Acquisition of respiratory and gastrointestinal pathogens among health care workers during the 2015 Hajj season

BACKGROUND

Data on the risk of transmission of infection to health care workers (HCWs) serving ill pilgrims during the Hajj is scarce.

METHODS

Two cohorts of HCWs, the first serving Hajj pilgrims in Mecca and the second serving patients in Al-Ahsa, were investigated for respiratory and gastrointestinal symptoms and pathogen carriage using multiplex polymerase chain reaction before and after the 2015 Hajj.

RESULTS

A total of 211 HCWs were enrolled of whom 92 were exposed to pilgrims (Mecca cohort), whereas 119 were not exposed (Al-Ahsa cohort). Symptoms were observed only in HCWs from the Mecca cohort, with 29.3% experiencing respiratory symptoms during the Hajj period or in the subsequent days and 3.3% having gastrointestinal symptoms. Acquisition rates of at least 1 respiratory virus were 14.7% in the Mecca cohort and 3.4% in the Al-Ahsa cohort (P = .003). Acquisition rates of at least 1 respiratory bacterium were 11.8% and 18.6% in the Mecca and Al-Ahsa cohorts, respectively (P = .09). Gastrointestinal pathogens were rarely isolated in both cohorts of HCWs and acquisition of pathogens after the Hajj was documented in only a few individuals.

CONCLUSIONS

HCWs providing care for pilgrims both acquire pathogens and present symptoms (especially respiratory symptoms) more frequently than those not working during Hajj.

A Randomized, Double-Blind, Double-Dummy Study of Glycopyrrolate/Formoterol Fumarate Metered Dose Inhaler Relative to Umeclidinium/Vilanterol Dry Powder Inhaler in COPD

INTRODUCTION

Glycopyrrolate/formoterol fumarate metered dose inhaler (GFF MDI), formulated using co-suspension delivery technology, is the only approved fixed-dose combination long-acting muscarinic antagonist/long-acting β₂-agonist (LAMA/LABA) delivered via MDI. Direct comparisons of GFF MDI versus other LAMA/LABAs have not previously been performed. We assessed the efficacy and safety of GFF MDI relative to umeclidinium/vilanterol dry powder inhaler (UV DPI) in patients with moderate-to-very severe chronic obstructive pulmonary disease (COPD).

METHODS

In this phase IIIb randomized, double-blind, double-dummy, multicenter, 24-week study, patients received GFF MDI 18/9.6 μg (equivalent to glycopyrronium/formoterol fumarate dihydrate 14.4/10 μg; two inhalations per dose, twice-daily; n = 559) or UV DPI 62.5/25 μg (one inhalation, once-daily; n = 560). Primary endpoints were change from baseline in morning pre-dose trough forced expiratory volume in 1 s (FEV₁) and peak change from baseline in FEV₁ within 2 h post-dose, both over 24 weeks. Additional lung function, symptom and safety endpoints were also assessed.

RESULTS

For the primary endpoints, GFF MDI was non-inferior to UV DPI (using a margin of - 50 mL) for peak FEV₁ (least squares mean [LSM] difference - 3.4 mL, 97.5% confidence interval [CI] - 32.8, 25.9) but not for trough FEV₁ (LSM difference - 87.2 mL; - 117.0, - 57.4). GFF MDI was nominally superior to UV DPI for onset of action (p < 0.0001) and was nominally non-inferior to UV DPI for all symptom endpoints (Transition Dyspnea Index focal score, Early Morning/Night-Time Symptoms COPD instrument scores, and COPD Assessment Test score). Exacerbation and safety findings were similar between groups.

CONCLUSIONS

Over 24 weeks of treatment, GFF MDI was non-inferior to UV DPI for peak FEV₁, but not for morning pre-dose trough FEV₁. GFF MDI had a faster onset of action versus UV DPI. There were no clinically meaningful differences between treatments in symptom endpoints. Both treatments were well tolerated with similar safety profiles.

TRIAL REGISTRATION

NCT03162055 (Clinicaltrials.gov) FUNDING: AstraZeneca.

Pseudoexfoliation syndrome: analysis of systemic comorbidities of 325 PEX-positive patients compared with 911 PEX-negative patients

PURPOSE

Pseudoexfoliation syndrome (PEX) is an age-related systemic elastic fibrillopathy disorder featuring an excessive production and accumulation of elastic fibre components in the extracellular matrix and is associated with impaired protective mechanisms against oxidative and cellular stress. PEX is diagnosed solely by ophthalmologists; however, PEX deposits have been detected in the connective tissues of many extraocular organ systems. This large, retrospective case-control study investigates whether patients with PEX have an increased risk of extraocular comorbidities.

