos, Ricardo; Bernal, Johan; Tafur, Mc Allister; Ovalle, Maria Victoria; Alali, Walid Q; Hume, Michael; Romero-Zuñiga, Juan Jose; Walls, Isabel; Doyle, Michael P

2014-02-01

The objective of this study was to determine Salmonella counts, serovars, and antimicrobial-resistant phenotypes on retail raw chicken carcasses in Colombia. A total of 301 chicken carcasses were collected from six departments (one city per department) in Colombia. Samples were analyzed for Salmonella counts using the most-probable-number method as recommended by the U.S. Department of Agriculture, Food Safety Inspection Service protocol. A total of 378 isolates (268 from our previous study) were serotyped and tested for antimicrobial susceptibility. The overall Salmonella count (mean log most probable number per carcass ± 95% confidence interval) and prevalence were 2.1 (2.0 to 2.3) and 37%, respectively. There were significant differences (P < 0.05) by Salmonella levels (i.e., counts and prevalence) by storage temperature (i.e., frozen, chilled, or ambient), retail store type (wet markets, supermarkets, and independent markets), and poultry company (chicken produced by integrated or nonintegrated company). Frozen chicken had the lowest Salmonella levels compared with chicken stored at other temperatures, chickens from wet markets had higher levels than those from other retail store types, and chicken produced by integrated companies had lower levels than nonintegrated companies. Thirty-one Salmonella serovars were identified among 378 isolates, with Salmonella Paratyphi B tartrate-positive (i.e., Salmonella Paratyphi B dT+) the most prevalent (44.7%), followed by Heidelberg (19%), Enteritidis (17.7%), Typhimurium (5.3%), and Anatum (2.1%). Of all the Salmonella isolates, 35.2% were resistant to 1 to 5 antimicrobial agents, 24.6% to 6 to 10, and 33.9% to 11 to 15. Among all the serovars obtained, Salmonella Paratyphi B dT+ and Salmonella Heidelberg were the most antimicrobial resistant. Salmonella prevalence was determined to be high, whereas cell numbers were relatively low. These data can be used in developing risk assessment models for preventing the

Nerve growth factor-enhanced airway responsiveness involves substance P in ferret intrinsic airway neurons.

PubMed

Wu, Z-X; Dey, R D

2006-07-01

Nerve growth factor (NGF), a member of the neurotrophin family, enhances synthesis of neuropeptides in sensory and sympathetic neurons. The aim of this study was to examine the effect of NGF on airway responsiveness and determine whether these effects are mediated through synthesis and release of substance P (SP) from the intrinsic airway neurons. Ferrets were instilled intratracheally with NGF or saline. Tracheal smooth muscle contractility to methacholine and electrical field stimulation (EFS) was assessed in vitro. Contractions of isolated tracheal smooth muscle to EFS at 10 and 30 Hz were significantly increased in the NGF treatment group (10 Hz: 33.57 +/- 2.44%; 30 Hz: 40.12 +/- 2.78%) compared with the control group (10 Hz: 27.24 +/- 2.14%; 30 Hz: 33.33 +/- 2.31%). However, constrictive response to cholinergic agonist was not significantly altered between the NGF treatment group and the control group. The NGF-induced modulation of airway smooth muscle to EFS was maintained in tracheal segments cultured for 24 h, a procedure that causes a significant anatomic and functional loss of SP-containing sensory fibers while maintaining viability of intrinsic airway neurons. The number of SP-containing neurons in longitudinal trunk and superficial muscular plexus and SP nerve fiber density in tracheal smooth muscle all increased significantly in cultured trachea treated with NGF. Pretreatment with CP-99994, an antagonist of neurokinin 1 receptor, attenuated the NGF-induced increased contraction to EFS in cultured segments but had no effect in saline controls. These results show that the NGF-enhanced airway smooth muscle contractile responses to EFS are mediated by the actions of SP released from intrinsic airway neurons.

Air-Q intubating laryngeal airway: A study of the second generation supraglottic airway device.

PubMed

Attarde, Viren Bhaskar; Kotekar, Nalini; Shetty, Sarika M

2016-05-01

Air-Q intubating laryngeal mask airway (ILA) is used as a supraglottic airway device and as a conduit for endotracheal intubation. This study aims to assess the efficacy of the Air-Q ILA regarding ease of insertion, adequacy of ventilation, rate of successful intubation, haemodynamic response and airway morbidity. Sixty patients presenting for elective surgery at our Medical College Hospital were selected. Following adequate premedication, baseline vital parameters, pulse rate and blood pressure were recorded. Air-Q size 3.5 for patients 50-70 kg and size 4.5 for 70-100 kg was selected. After achieving adequate intubating conditions, Air-Q ILA was introduced. Confirming adequate ventilation, appropriate sized endotracheal tube was advanced through the Air-Q blindly to intubate the trachea. Placement of the endotracheal tube in trachea was confirmed. Air-Q ILA was successfully inserted in 88.3% of patients in first attempt and 11.7% patients in second attempt. Ventilation was adequate in 100% of patients. Intubation was successful in 76.7% of patients with Air-Q ILA. 23.3% of patients were intubated by direct laryngoscopy following failure with two attempts using Air-Q ILA. Post-intubation the change in heart rate was statistically significant (P < 0.0001). 10% of patients were noted to have a sore throat and 5% of patients had mild airway trauma. Air-Q ILA is a reliable device as a supraglottic airway ensuring adequate ventilation as well as a conduit for endotracheal intubation. It benefits the patient by avoiding the stress of direct laryngoscopy and is also superior alternative device for use in a difficult airway.

Retinoic acid reverses the airway hyperresponsiveness but not the parenchymal defect that is associated with vitamin A deficiency.

PubMed

McGowan, Stephen E; Holmes, Amey Jo; Smith, Jennifer

2004-02-01

Airway hyperresponsiveness (AHR) is influenced by structural components of the bronchial wall, including the smooth muscle and connective tissue elements and the neuromuscular function. AHR is also influenced by parenchymally derived tethering forces on the bronchial wall, which maintain airway caliber by producing outward radial traction. Our previous work has shown that vitamin A-deficient (VAD) rats exhibit cholinergic hyperresponsiveness and a decrease in the expression and function of the muscarinic-2 receptors (M2R). We hypothesized that if decreases in radial traction from airway or parenchymal structures contributed to the VAD-related increase in AHR, then the radial traction would normalize more slowly than VAD-related alterations in neurotransmitter signaling. Rats remained vitamin A sufficient (VAS) or were rendered VAD and then maintained on the VAD diet in the presence or absence of supplementation with all-trans retinoic acid (RA). VAD was associated with an approximately twofold increase in respiratory resistance and elastance compared with VAS rats. Exposure to RA for 12 days but not 4 days restored resistance and elastance to control (VAS) levels. In VAD rats, AHR was accompanied by decreases in bronchial M2R gene expression and function, which were restored after 12 days of RA supplementation. Subepithelial bronchial elastic fibers were decreased by approximately 50% in VAD rats and were significantly restored by RA. The increase in AHR that is associated with VAD is accompanied by decreases in M2R expression and function that can be restored by RA and a reduction in airway elastic fibers that can be partially restored by RA.

Use of a Supraglottic Airway to Relieve Ventilation-Impeding Gastric Insufflation During Emergency Airway Management in an Infant.

PubMed

Dodd, Kenneth W; Strobel, Ashley M; Driver, Brian E; Reardon, Robert F

2016-10-01

Positive-pressure bag-valve-mask ventilation during emergency airway management often results in significant gastric insufflation, which may impede adequate ventilation and oxygenation. Current-generation supraglottic airways have beneficial features, such as channels for gastric decompression while ventilation is ongoing. A 5-week-old female infant required resuscitation for hypoxemic respiratory failure caused by rhinovirus with pneumonia. Bag-valve-mask ventilation led to gastric insufflation that compromised ventilation, thereby interfering with intubation because of precipitous oxygen desaturation during laryngoscopy. A current-generation supraglottic airway (LMA Supreme; Teleflex Inc, Morrisville, NC) was used to facilitate gastric decompression while ventilation and oxygenation was ongoing. After gastric decompression, ventilation was markedly improved and the pulse oxygen saturation improved to 100%. Intubation was successful on the next attempt, without oxygen desaturation. Current-generation supraglottic airways have 3 distinct advantages compared with first-generation supraglottic airways, which make them better devices for emergency airway management: gastric decompression ports, conduits for intubation, and higher oropharyngeal leak pressures. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Deletion of Pten Expands Lung Epithelial Progenitor Pools and Confers Resistance to Airway Injury

PubMed Central

Tiozzo, Caterina; De Langhe, Stijn; Yu, Mingke; Londhe, Vedang A.; Carraro, Gianni; Li, Min; Li, Changgong; Xing, Yiming; Anderson, Stewart; Borok, Zea; Bellusci, Saverio; Minoo, Parviz

2009-01-01

Rationale: Pten is a tumor-suppressor gene involved in stem cell homeostasis and tumorigenesis. In mouse, Pten expression is ubiquitous and begins as early as 7 days of gestation. Pten−/− mouse embryos die early during gestation indicating a critical role for Pten in embryonic development. Objectives: To test the role of Pten in lung development and injury. Methods: We conditionally deleted Pten throughout the lung epithelium by crossing Ptenflox/flox with Nkx2.1-cre driver mice. The resulting PtenNkx2.1-cre mutants were analyzed for lung defects and response to injury. Measurements and Main Results: PtenNkx2.1-cre embryonic lungs showed airway epithelial hyperplasia with no branching abnormalities. In adult mice, PtenNkx2.1-cre lungs exhibit increased progenitor cell pools composed of basal cells in the trachea, CGRP/CC10 double-positive neuroendocrine cells in the bronchi, and CC10/SPC double-positive cells at the bronchioalveolar duct junctions. Pten deletion affected differentiation of various lung epithelial cell lineages, with a decreased number of terminally differentiated cells. Over time, PtenNxk2.1-cre epithelial cells residing in the bronchioalveolar duct junctions underwent proliferation and formed uniform masses, supporting the concept that the cells residing in this distal niche may also be the source of procarcinogenic stem cells. Finally, increased progenitor cells in all the lung compartments conferred an overall selective advantage to naphthalene injury compared with wild-type control mice. Conclusions: Pten has a pivotal role in lung stem cell homeostasis, cell differentiation, and consequently resistance to lung injury. PMID:19574443

ISMRM Raw Data Format: A Proposed Standard for MRI Raw Datasets

PubMed Central

Inati, Souheil J.; Naegele, Joseph D.; Zwart, Nicholas R.; Roopchansingh, Vinai; Lizak, Martin J.; Hansen, David C.; Liu, Chia-Ying; Atkinson, David; Kellman, Peter; Kozerke, Sebastian; Xue, Hui; Campbell-Washburn, Adrienne E.; Sørensen, Thomas S.; Hansen, Michael S.

2015-01-01

Purpose This work proposes the ISMRM Raw Data (ISMRMRD) format as a common MR raw data format, which promotes algorithm and data sharing. Methods A file format consisting of a flexible header and tagged frames of k-space data was designed. Application Programming Interfaces were implemented in C/C++, MATLAB, and Python. Converters for Bruker, General Electric, Philips, and Siemens proprietary file formats were implemented in C++. Raw data were collected using MRI scanners from four vendors, converted to ISMRMRD format, and reconstructed using software implemented in three programming languages (C++, MATLAB, Python). Results Images were obtained by reconstructing the raw data from all vendors. The source code, raw data, and images comprising this work are shared online, serving as an example of an image reconstruction project following a paradigm of reproducible research. Conclusion The proposed raw data format solves a practical problem for the MRI community. It may serve as a foundation for reproducible research and collaborations. The ISMRMRD format is a completely open and community-driven format, and the scientific community is invited (including commercial vendors) to participate either as users or developers. PMID:26822475

Baicalein Reduces Airway Injury in Allergen and IL-13 Induced Airway Inflammation

PubMed Central

Mabalirajan, Ulaganathan; Ahmad, Tanveer; Rehman, Rakhshinda; Leishangthem, Geeta Devi; Dinda, Amit Kumar; Agrawal, Anurag; Ghosh, Balaram; Sharma, Surendra Kumar

2013-01-01

Background Baicalein, a bioflavone present in the dry roots of Scutellaria baicalensis Georgi, is known to reduce eotaxin production in human fibroblasts. However, there are no reports of its anti-asthma activity or its effect on airway injury. Methodology/Principal Findings In a standard experimental asthma model, male Balb/c mice that were sensitized with ovalbumin (OVA), treated with baicalein (10 mg/kg, ip) or a vehicle control, either during (preventive use) or after OVA challenge (therapeutic use). In an alternate model, baicalein was administered to male Balb/c mice which were given either IL-4 or IL-13 intranasally. Features of asthma were determined by estimating airway hyperresponsiveness (AHR), histopathological changes and biochemical assays of key inflammatory molecules. Airway injury was determined with apoptotic assays, transmission electron microscopy and assessing key mitochondrial functions. Baicalein treatment reduced AHR and inflammation in both experimental models. TGF-β1, sub-epithelial fibrosis and goblet cell metaplasia, were also reduced. Furthermore, baicalein treatment significantly reduced 12/15-LOX activity, features of mitochondrial dysfunctions, and apoptosis of bronchial epithelia. Conclusion/Significance Our findings demonstrate that baicalein can attenuate important features of asthma, possibly through the reduction of airway injury and restoration of mitochondrial function. PMID:23646158

Definitive airway management of patients presenting with a pre-hospital inserted King LT(S)-D laryngeal tube airway: a historical cohort study.

PubMed

Subramanian, Arun; Garcia-Marcinkiewicz, Annery G; Brown, Daniel R; Brown, Michael J; Diedrich, Daniel A

2016-03-01

The King LT(S)-D laryngeal tube (King LT) has gained popularity as a bridge airway for pre-hospital airway management. In this study, we retrospectively reviewed the use of the King LT and its associated airway outcomes at a single Level 1 trauma centre. The data on all adult patients presenting to the Mayo Clinic in Rochester, Minnesota with a King LT in situ from July 1, 2007 to October 10, 2012 were retrospectively evaluated. Data collected and descriptively analyzed included patient demographics, comorbidities, etiology of respiratory failure, airway complications, subsequent definitive airway management technique, duration of mechanical ventilation, and status at discharge. Forty-eight adult patients met inclusion criteria. The most common etiology for respiratory failure requiring an artificial airway was cardiac arrest [28 (58%) patients] or trauma [9 (19%) patients]. Four of the nine trauma patients had facial trauma. Surgical tracheostomy was the definitive airway management technique in 14 (29%) patients. An airway exchange catheter, direct laryngoscopy, and video laryngoscopy were used in 11 (23%), ten (21%), and ten (21%) cases, respectively. Seven (78%) of the trauma patients underwent surgical tracheostomy compared with seven (18%) of the medical patients. Adverse events associated with King LT use occurred in 13 (27%) patients, with upper airway edema (i.e., tongue engorgement and glottic edema) being most common (19%). In this study of patients presenting to a hospital with a King LT, the majority of airway exchanges required an advanced airway management technique beyond direct laryngoscopy. Upper airway edema was the most common adverse observation associated with King LT use.

Analysis of the interplay between neurochemical control of respiration and upper airway mechanics producing upper airway obstruction during sleep in humans.

PubMed

Longobardo, G S; Evangelisti, C J; Cherniack, N S

2008-02-01

with hypercapnia and hypoxia could prevent obstructed apnoeas with moderate but not with severe reductions in stiffness. Increases in controller gain, as might occur with hypoxia, converted obstructive to central apnoeas. Breathing CO2 eliminated apnoeas when the activity of the upper airway muscles was considered to change as a function of CO2 to some exponent. Low arousal thresholds and increased upper airway resistance are two factors that promoted the occurrence and persistence of obstructive sleep apnoeas.

A Meta-Analysis of the Global Prevalence Rates of Staphylococcus aureus and Methicillin-Resistant S. aureus Contamination of Different Raw Meat Products.

PubMed

Ou, Qianting; Peng, Yang; Lin, Dongxin; Bai, Chan; Zhang, Ting; Lin, Jialing; Ye, Xiaohua; Yao, Zhenjiang

2017-03-30

Previous research has indicated that raw meats are frequently contaminated with Staphylococcus aureus , but data regarding the pooled prevalence rates of S. aureus and methicillin-resistant S. aureus (MRSA) contamination in different types of raw meat products (beef, chicken, and pork) and across different periods, regions, and purchase locations remain inconsistent. We systematically searched the PubMed, EMBASE, Ovid, Web of Science, and HighWire databases to identify studies published up to June 2016. The STROBE guidelines were used to assess the quality of the 39 studies included in this meta-analysis. We observed no significant differences in the pooled prevalence rates of S. aureus and MRSA contamination identified in various raw meat products, with overall pooled prevalence rates of 29.2% (95% confidence interval [CI], 22.8 to 35.9%) and 3.2% (95% CI, 1.8 to 4.9%) identified for the two contaminants, respectively. In the subgroup analyses, the prevalence of S. aureus contamination in chicken products was highest in Asian studies and significantly decreased over time worldwide. In European studies, the prevalence rates of S. aureus contamination in chicken and pork products were lower than those reported on other continents. The pooled prevalence rates of S. aureus contamination in chicken and pork products and MRSA contamination in beef and pork products were significantly higher in samples collected from retail sources than in samples collected from slaughterhouses and processing plants. These results highlight the need for good hygiene during transportation to and manipulation at retail outlets to reduce the risk of transmission of S. aureus and MRSA from meat products to humans.

Novel and emerging nonpositive airway pressure therapies for sleep apnea.

PubMed

Park, John G; Morgenthaler, Timothy M; Gay, Peter C

2013-12-01

CPAP therapy has remained the standard of care for the treatment of sleep apnea for nearly 4 decades. Its overall effectiveness, however, has been limited by incomplete adherence despite many efforts to improve comfort. Conventional alternative therapies include oral appliances and upper airway surgeries. Recently, several innovative alternatives to CPAP have been developed. These novel approaches include means to increase arousal thresholds, electrical nerve stimulation, oral vacuum devices, and nasal expiratory resistive devices. We will review the physiologic mechanisms and the current evidence for these novel treatments.

Antigen challenge induces pulmonary airway eosinophil accumulation and airway hyperreactivity in sensitized guinea-pigs: the effect of anti-asthma drugs.

PubMed Central

Sanjar, S.; Aoki, S.; Kristersson, A.; Smith, D.; Morley, J.

1990-01-01

1. Guinea-pigs were sensitized with 3 injections of ovalbumin (OA) (1 or 10 micrograms per animal) using Al(OH)3 and pertussis vaccine as adjuvants at two week intervals. 2. Sensitized guinea-pigs were challenged with an aerosol of OA (0.1%) over a one hour period and both airway reactivity and cellular content of bronchoalveolar lavage (BAL) fluid were assessed at intervals for up to 7 days. 3. Guinea-pigs sensitized with 1 microgram of ovalbumin responded to an aerosol of OA with increased pulmonary airway eosinophilia, which was evident 1 day after challenge and was present for up to 7 days. Airway hyperreactivity was not detectable in these animals. 4. Guinea-pigs sensitized with 10 micrograms of ovalbumin responded to an aerosol of OA with increased pulmonary airway neutrophilia and eosinophilia and with increased airway reactivity which was maximal between 8 and 24 h after exposure to OA. 5. Depletion of circulating platelets or neutrophils, by use of selective antisera, did not alter either the magnitude of eosinophilia or the intensity of airway reactivity in sensitized guinea-pigs (10 micrograms) exposed to an aerosol of OA. 6. Pretreatment of sensitized guinea-pigs (10 micrograms) for 6 days with AH 21-132, aminophylline, dexamethasone or ketotifen inhibited pulmonary airway eosinophilia, but did not diminish airway hyperreactivity. Neither eosinophil accumulation nor development of airway hyperreactivity was influenced by treatment with mepyramine or salbutamol over a 6 day period before OA inhalation. 7. Although eosinophilia may occur in association with increased airway reactivity in this animal model, there is no evidence of a causal relationship. PMID:2361168

A mechanism for upper airway stability during slow wave sleep.

PubMed

McSharry, David G; Saboisky, Julian P; Deyoung, Pam; Matteis, Paul; Jordan, Amy S; Trinder, John; Smales, Erik; Hess, Lauren; Guo, Mengshuang; Malhotra, Atul

2013-04-01

The severity of obstructive sleep apnea is diminished (sometimes markedly) during slow wave sleep (SWS). We sought to understand why SWS stabilizes the upper airway. Increased single motor unit (SMU) activity of the major upper airway dilating muscle (genioglossus) should improve upper airway stability. Therefore, we hypothesized that genioglossus SMUs would increase their activity during SWS in comparison with Stage N2 sleep. The activity of genioglossus SMUs was studied on both sides of the transition between Stage N2 sleep and SWS. Sleep laboratory. Twenty-nine subjects (age 38 ± 13 yr, 17 males) were studied. SWS. Subjects slept overnight with fine-wire electrodes in their genioglossus muscles and with full polysomnographic and end tidal carbon dioxide monitors. Fifteen inspiratory phasic (IP) and 11 inspiratory tonic (IT) units were identified from seven subjects and these units exhibited significantly increased inspiratory discharge frequencies during SWS compared with Stage N2 sleep. The peak discharge frequency of the inspiratory units (IP and IT) was 22.7 ± 4.1 Hz in SWS versus 20.3 ± 4.5 Hz in Stage N2 (P < 0.001). The IP units also fired for a longer duration (expressed as a percentage of inspiratory time) during SWS (104.6 ± 39.5 %TI) versus Stage N2 sleep (82.6 ± 39.5 %TI, P < 0.001). The IT units fired faster during expiration in SWS (14.2 ± 1.8 Hz) versus Stage N2 sleep (12.6 ± 3.1 Hz, P = 0.035). There was minimal recruitment or derecruitment of units between SWS and Stage N2 sleep. Increased genioglossus SMU activity likely makes the airway more stable and resistant to collapse throughout the respiratory cycle during SWS.

Dietary raw versus retrograded resistant starch enhances apparent but not true magnesium absorption in rats.

PubMed

Heijnen, M L; van den Berg, G J; Beynen, A C

1996-09-01

Dietary raw (RS2) vs. retrograded resistant starch (RS3) raises apparent magnesium absorption in rats. The mechanism proposed is that RS2 enhances magnesium avaibility for absorption; it does this by increasing ileal solubility of magnesium due to a reduction in pH as a consequence of RS2 fermentation in the gut. The mechanism implies that dietary RS2 vs. RS3 would raise true magnesium absorption and stimulate reabsorption of endogenous magnesium, leading to a lower fecal excretion of endogenous magnesium. Dietary lactulose vs. glucose raises apparent magnesium absorption, and the mechanism proposed is similar to that for the stimulatory effect of RS2 vs. RS3. Thus, we measured in rats fed RS3, RS2, glucose or lactulose true magnesium absorption on the basis of the retention of the orally and intraperitoneally administered radiotracer 28Mg. Feeding rats RS2 instead of RS3 significantly enhanced apparent but not true magnesium absorption, because RS2 lowered fecal excretion of endogenous magnesium. When compared with dietary glucose, lactulose significantly raised both apparent and true magnesium absorption, but did not affect fecal excretion of endogenous magnesium. It is suggested that the proposed mechanism by which RS2 and lactulose would enhance magnesium absorption is disproved by the present data.

[Upper airway morphology in Down Syndrome patients under dexmedetomidine sedation].

