Cu(ATSM) Increases P-Glycoprotein Expression and Function at the Blood-Brain Barrier in C57BL6/J Mice.

P-glycoprotein (P-gp), expressed at the blood-brain barrier (BBB), is critical in preventing brain access to substrate drugs and effluxing amyloid beta (Aß), a contributor to Alzheimer's disease (AD). Strategies to regulate P-gp expression therefore may impact central nervous system (CNS) drug delivery and brain Aß levels. As we have demonstrated that the copper complex copper diacetyl bis(4-methyl-3-thiosemicarbazone) (Cu(ATSM)) increases P-gp expression and function in human brain endothelial cells, the present study assessed the impact of Cu(ATSM) on expression and function of P-gp in mouse brain endothelial cells (mBECs) and capillaries in vivo, as well as in peripheral organs. Isolated mBECs treated with Cu(ATSM) (100 nM for 24 h) exhibited a 1.6-fold increase in P-gp expression and a 20% reduction in accumulation of the P-gp substrate rhodamine 123. Oral administration of Cu(ATSM) (30 mg/kg/day) for 28 days led to a 1.5 & 1.3-fold increase in brain microvascular and hepatic expression of P-gp, respectively, and a 20% reduction in BBB transport of [3H]-digoxin. A metallomic analysis showed a 3.5 and 19.9-fold increase in Cu levels in brain microvessels and livers of Cu(ATSM)-treated mice. Our findings demonstrate that Cu(ATSM) increases P-gp expression and function at the BBB in vivo, with implications for CNS drug delivery and clearance of Aß in AD.

Fatty Acid-Binding Protein 4 is Essential for the Inflammatory and Metabolic Response of Microglia to Lipopolysaccharide.

Prolonged activation of microglia leads to excessive release of proinflammatory mediators, which are detrimental to brain health. Therefore, there are significant efforts to identify pathways mediating microglial activation. Recent studies have demonstrated that fatty acid-binding protein 4 (FABP4), a lipid binding protein, is a critical player in macrophage-mediated inflammation. Given that we have previously identified FABP4 in microglia, the aim of this study was to assess whether FABP4 activity contributed to inflammation, metabolism and immune function (i.e. immunometabolism) in immortalised mouse microglia (BV-2 cells) using the proinflammatory stimulus lipopolysaccharide (LPS) to induce general microglial activation. Microglial FABP4 expression was significantly increased following exposure to LPS, an outcome associated with a significant increase in microglial proliferation rate. LPS-stimulated BV-2 microglia demonstrated a significant increase in the production of reactive oxygen species (ROS) and tumour necrosis factor-alpha (TNF-α), phosphorylation of c-Jun N-terminal kinase (JNK), increased expression of Toll-like receptor 4 (TLR4), and reduced expression of uncoupling protein 2 (UCP2), all of which were reversed following FABP4 genetic silencing and chemical inhibition with BMS309403. The oxidation rate of 3H-oleic acid and microglial uptake of 3H-2-deoxy-D-glucose were modulated with LPS activation, processes which were restored with genetic and chemical inhibition of FABP4. This is the first study to report on the critical role of FABP4 in mediating the deleterious effects of LPS on microglial immunometabolism, suggesting that FABP4 may present as a novel therapeutic target to alleviate microglia-mediated neuroinflammation, a commonly reported factor in multiple neurodegenerative diseases.

Reduction in ABCG2 mRNA Expression in Human Immortalised Brain Microvascular Endothelial Cells by Ferric Ammonium Citrate is Mediated by Reactive Oxygen Species and Activation of ERK1/2 Signalling.

