Publications by authors named "Malan N"

Background: Understanding the neural mechanisms underlying migraine and other primary headache disorders is critical for the development of long-term cures. Magnetoencephalography (MEG), an imaging modality that measures neuronal currents and cortical excitability with high temporal and superior spatial resolution, has been increasingly used in neurological research. Initial MEG studies showed promise in directly recording cortical spreading depression-a cortical correlate of migraine with aura.

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During 2022, extreme rainfall occurred across southeast Australia, making it the wettest year on record. The oceanic impact of extreme rainfall events in normally 'dry' regions is not well understood, as their effects are challenging to observe. Here, we use unique multi-platform timeseries and spatial data from 36 autonomous ocean glider missions over 13 years, and we define an extreme salinity threshold inshore of the East Australian Current.

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Context: Previous research has shown the vast benefits associated with BhP. However, the dynamics of cortical activity in connection with Bhramari sound have not been investigated yet.

Aim: To investigate the cortical activity in connection with Bhramari sound.

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Background: There is a critical need for effective treatment of the core symptoms of autism spectrum disorder (ASD). The purinergic antagonist suramin may improve core symptoms through restoration of normal mitochondrial function and reduction of neuro-inflammation via its known antagonism of P2X and P2Y receptors. Nonclinical studies in fragile X knockout mice and the maternal immune activation model support these hypotheses.

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The brain is the key organ that orchestrates the stress response which translates to the retina. The retina is an extension of the brain and retinal symptoms in subjects with neurodegenerative diseases substantiated the eye as a window to the brain. The retina is used in this study to determine whether chronic stress reflects neurodegenerative signs indicative of neurodegenerative conditions.

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Background: Fitusiran, a subcutaneous investigational siRNA therapeutic, targets antithrombin with the goal of rebalancing haemostasis in people with haemophilia A or haemophilia B, regardless of inhibitor status. We aimed to evaluate the efficacy and safety of fitusiran prophylaxis in people with severe haemophilia without inhibitors.

Methods: This multicentre, open-label, randomised phase 3 study was conducted at 45 sites in 17 countries.

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Background: Whether systolic blood pressure (SBP) control in sustained volume-dependent primary hypertension is associated with blunted ANP (atrial natriuretic peptide) relationships with indexes of volume load is unknown.

Methods: Systemic hemodynamics (central pressure, echocardiographic aortic velocity and diameter measurements in the outflow tract), circulating ANP concentrations (ELISA assays) and glomerular and tubular function (24-hour urine collections [n=519]) were determined in a community of African ancestry (n=772).

Results: As compared with those with a controlled SBP, those with an uncontrolled SBP (n=198) showed lower ANP concentrations (<0.

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Ineffective stress-coping in Africans is associated with cardiac ischemia during acute mental stress. Ischemic conditions may be worsened by stress-induced release of glial-derived S100‑calcium-binding-protein β (S100B), which is pro-apoptotic for cardiomyocytes. Whether estradiol as coping regulator and cardio-protective factor will protect against pro-apoptotic effects, remains unclear.

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The advent of gallium 68 prostate specific membrane antigen (PSMA) PET imaging has revolutionized the diagnosis and treatment of prostate cancer. PSMA is a transmembrane glycoprotein that is overexpressed in prostate cancer and yields images with high tumor-to-background contrast. Effective "one-stop-shop" imaging of the prostate, lymph nodes, soft tissue, and bone is achieved with PSMA PET.

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Indium 111 DTPA Octreotide (Octreoscan) has been the pillar of Somatostatin receptor (SSTRs) imaging in nuclear medicine for over three decades. The advent of PET/CT brought new analogs of somatostatin that have higher affinity and improved resolution due to their labeling to Gallium 68 for positron imaging. The most used analogs include DOTATATE, DOTATOC and DOTANOC.

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Background: In a South African bi-ethnic cohort, defensive (DefS)/social support/avoidance coping strategies have been shown to influence cardiac troponin T (cTnT) levels through different stress signalling pathways. Personality traits (extraversion, neuroticism, conscientiousness, openness to experience, agreeableness) partially control stress coping responses and may affect prospective cardiac responses. Hence in this cohort, we aimed to examine relationships between personality traits and coping strategies, and to assess associations between cTnT changes over time, personality traits and coping strategies.

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Aims: Whether renal mechanisms of hypertension primarily translate into increases in systemic vascular resistance (SVR) in all populations is uncertain. We determined whether renal mechanisms associate with either increases in SVR (and impedance to flow) or systemic flow in a community of African ancestry.

Method: In a South African community sampled across the full adult age range (n = 546), we assessed stroke volume (SV), peak aortic flow (Q), SVR, characteristic impedance (Zc) and total arterial compliance (TAC) from velocity and diameter measurements in the outflow tract (echocardiography) and central arterial pressures.

