Bogota-VAC – A Newly Modified Temporary Abdominal Closure Technique

Background: We present Bogota-VAC, a newly modified temporary abdominal closure (TAC) technique for open abdomen condition after abdominal compartment syndrome (ACS). Methods: A thin isolation bag (Bogota bag) and a vacuum assisted closure (VAC) system were combined. A matching bag was tension-free fixed on the abdominal fascia by fascia suture. A ring shaped black polyurethane foam of the VAC system was placed into the gap between Bogota bag, abdominal fascia and the wound edge. A constant negative topic pressure of 50–75 mmHg was used in the VAC system. Results: Intra-abdominal pressure (IAP: 22 ± 2 mmHg)of four patients with ACS after severe traumatic brain injury and one patient with isolated ACS after blunt abdominal trauma decreased significantly (p = 0.01)after decompressive laparotomy and treatment with Bogota-VAC (IAP: 10 ± 2 mmHg) and remained low, measured via urinary bladder pressure. Intracranial pressure (ICP) in the four traumatic brain injury patients decreased from 42 ± 13 mmHg to 15 ± 3 mmHg after abdominal decompression. Cerebral perfusion pressure (57 ± 14 mmHg) increased to 74 ± 2 mmHg. Conclusion: The advantage of the presented Bogota-VAC is leak tightness, wound conditioning (soft tissue/fascia), skin protection and facilitation of nursing in combinationwith highest volume reserve capacity (VRC), thus preventing recurrent increased intra-abdominal and intracranial pressure in the initial phase after decompression of ACS compared to other TAC techniques

The use of visual methods to explore how children construct and assign meaning to the ''self'' within two urban communities in the Western Cape, South Africa

This study aimed to explore how children construct and assign meaning to the ''self'' within two urban communities of Cape Town in South Africa. Using a child participation methodological framework data were collected using Photovoice and community maps with 54 participants between the ages of 9 and 12. Feelings of safety, social connectedness, and children's spaces were found to be central to the ways in which the participants constructed and assigned meaning to the ''self.'' The study provides implications for intervention programmes aimed at improving children's well-being to be inclusive of activities aimed at improving children's self-concept, including the construction of safe spaces for children to play, learn, and form meaningful relationships

Multicolour correlative imaging using phosphor probes

Correlative light and electron microscopy exploits the advantages of optical methods, such as multicolour probes and their use in hydrated live biological samples, to locate functional units, which are then correlated with structural details that can be revealed by the superior resolution of electron microscopes. One difficulty is locating the area imaged by the electron beam in the much larger optical field of view. Multifunctional probes that can be imaged in both modalities and thus register the two images are required. Phosphor materials give cathodoluminescence (CL) optical emissions under electron excitation. Lanthanum phosphate containing thulium or terbium or europium emits narrow bands in the blue, green and red regions of the CL spectrum; they may be synthesised with very uniform-sized crystals in the 10- to 50-nm range. Such crystals can be imaged by CL in the electron microscope, at resolutions limited by the particle size, and with colour discrimination to identify different probes. These materials also give emissions in the optical microscope, by multiphoton excitation. They have been deposited on the surface of glioblastoma cells and imaged by CL. Gadolinium oxysulphide doped with terbium emits green photons by either ultraviolet or electron excitation. Sixty-nanometre crystals of this phosphor have been imaged in the atmospheric scanning electron microscope (JEOL ClairScope). This probe and microscope combination allow correlative imaging in hydrated samples. Phosphor probes should prove to be very useful in correlative light and electron microscopy, as fiducial markers to assist in image registration, and in high/super resolution imaging studies

Differential contributions of subthalamic beta rhythms and 1/f broadband activity to motor symptoms in Parkinson's disease.

Excessive beta oscillatory activity in the subthalamic nucleus (STN) is linked to Parkinson's Disease (PD) motor symptoms. However, previous works have been inconsistent regarding the functional role of beta activity in untreated Parkinsonian states, questioning such role. We hypothesized that this inconsistency is due to the influence of electrophysiological broadband activity -a neurophysiological indicator of synaptic excitation/inhibition ratio- that could confound measurements of beta activity in STN recordings. Here we propose a data-driven, automatic and individualized mathematical model that disentangles beta activity and 1/f broadband activity in the STN power spectrum, and investigate the link between these individual components and motor symptoms in thirteen Parkinsonian patients. We show, using both modeled and actual data, how beta oscillatory activity significantly correlates with motor symptoms (bradykinesia and rigidity) only when broadband activity is not considered in the biomarker estimations, providing solid evidence that oscillatory beta activity does correlate with motor symptoms in untreated PD states as well as the significant impact of broadband activity. These findings emphasize the importance of data-driven models and the identification of better biomarkers for characterizing symptom severity and closed-loop applications

Diabetes causes marked inhibition of mitochondrial metabolism in pancreatic β-cells