METHODS

Cases and controls were drawn from consecutive patients over 50 years of age undergoing in-house ophthalmological operations under general anaesthesia or in standby preparedness for general anaesthesia. The participants were grouped based solely on PEX-positive (n = 325) or PEX-negative (n = 911) status. The same teams of ophthalmologists and anaesthesiologists uniformly documented every known systemic comorbidity of each patient through two independent rounds of standard anamnestic procedure and protocols in preparation for general anaesthesia. For the purpose of this study, every systemic comorbidity was registered from these forms and subsequently categorized into 17 disease groups based on the International Classification of Diseases (ICD-10) of the World Health Organization (WHO). Odds ratios (ORs) comparing comorbidities in cases and controls were adjusted for age and gender using logistic regression.

RESULTS

After adjustment for multiple testing, patients with PEX had an increased odds ratio for respiratory OR 2.1 [1.4; 3.0], cardiac OR 2.5 [1.6; 4.2], vascular OR 2.0 [1.4; 2.8], and urogenital conditions OR 2.3 [1.4; 3.7]. Renal and psychiatric comorbidities were nominally significant. While no substantially higher frequency was found for hernias, aneurysms, aortic dissection, or varicose veins among PEX-positive patients, higher rates of cardiac valve disorders and benign prostate hyperplasia were found among the PEX-positive individuals.

CONCLUSION

In addition to confirming an increased risk of respiratory, cardiovascular, and urogenital comorbidities, our data found an increased risk of cardiac valve disorders and benign prostate hyperplasia among PEX-positive patients, which may be manifestations of the underlying systemic elastotic fibrillopathy and warrants further exploration, including future histological study.

Automation and standardisation of clinical molecular testing using PCR.Ai - A comparative performance study

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PCR.Ai is an automated final interpretation/verification step for in-house qPCR tests.

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PCR.Ai was compared to our routine analysis method.

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PCR.Ai was accurate for respiratory virus and norovirus detection.

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There were significant savings with PCR.Ai.

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PCR.Ai is a highly accurate time-saving tool for qPCR analysis.

Background

We undertook a prospective clinical study to evaluate PCR.Ai’s (www.pcr.ai) accuracy and impact when automating the manual data-analysis and quality control steps associated with routine clinical pathogen testing using real-time PCR (qPCR).

Objectives

We evaluated the impact of PCR.Ai when used as the final interpretation/verification step for routine in-house qPCR tests for respiratory pathogens and for norovirus for a total of 22,200 interpretations.

Study Design

We compared PCR.Ai to our existing manual interpretation, to determine accuracy and hands-on time savings. PCR.Ai was accurate.

Results and Conclusions

There was 100% concurrence between validated respiratory virus and norovirus detection by our manual routine analysis method and PCR.Ai. Furthermore, there were significant routine savings with PCR.Ai of 45 min/respiratory run and 32 min/norovirus run. Our conclusion is that PCR.Ai is a highly accurate time-saving tool that reduces complexity of qPCR analysis and hence the need for specialists and hands-on time. It demonstrated capabilities to enable us to get results out more quickly with lower costs and less risk of errors.

Laboratory contamination in airway microbiome studies

BACKGROUND

The low bacterial load in samples acquired from the lungs, have made studies on the airway microbiome vulnerable to contamination from bacterial DNA introduced during sampling and laboratory processing. We have examined the impact of laboratory contamination on samples collected from the lower airways by protected (through a sterile catheter) bronchoscopy and explored various in silico approaches to dealing with the contamination post-sequencing. Our analyses included quantitative PCR and targeted amplicon sequencing of the bacterial 16S rRNA gene.

RESULTS

The mean bacterial load varied by sample type for the 23 study subjects (oral wash>1st fraction of protected bronchoalveolar lavage>protected specimen brush>2nd fraction of protected bronchoalveolar lavage; p < 0.001). By comparison to a dilution series of know bacterial composition and load, an estimated 10-50% of the bacterial community profiles for lower airway samples could be traced back to contaminating bacterial DNA introduced from the laboratory. We determined the main source of laboratory contaminants to be the DNA extraction kit (FastDNA Spin Kit). The removal of contaminants identified using tools within the Decontam R package appeared to provide a balance between keeping and removing taxa found in both negative controls and study samples.

CONCLUSIONS

The influence of laboratory contamination will vary across airway microbiome studies. By reporting estimates of contaminant levels and taking use of contaminant identification tools (e.g. the Decontam R package) based on statistical models that limit the subjectivity of the researcher, the accuracy of inter-study comparisons can be improved.