PubMed

Subramanyam, Rajeev; Fleck, Robert; McAuliffe, John; Radhakrishnan, Rupa; Jung, Dorothy; Patino, Mario; Mahmoud, Mohamed

2016-01-01

Children with Down Syndrome are vulnerable to significant upper airway obstruction due to relative macroglossia and dynamic airway collapse. The objective of this study was to compare the upper airway dimensions of children with Down Syndrome and obstructive sleep apnea with normal airway under dexmedetomidine sedation. IRB approval was obtained. In this retrospective study, clinically indicated dynamic sagittal midline magnetic resonance images of the upper airway were obtained under low (1mcg/kg/h) and high (3mcg/kg/h) dose dexmedetomidine. Airway anteroposterior diameters and sectional areas were measured as minimum and maximum dimensions by two independent observers at soft palate (nasopharyngeal airway) and at base of the tongue (retroglossal airway). Minimum anteroposterior diameter and minimum sectional area at nasopharynx and retroglossal airway were significantly reduced in Down Syndrome compared to normal airway at both low and high dose dexmedetomidine. However, there were no significant differences between low and high dose dexmedetomidine in both Down Syndrome and normal airway. The mean apnea hypopnea index in Down Syndrome was 16±11. Under dexmedetomidine sedation, children with Down Syndrome and obstructive sleep apnea when compared to normal airway children show significant reductions in airway dimensions most pronounced at the narrowest points in the nasopharyngeal and retroglossal airways. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Upper airway morphology in Down Syndrome patients under dexmedetomidine sedation.

PubMed

Subramanyam, Rajeev; Fleck, Robert; McAuliffe, John; Radhakrishnan, Rupa; Jung, Dorothy; Patino, Mario; Mahmoud, Mohamed

2016-01-01

Children with Down Syndrome are vulnerable to significant upper airway obstruction due to relative macroglossia and dynamic airway collapse. The objective of this study was to compare the upper airway dimensions of children with Down Syndrome and obstructive sleep apnea with normal airway under dexmedetomidine sedation. IRB approval was obtained. In this retrospective study, clinically indicated dynamic sagittal midline magnetic resonance images of the upper airway were obtained under low (1mcg/kg/h) and high (3mcg/kg/h) dose dexmedetomidine. Airway anteroposterior diameters and sectional areas were measured as minimum and maximum dimensions by two independent observers at soft palate (nasopharyngeal airway) and at base of the tongue (retroglossal airway). Minimum anteroposterior diameter and minimum sectional area at nasopharynx and retroglossal airway were significantly reduced in Down Syndrome compared to normal airway at both low and high dose dexmedetomidine. However, there were no significant differences between low and high dose dexmedetomidine in both Down Syndrome and normal airway. The mean apnea hypopnea index in Down Syndrome was 16±11. Under dexmedetomidine sedation, children with Down Syndrome and obstructive sleep apnea when compared to normal airway children show significant reductions in airway dimensions most pronounced at the narrowest points in the nasopharyngeal and retroglossal airways. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

The Tulip GT® airway versus the facemask and Guedel airway: a randomised, controlled, cross-over study by Basic Life Support-trained airway providers in anaesthetised patients.

PubMed

Shaikh, A; Robinson, P N; Hasan, M

2016-03-01

We performed a randomised, controlled, cross-over study of lung ventilation by Basic Life Support-trained providers using either the Tulip GT® airway or a facemask with a Guedel airway in 60 anaesthetised patients. Successful ventilation was achieved if the provider produced an end-tidal CO2 > 3.5 kPa and a tidal volume > 250 ml in two of the first three breaths, within 60 sec and within two attempts. Fifty-seven (95%) providers achieved successful ventilation using the Tulip GT compared with 35 (58%) using the facemask (p < 0.0001). Comparing the Tulip GT and facemask, the mean (SD) end-tidal CO2 was 5.0 (0.7) kPa vs 2.5 (1.5) kPa, tidal volume was 494 (175) ml vs 286 (186) ml and peak inspiratory pressure was 18.3 (3.4) cmH2 O vs 13.6 (7) cmH2 O respectively (all p < 0.0001). Forty-seven (78%) users favoured the Tulip GT airway. These results are similar to a previous manikin study using the same protocol, suggesting a close correlation between human and manikin studies for this airway device. We conclude that the Tulip GT should be considered as an adjunct to airway management both within and outside hospitals when ventilation is being undertaken by Basic Life Support-trained airway providers. © 2015 The Association of Anaesthetists of Great Britain and Ireland.

Airway obstruction in children with infectious mononucleosis.

PubMed

Wohl, D L; Isaacson, J E

1995-09-01

Epstein-Barr Virus (EBV) infection generally has a benign clinical course. Upper airway obstruction is a known complication requiring the otolaryngologist's attention. EBV is usually associated with adolescence but has been increasingly documented in younger children. We review 36 pediatric admissions for infectious mononucleosis over a 12-year period at our institution, 11 of which required consultation for airway obstruction. Airway management was based on clinical severity and ranged from monitored observation, with or without nasopharyngeal stenting, to prolonged intubation or emergent tonsilloadenoidectomy. A rare case of a four-year-old with near total upper airway obstruction secondary to panpharyngeal and transglottic inflammatory edema prompted this review and is reported. The otolaryngologist must recognize the potential severity of EBV-related airway compromise and be prepared to manage it.

Airway responsiveness to mannitol in asthma is associated with chymase-positive mast cells and eosinophilic airway inflammation.

PubMed

Sverrild, A; Bergqvist, A; Baines, K J; Porsbjerg, C; Andersson, C K; Thomsen, S F; Hoffmann, H J; Gibson, P; Erjefält, J S; Backer, V

2016-02-01

Airway hyperresponsiveness (AHR) to inhaled mannitol is associated with indirect markers of mast cell activation and eosinophilic airway inflammation. It is unknown how AHR to mannitol relates to mast cell phenotype, mast cell function and measures of eosinophilic inflammation in airway tissue. We compared the number and phenotype of mast cells, mRNA expression of mast cell-associated genes and number of eosinophils in airway tissue of subjects with asthma and healthy controls in relation to AHR to mannitol. Airway hyperresponsiveness to inhaled mannitol was measured in 23 non-smoking, corticosteroid-free asthmatic individuals and 10 healthy controls. Mast cells and eosinophils were identified in mucosal biopsies from all participants. Mast cells were divided into phenotypes based on the presence of chymase. mRNA expression of mast cell-associated genes was measured by real-time PCR. The proportion of submucosal MCTC was higher in asthmatic individuals with AHR to mannitol compared with asthmatic individuals without AHR (median: 40.3% vs. 18.7%, P = 0.03). Increased submucosal MCTC numbers were associated with increased levels of mRNA for thymic stromal lymphopoietin (TSLP) and CPA3 in asthmatics. Reactivity to mannitol correlated significantly with eosinophils in submucosa (r(s): 0.56, P = 0.01). Airway hyperresponsiveness to inhaled mannitol is associated with an altered submucosal mast cell profile in asthmatic individuals. This mast cell profile is associated with increased levels of TSLP and CPA3. The degree of AHR to mannitol is correlated with the degree of eosinophilic inflammation in the airway submucosa. © 2015 John Wiley & Sons Ltd.

Novel therapeutic strategies for lung disorders associated with airway remodelling and fibrosis.

PubMed

Royce, Simon G; Moodley, Yuben; Samuel, Chrishan S

2014-03-01

Inflammatory cell infiltration, cytokine release, epithelial damage, airway/lung remodelling and fibrosis are central features of inflammatory lung disorders, which include asthma, chronic obstructive pulmonary disease, acute respiratory distress syndrome and idiopathic pulmonary fibrosis. Although the lung has some ability to repair itself from acute injury, in the presence of ongoing pathological stimuli and/or insults that lead to chronic disease, it no longer retains the capacity to heal, resulting in fibrosis, the final common pathway that causes an irreversible loss of lung function. Despite inflammation, genetic predisposition/factors, epithelial-mesenchymal transition and mechanotransduction being able to independently contribute to airway remodelling and fibrosis, current therapies for inflammatory lung diseases are limited by their ability to only target the inflammatory component of the disease without having any marked effects on remodelling (epithelial damage and fibrosis) that can cause lung dysfunction independently of inflammation. Furthermore, as subsets of patients suffering from these diseases are resistant to currently available therapies (such as corticosteroids), novel therapeutic approaches are required to combat all aspects of disease pathology. This review discusses emerging therapeutic approaches, such as trefoil factors, relaxin, histone deacetylase inhibitors and stem cells, amongst others that have been able to target airway inflammation and airway remodelling while improving related lung dysfunction. A better understanding of the mode of action of these therapies and their possible combined effects may lead to the identification of their clinical potential in the setting of lung disease, either as adjunct or alternative therapies to currently available treatments. © 2013.

Differential effects of phosphoramidon on neurokinin A- and substance P-induced airflow obstruction and airway microvascular leakage in guinea-pig.

PubMed Central

Lötvall, J. O.; Elwood, W.; Tokuyama, K.; Barnes, P. J.; Chung, K. F.

1991-01-01

1. The effects of the inhaled neuropeptides, neurokinin A (NKA) and substance P (SP) on lung resistance (RL) and airway microvascular permeability were studied in anaesthetized guinea-pigs. 2. Single doses of inhaled NKA (3 x 10(-5), 1 x 10(-4), 3 x 10(-4) M; 45 breaths) and SP (1 x 10(-4), 3 x 10(-4), 1 x 10(-3); 45 breaths) caused a dose-dependent increase in both RL and airway microvascular leakage, assessed as extravasation of the albumin marker, Evans blue dye. 3. NKA at 1 x 10(-4) and 3 x 10(-4) M resulted in a significantly higher increase in RL than SP at the same doses. 4. Inhaled SP (3 x 10(-4) M; 45 breaths) caused significantly higher Evans blue dye extravasation in main bronchi and proximal intrapulmonary airways compared to the same dose of NKA. 5. Pretreatment with the specific inhibitor of neural endopeptidase (NEP24.11), phosphoramidon, caused an approximately 100 fold leftward shift of the RL responses to inhaled NKA and SP. 6. Phosphoramidon significantly potentiated both NKA- and SP-induced airway microvascular leakage at proximal intrapulmonary airways, but not at any other airway level. 7. Inhibition of NEP24.11 potentiate both the SP- or NKA-induced airflow obstruction to a larger extent than the induced airway microvascular leakage, suggesting that NEP24.11 is more important in the modulation of the airflow obstruction observed after these mediators. PMID:1725766

Differential effects of phosphoramidon on neurokinin A- and substance P-induced airflow obstruction and airway microvascular leakage in guinea-pig.

PubMed

Lötvall, J O; Elwood, W; Tokuyama, K; Barnes, P J; Chung, K F

1991-12-01

1. The effects of the inhaled neuropeptides, neurokinin A (NKA) and substance P (SP) on lung resistance (RL) and airway microvascular permeability were studied in anaesthetized guinea-pigs. 2. Single doses of inhaled NKA (3 x 10(-5), 1 x 10(-4), 3 x 10(-4) M; 45 breaths) and SP (1 x 10(-4), 3 x 10(-4), 1 x 10(-3); 45 breaths) caused a dose-dependent increase in both RL and airway microvascular leakage, assessed as extravasation of the albumin marker, Evans blue dye. 3. NKA at 1 x 10(-4) and 3 x 10(-4) M resulted in a significantly higher increase in RL than SP at the same doses. 4. Inhaled SP (3 x 10(-4) M; 45 breaths) caused significantly higher Evans blue dye extravasation in main bronchi and proximal intrapulmonary airways compared to the same dose of NKA. 5. Pretreatment with the specific inhibitor of neural endopeptidase (NEP24.11), phosphoramidon, caused an approximately 100 fold leftward shift of the RL responses to inhaled NKA and SP. 6. Phosphoramidon significantly potentiated both NKA- and SP-induced airway microvascular leakage at proximal intrapulmonary airways, but not at any other airway level. 7. Inhibition of NEP24.11 potentiate both the SP- or NKA-induced airflow obstruction to a larger extent than the induced airway microvascular leakage, suggesting that NEP24.11 is more important in the modulation of the airflow obstruction observed after these mediators.

21 CFR 868.2600 - Airway pressure monitor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Airway pressure monitor. 868.2600 Section 868.2600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a devic...

'Prevalence and antimicrobial susceptibility of Listeria monocytogenes and methicillin-resistant Staphylococcus aureus strains from raw meat and meat products in Zaria, Nigeria.

PubMed

Ndahi, M D; Kwaga, J K P; Bello, M; Kabir, J; Umoh, V J; Yakubu, S E; Nok, A J

2014-03-01

The bacterial genera Listeria and Staphylococcus have been frequently isolated from food products and are responsible for a number of animal and human diseases. The aim of the study was to simultaneously isolate and characterize L. monocytogenes and Staphylococcus species from 300 samples of raw meat and meat products, to determine the susceptibility of the organisms to commonly used antimicrobial agents and to determine the presence of haemolysin A (hyl) virulence gene in L. monocytogenes and staphylococcal cassette chromosome mecA (SCCmec) gene in the Staph. aureus isolates using PCR. Of the 85 Listeria isolates tested, 12 L. monocytogenes were identified and tested for their sensitivity to 14 antimicrobial agents. All the 12 isolates (100%) were resistant to nine antimicrobial agents, but however sensitive to gentamicin. Only one isolate was found to harbour the hylA gene. Twenty-nine isolates were confirmed as Staph. aureus by the Microbact 12S identification system and were all presumptively identified as methicillin-resistant Staph. aureus species using oxacillin-resistant Staph. aureus basal medium (ORSAB). The 29 Staph. aureus isolates were tested for their sensitivity to 16 antimicrobial agents, and 11 were resistant to methicillin. None of the 11 Staph. aureus isolates harboured the methicillin resistance, mecA gene. Listeria monocytogenes and Staphylococcus aureus are important agents of foodborne diseases. Occurrence of these infectious agents was established in meat and meat products in Zaria, Nigeria. Majority of isolates obtained from this study, displayed multidrug resistance to commonly used antimicrobial agents, including methicillin resistance among the Staph. aureus isolates. The potential virulence of L. monocytogenes found in ready-to-eat food was documented by the carriage of hly A gene by one of the isolates. A different mechanism of methicillin resistance or different homologue of mec A gene may be circulating among Nigerian

Recurrent airway obstructions in a patient with benign tracheal stenosis and a silicone airway stent: a case report

PubMed Central

Sriram, KB; Robinson, PC

2008-01-01

Airway stents (silicone and metal stents) are used to treat patients with benign tracheal stenosis, who are symptomatic and in whom tracheal surgical reconstruction has failed or is not appropriate. However airway stents are often associated with complications such as migration, granuloma formation and mucous hypersecretion, which cause significant morbidity, especially in patients with benign tracheal stenosis and relatively normal life expectancy. We report a patient who had frequent critical airway obstructions over 8 years due to granuloma and mucus hypersecretion in a silicone airway stent. The problem was resolved when the silicone stent was removed and replaced with a covered self expanding metal stent. PMID:18840299

Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a systematic review and meta-analysis of six randomized controlled trials

PubMed Central

Lei, Qiang; Lv, Yunhui; Li, Kai; Ma, Lei; Du, Guodong; Xiang, Yan; Li, Xuqing

2017-01-01

ABSTRACT Objective: To evaluate systematically the effects of continuous positive airway pressure (CPAP) on blood pressure in patients with resistant hypertension and obstructive sleep apnea (OSA). Methods: The Cochrane Library, PubMed, ScienceDirect, and the Web of Science were searched for studies investigating the effects of CPAP on blood pressure in patients with resistant hypertension and OSA. The selected studies underwent quality assessment and meta-analysis, as well as being tested for heterogeneity. Results: Six randomized controlled trials were included in the meta-analysis. The pooled estimates of the changes in mean systolic blood pressure and mean diastolic blood pressure (as assessed by 24-h ambulatory blood pressure monitoring) were −5.40 mmHg (95% CI: −9.17 to −1.64; p = 0.001; I2 = 74%) and −3.86 mmHg (95% CI: −6.41 to −1.30; p = 0.00001; I2 = 79%), respectively. Conclusions: CPAP therapy can significantly reduce blood pressure in patients with resistant hypertension and OSA. PMID:28767770

A Different Microbiome Gene Repertoire in the Airways of Cystic Fibrosis Patients with Severe Lung Disease

PubMed Central

Bacci, Giovanni; Fiscarelli, Ersilia; Taccetti, Giovanni; Dolce, Daniela; Paganin, Patrizia; Morelli, Patrizia; Tuccio, Vanessa; De Alessandri, Alessandra; Lucidi, Vincenzina

2017-01-01

In recent years, next-generation sequencing (NGS) was employed to decipher the structure and composition of the microbiota of the airways in cystic fibrosis (CF) patients. However, little is still known about the overall gene functions harbored by the resident microbial populations and which specific genes are associated with various stages of CF lung disease. In the present study, we aimed to identify the microbial gene repertoire of CF microbiota in twelve patients with severe and normal/mild lung disease by performing sputum shotgun metagenome sequencing. The abundance of metabolic pathways encoded by microbes inhabiting CF airways was reconstructed from the metagenome. We identified a set of metabolic pathways differently distributed in patients with different pulmonary function; namely, pathways related to bacterial chemotaxis and flagellar assembly, as well as genes encoding efflux-mediated antibiotic resistance mechanisms and virulence-related genes. The results indicated that the microbiome of CF patients with low pulmonary function is enriched in virulence-related genes and in genes encoding efflux-mediated antibiotic resistance mechanisms. Overall, the microbiome of severely affected adults with CF seems to encode different mechanisms for the facilitation of microbial colonization and persistence in the lung, consistent with the characteristics of multidrug-resistant microbial communities that are commonly observed in patients with severe lung disease. PMID:28758937

Fisetin, a bioactive flavonol, attenuates allergic airway inflammation through negative regulation of NF-κB.

PubMed

Goh, Fera Y; Upton, Nadine; Guan, Shouping; Cheng, Chang; Shanmugam, Muthu K; Sethi, Gautam; Leung, Bernard P; Wong, W S Fred

2012-03-15

Persistent activation of nuclear factor-κB (NF-κB) has been associated with the development of asthma. Fisetin (3,7,3',4'-tetrahydroxyflavone), a naturally occurring bioactive flavonol, has been shown to inhibit NF-κB activity. We hypothesized that fisetin may attenuate allergic asthma via negative regulation of the NF-κB activity. Female BALB/c mice sensitized and challenged with ovalbumin developed airway inflammation. Bronchoalveolar lavage fluid was assessed for total and differential cell counts, and cytokine and chemokine levels. Lung tissues were examined for cell infiltration and mucus hypersecretion, and the expression of inflammatory biomarkers. Airway hyperresponsiveness was monitored by direct airway resistance analysis. Fisetin dose-dependently inhibited ovalbumin-induced increases in total cell count, eosinophil count, and IL-4, IL-5 and IL-13 levels recovered in bronchoalveolar lavage fluid. It attenuated ovalbumin-induced lung tissue eosinophilia and airway mucus production, mRNA expression of adhesion molecules, chitinase, IL-17, IL-33, Muc5ac and inducible nitric oxide synthase in lung tissues, and airway hyperresponsiveness to methacholine. Fisetin blocked NF-κB subunit p65 nuclear translocation and DNA-binding activity in the nuclear extracts from lung tissues of ovalbumin-challenged mice. In normal human bronchial epithelial cells, fisetin repressed TNF-α-induced NF-κB-dependent reporter gene expression. Our findings implicate a potential therapeutic value of fisetin in the treatment of asthma through negative regulation of NF-κB pathway. Copyright © 2012 Elsevier B.V. All rights reserved.

Pressure-volume behavior of the upper airway.

PubMed

Fouke, J M; Teeter, J P; Strohl, K P

1986-09-01

The study was performed to investigate the relationship between force generation and upper airway expansion during respiratory efforts by upper airway muscles. In 11 anesthetized dogs we isolated the upper airway (nasal, oral, pharyngeal, and laryngeal regions) by transecting the cervical trachea and sealing the nasal and oral openings. During spontaneous respiratory efforts the pressure within the sealed upper airway, used as an index of dilating force, decreased during inspiration. On alternate breaths the upper airway was opened to a pneumotachograph, and an increase in volume occurred, also during inspiration. Progressive hyperoxic hypercapnia produced by rebreathing increased the magnitude of change in pressure and volume. At any level of drive, peak pressure or volume occurred at the same point during inspiration. At any level of drive, volume and pressure changes increased with end-expiratory occlusion of the trachea. The force-volume relationship determined from measurements during rebreathing was compared with pressure-volume curves performed by passive inflation of the airway while the animal was apneic. The relationship during apnea was 1.06 +/- 0.55 (SD) ml/cmH2O, while the force-volume relationship from rebreathing trials was -1.09 +/- 0.45 ml/cmH2O. We conclude that there is a correspondence between force production and volume expansion in the upper airway during active respiratory efforts.

Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients

PubMed Central

D’Argenio, David A.; Wu, Manhong; Hoffman, Lucas R.; Kulasekara, Hemantha D.; Déziel, Eric; Smith, Eric E.; Nguyen, Hai; Ernst, Robert K.; Larson Freeman, Theodore J.; Spencer, David H.; Brittnacher, Mitchell; Hayden, Hillary S.; Selgrade, Sara; Klausen, Mikkel; Goodlett, David R.; Burns, Jane L.; Ramsey, Bonnie W.; Miller, Samuel I.

2009-01-01

Summary The opportunistic pathogen Pseudomonas aeruginosa undergoes genetic change during chronic airway infection of cystic fibrosis (CF) patients. One common change is a mutation inactivating lasR, which encodes a transcriptional regulator that responds to a homoserine lactone signal to activate expression of acute virulence factors. Colonies of lasR mutants visibly accumulated the iridescent intercellular signal 4-hydroxy-2-heptylquinoline. Using this colony phenotype, we identified P. aeruginosa lasR mutants that emerged in the airway of a CF patient early during chronic infection, and during growth in the laboratory on a rich medium. The lasR loss-of-function mutations in these strains conferred a growth advantage with particular carbon and nitrogen sources, including amino acids, in part due to increased expression of the catabolic pathway regulator CbrB. This growth phenotype could contribute to selection of lasR mutants both on rich medium and within the CF airway, supporting a key role for bacterial metabolic adaptation during chronic infection. Inactivation of lasR also resulted in increased β-lactamase activity that increased tolerance to ceftazidime, a widely used β-lactam antibiotic. Loss of LasR function may represent a marker of an early stage in chronic infection of the CF airway with clinical implications for antibiotic resistance and disease progression. PMID:17493132

Cluster-specific small airway modeling for imaging-based CFD analysis of pulmonary air flow and particle deposition in COPD smokers

NASA Astrophysics Data System (ADS)

Haghighi, Babak; Choi, Jiwoong; Choi, Sanghun; Hoffman, Eric A.; Lin, Ching-Long

2017-11-01

Accurate modeling of small airway diameters in patients with chronic obstructive pulmonary disease (COPD) is a crucial step toward patient-specific CFD simulations of regional airflow and particle transport. We proposed to use computed tomography (CT) imaging-based cluster membership to identify structural characteristics of airways in each cluster and use them to develop cluster-specific airway diameter models. We analyzed 284 COPD smokers with airflow limitation, and 69 healthy controls. We used multiscale imaging-based cluster analysis (MICA) to classify smokers into 4 clusters. With representative cluster patients and healthy controls, we performed multiple regressions to quantify variation of airway diameters by generation as well as by cluster. The cluster 2 and 4 showed more diameter decrease as generation increases than other clusters. The cluster 4 had more rapid decreases of airway diameters in the upper lobes, while cluster 2 in the lower lobes. We then used these regression models to estimate airway diameters in CT unresolved regions to obtain pressure-volume hysteresis curves using a 1D resistance model. These 1D flow solutions can be used to provide the patient-specific boundary conditions for 3D CFD simulations in COPD patients. Support for this study was provided, in part, by NIH Grants U01-HL114494, R01-HL112986 and S10-RR022421.

Durability of Silicone Airway Stents in the Management of Benign Central Airway Obstruction.

