Preceptor Perceptions of Pharmacy Student Performance Before and After a Curriculum Transformation.

Objective. To explore preceptors' perceptions about the performance of undergraduate pharmacy students during experiential placements in Australia, before and after curricular transformation.Methods. Using a semi-structured approach, we interviewed 26 preceptors who had recently supervised students who took part in the transformed curriculum and students from the previous curriculum. A directed content analysis approach was used to analyze the transcripts.Results. Preceptors described students from the transformed curriculum as having improved professional skills, behaviors, and attitudes and as having an increased ability to perform clinical activities compared to students of the previous curriculum. Preceptors also perceived that students in the transformed curriculum had improved clinical knowledge and knowledge application. They less frequently expressed that students in the transformed curriculum had lower-than-expected knowledge levels.Conclusion. The results of this study suggest that curricular transformation with a focus on skill-based and active learning can improve the performance of pharmacy students in terms of their professional behaviors and attitudes, skills, knowledge, and clinical abilities, as perceived by preceptors.

Circulating microRNAs in heart failure with reduced and preserved left ventricular ejection fraction.

AIM: The potential diagnostic utility of circulating microRNAs in heart failure (HF) or in distinguishing HF with reduced vs. preserved left ventricular ejection fraction (HFREF and HFPEF, respectively) is unclear. We sought to identify microRNAs suitable for diagnosis of HF and for distinguishing both HFREF and HFPEF from non-HF controls and HFREF from HFPEF. METHODS AND RESULTS: MicroRNA profiling performed on whole blood and corresponding plasma samples of 28 controls, 39 HFREF and 19 HFPEF identified 344 microRNAs to be dysregulated among the three groups. Further analysis using an independent cohort of 30 controls, 30 HFREF and 30 HFPEF, presented 12 microRNAs with diagnostic potential for one or both HF phenotypes. Of these, miR-1233, -183-3p, -190a, -193b-3p, -193b-5p, -211-5p, -494, and -671-5p distinguished HF from controls. Altered levels of miR-125a-5p, -183-3p, -193b-3p, -211-5p, -494, -638, and -671-5p were found in HFREF while levels of miR-1233, -183-3p, -190a, -193b-3p, -193b-5p, and -545-5p distinguished HFPEF from controls. Four microRNAs (miR-125a-5p, -190a, -550a-5p, and -638) distinguished HFREF from HFPEF. Selective microRNA panels showed stronger discriminative power than N-terminal pro-brain natriuretic peptide (NT-proBNP). In addition, individual or multiple microRNAs used in combination with NT-proBNP increased NT-proBNP's discriminative performance, achieving perfect intergroup distinction. Pathway analysis revealed that the altered microRNAs expression was associated with several mechanisms of potential significance in HF. CONCLUSIONS: We report specific microRNAs as potential biomarkers in distinguishing HF from non-HF controls and in differentiating between HFREF and HFPEF.

Circulating microRNAs as biomarkers of acute stroke.

MicroRNAs have been identified as key regulators of gene expression and thus their potential in disease diagnostics, prognosis and therapy is being actively pursued. Deregulation of microRNAs in cerebral pathogenesis has been reported to a limited extent in both animal models and human. Due to the complexity of the pathology, identifying stroke specific microRNAs has been a challenge. This study shows that microRNA profiles reflect not only the temporal progression of stroke but also the specific etiologies. A panel of 32 microRNAs, which could differentiate stroke etiologies during acute phase was identified and verified using a customized TaqMan Low Density Array (TLDA). Furthermore we also found 5 microRNAs, miR-125b-2*, -27a*, -422a, -488 and -627 to be consistently altered in acute stroke irrespective of age or severity or confounding metabolic complications. Differential expression of these 5 microRNAs was also observed in rat stroke models. Hence, their specificity to the stroke pathology emphasizes the possibility of developing these microRNAs into accurate and useful tools for diagnosis of stroke.

microRNAs Involved in Regulating Spontaneous Recovery in Embolic Stroke Model.

To date, miRNA expression studies on cerebral ischemia in both human and animal models have focused mainly on acute phase of ischemic stroke. In this study, we present the roles played by microRNAs in the spontaneous recovery phases in cerebral ischemia using rodent stroke models. Brain tissues were harvested at different reperfusion time points ranging from 0-168 hrs after middle cerebral artery occlusion using homologous emboli. MiRNA and mRNA expression profiles were investigated by microarray followed by multiple statistical analysis. Candidate transcripts were also validated by quantitative RT-PCR. Three specific groups of miRNAs were observed among a total of 346 differentially expressed miRNAs. miRNAs, miR-21, -142-3p, -142-5p, and -146a displayed significant upregulation during stroke recovery (48 hrs to 168 hrs) compared with those during acute phases (0 hrs to 24 hrs). On the other hand, an opposite trend was observed in the expression of miR-196a/b/c, -224 and -324-3p. Interestingly, miR-206, -290, -291a-5p and -30c-1*, positively correlated with the infarct sizes, with an initial increase up to 24hrs followed by a gradual decrease from 48 hrs to 168 hrs (R = 0.95). Taken together with the expression levels of corresponding mRNA targets, we have also found that Hedgehog, Notch, Wnt and TGF-ß signaling pathways could play significant roles in stroke recovery and especially in neuronal repair.

Non-Coding RNAs as Potential Neuroprotectants against Ischemic Brain Injury.