Effects of general anaesthesia in dorsal recumbency with and without vatinoxan on bronchoalveolar lavage cytology of healthy horses

Pneumonia is one of the potential complications of general anaesthesia in horses. Anaesthesia is known to increase neutrophils in bronchoalveolar lavage fluid (BALF) of horses after lateral recumbency, but studies after dorsal recumbency are lacking. Our primary aim was to determine when lung inflammation reaches its maximum and how rapidly BALF cytology returns to baseline after anaesthesia in dorsal recumbency. A secondary aim was to investigate the possible effect of vatinoxan, a novel drug, on the BALF cytology results. Six healthy experimental horses were enrolled in this observational crossover study. The horses were subject to repeated BALF and blood sampling for 7 days after general anaesthesia with two treatment protocols, and without anaesthesia (control). During the two treatments, the horses received either medetomidine-vatinoxan or medetomidine-placebo as premedication, and anaesthesia was induced with ketamine-midazolam and maintained with isoflurane for 1h in dorsal recumbency. The differences in BALF and blood variables between the two anaesthesia protocols and control were analysed with repeated measures analysis of variance models. In this study, anaesthesia in dorsal recumbency resulted in no clinically relevant changes in airway cytology that could be differentiated from the effect of repeated BALF sampling. No differences in BALF matrix metalloproteinase gelatinolytic activity could be detected between the two treatments or the control series. Marked increase in serum amyloid A was detected in some animals. Vatinoxan as premedication did not consistently affect lung cytology or blood inflammatory markers after anaesthesia.

Can medicines development improve outcomes in asthma and chronic obstructive pulmonary disease management by driving effectiveness?

Despite the availability of treatment guidelines and inhaled medications for asthma and chronic obstructive pulmonary disease (COPD), much remains to be done to lessen the burden of these respiratory diseases for patients. The challenge of selecting effective and efficacious drugs for patients is a key focus area for healthcare professionals. Here we discuss the concept of "drivers of effectiveness"- features of a medicine which may increase or decrease its effectiveness in the presence of real-world factors - and highlight the importance of considering these drivers in the early stages of drug development, and exploring their impact in carefully designed pragmatic trials. Using the Salford Lung Studies (SLS) in asthma and COPD as an illustrative example, we discuss various features of the inhaled corticosteroid/long-acting β2-agonist combination, fluticasone furoate/vilanterol (FF/VI), as potential drivers of effectiveness that may have contributed to the improved patient outcomes observed with initiation of FF/VI versus continuation of usual care in the UK primary care setting.

Sleep Quality and Congestion with Breathe Right Nasal Strips: Two Randomized Controlled Trials

Introduction

Two multicenter, double-blind, randomized controlled trials assessed the effect of Breathe Right Nasal Strips (BRNS) on sleep-related quality of life in otherwise healthy subjects with chronic nocturnal nasal congestion who reported trouble sleeping.

Methods

Subjects were randomized to BRNS or a placebo strip for approximately 8 h each night for 14 days. Efficacy was assessed in the clinic using the Nocturnal Rhinoconjunctivitis Quality of Life Questionnaire (NRQLQ).

Results

A total of 140 subjects were randomized in Study 1, and 130 in Study 2. There was no significant difference between BRNS and placebo on either the NRQLQ “Sleep Problems” domain or the “Feel Tired and Unrefreshed” item of the “Symptoms on Waking in the Morning” domain at day 7 or 14. There was, however, a significant change in the least squares mean difference from baseline to days 7 and 14 in both the BRNS and placebo arms for each of these endpoints. BRNS were well tolerated.

Conclusions

BRNS did not significantly improve subjective measures of sleep quality and nasal congestion compared with placebo strips in this population of chronic nocturnal congestion sufferers with self-reported sleep impairment, possibly due to a strong placebo effect.

Funding

GlaxoSmithKline Consumer Healthcare.

ClinicalTrials.gov Registration Numbers

Study 1: NCT03549117; Study 2: NCT03549130.

Preterm birth: Born too soon for the developing airway epithelium?

Birth prior to term interrupts the normal development of the respiratory system and consequently results in poor respiratory outcomes that persist throughout childhood. The mechanisms underpinning these poor respiratory outcomes are not well understood, but intrinsic abnormalities within the airway epithelium may be a contributing factor. Current evidence suggests that the airway epithelium is both structurally and functionally abnormal after preterm birth, with reports of epithelial thickening and goblet cell hyperplasia in addition to increased inflammation and apoptosis in the neonatal intensive care unit. However, studies focusing on the airway epithelium are limited and many questions remain unanswered; including whether abnormalities are a direct result of interrupted development, a consequence of exposure to inflammatory stimuli in the perinatal period or a combination of the two. In addition, the difficulty of accessing airway tissue has resulted in the majority of evidence being collected in the pre-surfactant era which may not reflect contemporary preterm birth. This review examines the consequences of preterm birth on the airway epithelium and explores the clinical relevance of currently available models whilst highlighting the need to develop a clinically relevant in vitro model to help further our understanding of the airway epithelium in preterm birth.

