Central and peripheral tau retention modulated by an anti-tau antibody.

Tau protein blood levels dependent on its distribution to peripheral organs and possible elimination from the body. Thus, the peripheral distribution of CSF-derived tau protein was explored, especially since there is a transition to blood-based biomarkers and the emerging idea that tau pathology may spread beyond brain. Near infrared fluorescence (NIRF) was mainly used to analyze tau (tau-NIRF) distribution after its intracisternal or intravenous injection.

Uptake of severe acute respiratory syndrome coronavirus 2 spike protein mediated by angiotensin converting enzyme 2 and ganglioside in human cerebrovascular cells.

Introduction: There is clinical evidence of neurological manifestations in coronavirus disease-19 (COVID-19). However, it is unclear whether differences in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)/spike protein (SP) uptake by cells of the cerebrovasculature contribute to significant viral uptake to cause these symptoms.

Methods: Since the initial step in viral invasion is binding/uptake, we used fluorescently labeled wild type and mutant SARS-CoV-2/SP to study this process.

Spike protein multiorgan tropism suppressed by antibodies targeting SARS-CoV-2.

While there is SARS-CoV-2 multiorgan tropism in severely infected COVID-19 patients, it's unclear if this occurs in healthy young individuals. In addition, for antibodies that target the spike protein (SP), it's unclear if these reduce SARS-CoV-2/SP multiorgan tropism equally. We used fluorescently labeled SP-NIRF to study viral behavior, using an in vivo dynamic imaging system and ex in vivo tissue analysis, in young mice.

SARS-CoV-2: is there neuroinvasion?

Background: SARS-CoV-2, a coronavirus (CoV), is known to cause acute respiratory distress syndrome, and a number of non-respiratory complications, particularly in older male patients with prior health conditions, such as obesity, diabetes and hypertension. These prior health conditions are associated with vascular dysfunction, and the CoV disease 2019 (COVID-19) complications include multiorgan failure and neurological problems. While the main route of entry into the body is inhalation, this virus has been found in many tissues, including the choroid plexus and meningeal vessels, and in neurons and CSF.

Cerebrospinal fluid drainage kinetics across the cribriform plate are reduced with aging.

Background: Continuous circulation and drainage of cerebrospinal fluid (CSF) are essential for the elimination of CSF-borne metabolic products and neuronal function. While multiple CSF drainage pathways have been identified, the significance of each to normal drainage and whether there are differential changes at CSF outflow regions in the aging brain are unclear.

Methods: Dynamic in vivo imaging of near infrared fluorescently-labeled albumin was used to simultaneously visualize the flow of CSF at outflow regions on the dorsal side (transcranial and -spinal) of the central nervous system.

Gravitational Test beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole.

The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tests can lead to large deviations in the predicted black-hole shadows that are inconsistent with even the current EHT measurements.

Operative vaginal delivery and pelvic floor complications.

Operative vaginal delivery (OVD) is associated with injury to the pelvic floor and compromise to the urinary, genital and gastrointestinal systems. There has been significant evolution in recent years in the practice of OVD (from the use of forceps to vacuum delivery), the conduct of delivery (from routine to selective episiotomy) and the recognition and management of obstetric anal sphincter injury (OASIS). This review article considers a number of key questions from the perspective of the clinical practitioner: What effects does OVD have on the pelvic floor? How can the effects of OVD on the pelvic floor be reduced? When and how should episiotomy be performed during OVD? How should future pregnancies following OVD and OASIS be managed? The place of episiotomy during OVD, a much debated strategy to prevent injury to the obstetric anal sphincter during OVD, is considered.

Port insertion for minimally invasive surgery: a report of practices in the Irish Republic.

Background: With rapidly evolving surgical technologies, minimally invasive surgery (MIS) has become the mainstay approach for many surgeons worldwide. As laparoscopic surgery was introduced in Ireland over two decades ago, we may be encountering a higher prevalence of related complications.

Aims: This study aimed to gather data pertaining to risk factors for port-site herniation in MIS.

Glymphatic distribution of CSF-derived apoE into brain is isoform specific and suppressed during sleep deprivation.

