Phenotyping exercise limitation of patients with Interstitial Fibrosing Lung Disease: the importance of exercise hemodynamics

INTRODUCTION AND OBJECTIVE

Left-heart dysfunction and pulmonary vasculopathy are increasingly recognized as contributing factors of exercise capacity limitation in interstitial fibrosing lung disease (IFLD). Moreover, the clinical significance of exercise pulmonary hypertension (ePH) in pulmonary and cardiac diseases has been documented, representing a risk factor for decreased exercise capacity and survival, progression to resting pulmonary hypertension (PH) and overall clinical worsening. We conducted a prospective study aiming at: (a) assessing the prevalence of PH and ePH in a cohort of 40 functionally limited patients with IFLD, (b) determining the post-capillary (postC) or pre-capillary (preC) etiology of either PH or ePH in this cohort, and (c) examining the correlations between invasively and non-invasively measured exercise variables among hemodynamic groups.

PATIENTS AND METHODS

40 IFLD patients underwent cardiopulmonary evaluation, including: clinical examination, lung function tests, 6-minute walking test, heart ultrasonography, cardiopulmonary exercise test and, finally, right heart catheterization (RHC). Resting hemodynamic evaluation was followed by the exercise protocol proposed by Herve et al, using a bedside cycle ergometer in the supine position. Abnormal elevation of mean pulmonary artery pressure (mPAP) above 30mmHg during exercise, with respect to abnormal elevation of cardiac output (CO) below 10 L/min (mPAP-CO ratio ⩾3 mmHg·min·L-1) was used to define ePH (Herve et al, 2015). Secondary hemodynamic evaluation involved detection of abnormal pulmonary arterial wedge pressure (PAWP) increase at peak exercise in relation to CO. Specifically, ΔPAWP/ΔCO >2 mmHg/L per minute determined an abnormal PAWP elevation (Bentley et al, 2020).

RESULTS

Among the 40-patient cohort, 25% presented postC PH, 37.5% preC PH, 27.5% ePH, with the remaining 10% recording normal hemodynamics. PAWP evaluation during exercise revealed a postC etiology in 4 out of the 11 patients presenting ePH, and a postC etiology in 6 out of the 15 patients presenting resting preC PH. Mean values of non-invasive variables did not display statistically significant differences among hemodynamic groups, except for: diffusing capacity for carbon monoxide (DLCO), carbon monoxide transfer coefficient (KCO) and the ratio of functional vital capacity to DLCO (FVC%/DLCO%), which were lower in both ePH and PH groups (p < 0.05). Resting values of CO, cardiac index (CI), stroke volume (SV) and pulmonary vascular compliance (PVC) were significantly impaired in ePH, preC-PH and postC-PH groups when compared to the normal group.

CONCLUSIONS

Both PH and ePH were highly prevalent within the IFLD patient group, suggesting that RHC should be offered more frequently in functionally limited patients. Diffusion capacity markers must thus guide decision making, in parallel to clinical evaluation. ePH was associated to lower resting CO and PVC, in a similar way to resting PH, indicating the relevance of cardiopulmonary function to exercise limitation. Finally, the use of the ΔPAWP/ΔCO>2 criterion further uncovered PH of postcapillary etiology, highlighting the complexity of hemodynamics in IFLD.

CLINICALTRIALS

gov ID: NCT03706820.

Cyclodextrins for the Delivery of Bioactive Compounds from Natural Sources: Medicinal, Food and Cosmetics Applications

Cyclodextrins have gained significant and established attention as versatile carriers for the delivery of bioactive compounds derived from natural sources in various applications, including medicine, food and cosmetics. Their toroidal structure and hydrophobic cavity render them ideal candidates for encapsulating and solubilizing hydrophobic and poorly soluble compounds. Most medicinal, food and cosmetic ingredients share the challenges of hydrophobicity and degradation that can be effectively addressed by various cyclodextrin types. Though not new or novel-their first applications appeared in the market in the 1970s-their versatility has inspired numerous developments, either on the academic or industrial level. This review article provides an overview of the ever-growing applications of cyclodextrins in the delivery of bioactive compounds from natural sources and their potential application benefits.

