68,193 research outputs found

    Koalas use a novel vocal organ to produce unusually low-pitched mating calls

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    SummaryDuring the breeding season, male koalas produce ‘bellow’ vocalisations that are characterised by a continuous series of inhalation and exhalation sections, and an extremely low fundamental frequency (the main acoustic correlate of perceived pitch) [1]. Remarkably, the fundamental frequency (F0) of bellow inhalation sections averages 27.1 Hz (range: 9.8–61.5 Hz [1]), which is 20 times lower than would be expected for an animal weighing 8 kg [2] and more typical of an animal the size of an elephant (Supplemental figure S1A). Here, we demonstrate that koalas use a novel vocal organ to produce their unusually low-pitched mating calls

    Reciprocal Inhibition of Adiponectin and Innate Lung Immune Responses to Chitin and Aspergillus fumigatus

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    Chitin is a structural biopolymer found in numerous organisms, including pathogenic fungi, and recognized as an immune-stimulating pathogen associated molecular pattern by pattern recognition molecules of the host immune system. However, programming and regulation of lung innate immunity to chitin inhalation in the context of inhalation of fungal pathogens such as Aspergillus fumigatus is complex and our understanding incomplete. Here we report that the systemic metabolism-regulating cytokine adiponectin is decreased in the lungs and serum of mice after chitin inhalation, with a concomitant decrease in surface expression of the adiponectin receptor AdipoR1 on lung leukocytes. Constitutive lung expression of acidic mammalian chitinase resulted in decreased inflammatory cytokine gene expression and neutrophil recruitment, but did not significantly affect lung adiponectin transcription. Exogenous recombinant adiponectin specifically dampened airway chitin-mediated eosinophil recruitment, while adiponectin deficiency resulted in increased airway eosinophils. The presence of adiponectin also resulted in decreased CCL11-mediated migration of bone marrow-derived eosinophils. In contrast to purified chitin, aspiration of viable conidia from the high chitin-expressing A. fumigatus isolate Af5517 resulted in increased neutrophil recruitment and inflammatory cytokine gene expression in adiponectin-deficient mice, while no significant changes were observed in response to the isolate Af293. Our results identify a novel role for the adiponectin pathway in inhibition of lung inflammatory responses to chitin and A. fumigatus inhalation

    Inhalation characteristics of asthma patients, COPD patients and healthy volunteers with the Spiromax® and Turbuhaler® devices: a randomised, cross-over study.

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    BACKGROUND: Spiromax® is a novel dry-powder inhaler containing formulations of budesonide plus formoterol (BF). The device is intended to provide dose equivalence with enhanced user-friendliness compared to BF Turbuhaler® in asthma and chronic obstructive pulmonary disease (COPD). The present study was performed to compare inhalation parameters with empty versions of the two devices, and to investigate the effects of enhanced training designed to encourage faster inhalation. METHODS: This randomised, open-label, cross-over study included children with asthma (n = 23), adolescents with asthma (n = 27), adults with asthma (n = 50), adults with COPD (n = 50) and healthy adult volunteers (n = 50). Inhalation manoeuvres were recorded with each device after training with the patient information leaflet (PIL) and after enhanced training using an In-Check Dial device. RESULTS: After PIL training, peak inspiratory flow (PIF), maximum change in pressure (∆P) and the inhalation volume (IV) were significantly higher with Spiromax than with the Turbuhaler device (p values were at least <0.05 in all patient groups). After enhanced training, numerically or significantly higher values for PIF, ∆P, IV and acceleration remained with Spiromax versus Turbuhaler, except for ∆P in COPD patients. After PIL training, one adult asthma patient and one COPD patient inhaled <30 L/min through the Spiromax compared to one adult asthma patient and five COPD patients with the Turbuhaler. All patients achieved PIF values of at least 30 L/min after enhanced training. CONCLUSIONS: The two inhalers have similar resistance so inhalation flows and pressure changes would be expected to be similar. The higher flow-related values noted for Spiromax versus Turbuhaler after PIL training suggest that Spiromax might have human factor advantages in real-world use. After enhanced training, the flow-related differences between devices persisted; increased flow rates were achieved with both devices, and all patients achieved the minimal flow required for adequate drug delivery. Enhanced training could be useful, especially in COPD patients

    Induction of chronic migraine phenotypes in a rat model after environmental irritant exposure

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    Air pollution is linked to increased emergency department visits for headache and migraine patients frequently cite chemicals or odors as headache triggers, but the association between air pollutants and headache is not well understood. We previously reported that chronic environmental irritant exposure sensitizes the trigeminovascular system response to nasal administration of environmental irritants. Here, we examine whether chronic environmental irritant exposure induces migraine behavioral phenotypes. Male rats were exposed to acrolein, a transient receptor potential channel ankyrin-1 (TRPA1) agonist, or room air by inhalation for 4 days before meningeal blood flow measurements, periorbital cutaneous sensory testing, or other behavioral testing. Touch-induced c-Fos expression in trigeminal nucleus caudalis was compared in animals exposed to room air or acrolein. Spontaneous behavior and olfactory discrimination was examined in open-field testing. Acrolein inhalation exposure produced long-lasting potentiation of blood flow responses to a subsequent TRPA1 agonist and sensitized cutaneous responses to mechanical stimulation. C-Fos expression in response to touch was increased in trigeminal nucleus caudalis in animals exposed to acrolein compared with room air. Spontaneous activity in an open-field and scent preference behavior was different in acrolein-exposed compared with room air-exposed animals. Sumatriptan, an acute migraine treatment blocked acute blood flow changes in response to TRPA1 or transient receptor potential vanilloid receptor-1 agonists. Pretreatment with valproic acid, a prophylactic migraine treatment, attenuated the enhanced blood flow responses observed after acrolein inhalation exposures. Environmental irritant exposure yields an animal model of chronic migraine in which to study mechanisms for enhanced headache susceptibility after chemical exposure