PURPOSE: The ATP-binding cassette (ABC) transport protein ABCG2 (also known as breast cancer resistance protein (BCRP)) is expressed at the luminal face of the blood-brain barrier (BBB), where it limits the brain uptake of a number of therapeutic drugs. We recently reported that the ABC efflux transporter P-glycoprotein (P-gp) was downregulated in human immortalised brain endothelial (hCMEC/D3) cells treated with ferric ammonium citrate (FAC). The aim of the present study, therefore, was to assess whether BCRP expression is also affected by FAC and identify any signalling mechanisms involved. METHODS: ABCG2 mRNA was assessed by RT-qPCR. Protein levels of BCRP, phosphorylated extracellular-regulated kinases 1 and 2 (p-ERK1/2) and total ERK 1/2 were assessed by Western blot. Reactive oxygen species (ROS) levels were determined using 2',7'-dichlorofluorescin diacetate. RESULTS: Treatment of hCMEC/D3 cells with FAC (250 µM, 72 h) significantly reduced ABCG2 mRNA levels (32.2 ± 3.7%) without a concomitant reduction in BCRP protein expression. ABCG2 mRNA levels were restored to control levels when co-treated with the antioxidant N-acetylcysteine (NAC), suggesting the effect of FAC was mediated by a ROS-sensitive pathway. We also found that FAC-treatment was associated with increased levels of p-ERK1/2, suggesting involvement of the ERK1/2 signalling pathway in the observed ABCG2 mRNA downregulation. The ERK1/2 signalling pathway inhibitor U0126 restored p-ERK1/2 levels and partially attenuated the FAC-induced reduction in ABCG2 mRNA. CONCLUSIONS: This study suggests that FAC-induced downregulation of ABCG2 mRNA is driven by ROS and ERK1/2 signalling, mechanisms which may be exploited to modulate BCRP expression at the BBB.

Presentation of the septic patient to the emergency department with respect to age and sex - a retrospective cross-sectional study.

OBJECTIVE: It is challenging to identify sepsis in the emergency department, in part due to the non-specific presentation of septic patients. Current clinical sepsis screening tools rely on vital signs but many patients present with near normal vital signs and are therefore not identified as septic. This suggests that variables, e.g. signs and symptoms, need to be included to improve sepsis detection in the emergency department. Our hypothesis was that the presentation of sepsis differs based age and sex. The potential differences in presentation could be used to apply to future sepsis screening tools. The aim was to analyze the prevalence of keywords reflecting the presentation of septic patients in the emergency department in relation to age and sex. METHOD: Retrospective cross-sectional study. Keywords reflecting sepsis presentation to the emergency department were quantified and compared between age categories and the sex. 479 patients admitted to the emergency department of Södersjukhuset, Stockholm during 2013 and discharged with an ICD-10 code consistent with sepsis were included. We adjusted for multiple comparisons by applying Bonferroni-adjusted significance levels for all comparisons. RESULT: "Pain" and "risk factors for sepsis" were significantly more common among patients younger than 65 years as compared with those 75 years and older: (n = 87/137; 63.5% vs n = 99/240; 41.3%, P-value < 0.000) and (n = 74/137; 54.0% vs 55/240; 22.9%, P-value < 0.000) respectively. "Risk factors for sepsis" was also significantly more common among patients between 65 and 74 years as compared with those 75 years and older: (n = 43/102; 42.2% vs 55/240; 22.9%, P-value < 0.000). "Pain" and "gastrointestinal symptoms" were significantly more common among women as compared with men: (n = 128/224; 57.1% vs n = 102/255; 40.0%, P-value < 0.000) and (n = 82/244; 36.6% vs n = 55/255; 21.6%, P-value < 0.000) respectively. CONCLUSION: The keywords "pain" and "risk factors for sepsis" were more common among younger patients and "pain" and "gastrointestinal symptoms" were more common among women. However, most keywords had a similar prevalence irrespective of age and sex. The results could potentially be used to augment sepsis screening tools or clinical decision tools.

Copper bis(thiosemicarbazone) complexes modulate P-glycoprotein expression and function in human brain microvascular endothelial cells.