PubMed

Karush, Justin M; Seder, Christopher W; Raman, Anish; Chmielewski, Gary W; Liptay, Michael J; Warren, William H; Arndt, Andrew T

2017-10-01

The literature is devoid of a comprehensive analysis of silicone airway stenting for benign central airway obstruction (BCAO). With the largest series in the literature to date, we aim to demonstrate the safety profile, pattern of re-intervention, and duration of silicone airway stents. An institutional database was used to identify patients with BCAO who underwent rigid bronchoscopy with dilation and silicone stent placement between 2002 and 2015 at Rush University Medical Center. During the study period, 243 stents were utilized in 63 patients with BCAO. Pure tracheal stenosis was encountered in 71% (45/63), pure tracheomalacia in 11% (7/63), and a hybrid of both in 17% (11/63). Median freedom from re-intervention was 104 (IQR 167) days. Most common indications for re-intervention include mucus accumulation (60%; 131/220), migration (28%; 62/220), and intubation (8%; 18/220). The most common diameters of stent placed were 12 mm (94/220) and 14 mm (96/220). The most common lengths utilized were 30 mm (60/220) and 40 mm (77/220). Duration was not effected by stent size when placed for discrete stenosis. However, 14 mm stents outperformed 12 mm when tracheomalacia was present (157 vs. 37 days; p = 0.005). Patients with a hybrid stenosis fared better when longer stents were used (60 mm stents outlasted 40 mm stents 173 vs. 56 days; p = 0.05). Rigid bronchoscopy with silicone airway stenting is a safe and effective option for the management of benign central airway obstruction. Our results highlight several strategies to improve stent duration.

Topical airway anesthesia for awake fiberoptic intubation: Comparison between airway nerve blocks and nebulized lignocaine by ultrasonic nebulizer

PubMed Central

Gupta, Babita; Kohli, Santvana; Farooque, Kamran; Jalwal, Gopal; Gupta, Deepak; Sinha, Sumit; Chandralekha

2014-01-01

Overview: Awake fiberoptic bronchoscope (FOB) guided intubation is the gold standard of airway management in patients with cervical spine injury. It is essential to sufficiently anesthetize the upper airway before the performance of awake FOB guided intubation in order to ensure patient comfort and cooperation. This randomized controlled study was performed to compare two methods of airway anesthesia, namely ultrasonic nebulization of local anesthetic and performance of airway blocks. Materials and Methods: A total of 50 adult patients with cervical spine injury were randomly allocated into two groups. Group L received airway anesthesia through ultrasonic nebulization of 10 ml of 4% lignocaine and Group NB received airway blocks (bilateral superior laryngeal and transtracheal recurrent laryngeal) each with 2 ml of 2% lignocaine and viscous lignocaine gargles. FOB guided orotracheal intubation was then performed. Hemodynamic variables at baseline and during the procedure, patient recall, vocal cord visibility, ease of intubation, coughing/gagging episodes, and signs of lignocaine toxicity were noted. Results: The observations did not reveal any significant differences in demographics or hemodynamic parameters at any time during the study. However, the time taken for intubation was significantly lower in Group NB as compared with the Group L. Group L had an increased number of coughing/gagging episodes as compared with Group NB. Vocal cord visibility and ease of intubation were better in patients who received airway blocks and hence the amount of supplemental lignocaine used was less in this group. Overall patient comfort was better in Group NB with fewer incidences of unpleasant recalls as compared with Group L. Conclusion: Upper airway blocks provide better quality of anesthesia than lignocaine nebulization as assessed by patient recall of procedure, coughing/gagging episodes, ease of intubation, vocal cord visibility, and time taken to intubate. PMID:25538514

Airway basement membrane perimeter in human airways is not a constant; potential implications for airway remodeling in asthma.

PubMed

McParland, Brent E; Paré, Peter D; Johnson, Peter R A; Armour, Carol L; Black, Judith L

2004-08-01

Many studies that demonstrate an increase in airway smooth muscle in asthmatic patients rely on the assumption that bronchial internal perimeter (P(i)) or basement membrane perimeter (P(bm)) is a constant, i.e., not affected by fixation pressure or the degree of smooth muscle shortening. Because it is the basement membrane that has been purported to be the indistensible structure, this study examines the assumption that P(bm) is not affected by fixation pressure. P(bm) was determined for the same human airway segment (n = 12) fixed at distending pressures of 0 cmH(2)O and 21 cmH(2)O in the absence of smooth muscle tone. P(bm) for the segment fixed at 0 cmH(2)O was determined morphometrically, and the P(bm) for the same segment, had the segment been fixed at 21 cmH(2)O, was predicted from knowing the luminal volume and length of the airway when distended to 21 cmH(2)O (organ bath-derived P(i)). To ensure an accurate transformation of the organ bath-derived P(i) value to a morphometry-derived P(bm) value, had the segment been fixed at 21 cmH(2)O, the relationship between organ bath-derived P(i) and morphometry-derived P(bm) was determined for five different bronchial segments distended to 21 cmH(2)O and fixed at 21 cmH(2)O (r(2) = 0.99, P < 0.0001). Mean P(bm) for bronchial segments fixed at 0 cmH(2)O was 9.4 +/- 0.4 mm, whereas mean predicted P(bm), had the segments been fixed at 21 cmH(2)O, was 14.1 +/- 0.5 mm (P < 0.0001). This indicates that P(bm) is not a constant when isolated airway segments without smooth muscle tone are fixed distended to 21 cmH(2)O. The implication of these results is that the increase in smooth muscle mass in asthma may have been overestimated in some previous studies. Therefore, further studies are required to examine the potential artifact using whole lungs with and without abolition of airway smooth muscle tone and/or inflation.

Substance P released from intrinsic airway neurons contributes to ozone-enhanced airway hyperresponsiveness in ferret trachea.

PubMed

Wu, Zhong-Xin; Satterfield, Brian E; Dey, Richard D

2003-08-01

Exposure to ozone (O3) induces airway hyperresponsiveness mediated partly through the release of substance P (SP) from nerve terminals in the airway wall. Although substantial evidence suggests that SP is released by sensory nerves, SP is also present in neurons of airway ganglia. The purpose of this study was to investigate the role of intrinsic airway neurons in O3-enhanced airway responsiveness in ferret trachea. To remove the effects of sensory innervation, segments of ferret trachea were maintained in culture conditions for 24 h before in vitro exposure to 2 parts/million of O3 or air for 1 h. Sensory nerve depletion was confirmed by showing that capsaicin did not affect tracheal smooth muscle responsiveness to cholinergic agonist or contractility responses to electrical field stimulation (EFS). Contractions of isolated tracheal smooth muscle to EFS were significantly increased after in vitro O3 exposure, but the constrictor response to cholinergic agonist was not altered. Pretreatment with CP-99994, an antagonist of the neurokinin 1 receptor, attenuated the increased contraction to EFS after O3 exposure but had no effect in the air exposure group. The number of SP-positive neurons in longitudinal trunk ganglia, the extent of SP innervation to superficial muscular plexus nerve cell bodies, and SP nerve fiber density in tracheal smooth muscle all increased significantly after O3 exposure. The results show that release of SP from intrinsic airway neurons contributes to O3-enhanced tracheal smooth muscle responsiveness by facilitating acetylcholine release from cholinergic nerve terminals.

Airway fires during surgery: Management and prevention

PubMed Central

Akhtar, Navaid; Ansar, Farrukh; Baig, Mirza Shahzad; Abbas, Akbar

2016-01-01

Airway fires pose a serious risk to surgical patients. Fires during surgery have been reported for many years with flammable anesthetic agents being the main culprits in the past. Association of airway fires with laser surgery is well-recognized, but there are reports of endotracheal tube fires ignited by electrocautery during pharyngeal surgery or tracheostomy or both. This uncommon complication has potentially grave consequences. While airway fires are relatively uncommon occurrences, they are very serious and can often be fatal. Success in preventing such events requires a thorough understanding of the components leading to a fire (fuel, oxidizer, and ignition source), as well as good communication between all members present to appropriately manage the fire and ensure patient safety. We present a case of fire in the airway during routine adenotonsillectomy. We will review the causes, preventive measures, and brief management for airway fires. PMID:27006554

Airway fires during surgery: Management and prevention.

PubMed

Akhtar, Navaid; Ansar, Farrukh; Baig, Mirza Shahzad; Abbas, Akbar

2016-01-01

Airway fires pose a serious risk to surgical patients. Fires during surgery have been reported for many years with flammable anesthetic agents being the main culprits in the past. Association of airway fires with laser surgery is well-recognized, but there are reports of endotracheal tube fires ignited by electrocautery during pharyngeal surgery or tracheostomy or both. This uncommon complication has potentially grave consequences. While airway fires are relatively uncommon occurrences, they are very serious and can often be fatal. Success in preventing such events requires a thorough understanding of the components leading to a fire (fuel, oxidizer, and ignition source), as well as good communication between all members present to appropriately manage the fire and ensure patient safety. We present a case of fire in the airway during routine adenotonsillectomy. We will review the causes, preventive measures, and brief management for airway fires.

Pituitary Adenylate Cyclase-Activating Polypeptide Reverses Ammonium Metavanadate-Induced Airway Hyperresponsiveness in Rats

PubMed Central

Tlili, Mounira; Sriha, Badreddine; Ben Rhouma, Khémais; Sakly, Mohsen; Wurtz, Olivier

2015-01-01

The rate of atmospheric vanadium is constantly increasing due to fossil fuel combustion. This environmental pollution favours vanadium exposure in particular to its vanadate form, causing occupational bronchial asthma and bronchitis. Based on the well admitted bronchodilator properties of the pituitary adenylate cyclase-activating polypeptide (PACAP), we investigated the ability of this neuropeptide to reverse the vanadate-induced airway hyperresponsiveness in rats. Exposure to ammonium metavanadate aerosols (5 mg/m3/h) for 15 minutes induced 4 hours later an array of pathophysiological events, including increase of bronchial resistance and histological alterations, activation of proinflammatory alveolar macrophages, and increased oxidative stress status. Powerfully, PACAP inhalation (0.1 mM) for 10 minutes alleviated many of these deleterious effects as demonstrated by a decrease of bronchial resistance and histological restoration. PACAP reduced the level of expression of mRNA encoding inflammatory chemokines (MIP-1α, MIP-2, and KC) and cytokines (IL-1α and TNF-α) in alveolar macrophages and improved the antioxidant status. PACAP reverses the vanadate-induced airway hyperresponsiveness not only through its bronchodilator activity but also by counteracting the proinflammatory and prooxidative effects of the metal. Then, the development of stable analogs of PACAP could represent a promising therapeutic alternative for the treatment of inflammatory respiratory disorders. PMID:26199679

Airway somatosensory deficits and dysphagia in Parkinson's disease.

PubMed

Hammer, Michael J; Murphy, Caitlin A; Abrams, Trisha M

2013-01-01

Individuals with Parkinson's disease (PD) often experience substantial impairment of swallow control, and are typically unaware of the presence or severity of their impairments suggesting that these individuals may also experience airway sensory deficits. However, the degree to which impaired swallow function in PD may relate to airway sensory deficits has yet to be formally tested. The purpose of this study was to examine whether airway sensory function is associated with swallow impairment in PD. Eighteen PD participants and 18 healthy controls participated in this study and underwent endoscopic assessment of airway somatosensory function, endoscopic assessment of swallow function, and clinical ratings of swallow and disease severity. PD participants exhibited abnormal airway somatosensory function and greater swallow impairment compared with healthy controls. Swallow and sensory deficits in PD were correlated with disease severity. Moreover, PD participants reported similar self-rated swallow function as healthy controls, and swallow deficits were correlated with sensory function suggesting an association between impaired sensory function and poor self-awareness of swallow deficits in PD. These results suggest that control of swallow is influenced by airway somatosensory function, that swallow-related deficits in PD are related to abnormal somatosensation, and that swallow and airway sensory function may degrade as a function of disease severity. Therefore, the basal ganglia and related neural networks may play an important role to integrate airway sensory input for swallow-related motor control. Furthermore, the airway deficits observed in PD suggest a disintegration of swallow-related sensory and motor control.

Improving the safety of remote site emergency airway management.

PubMed

Wijesuriya, Julian; Brand, Jonathan

2014-01-01

Airway management, particularly in non-theatre settings, is an area of anaesthesia and critical care associated with significant risk of morbidity & mortality, as highlighted during the 4th National Audit Project of the Royal College of Anaesthetists (NAP4). A survey of junior anaesthetists at our hospital highlighted a lack of confidence and perceived lack of safety in emergency airway management, especially in non-theatre settings. We developed and implemented a multifaceted airway package designed to improve the safety of remote site airway management. A Rapid Sequence Induction (RSI) checklist was developed; this was combined with new advanced airway equipment and drugs bags. Additionally, new carbon dioxide detector filters were procured in order to comply with NAP4 monitoring recommendations. The RSI checklists were placed in key locations throughout the hospital and the drugs and advanced airway equipment bags were centralised in the Intensive Care Unit (ICU). It was agreed with the senior nursing staff that an appropriately trained ICU nurse would attend all emergency situations with new airway resources upon request. Departmental guidelines were updated to include details of the new resources and the on-call anaesthetist's responsibilities regarding checks and maintenance. Following our intervention trainees reported higher confidence levels regarding remote site emergency airway management. Nine trusts within the Northern Region were surveyed and we found large variations in the provision of remote site airway management resources. Complications in remote site airway management due lack of available appropriate drugs, equipment or trained staff are potentially life threatening and completely avoidable. Utilising the intervention package an anaesthetist would be able to safely plan and prepare for airway management in any setting. They would subsequently have the drugs, equipment, and trained assistance required to manage any difficulties or complications

Synchronized imaging and acoustic analysis of the upper airway in patients with sleep-disordered breathing.

PubMed

Chang, Yi-Chung; Huon, Leh-Kiong; Pham, Van-Truong; Chen, Yunn-Jy; Jiang, Sun-Fen; Shih, Tiffany Ting-Fang; Tran, Thi-Thao; Wang, Yung-Hung; Lin, Chen; Tsao, Jenho; Lo, Men-Tzung; Wang, Pa-Chun

2014-12-01

Progressive narrowing of the upper airway increases airflow resistance and can produce snoring sounds and apnea/hypopnea events associated with sleep-disordered breathing due to airway collapse. Recent studies have shown that acoustic properties during snoring can be altered with anatomic changes at the site of obstruction. To evaluate the instantaneous association between acoustic features of snoring and the anatomic sites of obstruction, a novel method was developed and applied in nine patients to extract the snoring sounds during sleep while performing dynamic magnetic resonance imaging (MRI). The degree of airway narrowing during the snoring events was then quantified by the collapse index (ratio of airway diameter preceding and during the events) and correlated with the synchronized acoustic features. A total of 201 snoring events (102 pure retropalatal and 99 combined retropalatal and retroglossal events) were recorded, and the collapse index as well as the soft tissue vibration time were significantly different between pure retropalatal (collapse index, 2 ± 11%; vibration time, 0.2 ± 0.3 s) and combined (retropalatal and retroglossal) snores (collapse index, 13 ± 7% [P ≤ 0.0001]; vibration time, 1.2 ± 0.7 s [P ≤ 0.0001]). The synchronized dynamic MRI and acoustic recordings successfully characterized the sites of obstruction and established the dynamic relationship between the anatomic site of obstruction and snoring acoustics.

Fluid structure interaction simulations of the upper airway in obstructive sleep apnea patients before and after maxillomandibular advancement surgery.

PubMed

Chang, Kwang K; Kim, Ki Beom; McQuilling, Mark W; Movahed, Reza

2018-06-01

The purpose of this study was to analyze pharyngeal airflow using both computational fluid dynamics (CFD) and fluid structure interactions (FSI) in obstructive sleep apnea patients before and after maxillomandibular advancement (MMA) surgery. The airflow characteristics before and after surgery were compared with both CFD and FSI. In addition, the presurgery and postsurgery deformations of the airway were evaluated using FSI. Digitized pharyngeal airway models of 2 obstructive sleep apnea patients were generated from cone-beam computed tomography scans before and after MMA surgery. CFD and FSI were used to evaluate the pharyngeal airflow at a maximum inspiration rate of 166 ml per second. Standard steady-state numeric formulations were used for airflow simulations. Airway volume increased, pressure drop decreased, maximum airflow velocity decreased, and airway resistance dropped for both patients after the MMA surgery. These findings occurred in both the CFD and FSI simulations. The FSI simulations showed an area of marked airway deformation in both patients before surgery, but this deformation was negligible after surgery for both patients. Both CFD and FSI simulations produced airflow results that indicated less effort was needed to breathe after MMA surgery. The FSI simulations demonstrated a substantial decrease in airway deformation after surgery. These beneficial changes positively correlated with the large improvements in polysomnography outcomes after MMA surgery. Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Airway management after maxillectomy with free flap reconstruction.

PubMed

Brickman, Daniel S; Reh, Douglas D; Schneider, Daniel S; Bush, Ben; Rosenthal, Eben L; Wax, Mark K

2013-08-01

Maxillectomy defects require complex 3-dimensional reconstructions often best suited to microvascular free tissue transfer. Postoperative airway management during this procedure has little discussion in the literature and is often dictated by surgical dogma. The purpose of this article was to review our experience in order to evaluate the effect of airway management on perioperative outcomes in patients undergoing maxillectomy with free flap reconstruction. A retrospective chart review was performed on patients receiving maxillectomy with microvascular reconstruction at 2 institutions between 1999 and 2011. Patient's airways were managed with or without elective tracheotomy at the surgical team's discretion and different perioperative outcomes were measured. The primary outcome was incidence of airway complication including pneumonia and need for further airway intervention. Secondary outcome was measured as factors leading to perioperative performance of the tracheotomy. Seventy-nine of 143 patients received elective tracheotomy perioperatively. The incidence of airway complication was equivalent between groups (10.1% vs 9.4%; p = .89). Patients with cardiopulmonary comorbidities were more likely to receive perioperative tracheotomy (74.1% vs 50.9%; p = .03) without a difference in airway complications. Other patient cofactors did not have an impact on perioperative tracheotomy or airway complication rate. Elective tracheotomy may safely be avoided in a subset of patients undergoing maxillectomy with microvascular reconstruction. Elective tracheotomy should be considered in patients with cardiopulmonary risk factors. Copyright © 2012 Wiley Periodicals, Inc.

Randomised comparison of the effectiveness of the laryngeal mask airway supreme, i-gel and current practice in the initial airway management of prehospital cardiac arrest (REVIVE-Airways): a feasibility study research protocol.

PubMed

Benger, Jonathan Richard; Voss, Sarah; Coates, David; Greenwood, Rosemary; Nolan, Jerry; Rawstorne, Steven; Rhys, Megan; Thomas, Matthew

2013-01-01

Effective cardiopulmonary resuscitation with appropriate airway management improves outcomes following out-of-hospital cardiac arrest (OHCA). Historically, tracheal intubation has been accepted as the optimal form of OHCA airway management in the UK. The Joint Royal Colleges Ambulance Liaison Committee recently concluded that newer supraglottic airway devices (SADs) are safe and effective devices for hospital procedures and that their use in OHCA should be investigated. This study will address an identified gap in current knowledge by assessing whether it is feasible to use a cluster randomised design to compare SADs with current practice, and also to each other, during OHCA. The primary objective of this study is to assess the feasibility of a cluster randomised trial to compare the ventilation success of two newer SADs: the i-gel and the laryngeal mask airway supreme to usual practice during the initial airway management of OHCA. The secondary objectives are to collect data on ventilation success, further airway interventions required, loss of a previously established airway during transport, airway management on arrival at hospital (or termination of the resuscitation attempt), initial resuscitation success, survival to intensive care admission, survival to hospital discharge and patient outcome at 3 months. Ambulance paramedics will be randomly allocated to one of the three methods of airway management. Adults in medical OHCA attended by a trial paramedic will be eligible for the study. Approval for the study has been obtained from a National Health Service Research Ethics Committee with authority to review proposals for trials of a medical device in incapacitated adults. The results will be made publicly available on an open access website, and we will publish the findings in appropriate journals and present them at national and international conferences relevant to the subject field. ISRCTN: 18528625.

Randomised comparison of the effectiveness of the laryngeal mask airway supreme, i-gel and current practice in the initial airway management of prehospital cardiac arrest (REVIVE-Airways): a feasibility study research protocol

PubMed Central

Benger, Jonathan Richard; Voss, Sarah; Coates, David; Greenwood, Rosemary; Nolan, Jerry; Rawstorne, Steven; Rhys, Megan; Thomas, Matthew

2013-01-01

Introduction Effective cardiopulmonary resuscitation with appropriate airway management improves outcomes following out-of-hospital cardiac arrest (OHCA). Historically, tracheal intubation has been accepted as the optimal form of OHCA airway management in the UK. The Joint Royal Colleges Ambulance Liaison Committee recently concluded that newer supraglottic airway devices (SADs) are safe and effective devices for hospital procedures and that their use in OHCA should be investigated. This study will address an identified gap in current knowledge by assessing whether it is feasible to use a cluster randomised design to compare SADs with current practice, and also to each other, during OHCA. Methods and analysis The primary objective of this study is to assess the feasibility of a cluster randomised trial to compare the ventilation success of two newer SADs: the i-gel and the laryngeal mask airway supreme to usual practice during the initial airway management of OHCA. The secondary objectives are to collect data on ventilation success, further airway interventions required, loss of a previously established airway during transport, airway management on arrival at hospital (or termination of the resuscitation attempt), initial resuscitation success, survival to intensive care admission, survival to hospital discharge and patient outcome at 3 months. Ambulance paramedics will be randomly allocated to one of the three methods of airway management. Adults in medical OHCA attended by a trial paramedic will be eligible for the study. Ethics and dissemination Approval for the study has been obtained from a National Health Service Research Ethics Committee with authority to review proposals for trials of a medical device in incapacitated adults. The results will be made publicly available on an open access website, and we will publish the findings in appropriate journals and present them at national and international conferences relevant to the subject field. Trial

Safety and Efficacy of Thoracic External Beam Radiotherapy After Airway Stenting in Malignant Airway Obstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rochet, Nathalie, E-mail: nrochet@partners.org; Hauswald, Henrik; Schmaus, Martina

Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction. Methods and Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days. A median total dose of 50 Gy was delivered. Sixty-seven percent of the patients had reduced performance status (Karnofsky performance score, {<=}70). Results: EBRT had to be stopped prematurely inmore » 16 patients (37%), at a median total dose of 17 Gy, for various reasons. In this group of patients, the survival was poor, with a median overall survival (OS) of only 21 days. Twenty-seven patients (63%) completed radiotherapy as planned, with a median OS of 8.4 months. Fourteen of 43 patients (33%) developed at least one Common Terminology Criteria for Adverse Event of grade 3 to 5. The most common event was a malignant restenosis of the stent leading to asphyxia (n = 7), followed by fistula formation (n = 4), necrosis (n = 3), mediastinitis with abscess (n = 1), secondary nonmalignant airway stenosis (n = 1), and hemoptysis (n = 1). With the exception of one event, all events were associated with a local progression of the tumor. Conclusions: Although the long-term prognosis for patients with malignant airway obstruction is poor, airway stenting combined with EBRT offers a possible therapeutic option, achieving fast relief of acute respiratory distress with an associated antitumor effect, resulting in a potential survival benefit. However, due to local advanced tumor growth, increased rates of adverse events are to be expected, necessitating careful monitoring.« less

Bitter tasting compounds dilate airways by inhibiting airway smooth muscle calcium oscillations and calcium sensitivity

PubMed Central

Tan, Xiahui; Sanderson, Michael J

2014-01-01

Background and Purpose While selective, bitter tasting, TAS2R agonists can relax agonist-contracted airway smooth muscle (ASM), their mechanism of action is unclear. However, ASM contraction is regulated by Ca2+ signalling and Ca2+ sensitivity. We have therefore investigated how the TAS2R10 agonists chloroquine, quinine and denotonium regulate contractile agonist-induced Ca2+ signalling and sensitivity. Experimental Approach Airways in mouse lung slices were contracted with either methacholine (MCh) or 5HT and bronchodilation assessed using phase-contrast microscopy. Ca2+ signalling was measured with 2-photon fluorescence microscopy of ASM cells loaded with Oregon Green, a Ca2+-sensitive indicator (with or without caged-IP3). Effects on Ca2+ sensitivity were assessed on lung slices treated with caffeine and ryanodine to permeabilize ASM cells to Ca2+. Key Results The TAS2R10 agonists dilated airways constricted by either MCh or 5HT, accompanied by inhibition of agonist-induced Ca2+ oscillations. However, in non-contracted airways, TAS2R10 agonists, at concentrations that maximally dilated constricted airways, did not evoke Ca2+ signals in ASM cells. Ca2+ increases mediated by the photolysis of caged-IP3 were also attenuated by chloroquine, quinine and denotonium. In Ca2+-permeabilized ASM cells, the TAS2R10 agonists dilated MCh- and 5HT-constricted airways. Conclusions and Implications TAS2R10 agonists reversed bronchoconstriction by inhibiting agonist-induced Ca2+ oscillations while simultaneously reducing the Ca2+ sensitivity of ASM cells. Reduction of Ca2+ oscillations may be due to inhibition of Ca2+ release through IP3 receptors. Further characterization of bronchodilatory TAS2R agonists may lead to the development of novel therapies for the treatment of bronchoconstrictive conditions. PMID:24117140

Long-Acting Beta Agonists Enhance Allergic Airway Disease.