Neuron-specific proteasome activation exerts cell non-autonomous protection against amyloid-beta (Aβ) proteotoxicity in Caenorhabditis elegans

Proteostasis reinforcement is a promising approach in the design of therapeutic interventions against proteinopathies, including Alzheimer's disease. Understanding how and which parts of the proteostasis network should be enhanced is crucial in developing efficient therapeutic strategies. The ability of specific tissues to induce proteostatic responses in distal ones (cell non-autonomous regulation of proteostasis) is attracting interest. Although the proteasome is a major protein degradation node, nothing is known on its cell non-autonomous regulation. We show that proteasome activation in the nervous system can enhance the proteasome activity in the muscle of Caenorhabditis elegans. Mechanistically, this communication depends on Small Clear Vesicles, with glutamate as one of the neurotransmitters required for the distal regulation. More importantly, we demonstrate that this cell non-autonomous proteasome activation is translated into efficient prevention of amyloid-beta (Αβ)-mediated proteotoxic effects in the muscle of C. elegans but notably not to resistance against oxidative stress. Our in vivo data establish a mechanistic link between neuronal proteasome reinforcement and decreased Aβ proteotoxicity in the muscle. The identified distal communication may have serious implications in the design of therapeutic strategies based on tissue-specific proteasome manipulation.

In-Plate and In-Gel Assays for the Assessment of Proteasome Activity in Caenorhabditis elegans

This chapter describes two methods for the study of proteasome function in Caenorhabditis elegans (C. elegans). The first method, referred to as "in-plate activities," provides a quantitative measurement of proteasome activities in C. elegans lysates by means of a kinetic reaction in a 96-well plate. The second one, referred to as "in-gel activities," involves the separation of C. elegans protein lysates in a native polyacrylamide gel and the assessment of the activity of each proteasome form. Downstream immunoblotting also allows the semi-quantitative assessment of proteasome assembly. This chapter outlines two detailed protocols along with helpful schematics and representative results that will facilitate researchers to replicate both protocols accurately and reproducibly.

Nursing errors in intensive care unit and their association with burnout, anxiety, insomnia and working environment: a cross-sectional study

BACKGROUND

In intensive care units (ICU), commonly identified nursing errors may have a negative impact on short- and long-term patient outcomes. Current data is scarce regarding nurses' burnout, insomnia, and anxiety impact on medication and several other types of nursing errors. This study aimed to record the commonness of various nursing errors, including checking patient data, medication preparation and administration, and infection control measures. It also aimed to investigate if "nurse-related" or "ICU-related" features may be associated with nursing error occurrence.

MATERIAL-METHODS

A sample of nurses employed in four Greek ICUs was evaluated using the self-completed Athens Insomnia Scale, the State-Trait Anxiety Inventory Form Y, and the Maslach Burnout Inventory. Moreover, we also recorded the sociodemographic characteristics of the ICU nurses, data regarding nursing errors and common practices, and variables regarding the working environment. We conducted a multinominal regression analysis to identify the variables independently associated with each error/mistake.

RESULTS

Ninety ICU nurses from the 99 addressed returned the completed questionnaires. The most frequent mistakes referred to drug preparation and administration, with 43.3 % of nurses reporting being "always/very often" distracted when preparing a drug and 90 % that "half of the times" they administer medication at unscheduled hours, followed in frequency by errors regarding the proper use of antiseptic solutions. Medication errors were independently predicted by state anxiety, satisfaction regarding training, emotional exhaustion score, number of ICU beds, and weekdays off work per month. In contrast, errors regarding infection control were independently associated with weekdays off work per month.

CONCLUSION

Medication errors are the commonest type of nursing error. Although several risk factors have been identified, no universal "nurse-related" or "ICU-related" factor can predict all types of errors. HIPPOKRATIA 2022, 26 (3):110-117.