Background: Apolipoprotein E (apoE) is a major carrier of cholesterol and essential for synaptic plasticity. In brain, it's expressed by many cells but highly expressed by the choroid plexus and the predominant apolipoprotein in cerebrospinal fluid (CSF). The role of apoE in the CSF is unclear.

Proposed learning strategies of medical students in a clinical rotation in obstetrics and gynecology: a descriptive study.

Background: Medical students face many challenges when learning within clinical environments. How students plan to use their time and engage with learning opportunities is therefore critical, as it may be possible to highlight strategies that optimize the learning experience at an early stage in the rotation. The aim of the study was to describe the learning drivers and proposed learning strategies of medical students for a clinical rotation in obstetrics and gynecology.

Glymphatic clearance controls state-dependent changes in brain lactate concentration.

Brain lactate concentration is higher during wakefulness than in sleep. However, it is unknown why arousal is linked to an increase in brain lactate and why lactate declines within minutes of sleep. Here, we show that the glymphatic system is responsible for state-dependent changes in brain lactate concentration.

Suppression of glymphatic fluid transport in a mouse model of Alzheimer's disease.

Glymphatic transport, defined as cerebrospinal fluid (CSF) peri-arterial inflow into brain, and interstitial fluid (ISF) clearance, is reduced in the aging brain. However, it is unclear whether glymphatic transport affects the distribution of soluble Aβ in Alzheimer's disease (AD). In wild type mice, we show that Aβ40 (fluorescently labeled Aβ40 or unlabeled Aβ40), was distributed from CSF to brain, via the peri-arterial space, and associated with neurons.

Student and staff experiences of attendance monitoring in undergraduate obstetrics and gynecology: a cross-sectional survey.

Background: Despite the widespread introduction of active learning strategies to engage students across modern medical curricula, student attendance and attendance monitoring remain a challenging issue for medical educators. In addition, there is little published evidence available to medical educators regarding the use of attendance monitoring systems. The aim of this study was to evaluate the opinions of students and staff about the use of a paper-based student logbook to record student attendance across all clinical and classroom-based learning activities within an undergraduate clinical rotation in obstetrics and gynecology (OBGYN).

Team Objective Structured Bedside Assessment (TOSBA) as formative assessment in undergraduate Obstetrics and Gynaecology: a cohort study.

Background: Team Objective Structured Bedside Assessment (TOSBA) is a learning approach in which a team of medical students undertake a set of structured clinical tasks with real patients in order to reach a diagnosis and formulate a management plan and receive immediate feedback on their performance from a facilitator. TOSBA was introduced as formative assessment to an 8-week undergraduate teaching programme in Obstetrics and Gynaecology (O&G) in 2013/14. Each student completed 5 TOSBA sessions during the rotation.

The Effect of Body Posture on Brain Glymphatic Transport.

Unlabelled: The glymphatic pathway expedites clearance of waste, including soluble amyloid β (Aβ) from the brain. Transport through this pathway is controlled by the brain's arousal level because, during sleep or anesthesia, the brain's interstitial space volume expands (compared with wakefulness), resulting in faster waste removal. Humans, as well as animals, exhibit different body postures during sleep, which may also affect waste removal.

Direct neuronal glucose uptake heralds activity-dependent increases in cerebral metabolism.

Metabolically, the brain is a highly active organ that relies almost exclusively on glucose as its energy source. According to the astrocyte-to-neuron lactate shuttle hypothesis, glucose is taken up by astrocytes and converted to lactate, which is then oxidized by neurons. Here we show, using two-photon imaging of a near-infrared 2-deoxyglucose analogue (2DG-IR), that glucose is taken up preferentially by neurons in awake behaving mice.

Impact of a personal learning plan supported by an induction meeting on academic performance in undergraduate Obstetrics and Gynaecology: a cluster randomised controlled trial.

Background: A personal learning plan (PLP) is an approach to assist medical students maximise their learning experience within clinical rotations. The aim of this study was to investigate whether medical students who created a PLP supported by an induction meeting had an improved academic performance within an undergraduate clinical rotation.

Methods: A cluster randomised controlled study was conducted over a full academic year (2012/13).