Psychometric properties of Clinical Learning Environment Inventory and its association with Moroccan nursing students' satisfaction: A PLS-SEM approach

Background

The Clinical Learning Environment (CLE) is integral to pre-registration nursing curricula. Assessing the student's perceptions of their CLE is essential to adjust clinical placement to trainees' needs. Clinical Learning Environment Inventory (CLEI) appears to be widely used in measuring CLE, but no previous study has reported a full structural validity and its association with students' satisfaction in the Moroccan context.

Objectives

This study investigated the psychometric properties of the CLEI and its subscales association with Moroccan nursing students' satisfaction.

Methods

The research design was descriptive, cross-sectional, and conducted from March and June 2022 using convenience sampling in three nursing institutes of the Fez-Meknes region of Morocco. The selected sample involved Moroccan nursing students undertaking clinical practice. First, exploratory factor analysis (EFA) was used to determine the factor structure of the pilot sample (N = 143). The second sample (N = 206) was then used to confirm this structure using partial least squares structural equation modeling (PLS-SEM) confirmatory composite analysis (CCA). Finally, using a bootstrapping method, the significance of the structural path was evaluated.

Results

The CLEI scale depicted convergent validity (AVE = 0.56 - 0.71), discriminant validity, estimated by the square roots of AVE and bootstrapped HTMT confidence interval, and significant reliability (rhoC = 0.83 - 0.92). Using a bootstrapping approach, structural path significance displayed a substantial association between task orientation and students' satisfaction (β = 0.29, p <0.001). This ascertains that nurse students need well-planned guidelines from their facilitators in clinical wards.

Conclusions

The CLEI instrument revealed adequate psychometric properties and supported its original structure. As a result, the instrument might be used to measure students' perceptions of their CLE. Task orientation appeared to be the most important factor influencing the students' satisfaction in CLE.

Mercurial risk from dental amalgam use in a population of Moroccan dentists: A latent class regression approach

BACKGROUND

Dentists using dental amalgam are chronically exposed to low doses of elemental mercury. The complex toxico-kinetics of this systemic toxicant results in polymorphic and variable clinical phenotypes. In this context, adapted statistical methods are required to highlight potential adverse effects of occupational mercury exposure on dentists' health.

OBJECTIVE

The present study aims to analyze the distribution of self-reported subjective symptoms, commonly associated with chronic mercury poisoning, according to occupational mercury exposure in a population of Moroccan liberal dentists.

METHODS

In order to achieve the defined objectives, a three-step latent class regression was fitted. First a latent class analysis was performed to cluster the studied population according to their declared symptoms. Dentists were then classified in the defined latent classes based on their posterior probabilities. Finally, a logistic regression is fitted to identify predictors associated with the latent classes' membership.

RESULTS

The final obtained model showed acceptable calibration and discrimination. Its interpretation revealed that the increase of the frequency of amalgam use was associated with significant higher odds of belonging to the high risk latent class.

CONCLUSIONS

The present study represents an initial step towards the development of diagnosis model that predict clinical profiles according to occupational mercury exposure.

Preventive planning against mercury over-exposure among Moroccan dentists using multidimensional statistical methods

BACKGROUND: Mercury used in dental amalgams constitutes a significant source of chronic exposure to this heavy metal among dentists. Thus, the safety of dental amalgam remains a controversial issue despite its long history of use. In Morocco, most studies about dental mercury were mainly focused on the environmental risk related to the management of mercury-contaminated waste. OBJECTIVE: In order to evaluate the occupational exposure to mercury among liberal dentists practicing in two Moroccan regions, a multidimensional statistical approach was used to analyze the collected data. The main objective was to help establishing a targeted prevention plan aiming to reduce the mercury exposure among Moroccan dentists. METHODS: Fifteen variables from 146 dentists were elected for a three-step classification procedure: a multiple correspondence analysis followed by a hierarchical ascendant clustering consolidated by the k-Means algorithm. RESULTS: Three homogenous clusters were identified. The most important one includes 57.5% of the population as well as the majority of the risky factors. The characterization of these clusters allows proposing concise guidelines for a targeted preventive plan. CONCLUSIONS: A real mercurial risk has been observed in the studied population. However, its impact on health as well as the efficiency of simple preventive recommendations remains to be unveiled.