PubMed

Knight, John M; Mak, Garbo; Shaw, Joanne; Porter, Paul; McDermott, Catherine; Roberts, Luz; You, Ran; Yuan, Xiaoyi; Millien, Valentine O; Qian, Yuping; Song, Li-Zhen; Frazier, Vincent; Kim, Choel; Kim, Jeong Joo; Bond, Richard A; Milner, Joshua D; Zhang, Yuan; Mandal, Pijus K; Luong, Amber; Kheradmand, Farrah; McMurray, John S; Corry, David B

2015-01-01

Asthma is one of the most common of medical illnesses and is treated in part by drugs that activate the beta-2-adrenoceptor (β2-AR) to dilate obstructed airways. Such drugs include long acting beta agonists (LABAs) that are paradoxically linked to excess asthma-related mortality. Here we show that LABAs such as salmeterol and structurally related β2-AR drugs such as formoterol and carvedilol, but not short-acting agonists (SABAs) such as albuterol, promote exaggerated asthma-like allergic airway disease and enhanced airway constriction in mice. We demonstrate that salmeterol aberrantly promotes activation of the allergic disease-related transcription factor signal transducer and activator of transcription 6 (STAT6) in multiple mouse and human cells. A novel inhibitor of STAT6, PM-242H, inhibited initiation of allergic disease induced by airway fungal challenge, reversed established allergic airway disease in mice, and blocked salmeterol-dependent enhanced allergic airway disease. Thus, structurally related β2-AR ligands aberrantly activate STAT6 and promote allergic airway disease. This untoward pharmacological property likely explains adverse outcomes observed with LABAs, which may be overcome by agents that antagonize STAT6.

Myb permits multilineage airway epithelial cell differentiation

PubMed Central

Pan, Jie-hong; Adair-Kirk, Tracy L.; Patel, Anand C.; Huang, Tao; Yozamp, Nicholas S.; Xu, Jian; Reddy, E. Premkumar; Byers, Derek E.; Pierce, Richard A.; Holtzman, Michael J.; Brody, Steven L.

2014-01-01

The epithelium of the pulmonary airway is specially differentiated to provide defense against environmental insults, but also subject to dysregulated differentiation that results in lung disease. The current paradigm for airway epithelial differentiation is a one-step program whereby a p63+ basal epithelial progenitor cell generates a ciliated or secretory cell lineage, but the cue for this transition and whether there are intermediate steps is poorly defined. Here we identify transcription factor Myb as a key regulator that permits early multilineage differentiation of airway epithelial cells. Myb+ cells were identified as p63− and therefore distinct from basal progenitor cells, but were still negative for markers of differentiation. Myb RNAi treatment of primary-culture airway epithelial cells and Myb gene deletion in mice resulted in a p63− population with failed maturation of Foxj1+ ciliated cells, as well as Scbg1a1+ and Muc5ac+ secretory cells. Consistent with these findings, analysis of whole genome expression of Myb-deficient cells identified Myb-dependent programs for ciliated and secretory cell differentiation. Myb+ cells were rare in human airways but were increased in regions of ciliated cells and mucous cell hyperplasia in samples from subjects with chronic obstructive pulmonary disease. Together, the results show that a p63− Myb+ population of airway epithelial cells represents a distinct intermediate stage of differentiation that is required under normal conditions and may be heightened in airway disease. PMID:25103188

Color analysis of the human airway wall

NASA Astrophysics Data System (ADS)

Gopalakrishnan, Deepa; McLennan, Geoffrey; Donnelley, Martin; Delsing, Angela; Suter, Melissa; Flaherty, Dawn; Zabner, Joseph; Hoffman, Eric A.; Reinhardt, Joseph M.

2002-04-01

A bronchoscope can be used to examine the mucosal surface of the airways for abnormalities associated with a variety of lung diseases. The diagnosis of these abnormalities through the process of bronchoscopy is based, in part, on changes in airway wall color. Therefore it is important to characterize the normal color inside the airways. We propose a standardized method to calibrate the bronchoscopic imaging system and to tabulate the normal colors of the airway. Our imaging system consists of a Pentium PC and video frame grabber, coupled with a true color bronchoscope. The calibration procedure uses 24 standard color patches. Images of these color patches at three different distances (1, 1.5, and 2 cm) were acquired using the bronchoscope in a darkened room, to assess repeatability and sensitivity to illumination. The images from the bronchoscope are in a device-dependent Red-Green-Blue (RGB) color space, which was converted to a tri-stimulus image and then into a device-independent color space sRGB image by a fixed polynomial transformation. Images were acquired from five normal human volunteer subjects, two cystic fibrosis (CF) patients and one normal heavy smoker subject. The hue and saturation values of regions within the normal airway were tabulated and these values were compared with the values obtained from regions within the airways of the CF patients and the normal heavy smoker. Repeated measurements of the same region in the airways showed no measurable change in hue or saturation.

Comparison of analysis methods for airway quantification

NASA Astrophysics Data System (ADS)

Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.

2012-03-01

Diseased airways have been known for several years as a possible contributing factor to airflow limitation in Chronic Obstructive Pulmonary Diseases (COPD). Quantification of disease severity through the evaluation of airway dimensions - wall thickness and lumen diameter - has gained increased attention, thanks to the availability of multi-slice computed tomography (CT). Novel approaches have focused on automated methods of measurement as a faster and more objective means that the visual assessment routinely employed in the clinic. Since the Full-Width Half-Maximum (FWHM) method of airway measurement was introduced two decades ago [1], several new techniques for quantifying airways have been detailed in the literature, but no approach has truly become a standard for such analysis. Our own research group has presented two alternative approaches for determining airway dimensions, one involving a minimum path and the other active contours [2, 3]. With an increasing number of techniques dedicated to the same goal, we decided to take a step back and analyze the differences of these methods. We consequently put to the test our two methods of analysis and the FWHM approach. We first measured a set of 5 airways from a phantom of known dimensions. Then we compared measurements from the three methods to those of two independent readers, performed on 35 airways in 5 patients. We elaborate on the differences of each approach and suggest conclusions on which could be defined as the best one.

Proteolysis produced within biofilms of bacterial isolates from raw milk tankers.

PubMed

Teh, Koon Hoong; Flint, Steve; Palmer, Jon; Andrewes, Paul; Bremer, Phil; Lindsay, Denise

2012-06-15

In this study, six bacterial isolates that produced thermo-resistant enzymes isolated from the internal surfaces of raw milk tankers were evaluated for their ability to produce proteolysis within either single culture biofilms or co-culture biofilms. Biofilms were formed in an in vitro model system that simulated the upper internal surface of a raw milk tanker during a typical summer's day of milk collection in New Zealand. The bacterial isolates were further evaluated for their ability to form biofilms at 25, 30 and 37°C. Mutual and competitive effects were observed in some of the co-culture biofilms, with all isolates being able to form biofilms in either single culture or co-culture at the three temperatures. The proteolysis was also evaluated in both biofilms and corresponding planktonic cultures. The proteolysis per cell decreased as the temperature of incubation (20-37°C) increased. Furthermore, mutualistic interactions in terms of proteolysis were observed when cultures were grown as co-culture biofilms. This is the first study to show that proteolytic enzymes can be produced in biofilms on the internal surfaces of raw milk tankers. This has important implications for the cleaning and the temperature control of raw milk transport tankers. Copyright © 2012 Elsevier B.V. All rights reserved.

Intrathoracic airway wall detection using graph search and scanner PSF information

NASA Astrophysics Data System (ADS)

Reinhardt, Joseph M.; Park, Wonkyu; Hoffman, Eric A.; Sonka, Milan

1997-05-01

Measurements of the in vivo bronchial tree can be used to assess regional airway physiology. High-resolution CT (HRCT) provides detailed images of the lungs and has been used to evaluate bronchial airway geometry. Such measurements have been sued to assess diseases affecting the airways, such as asthma and cystic fibrosis, to measure airway response to external stimuli, and to evaluate the mechanics of airway collapse in sleep apnea. To routinely use CT imaging in a clinical setting to evaluate the in vivo airway tree, there is a need for an objective, automatic technique for identifying the airway tree in the CT images and measuring airway geometry parameters. Manual or semi-automatic segmentation and measurement of the airway tree from a 3D data set may require several man-hours of work, and the manual approaches suffer from inter-observer and intra- observer variabilities. This paper describes a method for automatic airway tree analysis that combines accurate airway wall location estimation with a technique for optimal airway border smoothing. A fuzzy logic, rule-based system is used to identify the branches of the 3D airway tree in thin-slice HRCT images. Raycasting is combined with a model-based parameter estimation technique to identify the approximate inner and outer airway wall borders in 2D cross-sections through the image data set. Finally, a 2D graph search is used to optimize the estimated airway wall locations and obtain accurate airway borders. We demonstrate this technique using CT images of a plexiglass tube phantom.

The new agreement of the international RIGA consensus conference on nasal airway function tests.

PubMed

Vogt, K; Bachmann-Harildstad, G; Lintermann, A; Nechyporenko, A; Peters, F; Wernecke, K D

2018-01-21

The report reflects an agreement based on the consensus conference of the International Standardization Committee on the Objective Assessment of the Nasal Airway in Riga, 2nd Nov. 2016. The aim of the conference was to address the existing nasal airway function tests and to take into account physical, mathematical and technical correctness as a base of international standardization as well as the requirements of the Council Directive 93/42/EEC of 14 June 1993 concerning medical devices. Rhinomanometry, acoustic rhinometry, peak nasal inspiratory flow, Odiosoft-Rhino, optical rhinometry, 24-h measurements, computational fluid dynamics, nasometry and the mirrow test were evaluated for important diagnostic criteria, which are the precision of the equipment including calibration and the software applied; validity with sensitivity, specificity, positive and negative predictive values, reliability with intra-individual and inter-individual reproducibility and responsiveness in clinical studies. For rhinomanometry, the logarithmic effective resistance was set as the parameter of high diagnostic relevance. In acoustic rhinometry, the area of interest for the minimal cross-sectional area will need further standardization. Peak nasal inspiratory flow is a reproducible and fast test, which showed a high range of mean values in different studies. The state of the art with computational fluid dynamics for the simulation of the airway still depends on high performance computing hardware and will, after standardization of the software and both the software and hardware for imaging protocols, certainly deliver a better understanding of the nasal airway flux.

Recurrent milk aspiration produces changes in airway mechanics, lung eosinophilia, and goblet cell hyperplasia in a murine model.

PubMed

Janahi, I A; Elidemir, O; Shardonofsky, F R; Abu-Hassan, M N; Fan, L L; Larsen, G L; Blackburn, M R; Colasurdo, G N

2000-12-01

Recurrent aspiration of milk into the respiratory tract has been implicated in the pathogenesis of a variety of inflammatory lung disorders including asthma. However, the lack of animal models of aspiration-induced lung injury has limited our knowledge of the pathophysiological characteristics of this disorder. This study was designed to evaluate the effects of recurrent milk aspiration on airway mechanics and lung cells in a murine model. Under light anesthesia, BALB/c mice received daily intranasal instillations of whole cow's milk (n = 7) or sterile physiologic saline (n = 9) for 10 d. Respiratory system resistance (Rrs) and dynamic elastance (Edyn,rs) were measured in anesthetized, tracheotomized, paralyzed and mechanically ventilated mice 24 h after the last aspiration of milk. Rrs and Edyn,rs were derived from transrespiratory and plethysmographic pressure signals. In addition, airway responses to increasing concentrations of i.v. methacholine (Mch) were determined. Airway responses were measured in terms of PD(100) (dose of Mch causing 100% increase from baseline Rrs) and Rrs,max (% increase from baseline at the maximal plateau response) and expressed as % control (mean +/- SE). We found recurrent milk aspiration did not affect Edyn and baseline Rrs values. However, airway responses to Mch were increased after milk aspiration when compared with control mice. These changes in airway mechanics were associated with an increased percentage of lymphocytes and eosinophils in the bronchoalveolar lavage, mucus production, and lung inflammation. Our findings suggest that recurrent milk aspiration leads to alterations in airway function, lung eosinophilia, and goblet cell hyperplasia in a murine model.

Interaction of ozone exposure with airway hyperresponsiveness and inflammation induced by trimellitic anhydride in sensitized guinea pigs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Jian; Chung, K.Fan

1997-09-01

The effect of prior ozone (O{sub 3}) exposure on airway hyperresponsiveness and inflammation induced by trimellitic anhydride (TMA) has been investigated in TMA-sensitized guinea pigs. Airway responsiveness was measured as the concentration of acetylcholine needed to increase baseline lung resistance (RL) by 300% (PC300). Ozone (3 ppm, for 3 h) caused an increase in-log PC300 at 1 h after exposure, with return of -log PC300 to control levels at 8 h. Ozone also increased baseline RL at 8 h. TMA challenge increase -log PC300 in TMA-sensitized guinea pigs at 8 h after challenge from 3.85 {+-} 0.09 to 4.11 {+-}more » 0.09. Ozone exposure prior to TMA challenge prevented the induction of airway hyperresponsiveness with a mean -log PC300 of 3.51 {+-} 0.20, which was not different from that of control TMA-Sensitized group. Baseline RL was significantly higher in ozone-pretreated animals after TMA challenge when compared to those of either control or challenged with TMA alone. Ozone had no effect on TMA challenge-induced BAL eosinophilia and neutrophilia. We conclude that a single exposure to ozone inhibits the increase in airway responsiveness, but increases the bronchoconstrictor response induced by TMA in TMA-Sensitized guinea pigs; however, the inflammatory airway response to TMA is unchanged by preexposure to ozone. 29 refs., 2 figs., 1 tab.« less

76 FR 23687 - Amendment of Federal Airways; Alaska

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-28

... Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action amends all Anchorage, AK, Federal airways... airways that currently use the Anchorage (ANC) VOR located on Fire Island, AK. The ANC VOR was upgraded to... Federal airways. * * * * * V-319 [Amended] From Yakutat, AK, via Johnstone Point, AK, INT Johnstone Point...

Control of upper airway muscle activity in younger versus older men during sleep onset

PubMed Central

Fogel, Robert B; White, David P; Pierce, Robert J; Malhotra, Atul; Edwards, Jill K; Dunai, Judy; Kleverlaan, Darci; Trinder, John

2003-01-01

Pharyngeal dilator muscles are clearly important in the pathophysiology of obstructive sleep apnoea syndrome (OSA). We have previously shown that the activity of both the genioglossus (GGEMG) and tensor palatini (TPEMG) are decreased at sleep onset, and that this decrement in muscle activity is greater in the apnoea patient than in healthy controls. We have also previously shown this decrement to be greater in older men when compared with younger ones. In order to explore the mechanisms responsible for this decrement in muscle activity nasal continuous positive airway pressure (CPAP) was applied to reduce negative pressure mediated muscle activation. We then investigated the effect of sleep onset (transition from predominantly α to predominantly θ EEG activity) on ventilation, upper airway muscle activation and upper airway resistance (UAR) in middle-aged and younger healthy men. We found that both GGEMG and TPEMG were reduced by the application of nasal CPAP during wakefulness, but that CPAP did not alter the decrement in activity in either muscle seen in the first two breaths following an α to θ transition. However, CPAP prevented both the rise in UAR at sleep onset that occurred on the control night, and the recruitment in GGEMG seen in the third to fifth breaths following the α to θ transition. Further, GGEMG was higher in the middle-aged men than in the younger men during wakefulness and was decreased more in the middle-aged men with the application of nasal CPAP. No differences were seen in TPEMG between the two age groups. These data suggest that the initial sleep onset reduction in upper airway muscle activity is due to loss of a ‘wakefulness’ stimulus, rather than to loss of responsiveness to negative pressure. In addition, it suggests that in older men, higher wakeful muscle activity is due to an anatomically more collapsible upper airway with more negative pressure driven muscle activation. Sleep onset per se does not appear to have a greater

Reference values for airway resistance in newborns, infants and preschoolers from a Latin American population.

PubMed

Gochicoa, Laura G; Thomé-Ortiz, Laura P; Furuya, María E Y; Canto, Raquel; Ruiz-García, Martha E; Zúñiga-Vázquez, Guillermo; Martínez-Ramírez, Filiberto; Vargas, Mario H

2012-05-01

Several studies have determined reference values for airway resistance measured by the interrupter technique (Rint) in paediatric populations, but only one has been done on Latin American children, and no studies have been performed on Mexican children. Moreover, these previous studies mostly included children aged 3 years and older; therefore, information regarding Rint reference values for newborns and infants is scarce. Rint measurements were performed on preschool children attending eight kindergartens (Group 1) and also on sedated newborns, infants and preschool children admitted to a tertiary-level paediatric hospital due to non-cardiopulmonary disorders (Group 2). In both groups, Rint values were inversely associated with age, weight and height, but the strongest association was with height. The linear regression equation for Group 1 (n = 209, height 86-129 cm) was Rint = 2.153 - 0.012 × height (cm) (standard deviation of residuals 0.181 kPa/L/s). The linear regression equation for Group 2 (n = 55, height 52-113 cm) was Rint = 4.575 - 0.035 × height (cm) (standard deviation of residuals 0.567 kPa/L/s). Girls tended to have slightly higher Rint values than boys, a difference that diminished with increasing height. In this study, Rint reference values applicable to Mexican children were determined, and these values are probably also applicable to other paediatric populations with similar Spanish-Amerindian ancestries. There was an inverse relationship between Rint and height, with relatively large between-subject variability. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.

A framework for understanding shared substrates of airway protection

PubMed Central

TROCHE, Michelle Shevon; BRANDIMORE, Alexandra Essman; GODOY, Juliana; HEGLAND, Karen Wheeler

2014-01-01

Deficits of airway protection can have deleterious effects to health and quality of life. Effective airway protection requires a continuum of behaviors including swallowing and cough. Swallowing prevents material from entering the airway and coughing ejects endogenous material from the airway. There is significant overlap between the control mechanisms for swallowing and cough. In this review we will present the existing literature to support a novel framework for understanding shared substrates of airway protection. This framework was originally adapted from Eccles' model of cough28 (2009) by Hegland, et al.42 (2012). It will serve to provide a basis from which to develop future studies and test specific hypotheses that advance our field and ultimately improve outcomes for people with airway protective deficits. PMID:25141195

Clinical review: Airway hygiene in the intensive care unit

PubMed Central

Jelic, Sanja; Cunningham, Jennifer A; Factor, Phillip

2008-01-01

Maintenance of airway secretion clearance, or airway hygiene, is important for the preservation of airway patency and the prevention of respiratory tract infection. Impaired airway clearance often prompts admission to the intensive care unit (ICU) and can be a cause and/or contributor to acute respiratory failure. Physical methods to augment airway clearance are often used in the ICU but few are substantiated by clinical data. This review focuses on the impact of oral hygiene, tracheal suctioning, bronchoscopy, mucus-controlling agents, and kinetic therapy on the incidence of hospital-acquired respiratory infections, length of stay in the hospital and the ICU, and mortality in critically ill patients. Available data are distilled into recommendations for the maintenance of airway hygiene in ICU patients. PMID:18423061

Airway persistence by the emerging multi-azole-resistant Rasamsonia argillacea complex in cystic fibrosis.

PubMed

Abdolrasouli, Alireza; Bercusson, Amelia C; Rhodes, Johanna L; Hagen, Ferry; Buil, Jochem B; Tang, Alison Y Y; de Boer, Leonard L; Shah, Anand; Milburn, Andrew J; Elborn, J Stuart; Jones, Andrew L; Meis, Jacques F; Fisher, Matthew C; Schelenz, Silke; Simmonds, Nicholas J; Armstrong-James, Darius

2018-04-27

Infections caused by Rasamsonia argillacea complex have been reported in various clinical settings. Cystic fibrosis (CF) is one of the main underlying conditions. An observational cohort study of CF patients with Rasamsonia in respiratory samples was conducted. Eight isolates from six patients were identified as R. argillacea complex and tested for antifungal susceptibility. All isolates had high MICs to voriconazole and posaconazole and low MECs to echinocandins. Four patients experienced lung function decline in the year preceding first Rasamsonia isolation. This continued in the year following first isolation in three out of four cases. Antifungal therapy was initiated in two patients, to which only one exhibited a clinical response. Three out of six patients died within three years of isolating Rasamsonia. Genotyping suggests that similar genotypes of Rasamsonia can persist in CF airways. Consistent with other fungi in CF, the clinical impact of airway colonization by Rasamsonia is variable. In certain patients, Rasamsonia may be able to drive clinical decline. In others, though a clear impact on lung function may be difficult to determine, the appearance of Rasamsonia acts as a marker of disease severity. In others it does not appear to have an obvious clinical impact on disease progression. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Airway complications in the head injured.

PubMed

Woo, P; Kelly, G; Kirshner, P

1989-07-01

Fifty head-injured patients who had tracheostomy were followed during rehabilitation by video fiberoptic laryngoscopy examination. Complications of aspiration (23/50), airway stenosis (13/50), and phonation dysfunction (16/24) were followed. Spontaneous resolution of aspiration may require a prolonged course. A majority of patients (37/50) had improvement and could be decannulated. Prognostic factors correlated to eventual decannulation included age, level on the Glasgow Coma Outcome Scale, and type of head injury. Those with poor neurologic improvement and glottic incompetence (13/50) are poor candidates for decannulation. Significant airway stenosis can involve both laryngeal and tracheal sites. Neurologic dysfunction may complicate the decannulation process after airway anatomy has been restored by surgery. Dysphonia resulting from intubation, peripheral laryngeal and nerve injury, or central laryngeal movement dysfunction are common. Preventive maintenance with ongoing evaluation can avoid airway crises such as aspiration pneumonia, hemoptysis, and innominate artery.

Videolaryngoscopy versus Fiber-optic Intubation through a Supraglottic Airway in Children with a Difficult Airway: An Analysis from the Multicenter Pediatric Difficult Intubation Registry.

