Parallel optical control of spatiotemporal neuronal spike activity using high-speed digital light processing.

Neurons in the mammalian neocortex receive inputs from and communicate back to thousands of other neurons, creating complex spatiotemporal activity patterns. The experimental investigation of these parallel dynamic interactions has been limited due to the technical challenges of monitoring or manipulating neuronal activity at that level of complexity. Here we describe a new massively parallel photostimulation system that can be used to control action potential firing in in vitro brain slices with high spatial and temporal resolution while performing extracellular or intracellular electrophysiological measurements.

Relation of symptoms and symptom duration to premature ventricular complex-induced cardiomyopathy.

Background: Frequent idiopathic premature ventricular complexes (PVCs) can result in a reversible form of cardiomyopathy. In this study, the determinants of PVC-induced left ventricular (LV) dysfunction were assessed.

Methods: The subjects of this study were 241 consecutive patients (115 men [48%], mean age 48 ± 14 years) referred for ablation of frequent PVCs.

Transient receptor potential channel m4 and m5 in magnocellular cells in rat supraoptic and paraventricular nuclei.

The neurohypophysial hormones, vasopressin (VP) and oxytocin (OT), are synthesised by magnocellular cells in the supraoptic nucleus (SON) and the paraventricular nucleus (PVN) of the hypothalamus. The release of VP into the general circulation from the neurohypophysis increases during hyperosmolality, hypotension and hypovolaemia. VP neurones increase hormone release by increasing their firing rate as a result of adopting a phasic bursting.

Lower extremity fatigue increases complexity of postural control during a single-legged stance.

Background: Non-linear approaches to assessment of postural control can provide insight that compliment linear approaches. Control entropy (CE) is a recently developed statistical tool from non-linear dynamical systems used to assess the complexity of non-stationary signals. We have previously used CE of high resolution accelerometry in running to show decreased complexity with exhaustive exercise.

Wavelet-based intensity analysis of mechanomyographic signals during single-legged stance following fatigue.

The von Tscharner (2000) "intensity analysis" describes the power of a non-stationary signal as a function of both frequency and time. The present study applied a version of this intensity analysis that utilizes Morlet wavelets as a means of gaining insight into the application of this technique as alternative to power spectral analysis for the evaluation of postural control strategy during the single-legged stance and to examine the effects of fatigue. Ten subjects (gender balanced, age: 25±3 years; height: 169.

Disseminated Mycobacterium haemophilum infection.

Mycobacterium haemophilum is a slow-growing organism first identified in 1978. Since that time, it has emerged as an unusual pathogen, but one that is identified increasingly, mainly affecting immunocompromised patients and healthy children. The range of disease caused by this organism includes skin and soft-tissue infections, pulmonary infections, lymphadenitis, and frequently, bone and joint infections.

Plasmacytoid dendritic cells are recruited to the colorectum and contribute to immune activation during pathogenic SIV infection in rhesus macaques.

In SIV/HIV infection, the gastrointestinal tissue dominates as an important site because of the impact of massive mucosal CD4 depletion and immune activation-induced tissue pathology. Unlike AIDS-susceptible rhesus macaques, natural hosts do not progress to AIDS and resolve immune activation earlier. Here, we examine the role of dendritic cells (DCs) in mediating immune activation and disease progression.

Preliminary evaluation of junior medical students' exposure and comfort with performing the basic head and neck examination.

Objective: To assess junior medical students' comfort levels in performing the head and neck physical examination (H&NPE) and perception of the importance of otolaryngology--head and neck surgery (OTO-HNS) in medical training before and after undergoing a department-led teaching session.

Design: Anonymous cross-sectional survey study, before and after educational intervention.

Methods: One hundred one second-year medical students participated in an H&NPE teaching session as part of their preclinical curriculum.

Pilot study of cardiac magnetic resonance imaging for detection of embolic source after ischemic stroke.

Background: Transesophageal echocardiography (TEE) is the standard for evaluating cardioembolic sources of stroke, although many strokes remain cryptogenic after TEE. Cardiac magnetic resonance (CMR) imaging may have advantages over TEE. We performed a prospective pilot study comparing CMR to TEE after stroke to assist in planning future definitive studies.

The changing landscape of healthcare and social policy.

The problems in traditional residential long-term care settings described in the lead paper are the tip of the iceberg in relation to changes in the landscape of healthcare and social policy in Canada over the past two decades. The primary purpose of this commentary is to identify some of the less visible changes and how these are affecting our perceptions, values and policy directions in "long-term care," however it is defined. The secondary purpose is to caution readers of the dangers of trying to resolve all social policy issues through medicare.

High prevalence of persistent parasitic infections in foreign-born, HIV-infected persons in the United States.

Background: Foreign-born, HIV-infected persons are at risk for sub-clinical parasitic infections acquired in their countries of origin. The long-term consequences of co-infections can be severe, yet few data exist on parasitic infection prevalence in this population.

Methodology/principal Findings: This cross-sectional study evaluated 128 foreign-born persons at one HIV clinic.