P-glycoprotein (P-gp) is an efflux transporter at the blood-brain barrier (BBB) that hinders brain access of substrate drugs and clears endogenous molecules such as amyloid beta (Aß) from the brain. As biometals such as copper (Cu) modulate many neuronal signalling pathways linked to P-gp regulation, it was hypothesised that the bis(thiosemicarbazone) (BTSC) Cu-releasing complex, copper II glyoxal bis(4-methyl-3-thiosemicarbazone) (CuII [GTSM]), would enhance P-gp expression and function at the BBB, while copper II diacetyl bis(4-methyl-3-thiosemicarbazone) (CuII [ATSM]), which only releases Cu under hypoxic conditions, would not modulate P-gp expression. Following treatment with 25-250 nM CuII (BTSC)s for 8-48 h, expression of P-gp mRNA and protein in human brain endothelial (hCMEC/D3) cells was assessed by RT-qPCR and Western blot, respectively. P-gp function was assessed by measuring accumulation of the fluorescent P-gp substrate, rhodamine 123 and intracellular Cu levels were quantified by inductively coupled plasma mass spectrometry. Interestingly, CuII (ATSM) significantly enhanced P-gp expression and function 2-fold and 1.3-fold, respectively, whereas CuII (GTSM) reduced P-gp expression 0.5-fold and function by 200%. As both compounds increased intracellular Cu levels, the effect of different BTSC backbones, independent of Cu, on P-gp expression was assessed. However, only the Cu-ATSM complex enhanced P-gp expression and this was mediated partly through activation (1.4-fold) of the extracellular signal-regulated kinase 1 and 2, an outcome that was significantly attenuated in the presence of an inhibitor of the mitogen-activated protein kinase regulatory pathway. Our findings suggest that CuII (ATSM) and CuII (GTSM) have the potential to modulate the expression and function of P-gp at the BBB to impact brain drug delivery and clearance of Aß.

Medium-Term Outcomes in Severely to Critically Ill Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

BACKGROUND: The medium- and long-term effects of severe acute respiratory syndrome coronavirus 2 infection on survivors are unknown. In the current study, we assessed the medium-term effects of coronavirus disease 2019 (COVID-19) on survivors of severe disease. METHODS: This is a retrospective, case series of 200 patients hospitalized across 3 large Birmingham hospitals with severe-to-critical COVID-19 infection 4-7 months from disease onset. Patients underwent comprehensive clinical, laboratory, imaging, lung function tests (LFTs), and quality of life and cognitive assessments. RESULTS: At 4-7 months after disease onset, 63.2% of patients reported persistent breathlessness; 53.5%, significant fatigue; 37.5%, reduced mobility; and 36.8% pain. Serum markers of inflammation and organ injuries that persisted at hospital discharge had normalized on follow-up, indicating no sustained immune response causing chronic maladaptive inflammation. Chest radiographs showed complete resolution in 82.8%, and significant improvement or no change in 17.2%. LFTs revealed gas transfer abnormalities in 80.0% and abnormal spirometric values in 37.6% of patients. Compared with patients who did not experience breathlessness, those who did had significantly higher incidences of comorbid conditions and residual chest radiographic and LFT abnormalities (P < .01 to all). For all parameters assessed and persisting symptoms there were no significant differences between patients in hospital wards and those in intensive treatment units. All patients reported a significantly reduced quality of life in all domains of the EQ-5D-5L quality-of-life measures. CONCLUSIONS: A significant proportion of severely ill patients with COVID-19 still experience symptoms of breathlessness, fatigue, pain, reduced mobility, depression and reduced quality of life 4-7 months after disease onset. Symptomatic patients tend to have more residual chest radiographic and LFT abnormalities.

Keywords reflecting sepsis presentation based on mode of emergency department arrival: a retrospective cross-sectional study.

BACKGROUND: Current sepsis screening tools are predominantly based on vital signs. However, patients with serious infections frequently present with normal vital signs and there has been an increased interest to include other variables such as symptoms in screening tools to detect sepsis. The majority of patients with sepsis arrive to the emergency department by emergency medical services. Our hypothesis was that the presentation of sepsis, including symptoms, may differ between patients arriving to the emergency department by emergency medical services and patients arriving by other means. This information is of interest to adapt future sepsis screening tools to the population in which they will be implemented. The aim of the current study was to compare the prevalence of keywords reflecting the clinical presentation of sepsis based on mode of arrival among septic patients presenting to the emergency department. METHODS: Retrospective cross-sectional study of 479 adult septic patients. Keywords reflecting sepsis presentation upon emergency department arrival were quantified and analyzed based on mode of arrival, i.e., by emergency medical services or by other means. We adjusted for multiple comparisons by applying Bonferroni-adjusted significance levels for all comparisons. Adjustments for age, gender, and sepsis severity were performed by stratification. All patients were admitted to the emergency department of Södersjukhuset, Stockholm, and discharged with an ICD-10 code compatible with sepsis between January 1, and December 31, 2013. RESULTS: "Abnormal breathing" (51.8% vs 20.5%, p value < 0.001), "abnormal circulation" (38.4% vs 21.3%, p value < 0.001), "acute altered mental status" (31.1% vs 13.1%, p value < 0.001), and "decreased mobility" (26.1% vs 10.7%, p value < 0.001) were more common among patients arriving by emergency medical services, while "pain" (71.3% vs 40.1%, p value < 0.001) and "risk factors for sepsis" (50.8% vs 30.8%, p value < 0.001) were more common among patients arriving by other means. CONCLUSIONS: The distribution of most keywords related to sepsis presentation was similar irrespective of mode of arrival; however, some differences were present. This information may be useful in clinical decision tools or sepsis screening tools.