PubMed

Burjek, Nicholas E; Nishisaki, Akira; Fiadjoe, John E; Adams, H Daniel; Peeples, Kenneth N; Raman, Vidya T; Olomu, Patrick N; Kovatsis, Pete G; Jagannathan, Narasimhan; Hunyady, Agnes; Bosenberg, Adrian; Tham, See; Low, Daniel; Hopkins, Paul; Glover, Chris; Olutoye, Olutoyin; Szmuk, Peter; McCloskey, John; Dalesio, Nicholas; Koka, Rahul; Greenberg, Robert; Watkins, Scott; Patel, Vikram; Reynolds, Paul; Matuszczak, Maria; Jain, Ranu; Khalil, Samia; Polaner, David; Zieg, Jennifer; Szolnoki, Judit; Sathyamoorthy, Kumar; Taicher, Brad; Riveros Perez, N Ricardo; Bhattacharya, Solmaletha; Bhalla, Tarun; Stricker, Paul; Lockman, Justin; Galvez, Jorge; Rehman, Mohamed; Von Ungern-Sternberg, Britta; Sommerfield, David; Soneru, Codruta; Chiao, Franklin; Richtsfeld, Martina; Belani, Kumar; Sarmiento, Lina; Mireles, Sam; Bilen Rosas, Guelay; Park, Raymond; Peyton, James

2017-09-01

The success rates and related complications of various techniques for intubation in children with difficult airways remain unknown. The primary aim of this study is to compare the success rates of fiber-optic intubation via supraglottic airway to videolaryngoscopy in children with difficult airways. Our secondary aim is to compare the complication rates of these techniques. Observational data were collected from 14 sites after management of difficult pediatric airways. Patient age, intubation technique, success per attempt, use of continuous ventilation, and complications were recorded for each case. First-attempt success and complications were compared in subjects managed with fiber-optic intubation via supraglottic airway and videolaryngoscopy. Fiber-optic intubation via supraglottic airway and videolaryngoscopy had similar first-attempt success rates (67 of 114, 59% vs. 404 of 786, 51%; odds ratio 1.35; 95% CI, 0.91 to 2.00; P = 0.16). In subjects less than 1 yr old, fiber-optic intubation via supraglottic airway was more successful on the first attempt than videolaryngoscopy (19 of 35, 54% vs. 79 of 220, 36%; odds ratio, 2.12; 95% CI, 1.04 to 4.31; P = 0.042). Complication rates were similar in the two groups (20 vs. 13%; P = 0.096). The incidence of hypoxemia was lower when continuous ventilation through the supraglottic airway was used throughout the fiber-optic intubation attempt. In this nonrandomized study, first-attempt success rates were similar for fiber-optic intubation via supraglottic airway and videolaryngoscopy. Fiber-optic intubation via supraglottic airway is associated with higher first-attempt success than videolaryngoscopy in infants with difficult airways. Continuous ventilation through the supraglottic airway during fiber-optic intubation attempts may lower the incidence of hypoxemia.

Small Airway Dysfunction and Abnormal Exercise Responses

PubMed Central

Petsonk, Edward L.; Stansbury, Robert C.; Beeckman-Wagner, Lu-Ann; Long, Joshua L.; Wang, Mei Lin

2016-01-01

Rationale Coal mine dust exposure can cause symptoms and loss of lung function from multiple mechanisms, but the roles of each disease process are not fully understood. Objectives We investigated the implications of small airway dysfunction for exercise physiology among a group of workers exposed to coal mine dust. Methods Twenty coal miners performed spirometry, first breathing air and then helium-oxygen, single-breath diffusing capacity, and computerized chest tomography, and then completed cardiopulmonary exercise testing. Measurements and Main Results Six participants meeting criteria for small airway dysfunction were compared with 14 coal miners who did not. At submaximal workload, miners with small airway dysfunction used a higher proportion of their maximum voluntary ventilation and had higher ventilatory equivalents for both O2 and CO2. Regression modeling indicated that inefficient ventilation was significantly related to small airway dysfunction but not to FEV1 or diffusing capacity. At the end of exercise, miners with small airway dysfunction had 27% lower O2 consumption. Conclusions Small airway abnormalities may be associated with important inefficiency of exercise ventilation. In dust-exposed individuals with only mild abnormalities on resting lung function tests or chest radiographs, cardiopulmonary exercise testing may be important in defining causes of exercise intolerance. PMID:27073987

Airway growth and development: a computerized 3-dimensional analysis.

PubMed

Schendel, Stephen A; Jacobson, Richard; Khalessi, Sadri

2012-09-01

The present study was undertaken to investigate the changes in the normal upper airway during growth and development using 3-dimensional computer analysis from cone-beam computed tomography (CBCT) data to provide a normative reference. The airway size and respiratory mode are known to have a relationship to facial morphology and the development of a malocclusion. The use of CBCT, 3-dimensional imaging, and automated computer analysis in treatment planning allows the upper airway to be precisely evaluated. In the present study, we evaluated the growth of the airway using 3-dimensional analysis and CBCT data from age 6 through old age, in 1300 normal individuals. The airway size and length increase until age 20 at which time a variable period of stability occurs. Next, the airway at first decreases slowly in size and then, after age 40, more rapidly. Normative data are provided in the present study for age groups from 6 to 60 years in relation to the airway total volume, smallest cross-sectional area and vertical length of the airway. This 3-dimensional data of the upper airway will provide a normative reference as an aid in the early understanding of respiration and dentofacial anatomy, which will help in early treatment planning. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Airway hyperreactivity in asymptomatic military personnel.

PubMed

Morris, Michael J; Schwartz, Darin S; Nohrenberg, Jana L; Dooley, Sean N

2007-11-01

Asthma is frequently diagnosed in military personnel despite strict guidelines that disqualify persons with active disease or a recent history of asthma. It is generally considered incompatible with military service, because of the regular physical training, outdoor training exercises, and deployments to remote locations. The objective of this study was to determine the prevalence of airway hyperreactivity in asymptomatic military personnel, as an estimate of subclinical reactive airway disease. A prospective study of healthy, asymptomatic, military personnel with no previous history of asthma and <1 year on active duty status was conducted. After completion of a screening questionnaire, personnel underwent baseline spirometry with a portable spirometer. Personnel with obstructive indices (based on published guidelines) and matched control subjects participated in an exercise test (1.5-mile run), with pre- and postexercise spirometry. A total of 222 asymptomatic military personnel completed baseline spirometry, and 31 (14%) were found have airway obstruction. A normal matched control group of 31 military personnel and 26 personnel with obstruction performed exercise spirometry. Twenty-three percent of the participants with obstruction demonstrated increased airway hyper-reactivity after exercise, based on a reduction in forced expiratory volume at 1 second, compared with 19% of control subjects. Asymptomatic airway obstruction has a prevalence of 14% in young military personnel. A significant percentage of individuals also have evidence of worsening obstruction during exercise. These data suggest that screening spirometry may identify early reactive airway disease in asymptomatic individuals and should be considered as a method to identify persons predisposed to developing symptomatic asthma.

Bronchoscopic management of critical central airway obstruction by thyroid cancer: Combination airway stenting using tracheal and inverted-Y carinal self-expanding metallic stents

PubMed Central

Madan, Karan; Shrestha, Prajowl; Garg, Rakesh; Hadda, Vijay; Mohan, Anant; Guleria, Randeep

2017-01-01

Central airway obstruction (CAO) can result from various benign and malignant etiologies. Anaplastic thyroid cancer (ATC) is the most aggressive form of thyroid cancer. Rapid airway compromise is the main cause of death in ATC. We report a patient with ATC who presented with a large neck mass leading to CAO with long segment tracheal and right main bronchial compression and respiratory failure. Urgent Rigid Bronchoscopy was performed for airway stabilization and patient was managed with a combination airway stenting approach. A combination of self expanding, metallic, covered inverted Y and straight tracheal stents was used to stabilize the near complete airway structure. We herein highlight the role of therapeutic rigid bronchoscopy with airway stenting as an efficacious treatment modality for management of malignant CAO. PMID:28360477

Antimicrobial resistance in the respiratory microbiota of people with cystic fibrosis.

PubMed

Sherrard, Laura J; Tunney, Michael M; Elborn, J Stuart

2014-08-23

Cystic fibrosis is characterised by chronic polymicrobial infection and inflammation in the airways of patients. Antibiotic treatment regimens, targeting recognised pathogens, have substantially contributed to increased life expectancy of patients with this disease. Although the emergence of antimicrobial resistance and selection of highly antibiotic-resistant bacterial strains is of major concern, the clinical relevance in cystic fibrosis is yet to be defined. Resistance has been identified in recognised cystic fibrosis pathogens and in other bacteria (eg, Prevotella and Streptococcus spp) detected in the airway microbiota, but their role in the pathophysiology of infection and inflammation in chronic lung disease is unclear. Increased antibiotic resistance in cystic fibrosis might be attributed to a range of complex factors including horizontal gene transfer, hypoxia, and biofilm formation. Strategies to manage antimicrobial resistance consist of new antibiotics or localised delivery of antimicrobial agents, iron sequestration, inhibition of quorum-sensing, and resistome analysis. Determination of the contributions of every bacterial species to lung health or disease in cystic fibrosis might also have an important role in the management of antibiotic resistance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Obstructive sleep apnea syndrome and upper airway inflammation.

PubMed

Inancli, Hasan M; Enoz, Murat

2010-01-01

Obstructive sleep apnea syndrome (OSAS) is associated with inflammatory processes and elevated plasma cytokines. Inflammatory processes associated with OSAS may also act as potential mediators of cardiovascular morbidity in these patients. OSAS is associated with elevated levels of C reactive protein (CRP), as a marker of inflammation and cardiovascular risk. At the inflammatory point of view, the levels of TNF-alpha, IL-6, hsCRP, adhesion molecules, monocyte chemo attractant protein-1 and resist in were markedly and significantly elevated in patients with sleep apnea than those in normal control subjects. We reviewed several recent patents and literature in English about OSAS and upper airway inflammation relation since 1966 from the Medline database.

21 CFR 868.5100 - Nasopharyngeal airway.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway. (a...

21 CFR 868.5110 - Oropharyngeal airway.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a...

21 CFR 868.5100 - Nasopharyngeal airway.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway. (a...

21 CFR 868.5100 - Nasopharyngeal airway.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway. (a...

21 CFR 868.5110 - Oropharyngeal airway.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a...

21 CFR 868.5100 - Nasopharyngeal airway.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway. (a...

21 CFR 868.5110 - Oropharyngeal airway.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a...

21 CFR 868.5110 - Oropharyngeal airway.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a...

Airway Strain during Mechanical Ventilation in an Intact Animal Model

PubMed Central

Sinclair, Scott E.; Molthen, Robert C.; Haworth, Steve T.; Dawson, Christopher A.; Waters, Christopher M.

2007-01-01

Rationale: Mechanical ventilation with large tidal volumes causes ventilator-induced lung injury in animal models. Little direct evidence exists regarding the deformation of airways in vivo during mechanical ventilation, or in the presence of positive end-expiratory pressure (PEEP). Objectives: To measure airway strain and to estimate airway wall tension during mechanical ventilation in an intact animal model. Methods: Sprague-Dawley rats were anesthetized and mechanically ventilated with tidal volumes of 6, 12, and 25 cm3/kg with and without 10–cm H2O PEEP. Real-time tantalum bronchograms were obtained for each condition, using microfocal X-ray imaging. Images were used to calculate circumferential and longitudinal airway strains, and on the basis of a simplified mathematical model we estimated airway wall tensions. Measurements and Main Results: Circumferential and longitudinal airway strains increased with increasing tidal volume. Levels of mechanical strain were heterogeneous throughout the bronchial tree. Circumferential strains were higher in smaller airways (less than 800 μm). Airway size did not influence longitudinal strain. When PEEP was applied, wall tensions increased more rapidly than did strain levels, suggesting that a “strain limit” had been reached. Airway collapse was not observed under any experimental condition. Conclusions: Mechanical ventilation results in significant airway mechanical strain that is heterogeneously distributed in the uninjured lung. The magnitude of circumferential but not axial strain varies with airway diameter. Airways exhibit a “strain limit” above which an abrupt dramatic rise in wall tension is observed. PMID:17626911

Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus from Retail Raw Chicken Meat.

PubMed

Li, Suixia; Wang, Panpan; Zhao, Jialin; Zhou, Luhong; Zhang, Pengfei; Fu, Chengyu; Meng, Jianghong; Wang, Xin

2018-04-01

The aim of this study was to investigate the toxin gene profile and antimicrobial resistance of Staphylococcus aureus isolates from raw chicken in the People's Republic of China. In total, 289 S. aureus isolates were characterized by antimicrobial susceptibility testing, and genes encoding enterotoxins, exfoliative toxins, Panton-Valentine leukocidin, and toxic shock syndrome toxin were revealed by PCR. Overall, 46.0% of the isolates were positive for one or more toxin genes. A high proportion of toxin genes were pvl (26.6%), followed by sej (12.5%), sea (9.0%), seh (8.3%), seb (6.9%), sec (6.9%), sed (4.8%), sei (3.1%), and see (2.4%). None of the isolates harbored seg, tsst-1, or exfoliative toxin genes. In total, 29 toxin gene profiles were obtained, and pvl (10.7%) was the most frequent genotype, followed by sea (5.9%), seb (4.8%), and sej (4.2%). Furthermore, 99.7% of the strains were resistant to at least one of the tested antimicrobial agents, and 87.2% of them displayed multidrug resistance. Resistance was most frequently observed to trimethoprim-sulfamethoxazole and erythromycin (86.2% for each), followed by tetracycline (69.9%), amoxicillin-clavulanic acid (45.0%), and ampicillin (42.6%). None of the strains were resistant to vancomycin. This study indicates that S. aureus isolates from raw chicken harbored multiple toxin genes and exhibited multiple antimicrobial resistance, which represents a potential health hazard for consumers.

FAMM Flap in Reconstructing Postsurgical Nasopharyngeal Airway Stenosis

PubMed Central

Nangole, Ferdinand Wanjala; Khainga, Stanley Ominde

2014-01-01

Introduction. Postsurgical nasopharyngeal airway stenosis can be a challenge to manage. The stenosis could be as a result of any surgical procedure in the nasopharyngeal region that heals extensive scarring and fibrosis. Objective. To evaluate patients with nasopharyngeal stenosis managed with FAMM flap. Study Design. Prospective study of patients with nasopharyngeal stenosis at the Kenyatta National Hospital between 2010 and 2013 managed with FAMM flap. Materials and Methods. Patients with severe nasopharyngeal airway stenosis were reviewed and managed with FAMM flaps at the Kenyatta National Hospital. Postoperatively they were assessed for symptomatic improvement in respiratory distress, patency of the nasopharyngeal airway, and donor site morbidity. Results. A total of 8 patients were managed by the authors in a duration of 4 years with nasopharyngeal stenosis. Five patients were managed with unilateral FAMM flaps in a two-staged surgical procedure. Four patients had complete relieve of the airway obstruction with a patent airway created. One patient had a patent airway created though with only mild improvement in airway obstruction. Conclusion. FAMM flap provides an alternative in the management of postsurgical severe nasopharyngeal stenosis. It is a reliable flap that is easy to raise and could provide adequate epithelium for the stenosed pharynx. PMID:25328699

Prevalence, identification of virulence factors, O-serogroups and antibiotic resistance properties of Shiga-toxin producing Escherichia coli strains isolated from raw milk and traditional dairy products.

PubMed

Ranjbar, Reza; Safarpoor Dehkordi, Farhad; Sakhaei Shahreza, Mohammad Hossein; Rahimi, Ebrahim

2018-01-01

Shiga-toxigenic Escherichia coli strains are one of the most important foodborne bacteria with an emergence of antibiotic resistance. Foodborne STEC strains are mainly associated with presence of certain virulence factors and O-seogroups. The present investigation was done to study the distribution of virulence factors, O-serogroups and antibiotic resistance properties of Shiga-toxigenic Escherichia coli isolated from milk and dairy products. Six-hundred samples were randomly collected and immediately transferred to laboratory. All samples were cultured and E. coli strains were isolated. STEC strains were identified based on the presence of putative virulence factors and subtypes. STEC isolates were subjected to multiplex PCR and disk diffusion methods. One-hundred and eighty-one out of 600 samples (30.16%) harbored E. coli . Prevalence of STEC strains was 10.66%. O157 (43.75%) and O26 (37.50%) were the most frequently identified serogroups. Aac(3)-IV (100%), CITM (96.87%) and tetA (76.56%) were the most commonly detected antibiotic resistance genes. STEC strains had the highest prevalence of resistance against ampicillin (100%), gentamicin (100%) and tetracycline (96.87%). Kashk and dough were negative for presence of E. coli strains. High prevalence of resistant-O157 strains and simultaneous presence of multiple virulence factors pose an important public health problem regarding the consumption of raw milk and dairy products.

A child with a difficult airway: what do I do next?

PubMed

Engelhardt, Thomas; Weiss, Markus

2012-06-01

Difficulties in pediatric airway management are common and continue to result in significant morbidity and mortality. This review reports on current concepts in approaching a child with a difficult airway. Routine airway management in healthy children with normal airways is simple in experienced hands. Mask ventilation (oxygenation) is always possible and tracheal intubation normally simple. However, transient hypoxia is common in these children usually due to unexpected anatomical and functional airway problems or failure to ventilate during rapid sequence induction. Anatomical airway problems (upper airway collapse and adenoid hypertrophy) and functional airway problems (laryngospasm, bronchospasm, insufficient depth of anesthesia and muscle rigidity, gastric hyperinflation, and alveolar collapse) require urgent recognition and treatment algorithms due to insufficient oxygen reserves. Early muscle paralysis and epinephrine administration aids resolution of these functional airway obstructions. Children with an 'impaired' normal (foreign body, allergy, and inflammation) or an expected difficult (scars, tumors, and congenital) airway require careful planning and expertise. Training in the recognition and management of these different situations as well as a suitably equipped anesthesia workstation and trained personnel are essential. The healthy child with an unexpected airway problem requires clear strategies. The 'impaired' normal pediatric airway may be handled by anesthetists experienced with children, whereas the expected difficult pediatric airway requires dedicated pediatric anesthesia specialist care and should only be managed in specialized centers.

Corticosteroid treatment inhibits airway hyperresponsiveness and lung injury in a murine model of chemical-induced airway inflammation.

PubMed

Wigenstam, Elisabeth; Jonasson, Sofia; Koch, Bo; Bucht, Anders

2012-11-15

Exposure to toxic alkylating mustard agents causes both acute and long-term effects to the lungs as indicated by increased number of inflammatory cells in airways, lung edema and lung tissue fibrosis. We have previously demonstrated that treatment with the corticosteroid dexamethasone 1 h after lung exposure to the nitrogen mustard analog melphalan protects mice from acute and sub-acute inflammatory responses, as well as from lung tissue fibrosis. In order to address the importance of early anti-inflammatory treatment, we investigated the therapeutic effect of dexamethasone administered 1, 2 or 6 h following exposure to melphalan. C57BL/6 mice were exposed to melphalan and treated with dexamethasone 1, 2 or 6 h after exposure. Twenty hours or 14 days post exposure mice were subjected to analysis of respiratory mechanics where the effects of incremental doses of methacholine on central and peripheral lung components were measured. We also determined the amount of inflammatory cells in the bronchoalveolar lavage fluid and measured the amount of collagen content in the lungs. Melphalan exposure increased airway hyperresponsiveness in both central and peripheral airways and induced an airway inflammation dominated by infiltration of macrophages and neutrophils. Dexamethasone given 1 h after exposure to melphalan provided better protection against airway inflammation than administration 2 or 6 h after exposure. Collagen deposition 14 days after exposure was decreased due to dexamethasone treatment. Early treatment with dexamethasone is important in order to reduce the airway hyperresponsiveness and inflammation caused by toxic alkylating mustards such as melphalan. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Diesel Exhaust Particle-Induced Airway Responses are Augmented in Obese Rats

PubMed Central

Moon, Kuk-Young; Park, Moo-Kyun; Leikauf, George D.; Park, Choon-Sik; Jang, An-Soo

2015-01-01

Air pollutants and obesity are important factors that contribute to asthma. The aim of this study was to assess the airway responsiveness and inflammation in Otsuka-Long Evans Tokushima Fatty (OLETF) obese rats and Long Evans Tokushima-Otsuka (LETO) nonobese rats exposed to diesel exhaust particles (DEPs). Otsuka Long Evans Tokushima fatty rats and LETO rats were exposed intranasally to DEP and then challenged with aerosolized DEP on days 6 to 8. Body plethysmography, bronchoalveolar lavage (BAL), and histology were performed. Enhanced pause (Penh) was measured as an indicator of airway resistance on day 9 and samples were collected on day 10. After exposure to DEP, the OLETF group exhibited a greater increase in Penh compared to that in the LETO group. Moreover, the BAL fluid in mice showed an increase in the total and differential cell counts in the DEP-exposed OLETF group compared to that in the DEP-exposed LETO group. Histological assessment of lung tissue from each group revealed that the DEP-exposed OLETF group tended to have increased inflammatory cell infiltrations in the prebronchial area. Increased peroxisome proliferator-activated receptor γ, coactivator 1β messenger RNA was observed in the lungs of obese rats compared to that in nonobese rats following DEP exposure. These data indicate that the DEP-exposed OLETF group had increased airway responses and inflammation compared to the DEP-exposed LETO group, indicating that diesel particulates and obesity may be co-contributors to asthma. PMID:24536021

Resistance to alveolar shape change limits range of force propagation in lung parenchyma.

PubMed

Ma, Baoshun; Smith, Bradford J; Bates, Jason H T

2015-06-01

We have recently shown that if the lung parenchyma is modeled in 2 dimensions as a network of springs arranged in a pattern of repeating hexagonal cells, the distortional forces around a contracting airway propagate much further from the airway wall than classic continuum theory predicts. In the present study we tested the hypothesis that this occurs because of the negligible shear modulus of a hexagonal spring network. We simulated the narrowing of an airway embedded in a hexagonal network of elastic alveolar walls when the hexagonal cells of the network offered some resistance to a change in shape. We found that as the forces resisting shape change approach about 10% of the forces resisting length change of an individual spring the range of distortional force propagation in the spring network fell of rapidly as in an elastic continuum. We repeated these investigations in a 3-dimensional spring network composed of space-filling polyhedral cells and found similar results. This suggests that force propagation away from a point of local parenchymal distortion also falls off rapidly in real lung tissue. Copyright © 2015 Elsevier B.V. All rights reserved.

Management of the difficult airway.

PubMed

Schwartz, D E; Wiener-Kronish, J P

1991-09-01

For clinicians involved in airway management, a plan of action for dealing with the difficult airway or a failed intubation should be developed well in advance of encountering a patient in whom intubation is not routine. When difficulty is anticipated, the equipment necessary for performing a difficult intubation should be immediately available. It also is prudent to have a surgeon skilled in performing a tracheotomy and a criothyroidotomy stand by. The intubation should be attempted in the awake state, preferably using the fiberoptic bronchoscope. The more challenging situation is when the difficult airway is confronted unexpectedly. After the first failed attempt at laryngoscopy, head position should be checked and the patient ventilated with oxygen by mask. A smaller styletted tube and possibly a different laryngoscope blade should be selected for a second attempt at intubation. The fiberoptic bronchoscope and other equipment for difficult intubation should be obtained. A second attempt should then be made. If this is unsuccessful, the patient should be reoxygenated, and assistance including a skilled anesthesiologist and surgeon should be summoned. On a third attempt, traction to the tongue can be applied by an assistant, a tube changer could be used to enter the larynx, or one of the other special techniques previously described can be used. If this third attempt fails, it may be helpful to have a physician more experienced in airway management attempt intubation after oxygen has been administered to the patient. If all attempts are unsuccessful, then invasive techniques to secure the airway will have to be performed.