Effects of exercise preconditioning and HSP72 on diaphragm muscle function during mechanical ventilation

BACKGROUND

Mechanical ventilation (MV) is a life-saving measure for patients in respiratory failure. However, prolonged MV results in significant diaphragm atrophy and contractile dysfunction, a condition referred to as ventilator-induced diaphragm dysfunction (VIDD). While there are currently no clinically approved countermeasures to prevent VIDD, increased expression of heat shock protein 72 (HSP72) has been demonstrated to attenuate inactivity-induced muscle wasting. HSP72 elicits cytoprotection via inhibition of NF-κB and FoxO transcriptional activity, which contribute to VIDD. In addition, exercise-induced prevention of VIDD is characterized by an increase in the concentration of HSP72 in the diaphragm. Therefore, we tested the hypothesis that increased HSP72 expression is required for the exercise-induced prevention of VIDD. We also determined whether increasing the abundance of HSP72 in the diaphragm, independent of exercise, is sufficient to prevent VIDD.

METHODS

Cause and effect was determined by inhibiting the endurance exercise-induced increase in HSP72 in the diaphragm of exercise trained animals exposed to prolonged MV via administration of an antisense oligonucleotide targeting HSP72. Additional experiments were performed to determine if increasing HSP72 in the diaphragm via genetic (rAAV-HSP72) or pharmacological (BGP-15) overexpression is sufficient to prevent VIDD.

RESULTS

Our results demonstrate that the exercise-induced increase in HSP72 protein abundance is required for the protective effects of exercise against VIDD. Moreover, both rAAV-HSP72 and BGP-15-induced overexpression of HSP72 were sufficient to prevent VIDD. In addition, modification of HSP72 in the diaphragm is inversely related to the expression of NF-κB and FoxO target genes.

CONCLUSIONS

HSP72 overexpression in the diaphragm is an effective intervention to prevent MV-induced oxidative stress and the transcriptional activity of NF-κB and FoxO. Therefore, overexpression of HSP72 in the diaphragm is a potential therapeutic target to protect against VIDD.

Aerodigestive disorders in dogs evaluated for cough using respiratory fluoroscopy and videofluoroscopic swallow studies

Aerodigestive diseases, hybrid disorders representing a pathologic link between respiratory and alimentary tracts, may manifest with respiratory signs without gastrointestinal signs. These are underdiagnosed in dogs due to poor clinical recognition and diagnostic limitations. We hypothesize that a subset of dogs presenting for cough without gastrointestinal signs would have occult aerodigestive disorders identified using videofluoroscopic swallow study (VFSS). Data were retrospectively obtained from 31 client-owned dogs presenting for cough, with thoracic radiographs, and a VFSS between April 2015 and December 2017. Exclusion criteria were cough of cardiac origin or gastrointestinal signs within 6 months. Swallow study parameters included pharyngeal/esophageal motility, laryngeal obstruction/defects, penetration-aspiration, reflux, excessive aerophagia, megaesophagus (ME), lower-esophageal sphincter achalasia-like syndrome (LES-AS), and sliding hiatal hernia (HH). The median (interquartile range) duration of cough was 4 (2-8) months. Thoracic radiographs were unremarkable in 11 dogs, with aspiration pneumonia suspected in seven. In 25/31 dogs (81%), VFSS abnormalities were detected and some dogs had more than one defect: pharyngeal (n=10) or esophageal hypomotility (n=10), reflux (n=9), penetration-aspiration (n=8), excessive aerophagia (n=6), laryngeal obstruction (n=3), ME (n=3), HH (n=2), and LES-AS (n=1). A respiratory disorder causing cough was identified in 17 dogs with VFSS abnormalities (laryngeal obstruction/defect and airway disease including chronic or eosinophilic bronchitis, tracheal/mainstem bronchial collapse, bronchiectasis, and bronchomalacia). An alimentary disorder identified on VFSS in absence of a discrete respiratory disorder causing cough was diagnosed in eight dogs. In conclusion, canine aerodigestive disorders can manifest as cough without alimentary signs. VFSS is a useful diagnostic to determine the contribution of esophageal/gastrointestinal pathology in dogs with cough.

Thoracic Manifestations of Ankylosing Spondylitis, Inflammatory Bowel Disease, and Relapsing Polychondritis

Ankylosing spondylitis, inflammatory bowel disease (IBD), and relapsing polychondritis are immune-mediated inflammatory diseases with variable involvement of lungs, heart and the chest wall. Ankylosing spondylitis is associated with anterior chest wall pain, restrictive lung disease, obstructive sleep apnea, apical fibrosis, spontaneous pneumothorax, abnormalities of cardiac valves and conduction system, and aortitis. Patients with IBD can develop necrobiotic lung nodules that can be misdiagnosed as malignancy or infection. Relapsing polychondritis involves large airways in at least half of the patients. Relapsing polychondritis can mimic asthma in some patients. Medications used to treat these inflammatory conditions can cause pulmonary complications such as infections, pneumonitis, and rarely serositis.