    Estimating past inhalation exposure to asbestos: a tool for risk attribution and disease screening

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    Introduction: Late presentation is common in mesothelioma. Reliable assessment of past exposure to asbestos is a necessary first step for risk attribution and for the development of a future screening programme. Such a programme could maximise access to trials of novel therapies and would pave the way for development of novel chemoprophylaxis strategies. This paper describes a method for individual exposure reconstruction along with data from a validation study. Methods: The exposure assessment method uses only descriptive information about the circumstances of the work that could be obtained from questioning the worker. The assessment is based on the tasks carried out and includes parameters for substance emission potential, activity emission potential, the effectiveness of any local control measures, passive emission, the fractional time the asbestos source is active and the efficiency of any respiratory protection worn. Results: There was a good association between the estimated and measured exposure levels. Pearson’s correlation coefficient between the log-transformed measurements and estimates from the model was 0.86, and 95% of the estimated individual values were within about a factor of ten of the associated measured value. The method described would be suitable for pre-selecting individuals at high risk of malignant pleural mesothelioma for screening using appropriate tools and/or enrolment in clinical trials of chemo-prophylaxis. Discussion: This method is of potential clinical value in developing novel treatment approaches for mesothelioma. Pilot studies to test this approach are urgently needed

    Influence of excipients on spray-dried powders for inhalation

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    Two areas attracting considerable attention when developing effective pulmonary drug delivery systems include the improvement of aerosolisation efficiency of the inhaled formulation and the controlled release of drug from the formulation following deposition within the lung. In this study, four saccharides were employed as excipients in the preparation of spray-dried powder formulations for the pulmonary drug delivery. Beta-cyclodextrin-, starch-, and sodium carboxymethylcellulose (NaCMC)-based spray-dried powders showed a significant (one-way ANOVA, Duncan's test, p < 0.05) increase in lower stage drug deposition in the Next Generation Impactor (NGI) when compared to lactose-based spray-dried powders. Furthermore, NaCMC-based spray-dried powder formulations exhibited a sustained drug release profile in dissolution testing; approximately 80% of salbutamol sulphate was released after an hour, whereas drug from the lactose-based spray-dried powder formulation was released within 5 min. Our results clearly demonstrate that the inclusion of NaCMC in spray-dried powder formulations increases the aerosolisation efficiency of the powder and also offers the potential for sustained drug release, which may be of benefit in the treatment of local and systemic conditions

    Nonhuman Primate Models of Respiratory Disease: Past, Present, and Future.

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    The respiratory system consists of an integrated network of organs and structures that primarily function for gas exchange. In mammals, oxygen and carbon dioxide are transmitted through a complex respiratory tract, consisting of the nasal passages, pharynx, larynx, and lung. Exposure to ambient air throughout the lifespan imposes vulnerability of the respiratory system to environmental challenges that can contribute toward development of disease. The importance of the respiratory system to human health is supported by statistics from the Centers for Disease Control and Prevention; in 2015, chronic lower respiratory diseases were the third leading cause of death in the United States. In light of the significant mortality associated with respiratory conditions that afflict all ages of the human population, this review will focus on basic and preclinical research conducted in nonhuman primate models of respiratory disease. In comparison with other laboratory animals, the nonhuman primate lung most closely resembles the human lung in structure, physiology, and mucosal immune mechanisms. Studies defining the influence of inhaled microbes, pollutants, or allergens on the nonhuman primate lung have provided insight on disease pathogenesis, with the potential for elucidation of molecular targets leading to new treatment modalities. Vaccine trials in nonhuman primates have been crucial for confirmation of safety and protective efficacy against infectious diseases of the lung in a laboratory animal model that recapitulates pathology observed in humans. In looking to the future, nonhuman primate models of respiratory diseases will continue to be instrumental for translating biomedical research for improvement of human health

    Effects of Δ⁹-tetrahydrocannabinol (THC) vapor inhalation in Sprague-Dawley and Wistar rats.

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    An inhalation system based on e-cigarette technology produces hypothermic and antinociceptive effects of Δ⁹-tetrahydrocannabinol (THC) in rats. Indirect comparison of some prior investigations suggested differential impact of inhaled THC between Wistar (WI) and Sprague-Dawley (SD) rats; thus, this study was conducted to directly compare the strains across inhaled and injected routes of administration. Groups (N = 8 per strain) of age-matched male SD and WI rats were prepared with radiotelemetry devices to measure temperature and then exposed to vapor from the propylene glycol (PG) vehicle or THC (25-200 mg/mL of PG) for 30 or 40 min. Additional studies evaluated effects of THC inhalation on plasma THC (50-200 mg/mL) and nociception (100-200 mg/mL) as well as the thermoregulatory effect of intraperitoneal injection of THC (5-30 mg/kg). Hypothermic effects of THC were more pronounced in SD rats, where plasma levels of THC were identical across strains, under either fixed inhalation conditions or injection of a mg/kg equivalent dose. Strain differences in hypothermia were largest after i.p. injection of THC, with SD rats exhibiting dose-dependent temperature reduction after 5 or 10 mg/kg, i.p. and the WI rats only exhibiting significant hypothermia after 20 mg/kg, i.p. The antinociceptive effects of inhaled THC (100, 200 mg/mL) did not differ significantly across the strains. These studies confirm an insensitivity of WI rats, compared with SD rats, to hypothermia induced by THC following inhalation conditions that produced identical plasma THC and antinociception. Thus, quantitative, albeit not qualitative, strain differences may be obtained when studying thermoregulatory effects of THC. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
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