Heightened long-term cardiovascular risks after exacerbation of chronic obstructive pulmonary disease

OBJECTIVE

To examine the risk of adverse cardiovascular (CV) events following an exacerbation of chronic obstructive pulmonary disease (COPD).

METHODS

This retrospective cohort study identified patients with COPD using administrative data from Alberta, Canada from 2014 to 2019. Exposure periods were 12 months following moderate or severe exacerbations; the reference period was time preceding a first exacerbation. The primary outcome was the composite of all-cause death or a first hospitalisation for acute coronary syndrome, heart failure (HF), arrhythmia or cerebral ischaemia. Time-dependent Cox regression models estimated covariate-adjusted risks associated with six exposure subperiods following exacerbation.

RESULTS

Among 1 42 787 patients (mean age 68.1 years and 51.7% men) 61 981 (43.4%) experienced at least one exacerbation and 34 068 (23.9%) died during median follow-up of 64 months. The primary outcome occurred in 43 564 (30.5%) patients with an incidence rate prior to exacerbation of 5.43 (95% CI 5.36 to 5.50) per 100 person-years. This increased to 95.61 per 100 person-years in the 1-7 days postexacerbation (adjusted HR 15.86, 95% CI 15.17 to 16.58) and remained increased for up to 1 year. The risk of both the composite and individual CV events was increased following either a moderate or a severe exacerbation, though greater and more prolonged following severe exacerbation. The highest magnitude of increased risk was observed for HF decompensation (1-7 days, HR 72.34, 95% CI 64.43 to 81.22).

CONCLUSION

Moderate and severe COPD exacerbations are independent risk factors for adverse CV events, especially HF decompensation. The impact of optimising COPD management on CV outcomes should be evaluated.

Asthma-related emergency admissions and associated healthcare resource use in Alberta, Canada

BACKGROUND

There is a lack of real-world research assessing asthma management following asthma-related emergency department (ED) discharges. The objective of this study was to characterise follow-up care, healthcare resource use (HCRU) and medical costs following ED admissions in Alberta, Canada.

METHODS

A retrospective cohort study was conducted on adults with asthma using longitudinal population-based administrative data from Alberta Health Services. Adult patients with asthma and ≥1 ED admission from 1 April 2015 to 31 March 2020 were included. ED admissions, outpatient visits, hospitalisations and asthma-specific medication use were measured in the 30 days before and up to 90 days after each asthma-related ED admission. Mean medical costs attributable to each type of HCRU were summarised. All outcomes were stratified by patient baseline disease severity.

RESULTS

Among 128 063 patients incurring a total of 20 142 asthma-related ED visits, a substantial rate of ED readmission was observed, with 10% resulting in readmissions within 7 days and 35% within 90 days. Rates increased with baseline asthma severity. Despite recommendations for patients to be followed up with an outpatient visit within 2-7 days of ED discharge, only 6% were followed up within 7 days. The mean total medical cost per patient was $C8143 in the 30 days prior to and $C5407 in the 30 days after an ED admission.

CONCLUSIONS

Despite recommendations regarding follow-up care for patients after asthma-related ED admissions, there are still low rates of outpatient follow-up visits and high ED readmission rates. New or improved multidimensional approaches must be integrated into follow-up care to optimise asthma control and prevent readmissions.

SABA use as an indicator for asthma exacerbation risk: an observational cohort study (SABINA Canada)

Background

Patients with asthma use short-acting β-agonists (SABA) to relieve symptoms but SABA alone does not treat underlying inflammation. Thus, over-reliance on SABA may result in poor asthma control and negative health outcomes.

Objective

To describe use of SABA and characterise the relationship with severe exacerbations in the Canadian provinces of Nova Scotia (NS) and Alberta (AB).

Methods

In this longitudinal Canadian SABA In Asthma (SABINA) study, patients with an asthma diagnosis were identified between 2016 and 2020 within two provincial administrative datasets (Health Data Nova Scotia and Alberta Health Services). All patients were followed for ≥24 months, with the first 12 months used to measure baseline asthma severity. Medication use and the relationship of SABA overuse (three or more canisters per year) with severe asthma exacerbations were characterised descriptively and via regression analysis.