Development of a Vertically Integrated Pharmacy Degree.

Whilst curriculum revision is commonplace, whole degree transformation is less so. In this paper we discuss the rationale, design and implementation of a unique pharmacy program by a research-intensive faculty. The new Monash pharmacy curriculum, which had its first intake in 2017, was built using a range of key innovations that aimed to produce graduates that demonstrate key conceptual understanding and all the skills required to deliver world-best patient outcomes. The key elements of the re-design are outlined and include the process and principles developed, as well as key features such as a student-centred individualised program of development arranged around specific, authentic tasks for each skill and earlier enhanced experiential placements where students become proficient in entrustable professional activities. It is hoped the dissemination of this process, as well as the lessons learnt in the process, will be useful to others looking to transform a health curriculum.

Management of functional communication, swallowing, cough and related disorders: consensus recommendations for speech and language therapy.

Communication problems (eg, dysphonia, dysfluency and language and articulation disorders), swallowing disorders (dysphagia and globus), cough and upper airway symptoms, resulting from functional neurological disorder (FND), are commonly encountered by speech and language professionals. However, there are few descriptions in the literature of the most effective practical management approaches. This consensus document aims to provide recommendations for assessment and intervention that are relevant to both adults and young people. An international panel of speech and language professionals with expertise in FND were approached to take part. Participants responded individually by email to a set of key questions regarding best practice for assessment and interventions. Next, a video conference was held in which participants discussed and debated the answers to these key questions, aiming to achieve consensus on each issue. Drafts of the collated consensus recommendations were circulated until consensus was achieved. FND should be diagnosed on the basis of positive clinical features. Speech and language therapy for FND should address illness beliefs, self-directed attention and abnormal movement patterns through a process of education, symptomatic treatment and cognitive behavioural therapy within a supportive therapeutic environment. We provide specific examples of these strategies for different symptoms. Speech and language professionals have a key role in the management of people with communication and related symptoms of FND. It is intended that these expert recommendations serve as both a practical toolkit and a starting point for further research into evidence-based treatments.

Effect of Changing From Closed-Book to Formulary-Allowed Examinations.

Objective. To determine whether allowing final-year Bachelor of Pharmacy students to use a medicines formulary during examinations modified their learning behaviors and performance, and to investigate students' perceptions about having this resource available during examinations.Methods. Student performance and examination difficulty (as measured by classification of examination questions as high or low according to Bloom's taxonomy of learning) in second semester examinations (formulary allowed) was compared with first semester examinations (closed book) in successive years. Students completed a survey regarding their study and examination approaches and experiences after both semesters.Results. Examinations in semester two had more questions rated higher on Bloom's taxonomy than did examinations in semester one. Data were collected from student surveys for closed book examinations (response rate of 25% and 19% in 2015 and 2016, respectively) and open book examinations (response rate of 22% and 15% in 2015 and 2016, respectively). Students' study approaches, hours studied per week, and anxiety (all self-reported) did not differ between semesters one and two, but students in semester two spent more time studying with a formulary compared with students in semester one. Qualitative analysis of student comments revealed students preferred the formulary-allowed examinations over the closed-book examinations. The majority of students (68%) agreed with the statement: "Knowing that I will have access to the AMH [Australian Medicines Handbook] during the exams allowed me to pay more attention to higher level skills such as analysis and evaluation."Conclusion. When students were allowed to use a formulary for examinations, they studied more using their formulary prior to the examination. Students performed similarly on examinations with a greater proportion of questions addressing higher levels of Bloom's taxonomy and on closed-book examinations that were comparatively less cognitively challenging.