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Type 3 diabetes (T3D) accurately reflects that dementia, e.g., Alzheimer's disease, represents insulin resistance and neurodegeneration in the brain.

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Objectives: Low or high sympatho-adrenal-medullary axis (SAM) and hypothalamic-pituitary-adrenal axis (HPA) dysregulation reflect chronic stress. Retinal vessel dynamics may relate to SAM, HPA activity and stroke risk. Our objectives were therefore to assess the relationships between retinal vessel, SAM and HPA responses, and to determine stroke risk.

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Background: Psychobiological processes linking stress and vascular diseases remain poorly understood. The retina and the brain share a common embryonic-diencephalon origin and blood-barrier physiology e.g.

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We examined whether there were differences in the circadian variation in blood pressure and the morning surge in blood pressure between black and white Africans. Clinic and ambulatory blood pressure data obtained from the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was examined (n = 406; 49% black African). Ambulatory blood pressure readings were fitted to a six-parameter double logistic equation to determine the power and rate of the morning surge in blood pressure.

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In August 2019, the Utah Department of Health (UDOH) received reports from health care providers of several cases of lung injury in persons who reported use of electronic cigarette (e-cigarette), or vaping, products (1,2). To describe the characteristics of medical care, potentially related conditions, and exposures among 83 patients in Utah, detailed medical abstractions were completed for 79 (95%) patients. Among patients receiving chart abstractions, 70 (89%) were hospitalized, 39 (49%) required breathing assistance, and many reported preexisting respiratory and mental health conditions.

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Background And Aims: Decreased heart-rate-variability (HRV) indicates increased sympathetic nervous system (SNS) activity and modulation with a shift in the sympatho-vagal balance towards SNS predominance. Increased SNS activity may precede volume-loading hypertension, contribute to increases in cardiac troponin T (cTnT), endothelial dysfunction and small vessel disease. Therefore, we investigated the retinal vasculature, HRV during flicker-light-induced-provocation (FLIP) and systemic cTnT, a marker of cardiac stress, to provide further evidence in support of the brain-retina-heart link.

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Background: Defensive coping (DefS) was associated with a vulnerable cardiovascular profile in blacks. The copeptin/vasopressin system is a manifestation of hypothalamic-pituitary-adrenal-axis activity and may act as an acute compensatory mechanism when there is a disruption in volume-loading homeostasis, i.e.

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Background: Brain-derived neurotrophic factor (BDNF) modulates brain health and cognition, which can interfere with executive cognitive function. BDNF was implicated with microcirculatory ischaemia and may reflect cardiomyocyte injury. We aimed to determine whether prospective changes (%Δ) in BDNF and cardiac troponin T (cTnT) will be associated with executive cognitive function in a bi-ethnic cohort.

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Acute mental stressor-induced cardiac stress responses might contribute to excessive myocardial strain and resultant cardiovascular episode risk. We assessed ethnicity-specific acute cardiac stress (by measuring cardiac troponin T (cTnT) and N-terminal prohormone of brain natriuretic peptide) related to hemodynamic activity. The prospective Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was conducted during 2007-2008 in South Africa.

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In motor imagery (MI) based brain-computer interface (BCI) signal analysis, mu and beta rhythms of electroencephalograms (EEGs) are widely investigated due to their high temporal resolution and capability to define the different movement-related mental tasks separately. However, due to the high dimensions and subject-specific behaviour of EEG features, there is a need for a suitable feature selection algorithm that can select the optimal features to give the best classification performance along with increased computational efficiency. The present study proposes a feature selection algorithm based on neighbourhood component analysis (NCA) with modification of the regularization parameter.

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Inflammation was cross-sectionally associated with subclinical wall remodeling and hypertension. Whether longitudinal changes (∆) in inflammation, myocyte injury (troponin T), and stretch (N-terminal-pro-B-type natriuretic peptide) are associated with hypertension and ECG left ventricular hypertrophy (ECG-LVH) is unclear. The first prospective analysis in Africa assessing these associations included a cohort of Black and White teachers (N = 338; aged 20-63 years).

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Objective: Glucose dysregulation is an independent risk factor for cardiovascular and neurodegenerative disease development through synaptic dysfunction resulting in cognitive decline. The aim of this study was to study the interplay between impaired glycaemic metabolism (hyperglycaemia and insulin resistance), cardiac stress (cardiac troponin T and N-terminal brain natriuretic peptide) and executive cognitive function prospectively, in a bi-ethnic sex cohort.

Methods: Black and White teachers (N = 338, aged 20-63 years) from the Sympathetic activity and Ambulatory Blood Pressure in Africans study were monitored over a 3-year period.

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