Modeling Subjective Symptoms Related to Micro-Hydrargyrism in a Population of Moroccan Dentists

Background

The ability of mercury to deposit throughout the body and alter a wide range of molecular and cellular pathways results in a polymorphic and complex clinical phenotype with over 250 possible symptoms. However, some of them are recurrently cited as evoking chronic mercury poisoning. In this light, dentists users of dental amalgams are chronically exposed to mercury so that in-depth epidemiological investigations and adapted statistical methods are required to highlight adverse effects of this exposure.

Methods

In order to study the health impact of the occupational mercury exposure in a population of liberal dentists practicing in two Moroccan regions, a list of eighteen subjective symptoms commonly associated with micro-hydrargyrism was drawn up. Then, seven statisctical models adapted to count data were fitted. Finally, three methods were used to compare their relative performance in order to choose the most appropriate one.

Results

The adopted logical path, from the response variable selection till models' comparison, led us to lean towards quasi-Poisson regression as the best way to predict the number of symptoms declared by dentists according to mercury exposure.

Conclusions

Interpretation of the selected model allowed us to conclude that the reduction of dental amalgam use allows the reduction of subjective symptoms related to mercury exposure.

Ajuga iva water extract antihypertensive effect on stroke-prone spontaneously hypertensive rats, vasorelaxant effects ex vivo and in vitro activity of fractions

ETHNOPHARMACOLOGICAL RELEVANCE

Ajuga iva (L.) Schreb. (Labiatae) (AI) is used in folk medicine for a variety of ailments, including diabetes mellitus and hypertension.

AIM OF THE STUDY

In this work, we aimed to investigate the antihypertensive and vasorelaxant effects of AI aqueous extract in stroke prone spontaneously hypertensive rats (SHR-SP).

MATERIAL AND METHODS

Male SHR-SP rats were orally force-fed AI aqueous extract (500 mg/kg body weight) daily for one week. Systolic blood pressure and urine output were recorded in vivo by non-invasive methods. AI vasoactive effects on noradrenaline contractile response and acetylcholine-evoked relaxation were assessed ex vivo on aorta rings of treated and untreated SHR-SP rats. AI extract was then subjected to bio-guided fractionation using solvents of increasing polarity. For each fraction, in vitro vasorelaxation assay was performed on noradrenaline-precontracted aorta of Wistar rats, in the absence/presence of N-nitro-L-arginine (L-NNA). HPLC analysis of AI total extract, and the most in vitro active AI residual aqueous extract fraction (A1) was performed using naringin, naringenin, apigenin, apigenin 7-O-glucoside as marker compounds.

RESULTS

AI aqueous extract (500 mg/kg) significantly (P < 0.05) decreased systolic blood pressure (SBP) in SHR-SP rats, while not affecting the urine output. In ex vivo experiments, the total extract decreased contractile response to noradrenaline of aortic rings isolated from AI-treated SHR-SP rats with or without addition of N-nitro-L-arginine, but endothelium dependent relaxation evoked by acetylcholine in noradrenaline-contracted aortic rings was not affected by the extract treatment. In vitro experiments on AI aqueous extract fractions showed that its polar fraction was the only one affecting in vitro noradrenaline induced contractions, but only in an endothelium dependent manner. This fraction was shown by HPLC-UV to contain flavonoid glycosides among other polar compounds whose activity and mode of action may be modified in vivo by metabolization.

CONCLUSION

These results support the use of AI as antihypertensive treatment in folk medicine. The systolic blood pressure decrease may be attributed at least in part to vasorelaxant glycosylated/polar phenolic compounds as flavonoids and/or their metabolites.

[Mercury exposure and dentists' health status in two regions of centrall Morocco: descriptive cross-sectional survey]

INTRODUCTION

mercury exposure is recognized as a worldwide public health concern. However, the effect of long-term exposure to low-doses of this heavy metal is still subject to debate. Due to the use of mercury in dental amalgam, dental health care professionals are chronically exposed to low-doses of this metal. In this context, we have conducted a descriptive cross-sectional survey among liberal dentists in two regions of the center of Morocco. In parallel, the global health status of participants was investigated to assess the relevance of a subsequent etiological survey.