Management of Fibrosing Interstitial Lung Diseases

A proportion of patients with interstitial lung diseases (ILDs), including the ILDs that are commonly associated with autoimmune diseases, develop a progressive fibrosing phenotype characterised by worsening of lung function, dyspnoea and quality of life, and early mortality. No drugs are approved for the treatment of ILDs other than idiopathic pulmonary fibrosis (IPF). At present, immunomodulatory medications are the mainstay of treatment for non-IPF ILDs. However, with the exception of systemic sclerosis-associated ILD, the evidence to suggest that immunosuppression may preserve lung function in patients with these ILDs comes only from retrospective, observational, or uncontrolled studies. In this article, we review the evidence for the treatments currently used to treat ILDs associated with autoimmune diseases and other ILDs and the ongoing trials of immunosuppressant and antifibrotic therapies in patients with these ILDs.Funding: Boehringer Ingelheim.

Pharmacological safety of Plinia cauliflora (Mart.) Kausel in rabbits

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Fruit peels of Plinia cauliflora are widely used in Brazilian traditional medicine.

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No studies have proved the safety of its pharmacological effects.

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We assessed the safety pharmacology of P. cauliflora extract (EEPC) in rabbits.

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EEPC did not cause any significant changes in several physiological systems.

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These data provide important safety data for its clinical use.

Fruit peels of Plinia cauliflora (Mart.) Kausel are widely used in Brazilian traditional medicine, but no studies have proved the safety of its pharmacological effects on the respiratory, cardiovascular, and central nervous systems. The present study assessed the safety pharmacology of P. cauliflora in New Zealand rabbits. First, an ethanol extract (EEPC) was selected for the pharmacological experiments and chemical characterization. Then, different groups of rabbits were orally treated with EEPC (200 and 2000 mg/kg) or vehicle. Acute behavioral and physiological alterations in the modified Irwin test, respiratory rate, arterial blood gas, and various cardiovascular parameters (i.e., heart rate, blood pressure, and electrocardiography) were evaluated. The main secondary metabolites that were identified in EEPC were ellagic acid, gallic acid, O-deoxyhexosyl quercetin, and the anthocyanin O-hexosyl cyanidin. No significant behavioral or physiological changes were observed in any of the groups. None of the doses of EEPC affected respiratory rate or arterial blood gas, with no changes on blood pressure or electrocardiographic parameters. The present study showed that EEPC did not cause any significant changes in respiratory, cardiovascular, or central nervous system function. These data provide scientific evidence of the effects of this species and important safety data for its clinical use.

Evaluating the Effects of Post-Intubation Endotracheal Suctioning Before Surgery on Respiratory Parameters in Children with Airway Secretion

Background

Endotracheal suctioning (ETS) is a common procedure in intubated patients for the clearance of secretions and improvement of oxygenation.

Objectives

Owing to the controversies in previous studies, we studied the effects of open ETS before surgery on respiratory parameters in children with pulmonary crackles.

Methods

In this clinical trial, 100 children with pulmonary crackles, candidates for surgery were randomly assigned into two groups. After intubation, in the group A (n = 50), deep and open suction was done until the crackle was cleared and in the group B (n = 50), anesthesia without suctioning was continued. Hemodynamic and respiratory parameters were compared.

Results

The patients in group A had higher oxygen saturation with a statistically significant difference in 15th to 75th minutes of the operation (P < 0.001) and in post-anesthetic care unit (P = 0.004). After suction, before and after extubation, there was a statistically significant reduction of crackles in the group A in comparison to the group B (P < 0.001). There was no statistically significant difference in the end-tidal CO₂, airway pressure and respiratory rate between the two groups (P > 0.05). Relevant complications and the emergence of anesthesia time were statistically lower in the group A (P < 0.001). There was no statistically significant change in terms of blood pressure in the two groups (P > 0.05). The heart rate in the 15th, 30th, and 45th minutes of surgery was statistically lower in the group B (P < 0.05).

Conclusions

This study indicates positive effects of open and deep suction in improving oxygen saturation and reducing complications and emergence time. Pulmonary auscultation of the group A before and after weaning was statistically better than group B. However, this study found no positive effect of ETS on airway pressure, ETCO₂, blood pressure, and respiratory rate. Meanwhile, increased heart rate in the group A might introduce the potential risk of dysrhythmia and hemodynamic instability.

A prospective multicentre study testing the diagnostic accuracy of an automated cough sound centred analytic system for the identification of common respiratory disorders in children

Background

The differential diagnosis of paediatric respiratory conditions is difficult and suboptimal. Existing diagnostic algorithms are associated with significant error rates, resulting in misdiagnoses, inappropriate use of antibiotics and unacceptable morbidity and mortality. Recent advances in acoustic engineering and artificial intelligence have shown promise in the identification of respiratory conditions based on sound analysis, reducing dependence on diagnostic support services and clinical expertise. We present the results of a diagnostic accuracy study for paediatric respiratory disease using an automated cough-sound analyser.