Increasing Intracellular Levels of Iron with Ferric Ammonium Citrate Leads to Reduced P-glycoprotein Expression in Human Immortalised Brain Microvascular Endothelial Cells.

PURPOSE: P-glycoprotein (P-gp) at the blood-brain barrier (BBB) precludes the brain penetration of many xenobiotics and mediates brain-to-blood clearance of ß-amyloid, which accumulates in the Alzheimer's disease (AD) brain. Zinc and copper are reported to modulate BBB expression and function of P-gp; however, the impact of exogenous iron, which accumulates in AD, on P-gp dynamics remains unknown. METHODS: P-gp protein and MDR1 transcript levels were assessed in immortalised human cerebral microvascular endothelial (hCMEC/D3) cells treated with ferric ammonium citrate (FAC; 250 µM, 72 h), by Western blotting and RT-qPCR, respectively. P-gp function was assessed using rhodamine-123 and [3H]-digoxin accumulation. Intracellular reactive oxygen species (ROS) levels were determined using 2',7'-dichlorofluorescin diacetate and intracellular iron levels quantified using a ferrozine assay. RESULTS: FAC treatment significantly reduced P-gp protein (36%) and MDR1 mRNA (16%) levels, with no significant change in rhodamine-123 or [3H]-digoxin accumulation. While P-gp/MDR1 downregulation was associated with elevated ROS and intracellular iron, MDR1 downregulation was not attenuated with the antioxidant N-acetylcysteine nor the iron chelators desferrioxamine and deferiprone, suggesting the involvement of a ROS-independent mechanism or incomplete iron chelation. CONCLUSIONS: These studies demonstrate that iron negatively regulates P-gp expression at the BBB, potentially impacting CNS drug delivery and brain ß-amyloid clearance.

Brain and blood biomarkers of tauopathy and neuronal injury in humans and rats with neurobehavioral syndromes following blast exposure.

Traumatic brain injury (TBI) is a risk factor for the later development of neurodegenerative diseases that may have various underlying pathologies. Chronic traumatic encephalopathy (CTE) in particular is associated with repetitive mild TBI (mTBI) and is characterized pathologically by aggregation of hyperphosphorylated tau into neurofibrillary tangles (NFTs). CTE may be suspected when behavior, cognition, and/or memory deteriorate following repetitive mTBI. Exposure to blast overpressure from improvised explosive devices (IEDs) has been implicated as a potential antecedent for CTE amongst Iraq and Afghanistan Warfighters. In this study, we identified biomarker signatures in rats exposed to repetitive low-level blast that develop chronic anxiety-related traits and in human veterans exposed to IED blasts in theater with behavioral, cognitive, and/or memory complaints. Rats exposed to repetitive low-level blasts accumulated abnormal hyperphosphorylated tau in neuronal perikarya and perivascular astroglial processes. Using positron emission tomography (PET) and the [18F]AV1451 (flortaucipir) tau ligand, we found that five of 10 veterans exhibited excessive retention of [18F]AV1451 at the white/gray matter junction in frontal, parietal, and temporal brain regions, a typical localization of CTE tauopathy. We also observed elevated levels of neurofilament light (NfL) chain protein in the plasma of veterans displaying excess [18F]AV1451 retention. These findings suggest an association linking blast injury, tauopathy, and neuronal injury. Further study is required to determine whether clinical, neuroimaging, and/or fluid biomarker signatures can improve the diagnosis of long-term neuropsychiatric sequelae of mTBI.

A Combination of Clioquinol, Zinc and Copper Increases the Abundance and Function of Breast Cancer Resistance Protein in Human Brain Microvascular Endothelial Cells.