Diabetes is a global health problem caused primarily by the inability of pancreatic β-cells to secrete adequate levels of insulin. The molecular mechanisms underlying the progressive failure of β-cells to respond to glucose in type-2 diabetes remain unresolved. Using a combination of transcriptomics and proteomics, we find significant dysregulation of major metabolic pathways in islets of diabetic βV59M mice, a non-obese, eulipidaemic diabetes model. Multiple genes/proteins involved in glycolysis/gluconeogenesis are upregulated, whereas those involved in oxidative phosphorylation are downregulated. In isolated islets, glucose-induced increases in NADH and ATP are impaired and both oxidative and glycolytic glucose metabolism are reduced. INS-1 β-cells cultured chronically at high glucose show similar changes in protein expression and reduced glucose-stimulated oxygen consumption: targeted metabolomics reveals impaired metabolism. These data indicate hyperglycaemia induces metabolic changes in β-cells that markedly reduce mitochondrial metabolism and ATP synthesis. We propose this underlies the progressive failure of β-cells in diabetes.Peer reviewe

Demography and disorders of German Shepherd Dogs under primary veterinarycare in the UK

The German Shepherd Dog (GSD) has been widely used for a variety of working roles. However, concerns for the health and welfare of the GSD have been widely aired and there is evidence that breed numbers are now in decline in the UK. Accurate demographic and disorder data could assist with breeding and clinical prioritisation. The VetCompassTM Programme collects clinical data on dogs under primary veterinary care in the UK. This study included all VetCompassTM dogs under veterinary care during 2013. Demographic, mortality and clinical diagnosis data on GSDs were extracted and reported

Calcium-dependent dynamics of cadherin interactions at cell–cell junctions

Cadherins play a key role in the dynamics of cell–cell contact formation and remodeling of junctions and tissues. Cadherin–cadherin interactions are gated by extracellular Ca^(2+), which serves to rigidify the cadherin extracellular domains and promote trans junctional interactions. Here we describe the direct visualization and quantification of spatiotemporal dynamics of N-cadherin interactions across intercellular junctions in living cells using a genetically encodable FRET reporter system. Direct measurements of transjunctional cadherin interactions revealed a sudden, but partial, loss of homophilic interactions (τ = 1.17 ± 0.06 s^(−1)) upon chelation of extracellular Ca^(2+). A cadherin mutant with reduced adhesive activity (W2A) exhibited a faster, more substantial loss of homophilic interactions (τ = 0.86 ± 0.02 s^(−1)), suggesting two types of native cadherin interactions—one that is rapidly modulated by changes in extracellular Ca^(2+) and another with relatively stable adhesive activity that is Ca^(2+) independent. The Ca^(2+)-sensitive dynamics of cadherin interactions were transmitted to the cell interior where β-catenin translocated to N-cadherin at the junction in both cells. These data indicate that cadherins can rapidly convey dynamic information about the extracellular environment to both cells that comprise a junction

Potassium modulation of methionine uptake in astrocytes in vitro

Methionine participates in a large variety of metabolic pathways in brain, and its transport may play an important regulatory role. The properties of methionine uptake were examined in a preparation of neonatal rat brain astrocytes. Uptake is linear for 15 minutes, up to 2.5 μM. At steady state conditions, methionine is concentrated 30–50-fold. Measured methionine homoexchange accounts for a significant fraction of uptake at concentrations greater than 10 μM. We recently reported that methionine uptake is decreased by elevations in extracellular K + . Potassium induced efflux cannot account for this apparent effect; and thus for concentrations less than 2.5μM, and for short times of incubation, measured rates of methionine uptake represent unidirectional flux. At extracellular concentrations of K + equal to 6.9 mM, the apparent V max of methionine transport is 182 pmol/min/mg protein, and the K m is 1.3 μM. Where K + is shifted to 11.9 mM, the K m remains unchanged, and the V max is reduced by half.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45429/1/11064_2004_Article_BF00965129.pd

Electrophysiological Properties of Embryonic Stem Cell-Derived Neurons

In vitro generation of functional neurons from embryonic stem (ES) cells and induced pluripotent stem cells offers exciting opportunities for dissecting gene function, disease modelling, and therapeutic drug screening. To realize the potential of stem cells in these biomedical applications, a complete understanding of the cell models of interest is required. While rapid advances have been made in developing the technologies for directed induction of defined neuronal subtypes, most published works focus on the molecular characterization of the derived neural cultures. To characterize the functional properties of these neural cultures, we utilized an ES cell model that gave rise to neurons expressing the green fluorescent protein (GFP) and conducted targeted whole-cell electrophysiological recordings from ES cell-derived neurons. Current-clamp recordings revealed that most neurons could fire single overshooting action potentials; in some cases multiple action potentials could be evoked by depolarization, or occurred spontaneously. Voltage-clamp recordings revealed that neurons exhibited neuronal-like currents, including an outward current typical of a delayed rectifier potassium conductance and a fast-activating, fast-inactivating inward current, typical of a sodium conductance. Taken together, these results indicate that ES cell-derived GFP+ neurons in culture display functional neuronal properties even at early stages of differentiation