Methods

We recorded cough sounds in typical clinical environments and the first five coughs were used in analyses. Analyses were performed using cough data and up to five-symptom input derived from patient/parent-reported history. Comparison was made between the automated cough analyser diagnoses and consensus clinical diagnoses reached by a panel of paediatricians after review of hospital charts and all available investigations.

Results

A total of 585 subjects aged 29 days to 12 years were included for analysis. The Positive Percent and Negative Percent Agreement values between the automated analyser and the clinical reference were as follows: asthma (97, 91%); pneumonia (87, 85%); lower respiratory tract disease (83, 82%); croup (85, 82%); bronchiolitis (84, 81%). Conclusion: The results indicate that this technology has a role as a high-level diagnostic aid in the assessment of common childhood respiratory disorders.

Trial registration

Australian and New Zealand Clinical Trial Registry (retrospective) - ACTRN12618001521213: 11.09.2018.

The utility of point-of-care ultrasound right-sided cardiac markers as a screening test for moderate to severe pulmonary hypertension in dogs

Dogs with respiratory disease can develop pulmonary hypertension (PH), a comorbid condition that can impact therapy and prognosis. Without confirmation using the criterion standard of echocardiography, this complication may be missed. Point-of-care ultrasound (POCUS) is a simple, non-invasive screening test that may suggest PH. It was hypothesized that in dogs POCUS right-sided cardiac markers (R-SCM) at the subxiphoid view would predict moderate to severe PH confirmed by echocardiography. Forty-three client-owned dogs that underwent respiratory evaluation with POCUS and echocardiography were included. POCUS R-SCM evaluated in the subxiphoid view included subjective caudal vena cava distention (CVC_sx), CVC_sx >1cm, gallbladder wall edema and ascites. PH was defined by tricuspid regurgitation pressure gradient (TRPG) as mild (30-49.9mmHg), moderate (50-74.9mmHg) or severe (>75mmHg). POCUS subxiphoid views were blindly evaluated post hoc and compared to echocardiography. Chi square test and one-way ANOVA were used to evaluate correlations between POCUS R-SCM and echocardiographic diagnosis of moderate to severe PH. Twenty-six dogs with PH, and 17 dogs without PH, were enrolled. There was no significant difference in the presence or absence of any R-SCM between dogs with and without PH. When dogs with no PH and mild PH were grouped and compared to dogs with moderate to severe PH (i.e., dogs for which treatment for PH would be recommended), no significant differences in R-SCM were noted. POCUS R-SCM using the CVC_sx view was not a sensitive screening test to identify dogs with PH in this study population.

Preventive effects of ketone ester BD-AcAc2 on central nervous system oxygen toxicity and concomitant acute lung injury

BACKGROUND

Recent studies indicated that ketone ester R,S-1,3-butanediol acetoacetate diester (BD-AcAc₂) may be effective in preventing central nervous system oxygen toxicity (CNS-OT) and concomitant acute lung injury, a serious medical problem to be faced when breathing hyperbaric oxygen (HBO). This study aimed to further investigate the protective effects of BD-AcAc₂ against CNS-OT and concomitant acute lung injury (ALI) in mice.

METHODS

Mice were treated with BD-AcAc₂ in peanut oil vehicle (2.5, 5.0 or 10.0 g·kg⁻² body weight) by gavage 20 minutes before 600 kPa HBO exposure. Control mice received the vehicle only. Seizure latency was recorded. Malondialdehyde content in brain and lung tissues, total protein level in bronchoalveolar lavage fluid (BLF) and lung water content were measured 60 minutes after the hyperbaric exposure. Histopathology of lung tissue was undertaken.

RESULTS

Compared with the vehicle alone, BD-AcAc₂ prolonged seizure latency in a dose-dependent manner (P < 0.01). The HBO-induced increase in brain malondialdehyde, BLF protein and lung water were significantly reduced by BD-AcAc₂ (P < 0.01).

CONCLUSION

Oral administration of the ketone ester BD-AcAc₂ significantly protected against CNS-OT and concomitant ALI. Alleviation of oxidative stress may be one underlying mechanism providing this effect.