Modulating the abundance of the blood-brain barrier (BBB) efflux transporter breast cancer resistance protein (BCRP) has the potential to impact brain levels of drugs and endogenous substrates. Studies have demonstrated that the metal ionophore clioquinol (CQ) increases BBB abundance of P-glycoprotein (P-gp), an effect associated with increased endothelial cell levels of Cu2+. This study therefore assessed whether human brain endothelial (hCMEC/D3) cell abundance and function of BCRP is modulated by CQ. hCMEC/D3 cells were treated with CQ, Zn2+ and Cu2+ (CZC) (0.5 µM, 0.5 µM, 0.1 µM, respectively) for 24 h and BCRP mRNA and protein abundance was determined by Western blot and qPCR, respectively. After a series of optimisation studies assessing specificity of bodipy prazosin (BP) and Ko143 as a substrate and inhibitor of BCRP, respectively, the impact of CZC on BP uptake was assessed. While CZC did not increase mRNA expression of BCRP, BCRP abundance was increased 1.8 ± 0.1-fold; this was associated with a 68.1 ± 3.3% reduction in accumulation of BP in hCMEC/D3 cells. This is the first study to demonstrate that augmenting metal ion availability enhances protein abundance and function of BCRP at the BBB, which may be exploited to modulate CNS access of therapeutics and endogenous substrates.

Development and validation of a LC-MS/MS assay for quantifying the uptake of docosahexaenoic acid-d5 into mouse microglia.

Docosahexaenoic acid (DHA) is a polyunsaturated fatty acid with the capacity to reduce the proinflammatory response of activated microglia that occurs during neuroinflammation. The uptake of DHA into microglia is essential for it to exert its neuroprotective effects. However, quantifying the uptake of DHA into microglia is complicated by the presence of endogenous DHA interfering with any quantification technique. A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was therefore developed and validated in order to assess the microglial uptake of docosahexaenoic acid-d5 (DHA-d5) as a surrogate for DHA. Using a mobile phase consisting of 90 % (v/v) acetonitrile and 10 % (v/v) water containing 2 mM ammonium acetate, a flow rate of 0.3 mL/min, and MS/MS detection in the negative ionization mode, DHA-d5 was detected at m/z transitions of 332.1/228.3/234.2, with good linearity between chromatographic area under the curve (AUC) and DHA-d5 mass (R2 = 0.999) over the range of 0.0063-0.1 ng. The precision and accuracy values for the quality control samples (0.0063, 0.025, and 0.1 ng) were less than 9.3 % and 96.6-109.8 %, respectively, and a comparison of DHA-d5 AUC when prepared in PBS or in microglial cell lysate demonstrated no significant difference between quantification of these quality control samples. Utilizing this quantification approach (with preparation of DHA-d5 calibration standards in PBS), the uptake of DHA-d5 into BV-2 microglial cells over a 15 min period was assessed, following the spiking of DHA-d5 at 50 ng/mL. Following protein normalization using a BCA protein assay, a rapid and linear uptake of DHA-d5 into BV-2 cells was observed in the first 2 min, after which a plateau in uptake was observed, in line with that reported for DHA uptake in other cell types. This novel LC-MS/MS technique can now be exploited to unravel the processes involved in microglial uptake of DHA, insights that may be used to maximize the anti-inflammatory effects of DHA in neuroinflammation.

The Effects of Clioquinol on P-glycoprotein Expression and Biometal Distribution in the Mouse Brain Microvasculature.

Previous studies have demonstrated that the ionophore clioquinol (CQ), in conjunction with the biometals copper and zinc, increases the expression of P-glycoprotein (P-gp) in human cerebral microvascular endothelial (hCMEC/D3) cells. As P-gp expression and function at the blood-brain barrier (BBB) is of great interest regarding CNS drug access and endogenous toxin trafficking (e.g., amyloid beta), the present study assessed the in vivo translation of these previous in vitro findings. Swiss outbred mice received an 11-day treatment of CQ (30 mg/kg) by oral gavage, after which brain microvessel-enriched fractions (MEFs) and surrounding interfaces (subcortical brain tissue and plasma) were extracted. P-gp expression was quantified in the MEF, and biometal concentrations in all 3 compartments were assessed via inductively coupled plasma mass spectrometry. CQ treatment did not modify the expression of P-gp, nor copper or zinc concentrations in the brain MEF under this treatment regime. Metallomic analysis revealed, however, that CQ reduced potassium and magnesium levels in the brain MEF and also lowered brain iron levels. This study has shown that under this dosing regimen, CQ does not increase BBB P-gp expression in Swiss outbred mice, but that CQ facilitates redistribution of certain metal ions within the brain MEF, plasma, and brain parenchyma.

