scholarly journals Biofilm Lithography: High-resolution cell patterning via optogenetic adhesin expression

2017 ◽  
Author(s):  
Xiaofan Jin ◽  
Ingmar H. Riedel-Kruse
Keyword(s):  
Cell Patterning ◽  
Biophysical Model ◽  
Microbial Consortia ◽  
Bacterial Biofilms ◽  
Surface Pretreatment ◽  
New Evidence ◽  
Resolution Cell ◽  
Stimulation Of

Bacterial biofilms represent a promising opportunity for engineering of microbial communities. However our ability to control spatial structure in biofilms remains limited. Here we engineerEscherichia coliwith a light-activated transcriptional promoter to optically regulate adhesin gene expression. When illuminated with patterned blue light, long-term viable biofilms with spatial resolution down to 25μmcan be formed on a variety of substrates and inside enclosed culture chambers without the need for surface pretreatment. A biophysical model suggests the patterning mechanism involves stimulation of transiently surface-adsorbed cells, lending new evidence to a previously proposed role of adhesin expression during natural biofilm maturation. Overall, this tool – termed ‘Biofilm Lithography’ – has distinct advantages over existing cell-depositing and patterning methods and provides the ability to grow structured biofilms, with applications towards an improved understanding natural biofilm communities, as well as the engineering of living biomaterials and bottom-up approaches to microbial consortia design.

scholarly journals Biofilm Lithography enables high-resolution cell patterning via optogenetic adhesin expression

2018 ◽  
Vol 115 (14) ◽  
pp. 3698-3703 ◽  
Author(s):  
Xiaofan Jin ◽  
Ingmar H. Riedel-Kruse
Keyword(s):  
Escherichia Coli ◽  
Cell Patterning ◽  
Biophysical Model ◽  
Microbial Consortia ◽  
Bacterial Biofilms ◽  
Surface Pretreatment ◽  
Resolution Cell ◽  
Stimulation Of

Bacterial biofilms represent a promising opportunity for engineering of microbial communities. However, our ability to control spatial structure in biofilms remains limited. Here we engineerEscherichia coliwith a light-activated transcriptional promoter (pDawn) to optically regulate expression of an adhesin gene (Ag43). When illuminated with patterned blue light, long-term viable biofilms with spatial resolution down to 25 μm can be formed on a variety of substrates and inside enclosed culture chambers without the need for surface pretreatment. A biophysical model suggests that the patterning mechanism involves stimulation of transiently surface-adsorbed cells, lending evidence to a previously proposed role of adhesin expression during natural biofilm maturation. Overall, this tool—termed “Biofilm Lithography”—has distinct advantages over existing cell-depositing/patterning methods and provides the ability to grow structured biofilms, with applications toward an improved understanding of natural biofilm communities, as well as the engineering of living biomaterials and bottom–up approaches to microbial consortia design.

scholarly journals Pre-motor versus motor cerebral cortex neuromodulation for chronic neuropathic pain

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Igor Lavrov ◽  
Timur Latypov ◽  
Elvira Mukhametova ◽  
Brian Lundstrom ◽  
Paola Sandroni ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Cerebral Cortex ◽  
Motor Cortex ◽  
Initial Assessment ◽  
Motor Cortex Stimulation ◽  
Chronic Neuropathic Pain ◽  
Long Term Effect ◽  
Stimulation Of

AbstractElectrical stimulation of the cerebral cortex (ESCC) has been used to treat intractable neuropathic pain for nearly two decades, however, no standardized approach for this technique has been developed. In order to optimize targeting and validate the effect of ESCC before placing the permanent grid, we introduced initial assessment with trial stimulation, using a temporary grid of subdural electrodes. In this retrospective study we evaluate the role of electrode location on cerebral cortex in control of neuropathic pain and the role of trial stimulation in target-optimization for ESCC. Location of the temporary grid electrodes and location of permanent electrodes were evaluated in correlation with the long-term efficacy of ESCC. The results of this study demonstrate that the long-term effect of subdural pre-motor cortex stimulation is at least the same or higher compare to effect of subdural motor or combined pre-motor and motor cortex stimulation. These results also demonstrate that the initial trial stimulation helps to optimize permanent electrode positions in relation to the optimal functional target that is critical in cases when brain shift is expected. Proposed methodology and novel results open a new direction for development of neuromodulation techniques to control chronic neuropathic pain.

The Role of 5–Hydroxytryptamine (5–HT) Receptor Subtypes and Plasticity in the 5–HT Systems in the Regulation of Nociceptive Sensitivity

Cephalalgia ◽  
1993 ◽  
Vol 13 (2) ◽  
pp. 75-85 ◽  
Author(s):  
Per Kristian Eide ◽  
Kjell Hole
Keyword(s):  
Receptor Activation ◽  
Term Treatment ◽  
Receptor Subtypes ◽  
Functional Changes ◽  
Nociceptive Sensitivity ◽  
Denervation Supersensitivity ◽  
Long Term Treatment ◽  
Stimulation Of

This review shows that the role of 5–hydroxytryptamine (5–HT) in the regulation of nociception depends on the 5–HT receptor subtypes involved and on long-term functional changes in the 5–HT receptors. Stimulation of the 5–HT 1 receptors, as well as of the 5–HT 2 and 5–HT 3 receptors, may reduce nociceptive sensitivity. In addition, activation of 5–HT 2 and 5–HT 3 receptors may also enhance nociceptive sensitivity. Up- or down-regulation of the 5–HT receptors may result in long-lasting changes, plasticity, in the 5–HT systems. Lesioning of 5–HT neurons induces denervation supersensitivity to 5–HT, and prolonged stimulation of 5–HT receptors may produce subsensitivity to 5–HT. In the spinal cord denervation supersensitivity to 5–HT may depend on reduced release of substance P (SP). An increase in the release of SP, on the other hand, may reduce the effects of 5–HT receptor activation. Long-term treatment with antidepressants which are used in clinical pain therapy appears to up-regulate the 5–HT 1 receptors and to down-regulate the 5–HT 2 receptors.