The impact of ambient particulate matter on hospital outpatient visits for respiratory and circulatory system disease in an urban Chinese population

There are limited evidence on the association between short-term exposure to ambient particulate matter (PM) and overall hospital outpatient visits for respiratory system disease (RESD) and cardio-cerebrovascular system disease (CCD) in high-polluted countries like China. Though previous epidemiological studies of RESD and CCD generally applied a linear relationship of the acute PM effects, it is unclear whether this linear exposure-response relationship holds in high pollution area. In this study, a time-series study during 2013 through 2016 was conducted to investigate 245,442 and 430,486 hospital visits for RESD and CCD respectively from Nanjing city, China. A combination of logistic generalized additive model (GAM) was used to evaluate the exposure-response associations. The results disclosed that a 10 μg/m³ increase in PM_2.5 and PM₁₀ concentration on the current day of exposure (lag 0) was associated with 0.36% (95% CI: -0.02%-0.73%) and 0.33% (0.07%-0.60%) increase in RESD; and 0.42% (0.00%-0.85%) and 0.37% (0.08%-0.67%) increase in CCD. The exposure-response association was approximately linear within 0-150 μg/m³ of PM concentration and non-linear across the full range of exposures. The effects of PM on RESD and CCD were sensitive to additional adjustment for co-pollutants, indicating the health effects of air pollution mixture in Nanjing city. There was no evidence of potential effect modification of RESD and CCD by season (cold and warm), age (5-64, 65-74, ≧75 years) and sex (male and female) groups. Though not statistically significant, the estimated risks in warm season were higher than those in cold season, suggesting potential synergistic effects of ambient PM pollution and temperature on triggering RESD and CCD.

Clinical efficacy of tadalafil compared to sildenafil in treatment of moderate to severe canine pulmonary hypertension: a pilot study

INTRODUCTION

Canine pulmonary hypertension (PH) is associated with high morbidity and mortality. Tadalafil, a phosphodiesterase-5 inhibitor used commonly in humans with PH, has not been evaluated in a clinical trial in dogs with naturally occurring PH. Our objectives were to compare the efficacy of tadalafil and sildenafil on PH assessed by peak tricuspid regurgitant flow velocity, estimated systolic pulmonary arterial pressure gradient, voluntary activity, quality of life, and safety profiles in dogs with moderate to severe PH.

ANIMALS

Twenty-three dogs with echocardiographic evidence of moderate to severe PH were enrolled.

METHODS

A prospective short-term, randomized, double-blinded pilot study was carried out. Dogs with PH were randomly allocated to receive sildenafil or tadalafil for 2 weeks and assessed via echocardiography, activity monitors, and owner-reported outcomes.

RESULTS

Collectively, phosphodiesterase-5 inhibition significantly decreased (improved) quality of life scores (p = 0.003) and visual analog score (p = 0.024) without significant between-treatment difference of these variables. Phosphodiesterase-5 inhibition did not significantly affect peak tricuspid regurgitant flow velocity (p = 0.056) or voluntary activity (p = 0.27). A total of 33% (7/21) of dogs experienced at least one adverse event during the study (tadalafil, n = 5; sildenafil, n = 2) with no significant difference between treatment type and incidence of adverse events (p = 0.36).

DISCUSSION

In this pilot study, phosphodiesterase-5 inhibition led to apparent improvement in quality of life scores without documenting superiority of tadalafil over sildenafil.

CONCLUSION

Tadalafil at a dose of 2 mg/kg once daily appears to be a viable alternative to sildenafil in dogs with moderate to severe PH.

Increased stress associated with head-out plethysmography testing can exacerbate respiratory effects and lead to mortality in rats

INTRODUCTION

DSM421, a dihydroorotate dehydrogenase inhibitor, was in preclinical development as a potential treatment option for malaria. When tested in a core battery of safety pharmacology assays, DSM421 did not produce any effects at oral doses up to 750 mg/kg in an Irwin test in rats, but a respiratory study in rats using head-out plethysmography resulted in substantial changes in respiratory function as well as moribundity and mortality at that and lower doses. An investigation was performed to determine the source of this discrepancy.

METHODS

Potential testing errors, differences in types of plethysmography testing chambers, effects on stress indicators, and off-target activity were investigated.

RESULTS

Respiratory changes and toxicity (resulting in euthanasia in extremis) were confirmed in a repeat, head-out plethysmography test, but the effects of DSM421 were much less severe overall when the rats were tested in whole-body chambers. Additionally, at the end of the 5-h post-dosing respiratory monitoring periods, levels of stress-related hormones (particularly corticosterone) were higher overall in the head-out, than in the whole-body, tested rats. Furthermore, DSM421 was found to produce changes in cardiovascular function in unrestrained rats, and it was shown to have off-target binding affinity at the adenosine A₃ receptor (which is associated with bronchoconstriction).

DISCUSSION

The generalized stress inherent to head-out plethysmography testing exacerbated the respiratory effects of DSM421 and was possibly compounded by DSM421's cardiovascular effects, thus artifactually resulting in moribundity and mortality in rats. Care should be taken when choosing whether to use head-out versus whole-body plethysmography chambers during respiratory function testing in animals.