Development of a self-report instrument for measuring in-class student engagement reveals that pretending to engage is a significant unrecognized problem.

Student engagement during classes includes behavioural, cognitive and emotional components, and is a pre-requisite for successful active learning environments. A novel approach to measuring student engagement was developed, involving triangulation of real-time student-self report, observation by trained observers and heart rate measurement. The self-report instrument was evaluated in four separate cohorts (n = 123) at Monash University and the University of North Carolina. The six item self-report demonstrated good reliability (Cronbach's alpha values ranged from 0.7-0.81). The self-report showed predictive validity in that small group activities were rated as significantly more engaging than didactic lecturing. Additionally, there was significant inter-instructor variability and within-class variability, indicating good discrimination between classroom activities. This self-report may prove useful to academic teaching staff in evaluating and refining their active learning activities. Independent observation was not found to correlate with student self-report, due in part to students who were pretending to engage being rated as engaged by an observer. Strikingly, students reported that they were pretending to engage for 23% of class time, even for highly regarded instructors. Individual participants were rated as engaged for 42 of the 46 intervals for which they reported that they had "pretended to engage", indicating that the two observers were unable to detect disengagement during periods in which students pretended to engage. Instructors should be aware that student cues such as eye contact and nodding may indicate pretending to engage. One particular self-report item; "I tried a new approach or way of thinking about the content", correlated positively with heart rates, and a controlled study reproduced this finding during two activities that required students to try a new approach to understanding a concept. Agreement with this item also correlated with superior performance on two in-class written assessment tasks (n = 101, p<0.01). Further use of this tool and related educational research may be useful to identify in-class activities that are engaging and likely to lead to improved student attainment of learning outcomes.

Ionophore and Biometal Modulation of P-glycoprotein Expression and Function in Human Brain Microvascular Endothelial Cells.

PURPOSE: Biometals such as zinc and copper have been shown to affect tight junction expression and subsequently blood-brain barrier (BBB) integrity. Whether these biometals also influence the expression and function of BBB transporters such as P-glycoprotein (P-gp) however is currently unknown. METHODS: Using the immortalised human cerebral microvascular endothelial (hCMEC/D3) cell line, an in-cell western assay (alongside western blotting) assessed relative P-gp expression after treatment with the metal ionophore clioquinol and biometals zinc and copper. The fluorescent P-gp substrate rhodamine-123 was employed to observe functional modulation, and inductively coupled plasma mass spectrometry (ICP-MS) provided information on biometal trafficking. RESULTS: A 24-h treatment with clioquinol, zinc and copper (0.5, 0.5 and 0.1 µM) induced a significant upregulation of P-gp (1.7-fold) assessed by in-cell western and this was confirmed with western blotting (1.8-fold increase). This same treatment resulted in a 23% decrease in rhodamine-123 accumulation over a 1 h incubation. ICP-MS demonstrated that while t8his combination treatment had no effect on intracellular zinc concentrations, the treatment significantly enhanced bioavailable copper (4.6-fold). CONCLUSIONS: Enhanced delivery of copper to human brain microvascular endothelial cells is associated with enhanced expression and function of the important efflux pump P-gp, which may provide therapeutic opportunities for P-gp modulation.

Cognitive benefits of lithium chloride in APP/PS1 mice are associated with enhanced brain clearance of ß-amyloid.