Educating the Educator: Teaching Airway Adjunct Techniques in Athletic Training

ERIC Educational Resources Information Center

Berry, David C.; Seitz, S. Robert

2011-01-01

The 5th edition of the "Athletic Training Education Competencies" ("Competencies") now requires athletic training educators (ATEs) to introduce into the curriculum various types of airway adjuncts including: (1) oropharyngeal airways (OPA), (2) nasopharyngeal airways (NPA), (3) supraglottic airways (SGA), and (4) suction. The addition of these…

Athletic Trainers' Knowledge Regarding Airway Adjuncts

ERIC Educational Resources Information Center

Edler, Jessica R.; Eberman, Lindsey E.; Kahanov, Leamor; Roman, Christopher; Mata, Heather Lynne

2015-01-01

Context: Research suggests that knowledge gaps regarding the appropriate use of airway adjuncts exist among various health care practitioners, and that knowledge is especially limited within athletic training. Objective: To determine the relationship between perceived knowledge (PK) and actual knowledge (AK) of airway adjunct use and the…

Automatic construction of subject-specific human airway geometry including trifurcations based on a CT-segmented airway skeleton and surface

PubMed Central

Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Wenzel, Sally E.; Lin, Ching-Long

2016-01-01

We propose a method to construct three-dimensional airway geometric models based on airway skeletons, or centerlines (CLs). Given a CT-segmented airway skeleton and surface, the proposed CL-based method automatically constructs subject-specific models that contain anatomical information regarding branches, include bifurcations and trifurcations, and extend from the trachea to terminal bronchioles. The resulting model can be anatomically realistic with the assistance of an image-based surface; alternatively a model with an idealized skeleton and/or branch diameters is also possible. This method systematically identifies and classifies trifurcations to successfully construct the models, which also provides the number and type of trifurcations for the analysis of the airways from an anatomical point of view. We applied this method to 16 normal and 16 severe asthmatic subjects using their computed tomography images. The average distance between the surface of the model and the image-based surface was 11% of the average voxel size of the image. The four most frequent locations of trifurcations were the left upper division bronchus, left lower lobar bronchus, right upper lobar bronchus, and right intermediate bronchus. The proposed method automatically constructed accurate subject-specific three-dimensional airway geometric models that contain anatomical information regarding branches using airway skeleton, diameters, and image-based surface geometry. The proposed method can construct (i) geometry automatically for population-based studies, (ii) trifurcations to retain the original airway topology, (iii) geometry that can be used for automatic generation of computational fluid dynamics meshes, and (iv) geometry based only on a skeleton and diameters for idealized branches. PMID:27704229

CD8+IL-17+ T Cells Mediate Neutrophilic Airway Obliteration in T-bet–Deficient Mouse Lung Allograft Recipients

PubMed Central

Dodd-o, Jeffrey M.; Coon, Tiffany A.; Miller, Hannah L.; Ganguly, Sudipto; Popescu, Iulia; O'Donnell, Christopher P.; Cardenes, Nayra; Levine, Melanie; Rojas, Mauricio; Weathington, Nathaniel M.; Zhao, Jing; Zhao, Yutong; McDyer, John F.

2015-01-01

Acute cellular rejection is a known risk factor for the development of obliterative bronchiolitis, which limits the long-term survival of lung transplant recipients. However, the T cell effector mechanisms in both of these processes remain incompletely understood. Using the mouse orthotopic lung transplant model, we investigated whether C57BL/6 T-bet−/− recipients of major histocompatibility complex (MHC)-mismatched BALB/c lung grafts develop rejection pathology and allospecific cytokine responses that differ from wild-type mice. T-bet−/− recipients demonstrated vigorous allograft rejection at 10 days, characterized by neutrophilic inflammation and predominantly CD8+ T cells producing allospecific IL-17 and/or IFN-γ, in contrast to IFN-γ–dominant responses in WT mice. CD4+ T cells produced IL-17 but not IFN-γ responses in T-bet−/− recipients, in contrast to WT controls. Costimulation blockade using anti-CD154 Ab significantly reduced allospecific CD8+IFN-γ+ responses in both T-bet−/− and WT mice but had no attenuating effect on lung rejection pathology in T-bet−/− recipients or on the development of obliterative airway inflammation that occurred only in T-bet−/− recipients. However, neutralization of IL-17A significantly attenuated costimulation blockade–resistant rejection pathology and airway inflammation in T-bet−/− recipients. In addition, CXCL1 (neutrophil chemokine) was increased in T-bet−/− allografts, and IL-17 induced CXCL1 from mouse lung epithelial cells in vitro. Taken together, our data show that T-bet–deficient recipients of complete MHC-mismatched lung allografts develop costimulation blockade–resistant rejection characterized by neutrophilia and obliterative airway inflammation that is predominantly mediated by CD8+IL-17+ T cells. Our data support T-bet–deficient mouse recipients of lung allografts as a viable animal model to study the immunopathogenesis of small airway injury in lung transplantation

Specificity of arrestin subtypes in regulating airway smooth muscle G protein-coupled receptor signaling and function.

PubMed

Pera, Tonio; Hegde, Akhil; Deshpande, Deepak A; Morgan, Sarah J; Tiegs, Brian C; Theriot, Barbara S; Choi, Yeon H; Walker, Julia K L; Penn, Raymond B

2015-10-01

Arrestins have been shown to regulate numerous G protein-coupled receptors (GPCRs) in studies employing receptor/arrestin overexpression in artificial cell systems. Which arrestin isoforms regulate which GPCRs in primary cell types is poorly understood. We sought to determine the effect of β-arrestin-1 or β-arrestin-2 inhibition or gene ablation on signaling and function of multiple GPCRs endogenously expressed in airway smooth muscle (ASM). In vitro [second messenger (calcium, cAMP generation)], ex vivo (ASM tension generation in suspended airway), and in vivo (invasive airway resistance) analyses were performed on human ASM cells and murine airways/whole animal subject to β-arrestin-1 or -2 knockdown or knockout (KO). In both human and murine model systems, knockdown or KO of β-arrestin-2 relative to control missense small interfering RNA or wild-type mice selectively increased (40-60%) β2-adrenoceptor signaling and function. β-arrestin-1 knockdown or KO had no effect on signaling and function of β2-adrenoceptor or numerous procontractile GPCRs, but selectively inhibited M3 muscarinic acetylcholine receptor signaling (∼50%) and function (∼25% ex vivo, >50% in vivo) without affecting EC50 values. Arrestin subtypes differentially regulate ASM GPCRs and β-arrestin-1 inhibition represents a novel approach to managing bronchospasm in obstructive lung diseases. © FASEB.

Interleukin-6 and lung inflammation: evidence for a causative role in inducing respiratory system resistance increments.

PubMed

Rubini, Alessandro

2013-10-01

Interleukin-6 is a multifunctional cytokine that has been shown to be increased in some pathological conditions involving the respiratory system such as those experimentally induced in animals or spontaneously occurring in humans. Experimental data demonstrating that interleukin-6 plays a significant role in commonly occurring respiratory system inflammatory diseases are reviewed here. Those diseases, i.e. asthma and chronic obstructive pulmonary disease, are characterised by mechanical derangements of the respiratory system, for the most part due to increased elastance and airway resistance. Recent findings showing that interleukin-6 has a causative role in determining an increase in airway resistance are reviewed. The end-inflation occlusion method was used to study the mechanical properties of the respiratory system before and after interleukin-6 administration. The cytokine was shown to induce significant, dose-dependent increments in both the resistive pressure dissipation due to frictional forces opposing the airflow in the airway (ohmic resistance) and the additional resistive pressure dissipation due to the visco-elastic properties of the system, i.e. stress relaxation (visco-elastic resistance). There were no alterations in respiratory system elastance. Even when administered to healthy mammals, interleukin-6 determines a significant effect on respiratory system resistance causing an increase in the mechanical work of breathing during inspiration. IL-6 hypothetically plays an active role in the pathogenesis of respiratory system diseases and the mechanisms that may be involved are discussed here.

Quercetin acutely relaxes airway smooth muscle and potentiates β-agonist-induced relaxation via dual phosphodiesterase inhibition of PLCβ and PDE4

PubMed Central

Emala, Charles W.

2013-01-01

Asthma is a disease of the airways with symptoms including exaggerated airway narrowing and airway inflammation. Early asthma therapies used methylxanthines to relieve symptoms, in part, by inhibiting cyclic nucleotide phosphodiesterases (PDEs), the enzyme responsible for degrading cAMP. The classification of tissue-specific PDE subtypes and the clinical introduction of PDE-selective inhibitors for chronic obstructive pulmonary disease (i.e., roflumilast) have reopened the possibility of using PDE inhibition in the treatment of asthma. Quercetin is a naturally derived PDE4-selective inhibitor found in fruits, vegetables, and tea. We hypothesized that quercetin relaxes airway smooth muscle via cAMP-mediated pathways and augments β-agonist relaxation. Tracheal rings from male A/J mice were mounted in myographs and contracted with acetylcholine (ACh). Addition of quercetin (100 nM-1 mM) acutely and concentration-dependently relaxed airway rings precontracted with ACh. In separate studies, pretreatment with quercetin (100 μM) prevented force generation upon exposure to ACh. In additional studies, quercetin (50 μM) significantly potentiated isoproterenol-induced relaxations. In in vitro assays, quercetin directly attenuated phospholipase C activity, decreased inositol phosphate synthesis, and decreased intracellular calcium responses to Gq-coupled agonists (histamine or bradykinin). Finally, nebulization of quercetin (100 μM) in an in vivo model of airway responsiveness significantly attenuated methacholine-induced increases in airway resistance. These novel data show that the natural PDE4-selective inhibitor quercetin may provide therapeutic relief of asthma symptoms and decrease reliance on short-acting β-agonists. PMID:23873842

Airway hyperresponsiveness; smooth muscle as the principal actor

PubMed Central

Lauzon, Anne-Marie; Martin, James G.

2016-01-01

Airway hyperresponsiveness (AHR) is a defining characteristic of asthma that refers to the capacity of the airways to undergo exaggerated narrowing in response to stimuli that do not result in comparable degrees of airway narrowing in healthy subjects. Airway smooth muscle (ASM) contraction mediates airway narrowing, but it remains uncertain as to whether the smooth muscle is intrinsically altered in asthmatic subjects or is responding abnormally as a result of the milieu in which it sits. ASM in the trachea or major bronchi does not differ in its contractile characteristics in asthmatics, but the more pertinent peripheral airways await complete exploration. The mass of ASM is increased in many but not all asthmatics and therefore cannot be a unifying hypothesis for AHR, although when increased in mass it may contribute to AHR. The inability of a deep breath to reverse or prevent bronchial narrowing in asthma may reflect an intrinsic difference in the mechanisms that lead to softening of contracted ASM when subjected to stretch. Cytokines such as interleukin-13 and tumor necrosis factor-α promote a more contractile ASM phenotype. The composition and increased stiffness of the matrix in which ASM is embedded promotes a more proliferative and pro-inflammatory ASM phenotype, but the expected dedifferentiation and loss of contractility have not been shown. Airway epithelium may drive ASM proliferation and/or molecular remodeling in ways that may lead to AHR. In conclusion, AHR is likely multifactorial in origin, reflecting the plasticity of ASM properties in the inflammatory environment of the asthmatic airway. PMID:26998246

Mechanosensitive ATP Release Maintains Proper Mucus Hydration of Airways

PubMed Central

Button, Brian; Okada, Seiko F.; Frederick, Charles Brandon; Thelin, William R.; Boucher, Richard C.

2013-01-01

The clearance of mucus from the airways protects the lungs from inhaled noxious and infectious materials. Proper hydration of the mucus layer enables efficient mucus clearance through beating of cilia on airway epithelial cells, and reduced clearance of excessively concentrated mucus occurs in patients with chronic obstructive pulmonary disease and cystic fibrosis. Key steps in the mucus transport process are airway epithelia sensing and responding to changes in mucus hydration. We reported that extracellular adenosine triphosphate (ATP) and adenosine were important luminal auto-crine and paracrine signals that regulated the hydration of the surface of human airway epithelial cultures through their action on apical membrane purinoceptors. Mucus hydration in human airway epithelial cultures was sensed by an interaction between cilia and the overlying mucus layer: Changes in mechanical strain, proportional to mucus hydration, regulated ATP release rates, adjusting fluid secretion to optimize mucus layer hydration. This system provided a feedback mechanism by which airways maintained mucus hydration in an optimum range for cilia propulsion. Understanding how airway epithelia can sense and respond to changes in mucus properties helps us to understand how the mucus clearance system protects the airways in health and how it fails in lung diseases such as cystic fibrosis. PMID:23757023

75 FR 13079 - Action Affecting Export Privileges; MAHAN AIRWAYS; Mahan Airways, Mahan Tower, No. 21, Azadegan...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-18

... AIRWAYS; Mahan Airways, Mahan Tower, No. 21, Azadegan St., M.A. Jenah Exp. Way, Tehran, Iran, Respondent... prohibited by the EAR by knowingly re-exporting to Iran three U.S.-origin aircraft, specifically Boeing 747s... (``Aircraft 4-6'') to Iran. As more fully discussed in the September 17, 2008 TDO Renewal Order, evidence...

[A comparison of various supraglottic airway devices for fiberoptical guided tracheal intubation].

PubMed

Metterlein, Thomas; Dintenfelder, Anna; Plank, Christoph; Graf, Bernhard; Roth, Gabriel

Fiberoptical assisted intubation via placed supraglottic airway devices has been described as safe and easy procedure to manage difficult airways. However visualization of the glottis aperture is essential for fiberoptical assisted intubation. Various different supraglottic airway devices are commercially available and might offer different conditions for fiberoptical assisted intubation. The aim of this study was to compare the best obtainable view of the glottic aperture using different supraglottic airway devices. With approval of the local ethics committee 52 adult patients undergoing elective anesthesia were randomly assigned to a supraglottic airway device (Laryngeal Tube, Laryngeal Mask Airway I-Gel, Laryngeal Mask Airway Unique, Laryngeal Mask Airway Supreme, Laryngeal Mask Airway Aura-once). After standardized induction of anaesthesia the supraglottic airway device was placed according to the manufacturers recommendations. After successful ventilation the position of the supraglottic airway device in regard to the glottic opening was examined with a flexible fiberscope. A fully or partially visible glottic aperture was considered as suitable for fiberoptical assisted intubation. Suitability for fiberoptical assisted intubation was compared between the groups (H-test, U-test; p<0.05). Demographic data was not different between the groups. Placement of the supraglottic airway device and adequate ventilation was successful in all attempts. Glottic view suitable for fiberoptical assisted intubation differed between the devices ranging from 40% for the laringeal tube (LT), 66% for the laryngeal mask airway Supreme, 70% for the Laryngeal Mask Airway I-Gel and 90% for both the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once. None of the used supraglottic airway devices offered a full or partial glottic view in all cases. However the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once seem to be more suitable for fiberoptical

A comparison of various supraglottic airway devices for fiberoptical guided tracheal intubation.

PubMed

Metterlein, Thomas; Dintenfelder, Anna; Plank, Christoph; Graf, Bernhard; Roth, Gabriel

Fiberoptical assisted intubation via placed supraglottic airway devices has been described as safe and easy procedure to manage difficult airways. However visualization of the glottis aperture is essential for fiberoptical assisted intubation. Various different supraglottic airway devices are commercially available and might offer different conditions for fiberoptical assisted intubation. The aim of this study was to compare the best obtainable view of the glottic aperture using different supraglottic airway devices. With approval of the local ethics committee 52 adult patients undergoing elective anesthesia were randomly assigned to a supraglottic airway device (Laryngeal Tube, Laryngeal Mask Airway I-Gel, Laryngeal Mask Airway Unique, Laryngeal Mask Airway Supreme, Laryngeal Mask Airway Aura-once). After standardized induction of anesthesia the supraglottic airway device was placed according to the manufacturers recommendations. After successful ventilation the position of the supraglottic airway device in regard to the glottic opening was examined with a flexible fiberscope. A fully or partially visible glottic aperture was considered as suitable for fiberoptical assisted intubation. Suitability for fiberoptical assisted intubation was compared between the groups (H-test, U-test; p<0.05). Demographic data was not different between the groups. Placement of the supraglottic airway device and adequate ventilation was successful in all attempts. Glottic view suitable for fiberoptical assisted intubation differed between the devices ranging from 40% for the laringeal tube (LT), 66% for the laryngeal mask airway Supreme, 70% for the Laryngeal Mask Airway I-Gel and 90% for both the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once. None of the used supraglottic airway devices offered a full or partial glottic view in all cases. However the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once seem to be more suitable for fiberoptical

Clinical phenotype of South-East Asian temporomandibular disorder patients with upper airway resistance syndrome.

PubMed

Tay, D K L; Pang, K P

2018-01-01

Clinical and radiographic characteristics of a subset of South East Asian temporomandibular disorder (TMD) patients with comorbid upper airway resistance syndrome (UARS) were documented in a multi-center prospective series of 86 patients (26 men and 60 women / mean age 35.7 years). All had excessive daytime sleepiness, high arousal index and Apnoea-Hypopnoea Index (AHI) <5. The mean body mass index was 20·1, mean arousal index 16·2, mean respiratory disturbance index 19·6, mean AHI 3·9 while the mean Epworth Sleepiness Scale was 14·8. Many had functional somatic complaints; 66·3% headaches, 41·9% neck aches, 53·5% masticatory muscle myalgia, 68·6% temporomandibular joint (TMJ) arthralgia while 90·7% reported sleep bruxism (SB). Unlike patients with obstructive sleep apnoea (OSA), hypertension was uncommon (4·7%) while depression was prevalent at 68·6% with short REM latency of <90 min and an increased REM composition >25% documented in 79·6% and 57·6% of these depressed patients, respectively. 65·1% displayed a posteriorly displaced condyle at maximum intercuspation with or without TMJ clicking. Most exhibited a forward head posture (FHP) characterised by loss of normal cervical lordosis (80·2%), C0-C1 narrowing (38·4%) or an elevated hyoid position (50%), and 91·9% had nasal congestion. We postulate the TMD-UARS phenotype may have originally developed as an adaptive response to 'awake' disordered breathing during growth. Patients with persistent TMD and/or reporting SB should be screened for UARS and chronic nasal obstruction, especially when they also present with FHP. The lateral cephalogram is a useful tool in the differentiation of UARS from other OSA phenotypes. © 2017 John Wiley & Sons Ltd.

Nitrogen Dioxide Exposure and Airway Responsiveness in ...

EPA Pesticide Factsheets

Controlled human exposure studies evaluating the effect of inhaled NO2 on the inherent responsiveness of the airways to challenge by bronchoconstricting agents have had mixed results. In general, existing meta-analyses show statistically significant effects of NO2 on the airway responsiveness of individuals with asthma. However, no meta-analysis has provided a comprehensive assessment of clinical relevance of changes in airway responsiveness, the potential for methodological biases in the original papers, and the distribution of responses. This paper provides analyses showing that a statistically significant fraction, 70% of individuals with asthma exposed to NO2 at rest, experience increases in airway responsiveness following 30-minute exposures to NO2 in the range of 200 to 300 ppb and following 60-minute exposures to 100 ppb. The distribution of changes in airway responsiveness is log-normally distributed with a median change of 0.75 (provocative dose following NO2 divided by provocative dose following filtered air exposure) and geometric standard deviation of 1.88. About a quarter of the exposed individuals experience a clinically relevant reduction in their provocative dose due to NO2 relative to air exposure. The fraction experiencing an increase in responsiveness was statistically significant and robust to exclusion of individual studies. Results showed minimal change in airway responsiveness for individuals exposed to NO2 during exercise. A variety of fa

Interventions designed using quality improvement methods reduce the incidence of serious airway events and airway cardiac arrests during pediatric anesthesia.

PubMed

Spaeth, James P; Kreeger, Renee; Varughese, Anna M; Wittkugel, Eric

2016-02-01

Although serious complications during pediatric anesthesia are less common than they were 20 years ago, serious airway events continue to occur. Based on Quality Improvement (QI) data from our institution, a QI project was designed to reduce the incidence of serious airway events and airway cardiac arrests. A quality improvement team consisting of members of the Department of Anesthesia was formed and QI data from previous years were analyzed. The QI team developed a Smart Aim, Key Driver Diagram, and specific Interventions that focused on the accessibility of emergency drugs, the use of nondepolarizing muscle relaxants for endotracheal intubation in children 2 years and younger, and the presence of anesthesia providers until emergence from anesthesia in high-risk patients. The percentage of cases where muscle relaxants were utilized in children 2 years and younger for endotracheal intubation and where atropine and succinylcholine were readily available increased at both our base and outpatient facilities. Over the 2.5-year study period, the incidence of serious airway events and airway cardiac arrests was reduced by 44% and 59%, respectively compared to the previous 2-year period. We utilized QI methodology to design and implement a project which led to greater standardization of clinical practice within a large pediatric anesthesia group. Based on an understanding of system issues impacting our clinical practice, we designed and tested interventions that led to a significant reduction in the incidence of serious airway events and airway cardiac arrests. © 2015 John Wiley & Sons Ltd.

Effect of Continuous Positive Airway Pressure on Airway Reactivity in Asthma. A Randomized, Sham-controlled Clinical Trial

PubMed Central

Sugar, Elizabeth A.; Brown, Robert H.; Drye, Lea T.; Irvin, Charles G.; Schwartz, Alan R.; Tepper, Robert S.; Wise, Robert A.; Yasin, Razan Z.; Busk, Michael F.

2016-01-01

Rationale: Studies have demonstrated that application of stress suppresses airway smooth muscle contractility. In animal models of asthma, continuous positive airway pressure (CPAP) reduced airway reactivity. Short-term studies of CPAP in patients with asthma showed reductions in airway reactivity. Objectives: To evaluate whether nocturnal CPAP decreased the provocative concentration of methacholine to reduce FEV1 by 20% (PC20). Methods: One hundred ninety-four individuals with asthma were randomized (1:1:1) to use CPAP with warmed, filtered, humidified air at night at pressures either less than 1 cm H2O (sham) or at 5 cm H2O or 10 cm H2O. The primary outcome was change in PC20 after 12 weeks. Measurements and Main Results: Adherence to CPAP was low in all groups. Regardless, all groups had a significant improvement in PC20, with 12 weeks/baseline PC20 ratios of 2.12, 1.73, and 1.78 for the sham, 5 cm H2O, and 10 cm H2O groups, respectively, and no significant differences between the active and sham groups. Changes in FEV1 and exhaled nitric oxide were minimal in all groups. The sham group had larger improvements in most patient-reported outcomes measuring asthma symptoms and quality of life, as well as sinus symptoms, than the 5 cm H2O group. The 10 cm H2O group showed similar but less consistent improvements in scores, which were not different from improvements in the sham group. Conclusions: Adherence to nocturnal CPAP was low. There was no evidence to support positive pressure as being effective for reducing airway reactivity in people with well-controlled asthma. Regardless, airway reactivity was improved in all groups, which may represent an effect of participating in a study and/or an effect of warm, humid, filtered air on airway reactivity. Clinical trial registered with www.clinicaltrials.gov (NCT01629823). PMID:27398992

Infection-induced airway fibrosis in two rat strains with differential susceptibility.

PubMed Central

McIntosh, J C; Simecka, J W; Ross, S E; Davis, J K; Miller, E J; Cassell, G H

1992-01-01

Chronic infections play a significant role in the morbidity and mortality of patients with chronic airflow limitation. By stimulating airway inflammation, persistent infection has the potential to cause airway fibrosis. However, in patient this condition is most typically found in lungs damaged by other factors, such as smoking, abnormal secretions, or barotrauma. We report the characterization of Mycoplasma pulmonis infection-induced lung fibrosis in two immunocompetent rat strains with no preexisting lung disease. The fibrosis was predominantly in the airways, as demonstrated by the findings for infected animals of increased airway inflammation, airway fibrosis, and airway wall thickness, which correlated with the collagen content of the lungs. Also, the physiological alterations were the opposite of those found in interstitial fibrosis, with a positive correlation between lung compliance and collagen content. The airway fibrosis was noted earlier and to a greater extent in Lewis rats than in Fisher rats, and this result apparently was related to regulation of the inflammatory response. Airway wall thickness, airway inflammation, and airway fibrosis are commonly reported in tissue specimens from patients with chronic airway diseases and have been shown to correlate with airflow limitation in patients with chronic obstructive pulmonary disease. Thus, this model may be useful in furthering our understanding of the role of chronic infection and airway inflammation in airflow obstruction. Images PMID:1612760

Infectious mononucleosis and bilateral peritonsillar abscesses resulting in airway obstruction.

PubMed

Burstin, P P; Marshall, C L

1998-12-01

Upper airway obstruction is an uncommon but recognized complication of infectious mononucleosis. The management depends upon the degree of airway compromise. In the case described, severe airway obstruction was treated by securing the airway with awake fibre-optic endoscopic intubation and then proceeding to tonsillectomy. Bilateral inferiorly loculated quinsies were encountered unexpectedly and drained. This is the first report of 'bilateral' quinsies, associated with infectious mononucleosis and severe airway obstruction. The association, pathogenesis and significance of this finding are also discussed.