Results

A total of 115 478 patients were identified (NS: n=8034; AB: n=107 444). SABA overuse was substantial across both provinces (NS: 39.4%; AB: 28.0%) and across all baseline disease severity categories. Patients in NS with SABA overuse had a mean±sd annual rate of 0.46±1.11 exacerbations, compared to 0.30±1.36 for those using fewer than three canisters of SABA. Patients in AB had mean±sd exacerbation rates of 0.31±0.86 and 0.17±0.62, respectively. The adjusted risk of severe exacerbation was associated with SABA overuse (NS: incidence ratio rate 1.36, 95% CI 1.18–1.56; AB: incidence ratio rate 1.32, 95% CI 1.27–1.38).

Conclusion

This study supports recent updates to Canadian Thoracic Society and Global Initiative for Asthma guidelines for asthma care. SABA overuse is associated with increased risk of severe exacerbations and can be used to identify patients at a higher risk for severe exacerbations.

This longitudinal study supports the recent updates to the CTS and GINA guidelines for asthma care. SABA utilisation can be used to identify patients at higher risk of severe exacerbation, regardless of disease severity.https://bit.ly/3Nd3USz

Lymphocyte subsets in the small intestine of piglets fed with probiotic and zinc: a qualitative and quantitative micro-anatomical study

BACKGROUND

Piglet mortality is a real concern to the pig farmers. The major cause is due to the late maturation of the immune system and dietary changes in post-weaned piglets. The potential role of probiotic and zinc in the stimulation of the immune system is well established. Hence, the present study was undertaken to evaluate alterations of T and B cells in the small intestine after dietary inclusion of probiotic and zinc in pre and post-weaned piglets.

MATERIALS AND METHODS

A total of 18 healthy LWY piglets, irrespective of sex obtained from 3 litters at the age-group of 20, 30 and 60 days. They were divided into a control group fed with basal diet and a treatment group fed with probiotic and zinc supplement along with the basal diet, consisting of three animals in each group. The piglets were weaned at 28 days of age. After sacrificing the animals at day 20, 30 and 60 from both the groups, the abdominal cavity was opened and small intestinal tissue samples were collected, processed and stained by indirect immunofluorescence technique. The slides were evaluated under the fluorescent light microscope. The data were statistically analyzed.

RESULTS

The different T and B cell subsets were recorded in the lining epithelium, core of villus, crypt area of LP and PP area. The number of CD4+, CD8+, IgA+ and IgM+ cells was higher in the treated piglets than the control group of animals, irrespective of segments of intestine and age-group.

CONCLUSIONS

It can be concluded that the dietary supplementation of probiotic and zinc was found to be good additives as they can stimulate the immune response in piglets, especially during the critical early post-weaning period.

Small intestinal mucosal cells in piglets fed with probiotic and zinc: a qualitative and quantitative microanatomical study

BACKGROUND

Probiotics and zinc are commonly used and beneficial in pig production. This work aimed to assess the effects of probiotic and zinc on the mucosal cells of the small intestine in respect to digestive capacity and immunity in pre- and post-weaned piglets.

MATERIALS AND METHODS

Eighteen Large White Yorkshire piglets were divided equally into control and treatment groups. The piglets were maintained in standard management conditions and were weaned at 28 days of age. The treatment group of piglets fed a mixture of probiotics orally at 1.25 × 109 CFU/day and zinc at 2000 ppm/day from birth to 10 days of age. At three different age-groups viz. day 20 (pre-weaning) and, day 30 and day 60 (post-weaning), the animals were sacrificed. For histomorphology, the tissue samples were processed and stained with Mayer's haematoxylin and eosin for routine study, combined periodic acid-Schiff-Alcian blue for mucopolysaccharides and Masson-Hamperl argentaffin technique for argentaffin cells. The stained slides were observed under the microscope. The samples were processed as per the standard procedure for scanning and transmission electron microscopy. The statistical analysis of the data using the appropriate statistical tests was also conducted.