Epidemiological evidence suggests that people with bipolar disorder prescribed lithium exhibit a lower risk of Alzheimer's disease (AD) relative to those prescribed other mood-stabilizing medicines. Lithium chloride (LiCl) reduces brain ß-amyloid (Aß) levels, and the brain clearance of Aß is reduced in AD. Therefore, the purpose of this study was to assess whether the cognitive benefits of LiCl are associated with enhanced brain clearance of exogenously-administered Aß. The brain clearance of intracerebroventricularly (icv) administered 125I-Aß42 was assessed in male Swiss outbred mice administered daily oral NaCl or LiCl (300 mg/kg for 21 days). LiCl exhibited a 31% increase in the brain clearance of 125I-Aß42 over 10 min, which was associated with a 1.6-fold increase in brain microvascular expression of the blood-brain barrier efflux transporter low density lipoprotein receptor-related protein 1 (LRP1) and increased cerebrospinal fluid (CSF) bulk-flow. 8-month-old female wild type (WT) and APP/PS1 mice were also administered daily NaCl or LiCl for 21 days, which was followed by cognitive assessment by novel object recognition and water maze, and measurement of soluble Aß42, plaque-associated Aß42, and brain efflux of 125I-Aß42. LiCl treatment restored the long-term spatial memory deficit observed in APP/PS1 mice as assessed by the water maze (back to similar levels of escape latency as WT mice), but the short-term memory deficit remained unaffected by LiCl treatment. While LiCl did not affect plaque-associated Aß42, soluble Aß42 levels were reduced by 49.9% in APP/PS1 mice receiving LiCl. The brain clearance of 125I-Aß42 decreased by 27.8% in APP/PS1 mice, relative to WT mice, however, LiCl treatment restored brain 125I-Aß42 clearance in APP/PS1 mice to a rate similar to that observed in WT mice. These findings suggest that the cognitive benefits and brain Aß42 lowering effects of LiCl are associated with enhanced brain clearance of Aß42, possibly via brain microvascular LRP1 upregulation and increased CSF bulk-flow, identifying a novel mechanism of protection by LiCl for the treatment of AD.

Reduced blood-brain barrier expression of fatty acid-binding protein 5 is associated with increased vulnerability of APP/PS1 mice to cognitive deficits from low omega-3 fatty acid diets.

Lower levels of the cognitively beneficial docosahexaenoic acid (DHA) are often observed in Alzheimer's disease (AD) brains. Brain DHA levels are regulated by the blood-brain barrier (BBB) transport of plasma-derived DHA, a process facilitated by fatty acid-binding protein 5 (FABP5). This study reports a 42.1 ± 12.6% decrease in the BBB transport of 14 C-DHA in 8-month-old AD transgenic mice (APPswe,PSEN1∆E9) relative to wild-type mice, associated with a 34.5 ± 6.7% reduction in FABP5 expression in isolated brain capillaries of AD mice. Furthermore, short-term spatial and recognition memory deficits were observed in AD mice on a 6-month n-3 fatty acid-depleted diet, but not in AD mice on control diet. This intervention led to a dramatic reduction (41.5 ± 11.9%) of brain DHA levels in AD mice. This study demonstrates FABP5 deficiency and impaired DHA transport at the BBB are associated with increased vulnerability to cognitive deficits in mice fed an n-3 fatty acid-depleted diet, in line with our previous studies demonstrating a crucial role of FABP5 in BBB transport of DHA and cognitive function.

Neurovascular Alterations in Alzheimer's Disease: Transporter Expression Profiles and CNS Drug Access.

Despite a century of steady and incremental progress toward understanding the underlying biochemical mechanisms, Alzheimer's disease (AD) remains a complicated and enigmatic disease, and greater insight will be necessary before substantive clinical success is realised. Over the last decade in particular, a large body of work has highlighted the cerebral microvasculature as an anatomical region with an increasingly apparent role in the pathogenesis of AD. The causative interplay and temporal cascade that manifest between the brain vasculature and the wider disease progression of AD are not yet fully understood, and further inquiry is required to properly characterise these relationships. The purpose of this review is to highlight the recent advancements in research implicating neurovascular factors in AD, at both the molecular and anatomical levels. We begin with a brief introduction of the biochemical and genetic aspects of AD, before reviewing the essential concepts of the blood-brain barrier (BBB) and the neurovascular unit (NVU). In detail, we then examine the evidence demonstrating involvement of BBB dysfunction in AD pathogenesis, highlighting the importance of neurovascular components in AD. Lastly, we include within this review research that focuses on how altered properties of the BBB in AD impact upon CNS exposure of therapeutic agents and the potential clinical impact that this may have on people with this disease.