Postnatal development of A-type and Kv1- and Kv2-mediated potassium channel currents in neocortical pyramidal neurons.

Potassium channels regulate numerous aspects of neuronal excitability, and several voltage-gated K(+) channel subunits have been identified in pyramidal neurons of rat neocortex. Previous studies have either considered the development of outward current as a whole or divided currents into transient, A-type and persistent, delayed rectifier components but did not differentiate between current components defined by α-subunit type. To facilitate comparisons of studies reporting K(+) currents from animals of different ages and to understand the functional roles of specific current components, we characterized the postnatal development of identified Kv channel-mediated currents in pyramidal neurons from layers II/III from rat somatosensory cortex.

The role of interpolation in PVC-induced cardiomyopathy.

Background: Frequent premature ventricular complexes (PVCs) can cause cardiomyopathy. The mechanism is not known and may be multifactorial.

Objective: This study assessed the role of PVC interpolation in PVC-induced cardiomyopathy.

Experimental and modelling data contradict the idea of respiratory down-regulation in plant tissues at an internal [O2] substantially above the critical oxygen pressure for cytochrome oxidase.

• Some recent data on O(2) scavenging by root segments showed a two-phase reduction in respiration rate starting at/above 21 kPa O(2) in the respirometer medium. The initial decline was attributed to a down-regulation of respiration, involving enzymes other than cytochrome oxidase, and interpreted as a means of conserving O(2). As this appeared to contradict earlier findings, we sought to clarify the position by mathematical modelling of the respirometer system.

Reasons for the presence or absence of convective (pressurized) ventilation in the genus Equisetum.

• The very high rates of convective ventilation reported recently in Equisetum telmateia (up to 120 cm(3) min(-1); internal wind speed, 10 cm s(-1)) prompted this study of a further eight species for the presence or absence of convection and the possible reasons for this. • Convection rates were examined in relation to anatomical pathways, internal resistance to applied pressurized gas flow and stomata. • Only species with interconnecting cortical aerenchyma in branches (when present), shoots and rhizomes induced convection.

The acute effect of whole-body vibration on the vertical jump height.

To determine the effectiveness of a single, 1-minute bout of whole-body vibration (WBV) as a viable warm-up activity, 90 subjects (30 men; 60 women, mean age = 19 ± 1 years) were recruited and randomly assigned to either a nonvibration control group or 1 of 8 WBV treatments (4 frequencies × 2 AMplitudes). Subjects stood with the feet shoulder width apart and the knees flexed 10° on a Next Generation Power Plate for 1 minute with the frequency (30, 35, 40, or 50 Hz) and amplitude (2-4 or 4-6 mm) settings at the assigned levels. Before, 1, 5, 10, 15, 20, 25, and 30 minutes after the WBV or control treatment, subjects performed a series of countermovement vertical jumps (CMJs) measured using a Vertec vertical jump tester.

Transoral laser microsurgery for laryngeal cancer: a primer and review of laser dosimetry.

Transoral laser microsurgery (TLM) is an emerging technique for the management of laryngeal and other head and neck malignancies. It is increasingly being used in place of traditional open surgery because of lower morbidity and improved organ preservation. Since the surgery is performed from the inside working outward as opposed to working from the outside in, there is less damage to the supporting structures that lie external to the tumor.

Oxytocin release in magnocellular nuclei: neurochemical mediators and functional significance during gestation.

When released from dendrites within the supraoptic (SON) and paraventricular (PVN) nuclei (intranuclear release) during suckling, oxytocin exerts autocrine and paracrine effects on oxytocin neurons that are necessary for the unique timing and episodic pattern of oxytocin release into the systemic circulation that is characteristic of lactation. Recent reports have shown that stimulation of central noradrenergic and histaminergic receptors are both necessary for intranuclear release of oxytocin in response to suckling. In addition, in vitro studies indicate that excitatory amino acids may also be critical for central oxytocin secretion, although in vivo experiments have not provided direct support for this hypothesis.

Biocytin-labelling and its impact on late 20th century studies of cortical circuitry.

In recognition of the impact that a powerful new anatomical tool, such as the Golgi method, can have, this essay highlights the enormous influence that biocytin-filling has had on modern neuroscience. This method has allowed neurones that have been recorded intracellularly, 'whole-cell' or juxta-cellularly, to be identified anatomically, forming a vital link between functional and structural studies. It has been applied throughout the nervous system and has become a fundamental component of our technical armoury.

Alignment effects on a neutron imaging system using coded apertures.

A high resolution neutron imaging system is being developed and tested on the OMEGA laser facility for inertial confinement fusion experiments. This diagnostic uses a coded imaging technique with a penumbral or an annular aperture. The sensitiveness of these techniques to misalignment was pointed out with both experiments and simulations.

Relationship between burden of premature ventricular complexes and left ventricular function.

Background: Frequent idiopathic premature ventricular complexes (PVCs) can result in a reversible form of left ventricular dysfunction. The factors resulting in impaired left ventricular function are unclear. Whether a critical burden of PVCs can result in cardiomyopathy has not been determined.