METHODS

data were collected through a self-reported questionnaire. Occupational exposure of dentists to mercury was evaluated based on their use of dental amalgam. Moreover, the other common factors increasing the background pollution or inducing exposure peaks were also investigated. On the other hand, smoking, vaccination, fish consumption, and the number of dental amalgam in mouth were considered as non-occupational exposure sources. Finally, the self-reported global health problems of participants were collected.

RESULTS

192 dentists were included in the present study. Seventy-six percent (76.04%) of them declared using dental amalgam in their practice. Moreover, the presence of dental amalgam in mouth was identified as the main non-occupational source of exposure to mercury (63.45% of participants). Finally, most of participants (46.35%) have expressed neuropsychological complaints.

CONCLUSION

altogether, our results revealed a real mercury exposure in the studied population. Thus, effective preventive measures should be promoted to minimize the mercury exposure in dental offices. Moreover, an etiological study will be of great interest to reveal the impact of mercury exposure in this population.

Variants of Transient Receptor Potential Melastatin Member 4 in Childhood Atrioventricular Block

Background

Transient receptor potential melastatin member 4 (TRPM4) is a nonselective cation channel. TRPM4 mutations have been linked to cardiac conduction disease and Brugada syndrome. The mechanisms underlying TRPM4‐dependent conduction slowing are not fully understood. The aim of this study was to characterize TRPM4 genetic variants found in patients with congenital or childhood atrioventricular block.

Methods and Results

Ninety‐one patients with congenital or childhood atrioventricular block were screened for candidate genes. Five rare TRPM4 genetic variants were identified and investigated. The variants were expressed heterologously in HEK293 cells. Two of the variants, A432T and A432T/G582S, showed decreased expression of the protein at the cell membrane; inversely, the G582S variant showed increased expression. Further functional characterization of these variants using whole‐cell patch‐clamp configuration showed a loss of function and a gain of function, respectively. We hypothesized that the observed decrease in expression was caused by a folding and trafficking defect. This was supported by the observation that incubation of these variants at lower temperature partially rescued their expression and function. Previous studies have suggested that altered SUMOylation of TRPM4 may cause a gain of function; however, we did not find any evidence that supports SUMOylation as being directly involved for the gain‐of‐function variant.

Conclusions

This study underpins the role of TRPM4 in the cardiac conduction system. The loss‐of‐function variants A432T/G582S found in 2 unrelated patients with atrioventricular block are most likely caused by misfolding‐dependent altered trafficking. The ability to rescue this variant with lower temperature may provide a novel use of pharmacological chaperones in treatment strategies.

Targeted resequencing identifies TRPM4 as a major gene predisposing to progressive familial heart block type I

BACKGROUND

Progressive cardiac conduction disease (PCCD) is one of the most common cardiac conduction disturbances. It has been causally related to rare mutations in several genes including SCN5A, SCN1B, TRPM4, LMNA and GJA5.

METHODS AND RESULTS

In this study, by applying targeted next-generation sequencing (NGS) in 95 unrelated patients with PCCD, we have identified 13 rare variants in the TRPM4 gene, two of which are currently absent from public databases. This gene encodes a cardiac calcium-activated cationic channel which precise role and importance in cardiac conduction and disease is still debated. One novel variant, TRPM4-p.I376T, is carried by the proband of a large French 4-generation pedigree. Systematic familial screening showed that a total of 13 family members carry the mutation, including 10 out of the 11 tested affected individuals versus only 1 out of the 21 unaffected ones. Functional and biochemical analyses were performed using HEK293 cells, in whole-cell patch-clamp configuration and Western blotting. TRPM4-p.I376T results in an increased current density concomitant to an augmented TRPM4 channel expression at the cell surface.

CONCLUSIONS

This study is the first extensive NGS-based screening of TRPM4 coding variants in patients with PCCD. It reports the third largest pedigree diagnosed with isolated Progressive Familial Heart Block type I and confirms that this subtype of PCCD is caused by mutation-induced gain-of-expression and function of the TRPM4 ion channel.

Functional interaction between S1 and S4 segments in voltage-gated sodium channels revealed by human channelopathies

The p.I141V mutation of the voltage-gated sodium channel is associated with several clinical hyper-excitability phenotypes. To understand the structural bases of the p.I141V biophysical alterations, molecular dynamics simulations were performed. These simulations predicted that the p.I141V substitution induces the formation of a hydrogen bond between the Y168 residue of the S2 segment and the R225 residue of the S4 segment. We generated a p.I141V-Y168F double mutant for both the Na_v1.4 and Na_v1.5 channels. The double mutants demonstrated the abolition of the functional effects of the p.I141V mutation, consistent with the formation of a specific interaction between Y168-S2 and R225-S4. The single p.Y168F mutation, however, positively shifted the activation curve, suggesting a compensatory role of these residues on the stability of the voltage-sensing domain.