Removal of obstructing T-tube and stabilization of the airway.

PubMed

Athavale, Sanjay M; Dang, Jennifer; Rangarajan, Sanjeet; Garrett, Gaelyn

2011-05-01

Although they are extremely effective in maintaining tracheal and subglottic patency, T-tubes themselves can result in airway obstruction from plugging. Many practitioners educate patients on placing a small (5.0) endotracheal tube (ETT) through the tracheal limb of the T-tube if they develop airway obstruction. Unfortunately, this can be a difficult task to complete during acute airway obstruction. In this article, we describe a simple set of steps for rapid relief of airway obstruction and stabilization of the airway in the event of T-tube obstruction. This method requires removal of the T-tube with a Kelly clamp and stabilization of the airway with a tracheostomy tube. Although it is simple, we hope that this technique will prevent morbidity and mortality from acute airway obstructions related to T-tubes. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Population Genetics and Antimicrobial Susceptibility of Canine Campylobacter Isolates Collected before and after a Raw Feeding Experiment

PubMed Central

Roine, Johanna; Hänninen, Marja-Liisa; Hielm-Björkman, Anna; Kivistö, Rauni

2015-01-01

In recent years, increasing numbers of consumers have become interested in feeding raw food for their pet dogs as opposed to commercial dry food, in the belief of health advantages. However, raw meat and internal organs, possibly contaminated by pathogens such as Campylobacter spp., may pose a risk of transmission of zoonoses to the pet owners. Campylobacter jejuni is the leading cause of bacterial gastroenteritis in humans but C. upsaliensis has also been associated with human disease. In this study we investigated the effect of different feeding strategies on the prevalence of Campylobacter spp. in Finnish dogs. We further characterized the isolates using multilocus sequence typing (MLST), whole-genome (wg) MLST and antimicrobial susceptibility testing. Dogs were sampled before and after a feeding period consisting of commercial raw feed or dry pellet feed. Altogether 56% (20/36) of the dogs yielded at least one Campylobacter-positive fecal sample. C. upsaliensis was the major species detected from 39% of the dogs before and 30% after the feeding period. Two C. jejuni isolates were recovered, both from raw-fed dogs after the dietary regimen. The isolates represented the same genotype (ST-1326), suggesting a common infection source. However, no statistically significant correlation was found between the feeding strategies and Campylobacter spp. carriage. The global genealogy of MLST types of dog and human C. upsaliensis isolates revealed weakly clonal population structure as most STs were widely dispersed. Major antimicrobial resistance among C. upsaliensis isolates was against streptomycin (STR MIC > 4mg/l). Apart from that, all isolates were highly susceptible against the antimicrobials tested. Mutations were found in the genes rpsL or rpsL and rsmG in streptomycin resistant isolates. In conclusion, increasing trend to feed dogs with raw meat warrants more studies to evaluate the risk associated with raw feeding of pets in transmission of zoonoses to humans

Patterns of recruitment and injury in a heterogeneous airway network model

PubMed Central

Stewart, Peter S.; Jensen, Oliver E.

2015-01-01

In respiratory distress, lung airways become flooded with liquid and may collapse due to surface-tension forces acting on air–liquid interfaces, inhibiting gas exchange. This paper proposes a mathematical multiscale model for the mechanical ventilation of a network of occluded airways, where air is forced into the network at a fixed tidal volume, allowing investigation of optimal recruitment strategies. The temporal response is derived from mechanistic models of individual airway reopening, incorporating feedback on the airway pressure due to recruitment. The model accounts for stochastic variability in airway diameter and stiffness across and between generations. For weak heterogeneity, the network is completely ventilated via one or more avalanches of recruitment (with airways recruited in quick succession), each characterized by a transient decrease in the airway pressure; avalanches become more erratic for airways that are initially more flooded. However, the time taken for complete ventilation of the network increases significantly as the network becomes more heterogeneous, leading to increased stresses on airway walls. The model predicts that the most peripheral airways are most at risk of ventilation-induced damage. A positive-end-expiratory pressure reduces the total recruitment time but at the cost of larger stresses exerted on airway walls. PMID:26423440

Computational Flow Modeling of Human Upper Airway Breathing

NASA Astrophysics Data System (ADS)

Mylavarapu, Goutham

Computational modeling of biological systems have gained a lot of interest in biomedical research, in the recent past. This thesis focuses on the application of computational simulations to study airflow dynamics in human upper respiratory tract. With advancements in medical imaging, patient specific geometries of anatomically accurate respiratory tracts can now be reconstructed from Magnetic Resonance Images (MRI) or Computed Tomography (CT) scans, with better and accurate details than traditional cadaver cast models. Computational studies using these individualized geometrical models have advantages of non-invasiveness, ease, minimum patient interaction, improved accuracy over experimental and clinical studies. Numerical simulations can provide detailed flow fields including velocities, flow rates, airway wall pressure, shear stresses, turbulence in an airway. Interpretation of these physical quantities will enable to develop efficient treatment procedures, medical devices, targeted drug delivery etc. The hypothesis for this research is that computational modeling can predict the outcomes of a surgical intervention or a treatment plan prior to its application and will guide the physician in providing better treatment to the patients. In the current work, three different computational approaches Computational Fluid Dynamics (CFD), Flow-Structure Interaction (FSI) and Particle Flow simulations were used to investigate flow in airway geometries. CFD approach assumes airway wall as rigid, and relatively easy to simulate, compared to the more challenging FSI approach, where interactions of airway wall deformations with flow are also accounted. The CFD methodology using different turbulence models is validated against experimental measurements in an airway phantom. Two case-studies using CFD, to quantify a pre and post-operative airway and another, to perform virtual surgery to determine the best possible surgery in a constricted airway is demonstrated. The unsteady

Characteristics of Escherichia coli from raw vegetables at a retail market in the Czech Republic.

PubMed

Skočková, Alena; Karpíšková, Renáta; Koláčková, Ivana; Cupáková, Šárka

2013-10-15

A large epidemic caused by shigatoxigenic Escherichia coli (E. coli) in spring 2011 in Germany resulted in reduction of trust in the health safety of raw vegetables and sprouted seeds. This study focused on the detection and characterization of E. coli in raw vegetables and sprouted seeds sold in the Czech Republic. Out of 91 samples, 24 (26.4%) were positive for the presence of E. coli. Resistance to antimicrobial agents was determined by the disk diffusion method and E-test. Polymerase chain reaction was used for the detection of selected genes encoding virulence--eaeA, hly, stx1, and stx2 and genes encoding resistance to tetracycline--tet(A), tet(B), tet(C), and tet(G) and to β-lactams--blaTEM, blaSHV, and blaCTX. The blaTEM gene was detected in two isolates, the tet(B) gene in three and tet(A) in one isolate. No hly, stx1, or stx2 genes were present, but the eaeA gene was found in three (11.1%) isolates from imported vegetables. These isolates can be considered as potentially enteropathogenic. Results of this study show that raw vegetables and sprouted seeds sold in the retail market can represent a potential risk for consumers. © 2013.

Role of Airway Recruitment and Derecruitment in Lung Injury

PubMed Central

Ghadiali, S. N.; Huang, Y.

2011-01-01

The mechanical forces generated during the ventilation of patients with acute lung injury causes significant lung damage and inflammation. Low-volume ventilation protocols are commonly used to prevent stretch-related injury that occurs at high lung volumes. However, the cyclic closure and reopening of pulmonary airways at low lung volumes, i.e., derecruitment and recruitment, also causes significant lung damage and inflammation. In this review, we provide an overview of how biomedical engineering techniques are being used to elucidate the complex physiological and biomechanical mechanisms responsible for cellular injury during recruitment/derecruitment. We focus on the development of multiscale, multiphysics computational models of cell deformation and injury during airway reopening. These models, and the corresponding in vitro experiments, have been used to both elucidate the basic mechanisms responsible for recruitment/derecruitment injury and to develop alternative therapies that make the epithelium more resistant to injury. For example, models and experiments indicate that fluidization of the cytoskeleton is cytoprotective and that changes in cytoskeletal structure and cell mechanics can be used to mitigate the mechanotransduction of oscillatory pressure into inflammatory signaling. The continued application of biomedical engineering techniques to the problem of recruitment/derecruitment injury may therefore lead to novel and more effective therapies. PMID:22011235

A quasi-3D wire approach to model pulmonary airflow in human airways.

PubMed

Kannan, Ravishekar; Chen, Z J; Singh, Narender; Przekwas, Andrzej; Delvadia, Renishkumar; Tian, Geng; Walenga, Ross

2017-07-01

The models used for modeling the airflow in the human airways are either 0-dimensional compartmental or full 3-dimensional (3D) computational fluid dynamics (CFD) models. In the former, airways are treated as compartments, and the computations are performed with several assumptions, thereby generating a low-fidelity solution. The CFD method displays extremely high fidelity since the solution is obtained by solving the conservation equations in a physiologically consistent geometry. However, CFD models (1) require millions of degrees of freedom to accurately describe the geometry and to reduce the discretization errors, (2) have convergence problems, and (3) require several days to simulate a few breathing cycles. In this paper, we present a novel, fast-running, and robust quasi-3D wire model for modeling the airflow in the human lung airway. The wire mesh is obtained by contracting the high-fidelity lung airway surface mesh to a system of connected wires, with well-defined radii. The conservation equations are then solved in each wire. These wire meshes have around O(1000) degrees of freedom and hence are 3000 to 25 000 times faster than their CFD counterparts. The 3D spatial nature is also preserved since these wires are contracted out of the actual lung STL surface. The pressure readings between the 2 approaches showed minor difference (maximum error = 15%). In general, this formulation is fast and robust, allows geometric changes, and delivers high-fidelity solutions. Hence, this approach has great potential for more complicated problems including modeling of constricted/diseased lung sections and for calibrating the lung flow resistances through parameter inversion. Copyright © 2016 John Wiley & Sons, Ltd.

DEVELOPMENT OF THE SMALL AIRWAYS AND ALVEOLI FROM CHILDHOOD TO ADULT LUNG MEASURED BY AEROSOL-DERIVED AIRWAY MORPHOMETRY

EPA Science Inventory

Understanding the human development of pulmonary airspaces is important for calculating the dose from exposure to inhaled materials as a function of age. We have measured, in vivo, the airspace caliber of the small airways and alveoli by aerosol-derived airway morphometry (ADAM) ...

Central Airway Obstruction: Benign Strictures, Tracheobronchomalacia, and Malignancy-related Obstruction.

PubMed

Murgu, Septimiu Dan; Egressy, Katarine; Laxmanan, Balaji; Doblare, Guillermo; Ortiz-Comino, Rosamaria; Hogarth, D Kyle

2016-08-01

The purpose of this article is to provide an update on methods for palliating symptoms in patients with histologically benign and malignant central airway obstruction. We review the published literature within the past decade on postintubation, posttracheostomy, and TB- and transplant-related airway strictures; tracheobronchomalacia; and malignant airway obstruction. We review terminology, classification systems, and parameters that impact treatment decisions. The focus is on how airway stent insertion fits into the best algorithm of care. Several case series and cohort studies demonstrate that airway stents improve dyspnea, lung function, and quality of life in patients with airway obstruction. Airway stenting, however, is associated with high rates of adverse events and should be used only when curative open surgical interventions are not feasible or are contraindicated. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Prehospital airway management on rescue helicopters in the United Kingdom.

PubMed

Schmid, M; Mang, H; Ey, K; Schüttler, J

2009-06-01

Adequate equipment is one prerequisite for advanced, out of hospital, airway management. There are no data on current availability of airway equipment on UK rescue helicopters. An internet search revealed all UK rescue helicopters, and a questionnaire was sent to the bases asking for available airway management items. We identified 27 helicopter bases and 26 (96%) sent the questionnaire back. Twenty-four bases (92%) had at least one supraglottic airway device; 16 (62%) helicopters had material for establishing a surgical airway (e.g. a cricothyroidotomy set); 88% of the helicopters had CO(2) detection; 25 (96%) helicopters carried automatic ventilators; among these, four (15%) had sophisticated ventilators and seven (27%) helicopters carried special face masks suitable for non-invasive ventilation. We found a wide variation in the advanced airway management equipment that was carried routinely on air ambulances. Current guidelines for airway management are not met by all UK air ambulances.

CT-assessed large airway involvement and lung function decline in eosinophilic asthma: The association between induced sputum eosinophil differential counts and airway remodeling.

PubMed

Inoue, Hideki; Ito, Isao; Niimi, Akio; Matsumoto, Hisako; Matsuoka, Hirofumi; Jinnai, Makiko; Takeda, Tomoshi; Oguma, Tsuyoshi; Otsuka, Kojiro; Nakaji, Hitoshi; Tajiri, Tomoko; Iwata, Toshiyuki; Nagasaki, Tadao; Kanemitsu, Yoshihiro; Mishima, Michiaki

2016-11-01

Eosinophilic asthma (EA) is a distinct clinical phenotype characterized by eosinophilic airway inflammation and airway remodeling. Few studies have used computed tomography (CT) scanning to assess the association between sputum eosinophil differential counts and airway involvement. We aimed to investigate the clinical characteristics and airway involvement of EA, and to examine the correlation between induced sputum eosinophil differential counts and CT-assessed airway remodeling. We retrospectively divided 63 patients with stable asthma receiving inhaled corticosteroids into 2 groups: 26 patients with EA (sputum eosinophil >3%) and 37 patients with non-eosinophilic asthma (NEA). Clinical measurements such as spirometry, fractional exhaled nitric oxide levels (FeNO), and CT-assessed indices of airway involvement were compared between the groups. Multivariate analysis was performed to identify determinants of the percentage of wall area (WA%). The EA group had significantly longer asthma duration, lower pulmonary function, and higher FeNO than the NEA group. Also, the EA group had higher WA% and smaller airway luminal area than the NEA group. Sputum eosinophil differential counts and WA% were positively correlated. The multivariate linear regression analysis showed that the factors associated with WA% included sputum eosinophil differential counts, age, and body mass index. However, asthma duration was not associated with WA%. Our CT-assessed findings demonstrated large airway involvement in EA, and we observed a positive association between induced sputum eosinophil differential counts and WA%. The findings indicate that induced sputum eosinophil differential counts may be associated with airway remodeling in patients with stable asthma.

Pulmonary function in men after oxygen breathing at 3.0 ATA for 3.5 h

NASA Technical Reports Server (NTRS)

Clark, J. M.; Jackson, R. M.; Lambertsen, C. J.; Gelfand, R.; Hiller, W. D. B.; Unger, M.

1991-01-01

A complete description of pulmonary measurements obtained after continuous O2 exposure of 13 healthy men at 3.0 ATA for 3.5 h is presented. Measurements included flow-volume loops, spirometry, and airway resistance(n = 12); CO diffusing capacity (n = 11); closing volumes (n= 6); and air vs. HeO2 forced vital capacity maneuvers (n = 5). The average difference in maximum mid expiratory flows at 50 percent vital capacity on air and HeO2 was found to be significantly reduced postexposure by 18 percent. Raw and CO diffusing capacity were not changed postexposure. It is concluded that the relatively large change in forced expiratory flow at 25-75 percent of vital capacity compared with the mean forced expiratory volume in 1 s, the reduction in density dependence of flow, and the normal Raw postexposure are all consistent with flow limitation in peripheral airways as a major cause of the observed reduction in expiratory flow.

Airway exchange of highly soluble gases.

PubMed

Hlastala, Michael P; Powell, Frank L; Anderson, Joseph C

2013-03-01

Highly blood soluble gases exchange with the bronchial circulation in the airways. On inhalation, air absorbs highly soluble gases from the airway mucosa and equilibrates with the blood before reaching the alveoli. Highly soluble gas partial pressure is identical throughout all alveoli. At the end of exhalation the partial pressure of a highly soluble gas decreases from the alveolar level in the terminal bronchioles to the end-exhaled partial pressure at the mouth. A mathematical model simulated the airway exchange of four gases (methyl isobutyl ketone, acetone, ethanol, and propylene glycol monomethyl ether) that have high water and blood solubility. The impact of solubility on the relative distribution of airway exchange was studied. We conclude that an increase in water solubility shifts the distribution of gas exchange toward the mouth. Of the four gases studied, ethanol had the greatest decrease in partial pressure from the alveolus to the mouth at end exhalation. Single exhalation breath tests are inappropriate for estimating alveolar levels of highly soluble gases, particularly for ethanol.

Airway exchange of highly soluble gases

PubMed Central

Powell, Frank L.; Anderson, Joseph C.

2013-01-01

Highly blood soluble gases exchange with the bronchial circulation in the airways. On inhalation, air absorbs highly soluble gases from the airway mucosa and equilibrates with the blood before reaching the alveoli. Highly soluble gas partial pressure is identical throughout all alveoli. At the end of exhalation the partial pressure of a highly soluble gas decreases from the alveolar level in the terminal bronchioles to the end-exhaled partial pressure at the mouth. A mathematical model simulated the airway exchange of four gases (methyl isobutyl ketone, acetone, ethanol, and propylene glycol monomethyl ether) that have high water and blood solubility. The impact of solubility on the relative distribution of airway exchange was studied. We conclude that an increase in water solubility shifts the distribution of gas exchange toward the mouth. Of the four gases studied, ethanol had the greatest decrease in partial pressure from the alveolus to the mouth at end exhalation. Single exhalation breath tests are inappropriate for estimating alveolar levels of highly soluble gases, particularly for ethanol. PMID:23305981

Inhibition of pan neurotrophin receptor p75 attenuates diesel particulate-induced enhancement of allergic airway responses in C57/B16J mice.

PubMed

Farraj, Aimen K; Haykal-Coates, Najwa; Ledbetter, Allen D; Evansky, Paul A; Gavett, Stephen H

2006-06-01

Recent investigations have linked neurotrophins, including nerve growth factor (NGF), neurotrophin-3 (NT-3), and brain-derived neurotrophic factor (BDNF), to allergic airways diseases. Antibody blockade of NGF attenuates airway resistance in allergic mice. Diesel exhaust particle (DEP) exposure has been linked to asthma exacerbation in many cities with vehicular traffic congestion. We tested the hypothesis that DEP-induced enhancement of the hallmark features of allergic airway disease in a murine model is dependent on the function of the pan neurotrophin receptor p75. Ovalbumin (OVA)-sensitized C57B1/6J mice were intranasally instilled with an antibody against the p75 receptor or saline alone 1 h before OVA challenge. The mice were then exposed nose-only to the PM2.5 fraction of SRM2975 DEP or air alone for 5 h beginning 1 h after OVA challenge. Two days later, air-exposed OVA-allergic mice developed a small but insignificant increase in methacholine-induced airflow obstruction relative to air-exposed, vehicle-sensitized mice. DEP-exposed OVA-allergic mice had a significantly greater degree of airway obstruction than all other groups. Instillation of anti-p75 significantly attenuated the DEP-induced increase in airway obstruction in OVA-allergic mice to levels similar to non-sensitized mice. The DEP-induced exacerbation of allergic airway responses may, in part, be mediated by neurotrophins.

[Helium-Oxigen (Heliox) mixture in airway obstruction

PubMed

Ulhôa, C A; Larner, L

2000-01-01

OBJECTIVE: Demonstrate the effectiveness and the good outcome of the patients treated with helium-oxygen (Heliox) mixture. This mixture (Heliox) has been used in patients with airway obstruction, from different ethiologies, who did not respond to a conventional treatment with oxygen. METHODS: Case report of five patients that received Heliox as treatment for airway obstruction. All of them had good results without side effects during the treatment. CONCLUSION: Heliox is a promising treatment for severe airway obstruction with good results in a short period of time, until the final treatment is established.

Effects of fixed functional therapy on tongue and hyoid positions and posterior airway.

PubMed

Ozdemir, Fulya; Ulkur, Feyza; Nalbantgil, Didem

2014-03-01

To evaluate how therapy with a fixed functional appliance affects airway dimensions, dentoalveolar changes, and tongue and hyoid positions. A retrospective study was carried out on 46 pre- and posttreatment lateral cephalometric radiographs of 23 post-peak Class II patients (12 girls, 11 boys) treated with a Forsus Fatigue Resistant Device (FRD) appliance. The radiographies were taken at the start and at the end of Forsus FRD appliance therapy when a Class I or overcorrected Class I canine and molar relationship was achieved. The process took an average of 5 months 13 days ± 1 month 4 days. Skeletal and dental parameters were measured using Dolphin software, and the sagittal airway area was measured by AutoCAD software. Analyses of the pre- and posttreatment means revealed that there was no statistically significant skeletal correction of the sagittal malocclusion; increase of lower incisor inclination, decrease of upper incisor inclination, decrease of interincisal angle, and rotation of occlusal plane all contributed to the reduction of overjet. The tongue area and intermaxillary space area increased in response to these dentoalveolar changes; however, there was no statistically significant change in the hyoid position or the oropharyngeal area between the two time points. The dentoalveolar changes produced by Forsus FRD appliance did not cause any significant posterior airway changes in young adult patients.

CLONING AND CHARACTERIZATION OF OSTEOCLAST PRECURSORS FROM THE RAW264.7 CELL LINE

PubMed Central

Cuetara, Bethany L. V.; Crotti, Tania N.; O'Donoghue, Anthony J.

2006-01-01

SUMMARY Osteoclasts are bone-resorbing cells that differentiate from macrophage precursors in response to receptor activator of NF-κB (RANKL). In vitro models of osteoclast differentiation are principally based on primary cell culture, which are poorly suited to molecular and transgene studies due to the limitations associated with the use of primary macrophage. RAW264.7 is a transfectable macrophage cell line with the capacity to form osteoclast-like cells. In the present study we have identified osteoclast precursors among clones of RAW264.7 cells. RAW264.7 cell were cloned by limiting dilution and induced to osteoclast differentiation by treatment with recombinant RANKL. Individual RAW264.7 cell clones formed tartrate resistant acid phosphatase (TRAP) positive multinuclear cells to various degrees with RANKL treatment. All clones tested expressed the RANKL receptor RANK. Each of the clones expressed the osteoclast marker genes TRAP and cathepsin-K mRNA with RANKL treatment. However, we noted that only select clones were able to form large, well-spread, TRAP positive multinuclear cells. Clones capable of forming large TRAP positive multinuclear cells also expressed β3 integrin and calcitonin receptor mRNAs and were capable of resorbing a mineralized matrix. All clones tested activated NF-κB with RANKL treatment. cDNA expression profiling of osteoclast precursor RAW264.7 cell clones demonstrates appropriate expression of a large number of genes before and after osteoclastic differentiation. These osteoclast precursor RAW264.7 cell clones provide a valuable model for dissecting the cellular and molecular regulation of osteoclast differentiation and activation. PMID:16948499

Decreased airway narrowing and smooth muscle contraction in hyperresponsive pigs.

PubMed

Turner, Debra J; Noble, Peter B; Lucas, Matthew P; Mitchell, Howard W

2002-10-01

Increased smooth muscle contractility or reduced smooth muscle mechanical loads could account for the excessive airway narrowing and hyperresponsiveness seen in asthma. These mechanisms were investigated by using an allergen-induced porcine model of airway hyperresponsiveness. Airway narrowing to electric field stimulation was measured in isolated bronchial segments, over a range of transmural pressures (0-20 cmH(2)O). Contractile responses to ACh were measured in bronchial segments and in isolated tracheal smooth muscle strips isolated from control and test (ovalbumin sensitized and challenged) pigs. Test airways narrowed less than controls (P < 0.0001). Test pigs showed reduced contractility to ACh, both in isolated bronchi (P < 0.01) and smooth muscle strips (P < 0.01). Thus isolated airways from pigs exhibiting airway hyperresponsiveness in vivo are hyporesponsive in vitro. The decreased narrowing in bronchi from hyperresponsive pigs may be related to decreased smooth muscle contractility. These data suggest that mechanisms external to the airway wall may be important to the hyperresponsive nature of sensitized lungs.