Over the past decade, scientific discoveries have highlighted new roles for a unique class of non-coding RNAs. Transcribed from the genome, these non-coding RNAs have been implicated in determining the biological complexity seen in mammals by acting as transcriptional and translational regulators. Non-coding RNAs, which can be sub-classified into long non-coding RNAs, microRNAs, PIWI-interacting RNAs and several others, are widely expressed in the nervous system with roles in neurogenesis, development and maintenance of the neuronal phenotype. Perturbations of these non-coding transcripts have been observed in ischemic preconditioning as well as ischemic brain injury with characterization of the mechanisms by which they confer toxicity. Their dysregulation may also confer pathogenic conditions in neurovascular diseases. A better understanding of their expression patterns and functions has uncovered the potential use of these riboregulators as neuroprotectants to antagonize the detrimental molecular events taking place upon ischemic-reperfusion injury. In this review, we discuss the various roles of non-coding RNAs in brain development and their mechanisms of gene regulation in relation to ischemic brain injury. We will also address the future directions and open questions for identifying promising non-coding RNAs that could eventually serve as potential neuroprotectants against ischemic brain injury.

MicroRNA 320a functions as a novel endogenous modulator of aquaporins 1 and 4 as well as a potential therapeutic target in cerebral ischemia.

Aquaporins facilitate efficient diffusion of water across cellular membranes, and water homeostasis is critically important in conditions such as cerebral edema. Changes in aquaporin 1 and 4 expression in the brain are associated with cerebral edema, and the lack of water channel modulators is often highlighted. Here we present evidence of an endogenous modulator of aquaporin 1 and 4. We identify miR-320a as a potential modulator of aquaporin 1 and 4 and explore the possibility of using miR-320a to alter the expression of aquaporin 1 and 4 in normal and ischemic conditions. We show that precursor miR-320a can function as an inhibitor, whereas anti-miR-320a can act as an activator of aquaporin 1 and 4 expressions. We have also shown that anti-miR-320a could bring about a reduction of infarct volume in cerebral ischemia with a concomitant increase in aquaporins 1 and 4 mRNA and protein expression.

MicroRNAs in Cerebral Ischemia.

Pathogenesis of cerebral ischemia has so far been described in the context of proteins and the pathways that they regulate. The discovery of biomarkers has also been focussed mainly on proteins and to some extent on the mRNAs that encode them. The knowledge on the role of microRNAs in understanding the pathogenesis of cerebral ischemia is still at its infancy. In this study, using rat models subjected to middle cerebral artery occlusion, we have profiled the microRNAs at different reperfusion times (0 to 48 h) to understand the progression of cerebral ischemia. We have also attempted to correlate the expression of microRNAs to treatment with an NMDA antagonist (MK801) and to protein expression with the hope of demonstrating the potential use of microRNAs as early biomarkers of stroke.

Expression profile of MicroRNAs in young stroke patients.

BACKGROUND: The methods currently available for diagnosis and prognosis of cerebral ischaemia still require further improvements. Micro-RNAs (small non-coding RNAs) have been recently reported as useful biomarkers in diseases such as cancer and diabetes. We therefore carried out microRNA (miRNA) profiling from peripheral blood to detect and identify characteristic patterns in ischaemic stroke. METHODS/PRINCIPAL FINDINGS: The ischaemic stroke patients aged between 18-49 years, characterized based on World Health Organization clinical criteria were further classified according to TOAST classification, a) Large-vessel atherosclerosis [n=8] b) Small-vessel disease [n=3] c) Cardioembolism [n=5] d) Undetermined cause [n=3]. The patients' functional status at the time of blood sampling (at the outpatient clinics) was evaluated with the modified Rankin Scale (mRS). Blood samples from normal (n=5) individuals were used as controls. Total RNA extracted from whole blood was subjected to miroRNA profiling and real-time PCR analysis. miRNAs that are implicated in the endothelial/vascular function, erythropoiesis, angiogenesis and neural function showed differential expression profile as compared to the normal control. Interestingly, miRNAs that are involved in hypoxic conditions have also been found in our miRNA profiles. CONCLUSION: We demonstrate that the peripheral blood miRNAs and their profiles can be developed as biomarkers in diagnosis and prognosis of cerebral ischaemic stroke. The dysregulated miRNAs have been detectable even after several months from the onset of stroke in what is usually regarded as neurologically stable patients.

MicroRNA expression in the blood and brain of rats subjected to transient focal ischemia by middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: Several hundred small RNAs called microRNAs (miRNAs) have been identified and characterized from various organisms, including humans. In humans, some of these miRNAs have been found to regulate (patho)physiologic conditions such as tumor progression/regression, cholesterol and glucose homeostasis, etc. In this report, we present data on the miRNAs expressed under ischemic conditions in both the brain and blood of rats subjected to middle cerebral artery occlusion (MCAo). METHODS: Sprague-Dawley rats subjected to MCAo were reperfused for either 24 or 48 hours, and both blood and brain samples were harvested. miRNA expression profiling and oligonucleotide microarray were carried out, and the data were validated by quantitative real-time polymerase chain reaction and correlated with published data on protein and gene expression in MCAo rats. RESULTS: We report here for the first time the involvement of miRNA regulation in brain pathogenesis associated with MCAo. Comparison with the corresponding DNA microarray data revealed that the target mRNA expression is correlated with the regulation of miRNA. We have also provided evidence that some of the miRNAs that are highly expressed in the ischemic brain can be detected in blood samples. CONCLUSIONS: Further studies are needed to evaluate the possible use of miRNAs as biomarkers in stroke and related pathologies.