Growth of Zika virus in human reconstituted respiratory, intestinal, vaginal and neural tissues

OBJECTIVES

Zika virus (ZIKV) is mostly mosquito borne but it can also be transmitted via the sexual route and persists in semen for a prolonged time. Moreover, viral RNA has been detected in breast milk, saliva, lacrimal fluids and urine, suggesting other possible transmission routes. The aim of our research is to better define ZIKV tropism.

METHODS

We investigated the tropism of Asian and African strains of ZIKV using human-derived neural, vaginal, intestinal and respiratory tissues.

RESULTS

Asian and African strains of ZIKV were able to grow in all tissues tested, although with different efficiency (7.3 log RNA copies released apically in vaginal tissues versus 9.8 log RNA copies released in intestinal tissues), without the need for major adaptation.

CONCLUSIONS

Our results underline that ZIKV tropism may be broader than expected in humans and stress the need to better explore all possible virus-shedding sites and transmission routes.

Respiratory frequency plasticity during development

Respiratory frequency plasticity is a long-lasting increase in breathing frequency due to a perturbation. Mechanisms underlying respiratory frequency are poorly understood, and there is little evidence of frequency plasticity in neonates. This hybrid review/research article discusses available literature regarding frequency plasticity and highlights potential research opportunities. Also, we include data demonstrating a model of frequency plasticity using isolated neonatal rat brainstem-spinal cord preparations. Specifically, substance P (SubP) application induced a long-lasting (>60 min) increase in spontaneous respiratory motor burst frequency, particularly in brainstem-spinal cords with the pons attached; there were no male/female differences. SubP-induced frequency plasticity is dependent on the application pattern, such that intermittent (rather than sustained) SubP applications induce more frequency plasticity. SubP-induced frequency plasticity was blocked by a neurokinin-1 receptor antagonist. Thus, the newborn rat respiratory control system has the capacity to express frequency plasticity. Identifying mechanisms that induce frequency plasticity may lead to novel methods to safely treat breathing disorders in premature and newborn infants.

Hebei Spirit oil spill and its long-term effect on children's asthma symptoms

On December 7th, 2007, an estimated 12,547 kL of crude oil was spilled from the collision of Hebei Spirit near residential area. Our previous study demonstrated worsening of children's asthma symptoms one year after the accident. This study investigated long-term effect of the oil spill on children's asthma symptoms up to five years after the accident. All elementary and middle school students in the exposure area were surveyed on one year (n = 655), three years (664), and five years (611) after the accident. Oil spill exposure was estimated using two estimates including distance from the oil spill (A) and modeled estimates of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds (B), and each was dichotomously categorized (A: high-exposure vs low-exposure; B: ≥20 mg/m³ vs < 20 mg/m³). Asthma symptoms were evaluated using a standard questionnaire. Oil spill exposure estimates were associated with asthma symptoms on one year (odds ratio (95% confidence interval) A: 1.9 (1.1-3.1); B: 1.6 (0.9-2.7)), three years (A: 1.9 (1.1-3.2); B: 1.3 (0.8-2.2)), and five years (A: 1.2 (0.7-1.9); B: 1.8 (1.1-2.8)) after the oil spill. Significant longitudinal relationship between oil spill exposure estimates and asthma symptoms was also observed (A: 1.6 (1.2-2.2); B: 1.6 (1.1-2.1)). Overall, the effect of oil spill exposure estimates was more severe on younger children. Oil spill exposure estimates were associated with asthma symptoms in children up to five years after the oil spill.

The disappearing Salton Sea: A critical reflection on the emerging environmental threat of disappearing saline lakes and potential impacts on children's health

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown dust and dust storms. In California, such factors are leading to the rapid shrinking of the Salton Sea, a 345 mile² land-locked "sea" situated near the southeastern rural border region known as the Imperial Valley. The region is anticipated to experience a dramatic increase in wind-blown dust and existing studies suggest a significant impact on the health and quality of life for nearby residents of this predominantly low-income, Mexican-American community. The discussion calls attention to the public health dimensions of the Salton Sea crisis. We know little about the possible long-term health effects of exposure to mobilized lakebed sediments or the numerous toxic contaminants that may become respirable on entrained particles. We draw on existing epidemiological literature of other known sources of wind-blown dust, such as desert dust storms, and related health effects to begin to understand the potential public health impact of wind-blown dust exposure. The increased production of wind-blown dust and environmental exposures to such non-combustion related sources of particulate matter are a growing health threat, due in part to drought coupled with increasing pressures on limited water resources. Recent population-based studies have linked dust storms with cardiovascular mortality, asthma hospitalization and decrease in pulmonary function in both adults and children. A growing number of studies provide evidence of the acute health effects of wind-blown dust exposures among children, which with repeated insults have the potential to influence respiratory health over time. The shrinking of the Salton Sea illustrates a public health and environmental justice crisis that requires action and attention to protect the health and well-being of local communities.