Effects of conventional tobacco smoke and nicotine-free cigarette smoke on airway inflammation, airway remodelling and lung function in a triple allergen model of severe asthma.

PubMed

Tilp, C; Bucher, H; Haas, H; Duechs, M J; Wex, E; Erb, K J

2016-07-01

Patients with asthma who smoke have reduced lung function, increased exacerbation rates and increased steroid resistance compared to non-smoking asthmatics. In mice, cigarette smoke has been reported to have both pro- and anti-Th2 response effects. We hypothesized that combining tobacco cigarette smoke (tCS) with allergen exposure increases inflammation, airway remodelling and lung function in mice. To test this hypothesis, we combined a severe triple allergen model with tCS exposure and investigated whether effects were due to Toll-like receptor 4 signalling and/or nicotine and also observed when nicotine-free cigarettes were used. Mice were sensitized with ovalbumin, cockroach and house dust mite allergen in alum followed by intratracheal challenges with allergen twice a week for 6 weeks or additionally exposed to tCS during the allergen challenge period. Nicotine or nicotine-free herbal cigarette smoke was also applied to allergen challenged mice. tCS significantly reduced eosinophil numbers, IL-4 and IL-5 concentrations in the lung, total and allergen-specific IgE in serum, improved lung function and reduced collagen I levels. With the exception of collagen I all parameters reduced by tobacco cigarette smoke were also reduced in Toll-like receptor 4-deficient mice. Nicotine-free cigarette smoke also had significant anti-inflammatory effects on eosinophils, IL-4 and IL-5 concentrations in the lung and reduced airway hyperreactivity, albeit weaker than tobacco smoke. Applying nicotine alone also reduced Th2 cytokine levels and eosinophil numbers in the airways. Our experiments show that tCS exposure reduces allergen-induced Th2 response in the lung and associated collagen I production and development of airway hyperreactivity. With the exception on collagen I formation, these effects were not dependent on Toll-like receptor 4. The observed anti-Th2 effects of both nicotine and nicotine-free herbal cigarette smoke together suggests that tCS reduces the Th2

Role of IRE1α/XBP-1 in Cystic Fibrosis Airway Inflammation

PubMed Central

Ribeiro, Carla M. P.; Lubamba, Bob A.

2017-01-01

Cystic fibrosis (CF) pulmonary disease is characterized by chronic airway infection and inflammation. The infectious and inflamed CF airway environment impacts on the innate defense of airway epithelia and airway macrophages. The CF airway milieu induces an adaptation in these cells characterized by increased basal inflammation and a robust inflammatory response to inflammatory mediators. Recent studies have indicated that these responses depend on activation of the unfolded protein response (UPR). This review discusses the contribution of airway epithelia and airway macrophages to CF airway inflammatory responses and specifically highlights the functional importance of the UPR pathway mediated by IRE1/XBP-1 in these processes. These findings suggest that targeting the IRE1/XBP-1 UPR pathway may be a therapeutic strategy for CF airway disease. PMID:28075361

SUBCHRONIC ENDOTOXIN INHALATION CAUSES PERSISTENT AIRWAY DISEASE

EPA Science Inventory

ABSTRACT

The endotoxin component of organic dusts causes acute reversible airflow obstruction and airway inflammation. To test the hypothesis that endotoxin alone causes airway remodeling, we have compared the response of two inbred mouse strains to subchronic endotoxin ...

Are prehospital airway management resources compatible with difficult airway algorithms? A nationwide cross-sectional study of helicopter emergency medical services in Japan.

PubMed

Ono, Yuko; Shinohara, Kazuaki; Goto, Aya; Yano, Tetsuhiro; Sato, Lubna; Miyazaki, Hiroyuki; Shimada, Jiro; Tase, Choichiro

2016-04-01

Immediate access to the equipment required for difficult airway management (DAM) is vital. However, in Japan, data are scarce regarding the availability of DAM resources in prehospital settings. The purpose of this study was to determine whether Japanese helicopter emergency medical services (HEMS) are adequately equipped to comply with the DAM algorithms of Japanese and American professional anesthesiology societies. This nationwide cross-sectional study was conducted in May 2015. Base hospitals of HEMS were mailed a questionnaire about their airway management equipment and back-up personnel. Outcome measures were (1) call for help, (2) supraglottic airway device (SGA) insertion, (3) verification of tube placement using capnometry, and (4) the establishment of surgical airways, all of which have been endorsed in various airway management guidelines. The criteria defining feasibility were the availability of (1) more than one physician, (2) SGA, (3) capnometry, and (4) a surgical airway device in the prehospital setting. Of the 45 HEMS base hospitals questioned, 42 (93.3 %) returned completed questionnaires. A surgical airway was practicable by all HEMS. However, in the prehospital setting, back-up assistance was available in 14.3 %, SGA in 16.7 %, and capnometry in 66.7 %. No HEMS was capable of all four steps. In Japan, compliance with standard airway management algorithms in prehospital settings remains difficult because of the limited availability of alternative ventilation equipment and back-up personnel. Prehospital health care providers need to consider the risks and benefits of performing endotracheal intubation in environments not conducive to the success of this procedure.

Mechanisms of mechanical strain memory in airway smooth muscle.

PubMed

Kim, Hak Rim; Hai, Chi-Ming

2005-10-01

We evaluated the hypothesis that mechanical deformation of airway smooth muscle induces structural remodeling of airway smooth muscle cells, thereby modulating mechanical performance in subsequent contractions. This hypothesis implied that past experience of mechanical deformation was retained (or "memorized") as structural changes in airway smooth muscle cells, which modulated the cell's subsequent contractile responses. We termed this phenomenon mechanical strain memory. Preshortening has been found to induce attenuation of both force and isotonic shortening velocity in cholinergic receptor-activated airway smooth muscle. Rapid stretching of cholinergic receptor-activated airway smooth muscle from an initial length to a final length resulted in post-stretch force and myosin light chain phosphorylation that correlated significantly with initial length. Thus post-stretch muscle strips appeared to retain memory of the initial length prior to rapid stretch (mechanical strain memory). Cytoskeletal recruitment of actin- and integrin-binding proteins and Erk 1/2 MAPK appeared to be important mechanisms of mechanical strain memory. Sinusoidal length oscillation led to force attenuation during oscillation and in subsequent contractions in intact airway smooth muscle, and p38 MAPK appeared to be an important mechanism. In contrast, application of local mechanical strain to cultured airway smooth muscle cells induced local actin polymerization and cytoskeletal stiffening. It is conceivable that deep inspiration-induced bronchoprotection may be a manifestation of mechanical strain memory such that mechanical deformation from past breathing cycles modulated the mechanical performance of airway smooth muscle in subsequent cycles in a continuous and dynamic manner.

Rhinovirus disrupts the barrier function of polarized airway epithelial cells.

PubMed

Sajjan, Umadevi; Wang, Qiong; Zhao, Ying; Gruenert, Dieter C; Hershenson, Marc B

2008-12-15

Secondary bacterial infection following rhinovirus (RV) infection has been recognized in chronic obstructive pulmonary disease. We sought to understand mechanisms by which RV infection facilitates secondary bacterial infection. Primary human airway epithelial cells grown at air-liquid interface and human bronchial epithelial (16HBE14o-) cells grown as polarized monolayers were infected apically with RV. Transmigration of bacteria (nontypeable Haemophilus influenzae and others) was assessed by colony counting and transmission electron microscopy. Transepithelial resistance (R(T)) was measured by using a voltmeter. The distribution of zona occludins (ZO)-1 was determined by immunohistochemistry and immunoblotting. Epithelial cells infected with RV showed 2-log more bound bacteria than sham-infected cultures, and bacteria were recovered from the basolateral media of RV- but not sham-infected cells. Infection of polarized airway epithelial cell cultures with RV for 24 hours caused a significant decrease in R(T) without causing cell death or apoptosis. Ultraviolet-treated RV did not decrease R(T), suggesting a requirement for viral replication. Reduced R(T) was associated with increased paracellular permeability, as determined by flux of fluorescein isothiocyanate (FITC)-inulin. Neutralizing antibodies to tumor necrosis factor (TNF)-alpha, IFN-gamma and IL-1beta reversed corresponding cytokine-induced reductions in R(T) but not that induced by RV, indicating that the RV effect is independent of these proinflammatory cytokines. Confocal microscopy and immunoblotting revealed the loss of ZO-1 from tight junction complexes in RV-infected cells. Intranasal inoculation of mice with RV1B also caused the loss of ZO-1 from the bronchial epithelium tight junctions in vivo. RV facilitates binding, translocation, and persistence of bacteria by disrupting airway epithelial barrier function.

RGS4 Overexpression in Lung Attenuates Airway Hyperresponsiveness in Mice.

PubMed

Madigan, Laura A; Wong, Gordon S; Gordon, Elizabeth M; Chen, Wei-Sheng; Balenga, Nariman; Koziol-White, Cynthia J; Panettieri, Reynold A; Levine, Stewart J; Druey, Kirk M

2018-01-01

A cardinal feature of asthma is airway hyperresponsiveness (AHR) to spasmogens, many of which activate G protein-coupled receptors (GPCRs) on airway smooth muscle (ASM) cells. Asthma subtypes associated with allergy are characterized by eosinophilic inflammation in the lung due to the type 2 immune response to allergens and proinflammatory mediators that promote AHR. The degree to which intrinsic abnormalities of ASM contribute to this phenotype remains unknown. The regulators of G protein signaling (RGS) proteins are a large group of intracellular proteins that inhibit GPCR signaling pathways. RGS2- and RGS5-deficient mice develop AHR spontaneously. Although RGS4 is upregulated in ASM from patients with severe asthma, the effects of increased RGS4 expression on AHR in vivo are unknown. Here, we examined the impact of forced RGS4 overexpression in lung on AHR using transgenic (Tg) mice. Tg RGS4 was expressed in bronchial epithelium and ASM in vivo, and protein expression in lung was increased at least 4-fold in Tg mice compared with wild-type (WT) mice. Lung slices from Tg mice contracted less in response to the m3 muscarinic receptor agonist methacholine compared with the WT, although airway resistance in live, unchallenged mice of both strains was similar. Tg mice were partially protected against AHR induced by fungal allergen challenge due to weakened contraction signaling in ASM and reduced type 2 cytokine (IL-5 and IL-13) levels in Tg mice compared with the WT. These results provide support for the hypothesis that increasing RGS4 expression and/or function could be a viable therapeutic strategy for asthma.

T helper 1 background protects against airway hyperresponsiveness and inflammation in guinea pigs with persistent respiratory syncytial virus infection.

PubMed

Sutton, Troy C; Tayyari, Farnoosh; Khan, M Aatif; Manson, Heather E; Hegele, Richard G

2007-05-01

A family history of allergy has been implicated in children who develop post-bronchiolitis wheezing and asthma. In a guinea pig model of respiratory syncytial virus (RSV) lung infection, we evaluated the role of host Th1 background (either genetic or induced) on the development of a persistent infection, nonspecific airway hyperresponsiveness (AHR) and airway inflammation. Allergy resistant/T helper 1 (Th1)-skewed strain 2 guinea pigs (STR2) and cytosine phosphate guanine oligodeoxynucleotides (CpG-ODN) (Th1 stimuli) pretreated Cam Hartley guinea pigs (CH) were inoculated with RSV and compared with virus-inoculated allergy-susceptible/Th2-skewed CHs and to sham-inoculated STR2 and CH, 60 d post-inoculation. We measured titers of intrapulmonary RSV, lung interferon (IFN)-gamma and interleukin (IL)-5 mRNA expression, AHR and airway T cells and eosinophils. All virus-inoculated groups of animals showed evidence of persistent RSV lung infection; however, Th2-skewed guinea pigs had virus-associated AHR and significantly greater levels of airway T cells and eosinophils. In conclusion, RSV can establish persistent infection of the guinea pig lung regardless of host Th1/Th2 background; however; a host Th1 background limits the extent of virus-associated AHR and airway inflammation. Heterogeneity in virus-host interactions may be relevant to understanding why some children hospitalized for RSV bronchiolitis go on to develop recurrent wheezing/asthma symptoms.

Airway driving pressure and lung stress in ARDS patients.

PubMed

Chiumello, Davide; Carlesso, Eleonora; Brioni, Matteo; Cressoni, Massimo

2016-08-22

Lung-protective ventilation strategy suggests the use of low tidal volume, depending on ideal body weight, and adequate levels of PEEP. However, reducing tidal volume according to ideal body weight does not always prevent overstress and overstrain. On the contrary, titrating mechanical ventilation on airway driving pressure, computed as airway pressure changes from PEEP to end-inspiratory plateau pressure, equivalent to the ratio between the tidal volume and compliance of respiratory system, should better reflect lung injury. However, possible changes in chest wall elastance could affect the reliability of airway driving pressure. The aim of this study was to evaluate if airway driving pressure could accurately predict lung stress (the pressure generated into the lung due to PEEP and tidal volume). One hundred and fifty ARDS patients were enrolled. At 5 and 15 cmH2O of PEEP, lung stress, driving pressure, lung and chest wall elastance were measured. The applied tidal volume (mL/kg of ideal body weight) was not related to lung gas volume (r (2) = 0.0005 p = 0.772). Patients were divided according to an airway driving pressure lower and equal/higher than 15 cmH2O (the lower and higher airway driving pressure groups). At both PEEP levels, the higher airway driving pressure group had a significantly higher lung stress, respiratory system and lung elastance compared to the lower airway driving pressure group. Airway driving pressure was significantly related to lung stress (r (2) = 0.581 p < 0.0001 and r (2) = 0.353 p < 0.0001 at 5 and 15 cmH2O of PEEP). For a lung stress of 24 and 26 cmH2O, the optimal cutoff value for the airway driving pressure were 15.0 cmH2O (ROC AUC 0.85, 95 % CI = 0.782-0.922); and 16.7 (ROC AUC 0.84, 95 % CI = 0.742-0.936). Airway driving pressure can detect lung overstress with an acceptable accuracy. However, further studies are needed to establish if these limits could be used for ventilator settings.

Airway disease phenotypes in animal models of cystic fibrosis.

PubMed

McCarron, Alexandra; Donnelley, Martin; Parsons, David

2018-04-02

In humans, cystic fibrosis (CF) lung disease is characterised by chronic infection, inflammation, airway remodelling, and mucus obstruction. A lack of pulmonary manifestations in CF mouse models has hindered investigations of airway disease pathogenesis, as well as the development and testing of potential therapeutics. However, recently generated CF animal models including rat, ferret and pig models demonstrate a range of well characterised lung disease phenotypes with varying degrees of severity. This review discusses the airway phenotypes of currently available CF animal models and presents potential applications of each model in airway-related CF research.

Regional differences of the contractile responses to acetylcholine and neurokinin A in rabbit airway: heterogeneous distribution of the metabolic enzymes.

PubMed

Goroumaru-Shinkai, M; Yamamoto, R; Funayama, N; Takayanagi, I

1992-11-01

1. Experiments were designed to determine whether differences exist in the sensitivity to muscarinic and tachykinin agonists in rabbit airways. 2. The rank order of sensitivity (pD2 value) to acetylcholine was: trachea > proximal bronchus > distal bronchus, whereas no regional difference was observed in the sensitivity to carbamylcholine which is resistant to acetylcholinesterase. 3. Acetylcholinesterase activity was greater in the distal than in the proximal airway. 4. In the absence of the peptidase inhibitor, phosphoramidon, the pD2 values of neurokinin A (NKA) and substance P (SP) in trachea were significantly greater than that in bronchus, whereas no regional difference was observed in the NK1 selective agonist, substance P methyl ester (SPOMe). 5. Application of phosphoramidon (10 microM) to avoid peptide degradation abolished the regional difference of the pD2 values of SP. 6. In conclusion, regional differences in sensitivities to acetylcholine and NKA in the rabbit airway were suggested to be due to distribution to the metabolic enzymes of these drugs.

Infectious mononucleosis presenting as upper airway obstruction.

PubMed

Jain, Vivek; Singhi, Sunit; Desai, Ravi V

2003-01-01

Upper airway obstruction though a common complication of infectious mononucleosis is rarely considered in differential diagnosis of stridor. We report a three-year-old child who had upper airway obstruction due to infectious mononucleosis, managed conservatively with oxygen, intravenous fluids and steroids.

How the airway smooth muscle in cystic fibrosis reacts in proinflammatory conditions: implications for airway hyper-responsiveness and asthma in cystic fibrosis.

PubMed

McCuaig, Sarah; Martin, James G

2013-04-01

Among patients with cystic fibrosis there is a high prevalence (40-70%) of asthma signs and symptoms such as cough and wheezing and airway hyper-responsiveness to inhaled histamine or methacholine. Whether these abnormal airway responses are due to a primary deficiency in the cystic fibrosis transmembrane conductance regulator (CFTR) or are secondary to the inflammatory environment in the cystic fibrosis lungs is not clear. A role for the CFTR in smooth muscle function is emerging, and alterations in contractile signalling have been reported in CFTR-deficient airway smooth muscle. Persistent bacterial infection, especially with Pseudomonas aeruginosa, stimulates interleukin-8 release from the airway epithelium, resulting in neutrophilic inflammation. Increased neutrophilia and skewing of CFTR-deficient T-helper cells to type 2 helper T cells creates an inflammatory environment characterised by high concentrations of tumour necrosis factor α, interleukin-8, and interleukin-13, which might all contribute to increased contractility of airway smooth muscle in cystic fibrosis. An emerging role of interleukin-17, which is raised in patients with cystic fibrosis, in airway smooth muscle proliferation and hyper-responsiveness is apparent. Increased understanding of the molecular mechanisms responsible for the altered smooth muscle physiology in patients with cystic fibrosis might provide insight into airway dysfunction in this disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modeling TH 2 responses and airway inflammation to understand fundamental mechanisms regulating the pathogenesis of asthma.

PubMed

Foster, Paul S; Maltby, Steven; Rosenberg, Helene F; Tay, Hock L; Hogan, Simon P; Collison, Adam M; Yang, Ming; Kaiko, Gerard E; Hansbro, Philip M; Kumar, Rakesh K; Mattes, Joerg

2017-07-01

In this review, we highlight experiments conducted in our laboratories that have elucidated functional roles for CD4 + T-helper type-2 lymphocytes (T H 2 cells), their associated cytokines, and eosinophils in the regulation of hallmark features of allergic asthma. Notably, we consider the complexity of type-2 responses and studies that have explored integrated signaling among classical T H 2 cytokines (IL-4, IL-5, and IL-13), which together with CCL11 (eotaxin-1) regulate critical aspects of eosinophil recruitment, allergic inflammation, and airway hyper-responsiveness (AHR). Among our most important findings, we have provided evidence that the initiation of T H 2 responses is regulated by airway epithelial cell-derived factors, including TRAIL and MID1, which promote T H 2 cell development via STAT6-dependent pathways. Further, we highlight studies demonstrating that microRNAs are key regulators of allergic inflammation and potential targets for anti-inflammatory therapy. On the background of T H 2 inflammation, we have demonstrated that innate immune cells (notably, airway macrophages) play essential roles in the generation of steroid-resistant inflammation and AHR secondary to allergen- and pathogen-induced exacerbations. Our work clearly indicates that understanding the diversity and spatiotemporal role of the inflammatory response and its interactions with resident airway cells is critical to advancing knowledge on asthma pathogenesis and the development of new therapeutic approaches. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Double stenting with silicone and metallic stents for malignant airway stenosis.

PubMed

Matsumoto, Keitaro; Yamasaki, Naoya; Tsuchiya, Tomoshi; Miyazaki, Takuro; Kamohara, Ryotaro; Hatachi, Go; Nagayasu, Takeshi

2017-08-01

For severe malignant airway stenosis, there are several types of commercially available airway stents, and each has its own advantages and disadvantages. We herein describe the safety and efficacy of combination stenting with silicone and metallic stents for patients with extended malignant airway stenosis. Seven patients with malignant airway stenosis were treated via combination stenting with a silicone stent and a metallic stent for extended airway stenosis from the central to peripheral airways. Five patients were diagnosed with advanced esophageal cancer, two of whom had tracheoesophageal fistulas. One patient had adenoid cystic carcinoma, and another had mediastinal tumor. There were no specific complications related to the double stenting. Combination stenting with silicone and metallic stents proved to be a safe option for patients with severe, extended, and complicated malignant airway stenosis.

Relating small airways to asthma control by using impulse oscillometry in children.

PubMed

Shi, Yixin; Aledia, Anna S; Tatavoosian, Ahramahzd V; Vijayalakshmi, Shruthi; Galant, Stanley P; George, Steven C

2012-03-01

Previous reports suggest that the peripheral airways are associated with asthma control. Patient history, although subjective, is used largely to assess asthma control in children because spirometric results are many times normal values. Impulse oscillometry (IOS) is an objective and noninvasive measurement of lung function that has the potential to examine independently both small- and large-airway obstruction. We sought to determine the utility of IOS in assessing asthma control in children. Asthmatic and healthy children (6-17 years) were enrolled in the study. Spirometric and IOS (resistance of the respiratory system at 5 Hz [R5] and 20 Hz [R20], reactance of the respiratory system at 5 Hz [X5], resonant frequency of reactance [Fres], and area under the reactance curve between 5 Hz and Fres [reactance area {AX}]) values were collected in triplicate before and after a bronchodilator was administered. The physicians were blinded to the IOS measurements and assessed asthma control using American Thoracic Society guidelines. Small-airway IOS measurements, including the difference of R5 and R20 [R5-20], X5, Fres, and AX, of children with uncontrolled asthma (n = 44) were significantly different from those of children with controlled asthma (n = 57) and healthy children (n = 14), especially before the administration of a bronchodilator. However, there was no difference in large-airway IOS values (R20). No differences were found between children with controlled asthma and healthy children in any of the end points. Receiver operating characteristic analysis showed cut points for baseline R5-20 (1.5 cm H(2)O · L(-1) · s) and AX (9.5 cm H(2)O · L(-1)) that effectively discriminated controlled versus uncontrolled asthma (area under the curve, 0.86 and 0.84) and correctly classified more than 80% of the population. Uncontrolled asthma is associated with small-airways dysfunction, and IOS might be a reliable and noninvasive method to assess asthma control in children

Covered Balloon-Expanding Stents in Airway Stenosis.

PubMed

Majid, Adnan; Kheir, Fayez; Chung, Jey; Alape, Daniel; Husta, Bryan; Oh, Scott; Folch, Erik

2017-04-01

The balloon-expanding stents are widely available but rarely described for use within the tracheobronchial tree. This report describes our experience with these stents in airway stenosis particularly as a lobar salvage therapy. This was a retrospective review of all records in which the balloon-expanding stents were used at a tertiary medical center. Ages, sex, location of stenosis, etiology of stenosis, stent size, duration of stent placement and associated interventions for airway stenosis were recorded. Patient's self-reported respiratory symptoms, dyspnea scale, and radiographic imaging at baseline and after stent placement were also reported. Twenty-one Atrium iCAST stents were inserted in 18 patients with malignant and benign airway disease. The median age was 69.5 years (interquartile range, 53.5 to 74). Most stents (n=20, 95%) were deployed in the lobar airways. There was a significant improvement in the modified Medical Research Council dyspnea scale from median of 3 to 2 (P<0.05). Self-reported respiratory symptoms improved in 14 patients (78%, P<0.05). Radiographic improvement post Atrium iCAST stent placement was achieved in 15 patients (83%). No deaths were related to airway stenting complications. Adverse events related to stents included migration (n=2, 9.5%), granulation tissue formation (n=2, 9.5%) and mucus plugging (n=1, 4.8%). Lobar stenting with balloon-expanding metallic stents appears feasible, safe and improves symptoms as well as radiographic atelectasis in patients with lobar airway stenosis in this small case series. Larger studies are needed to confirm this observation and to address long-term safety.