An update on the management of gout

2018 ◽  
Vol 56 (1) ◽  
pp. 9-12 ◽  
Keyword(s):  
Treatment Options ◽  
New Drugs ◽  
British Society ◽  
European League Against Rheumatism ◽  
Urate Lowering Treatment ◽  
The Uk ◽  
New Evidence ◽  
Urate Crystals

Gout is the most common form of inflammatory arthritis and its incidence in the UK has steadily increased from 1.5% in 1997 to 2.5% in 2012.1,2 It is characterised by deposition of monosodium urate crystals in joints and tissues and usually presents with intermittent painful attacks followed by long periods of remission.3 It has been suggested that the management of gout in the UK remains suboptimal.1 In 2004, we concluded that there was a woeful lack of evidence to guide treatment or prophylaxis for gout, particularly with regard to choice of drug or doses.4 The introduction of new drugs and new evidence on the efficacy and safety of treatment options has led the European League Against Rheumatism (EULAR) and the British Society of Rheumatology (BSR) to update their guidelines on the management of gout.2,5 Nevertheless, there are differing views on target serum uric acid (SUA) levels and the role of urate lowering treatment (ULT).2,5–7 Here, we review the latest guidance on the management of gout and consider the role of long-term ULT.

scholarly journals Ceramide sensitizes astrocytes to oxidative stress: protective role of cannabinoids

2004 ◽  
Vol 380 (2) ◽  
pp. 435-440 ◽  
Author(s):  
Arkaitz CARRACEDO ◽  
Math J. H. GEELEN ◽  
María DIEZ ◽  
Kentaro HANADA ◽  
Manuel GUZMÁN ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
De Novo ◽  
Glioma Cells ◽  
Protective Role ◽  
Dependent Manner ◽  
Ceramide Synthesis ◽  
Ceramide Accumulation ◽  
Stimulation Of

Cannabinoids induce apoptosis on glioma cells via stimulation of ceramide synthesis de novo, whereas they do not affect viability of primary astrocytes. In the present study, we show that incubation with Δ9-tetrahydrocannabinol did not induce accumulation of ceramide on astrocytes, although incubation of these cells in a serum-free medium (with or without cannabinoids) led to stimulation of ceramide synthesis de novo and sensitization to oxidative stress. Thus treatment with H2O2 induced apoptosis of 5-day-serum-deprived astrocytes and this effect was abrogated by pharmacological blockade of ceramide synthesis de novo. The sensitizing effect of ceramide accumulation may depend on p38 mitogen-activated protein kinase activation rather than on other ceramide targets. Finally, a protective role of cannabinoids on astrocytes is shown as a long-term incubation with cannabinoids prevented H2O2-induced loss of viability in a CB1 receptor-dependent manner. In summary, our results show that whereas challenge of glioma cells with cannabinoids induces accumulation of de novo-synthesized ceramide and apoptosis, long-term treatment of astrocytes with these compounds does not stimulate this pathway and also abrogates the sensitizing effects of ceramide accumulation.

New Evidence for a Role of Allograft Accommodation in Long-Term Tolerance

2006 ◽  
Vol 82 (9) ◽  
pp. 1185-1193 ◽  
Author(s):  
Jean Marie Heslan ◽  
Karine Renaudin ◽  
Pamela Thebault ◽  
Regis Josien ◽  
Maria-Cristina Cuturi ◽  
...  
Keyword(s):  
New Evidence

scholarly journals The relative contribution of shape and colour to object memory

2020 ◽  
Vol 48 (8) ◽  
pp. 1504-1521
Author(s):  
Irene Reppa ◽  
Kate E. Williams ◽  
W. James Greville ◽  
Jo Saunders
Keyword(s):  
Long Term Memory ◽  
Object Representations ◽  
Interference Effects ◽  
Practice Phase ◽  
Object Property ◽  
Relative Contribution ◽  
Induced Forgetting ◽  
New Evidence

AbstractThe current studies examined the relative contribution of shape and colour in object representations in memory. A great deal of evidence points to the significance of shape in object recognition, with the role of colour being instrumental under certain circumstances. A key but yet unanswered question concerns the contribution of colour relative to shape in mediating retrieval of object representations from memory. Two experiments (N=80) used a new method to probe episodic memory for objects and revealed the relative contribution of colour and shape in recognition memory. Participants viewed pictures of objects from different categories, presented one at a time. During a practice phase, participants performed yes/no recognition with some of the studied objects and their distractors. Unpractised objects shared shape only (Rp–Shape), colour only (Rp–Colour), shape and colour (Rp–Both), or neither shape nor colour (Rp–Neither), with the practised objects. Interference effects in memory between practised and unpractised items were revealed in the forgetting of related unpractised items – retrieval-induced forgetting. Retrieval-induced forgetting was consistently significant for Rp–Shape and Rp–Colour objects. These findings provide converging evidence that colour is an automatically encoded object property, and present new evidence that both shape and colour act simultaneously and effectively to drive retrieval of objects from long-term memory.

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