RESULTS

The mucosal epithelium of villi and crypts were lined by enterocytes, goblet cells, argentaffin cells, microfold (M-cell) cells, tuft cells and intraepithelial lymphocytes. The multipotent stem cells were located at the crypt base. The length of the enterocyte microvilli was significantly longer (p < 0.05) in the treatment group of piglets. The number of different types of goblet cells and argentaffin cells was more in treated piglets irrespective of segments of intestine and age. The intraepithelial lymphocytes were located in apical, nuclear and basal positions in the lining epithelium of both villus tip and base with their significant increase in the treatment group of piglets. The transmission electron microscopy revealed the frequent occurrence of tuft cells in the lining mucosa of the small intestine in treated piglets.

CONCLUSIONS

Dietary supplementation of probiotic and zinc induced the number of different mucosal cells of villi and crypts in the small intestine that might suggest the greater absorptive capacity of nutrients and effective immunity in critical pre and post-weaned piglets.

Pharmacological targeting of MYC-regulated IRE1/XBP1 pathway suppresses MYC-driven breast cancer

The unfolded protein response (UPR) is a cellular homeostatic mechanism that is activated in many human cancers and plays pivotal roles in tumor progression and therapy resistance. However, the molecular mechanisms for UPR activation and regulation in cancer cells remain elusive. Here, we show that oncogenic MYC regulates the inositol-requiring enzyme 1 (IRE1)/X-box binding protein 1 (XBP1) branch of the UPR in breast cancer via multiple mechanisms. We found that MYC directly controls IRE1 transcription by binding to its promoter and enhancer. Furthermore, MYC forms a transcriptional complex with XBP1, a target of IRE1, and enhances its transcriptional activity. Importantly, we demonstrate that XBP1 is a synthetic lethal partner of MYC. Silencing of XBP1 selectively blocked the growth of MYC-hyperactivated cells. Pharmacological inhibition of IRE1 RNase activity with small molecule inhibitor 8866 selectively restrained the MYC-overexpressing tumor growth in vivo in a cohort of preclinical patient-derived xenograft models and genetically engineered mouse models. Strikingly, 8866 substantially enhanced the efficacy of docetaxel chemotherapy, resulting in rapid regression of MYC-overexpressing tumors. Collectively, these data establish the synthetic lethal interaction of the IRE1/XBP1 pathway with MYC hyperactivation and provide a potential therapy for MYC-driven human breast cancers.

Dimeric structure of pseudokinase RNase L bound to 2-5A reveals a basis for interferon-induced antiviral activity

RNase L is an ankyrin repeat domain-containing dual endoribonuclease-pseudokinase that is activated by unusual 2,′5′-oligoadenylate (2-5A) second messengers and which impedes viral infections in higher vertebrates. Despite its importance in interferon-regulated antiviral innate immunity, relatively little is known about its precise mechanism of action. Here we present a functional characterization of 2.5 Å and 3.25 Å X-ray crystal and small-angle X-ray scattering structures of RNase L bound to a natural 2-5A activator with and without ADP or the nonhydrolysable ATP mimetic AMP-PNP. These studies reveal how recognition of 2-5A through interactions with the ankyrin repeat domain and the pseudokinase domain, together with nucleotide binding, imposes a rigid intertwined dimer configuration that is essential for RNase catalytic and antiviral functions. The involvement of the pseudokinase domain of RNase L in 2-5A sensing, nucleotide binding, dimerization, and ribonuclease functions highlights the evolutionary adaptability of the eukaryotic protein kinase fold.

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Structural basis for RNase L regulation by 2-5A and nucleotide (ADP or ATP) binding

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Recognition of 2-5A is mediated by both ankyrin repeat and protein kinase domains

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Nucleotide enforces a closed conformation of the kinase domain

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Nucleotide binding to the pseudokinase domain is essential for RNA cleavage function