Force-controlled patch clamp of beating cardiac cells

From its invention in the 1970s, the patch clamp technique is the gold standard in electrophysiology research and drug screening because it is the only tool enabling accurate investigation of voltage-gated ion channels, which are responsible for action potentials. Because of its key role in drug screening, innovation efforts are being made to reduce its complexity toward more automated systems. While some of these new approaches are being adopted in pharmaceutical companies, conventional patch-clamp remains unmatched in fundamental research due to its versatility. Here, we merged the patch clamp and atomic force microscope (AFM) techniques, thus equipping the patch-clamp with the sensitive AFM force control. This was possible using the FluidFM, a force-controlled nanopipette based on microchanneled AFM cantilevers. First, the compatibility of the system with patch-clamp electronics and its ability to record the activity of voltage-gated ion channels in whole-cell configuration was demonstrated with sodium (NaV1.5) channels. Second, we showed the feasibility of simultaneous recording of membrane current and force development during contraction of isolated cardiomyocytes. Force feedback allowed for a gentle and stable contact between AFM tip and cell membrane enabling serial patch clamping and injection without apparent cell damage.

Cellular hyper-excitability caused by mutations that alter the activation process of voltage-gated sodium channels

Voltage-gated sodium channels (Na_v) are widely expressed as macro-molecular complexes in both excitable and non-excitable tissues. In excitable tissues, the upstroke of the action potential is the result of the passage of a large and rapid influx of sodium ions through these channels. Na_V dysfunction has been associated with an increasingly wide range of neurological, muscular and cardiac disorders. The purpose of this review is to summarize the recently identified sodium channel mutations that are linked to hyper-excitability phenotypes and associated with the alteration of the activation process of voltage gated sodium channels. Indeed, several clinical manifestations that demonstrate an alteration of tissue excitability were recently shown to be strongly associated with the presence of mutations that affect the activation process of the Na_v. These emerging genotype-phenotype correlations have expanded the clinical spectrum of sodium channelopathies to include disorders which feature a hyper-excitability phenotype that may or may not be associated with a cardiomyopathy. The p.I141V mutation in SCN4A and SCN5A, as well as its homologous p.I136V mutation in SCN9A, are interesting examples of mutations that have been linked to inherited hyperexcitability myotonia, exercise-induced polymorphic ventricular arrhythmias and erythromelalgia, respectively. Regardless of which sodium channel isoform is investigated, the substitution of the isoleucine to valine in the locus 141 induces similar modifications in the biophysical properties of the Na_v by shifting the voltage-dependence of steady state activation toward more negative potentials.

Complex genetic background in a large family with Brugada syndrome

The Brugada syndrome (BrS) is an inherited arrhythmia characterized by ST-segment elevation in V1-V3 leads and negative T wave on standard ECG. BrS patients are at risk of sudden cardiac death (SCD) due to ventricular tachyarrhythmia. At least 17 genes have been proposed to be linked to BrS, although recent findings suggested a polygenic background. Mutations in SCN5A, the gene coding for the cardiac sodium channel Nav1.5, have been found in 15-30% of index cases. Here, we present the results of clinical, genetic, and expression studies of a large Iranian family with BrS carrying a novel genetic variant (p.P1506S) in SCN5A. By performing whole-cell patch-clamp experiments using HEK293 cells expressing wild-type (WT) or p.P1506S Nav1.5 channels, hyperpolarizing shift of the availability curve, depolarizing shift of the activation curve, and hastening of the fast inactivation process were observed. These mutant-induced alterations lead to a loss of function of Nav1.5 and thus suggest that the p.P1506S variant is pathogenic. In addition, cascade familial screening found a family member with BrS who did not carry the p.P1506S mutation. Additional next generation sequencing analyses revealed the p.R25W mutation in KCNH2 gene in SCN5A-negative BrS patients. These findings illustrate the complex genetic background of BrS found in this family and the possible pathogenic role of a new SCN5A genetic variant.