Search Results

Introduction

Merton Sandler

in 5-Hydroxytryptamine in Psychiatry: A Spectrum of Ideas

It is hard to believe that only ten years have gone by since Peroutka and Snyder's breakthrough in the 5-hydroxytryptamine (5-HT, serotonin) receptor field. There were good precedents with ... More

It is hard to believe that only ten years have gone by since Peroutka and Snyder's breakthrough in the 5-hydroxytryptamine (5-HT, serotonin) receptor field. There were good precedents with adrenoceptors and histamine receptors and it seemed sensible that multiple 5-HT receptors would also exist, but to find them one had to wait until the technology was right. But with a combination of receptor binding technology and classical pharmacology over the past decade everything fell into place. One of the most striking papers to emerge during the past year was that of Julius et al. who transfected 5-HTlc receptors into rat fibroblasts where they are not normally present. They found they were dealing with a protooncogene, and when these altered fibroblasts were transplanted into the nude mouse they gave rise to tumour formation. Nagatsu and his colleagues in Japan have been able to transfer the tyrosine hydroxylase cDNA into non-neuronal cells, for future use in intracerebral grafting. This is but one example of many that will be found within this volume of how the curtain is beginning to lift on many areas of biological psychiatry and, most particularly, on the subtle role of 5-HT.Less

Pathology

Claire Nightingale and Jonathan Sandy

in Illustrated Questions in Orthodontics

The Hybrid Voice of Monophonic Motets

Judith A. Peraino

in Giving Voice to Love: Song and Self-Expression from the Troubadours to Guillaume de Machaut

This chapter examines a subgenre of monophonic songs labeled motet enté (meaning “grafted motet”) in some medieval sources. These songs were conceived and crafted from the fusing of the single-voiced ... More

This chapter examines a subgenre of monophonic songs labeled motet enté (meaning “grafted motet”) in some medieval sources. These songs were conceived and crafted from the fusing of the single-voiced chanson and the multi-voiced motet. The term “motet” is itself multivalent, for medieval sources often refer to refrains as “motets.” Refrains conceptually multiply and blur voices; thus they encapsulate in a figurative way the literal, aural effects of polyphonic motets. Composers, with the horticultural technique of grafting in mind, worked the many guises and voices of the motet into single-stanza, free-verse songs that strongly resemble triplum or motetus parts, but which are emphatically monophonic. As a compositional practice, grafting has an analog in present-day “sampling” found in popular music; both grafting and sampling create musical hybrids that ask readers and listeners to access their knowledge of multiple musical and literary contexts. The medieval “monophonic motet,” as both a product of grafting and a graft onto the central chanson repertory, calls attention to the cross-genre, and in some cases cross-gender, dialogues contained within a single voice.Less

MODELS OF MANY-CHAIN SYSTEMS

Glenn H. Fredrickson

in The Equilibrium Theory of Inhomogeneous Polymers

This chapter discusses methods for converting the many body problem in interacting polymer fluids to a statistical field theory. Auxiliary field transforms are introduced, that decouple interactions ... More

This chapter discusses methods for converting the many body problem in interacting polymer fluids to a statistical field theory. Auxiliary field transforms are introduced, that decouple interactions among polymer species and reduce the problem to that of individual polymers interacting with one or more fluctuating fields — the subject of Chapter 3. Examples of models for a variety of systems are enumerated, including polymer solutions, blends, block and graft copolymers, polyelectrolytes, liquid crystalline polymers, and polymer brushes.Less

Dermatology

Iqbal Khan (ed.)

in Title Pages

Vascular Surgery

Richard G. Molloy, Graham J. MacKay, Campbell S. Roxburgh, and Martha M. Quinn (eds)

in SBAs and EMIs for the General Surgery FRCS

Criteria for Biological Interventions for Spinal Cord Injury Repair

Keith Tansey and Byron A Kakulas

in Restorative Neurology of Spinal Cord Injury

This chapter reviews the pathophysiological status of the spinal cord after injury and establishes criteria for biological intervention. It details the pathological cascade that occurs during the ... More

This chapter reviews the pathophysiological status of the spinal cord after injury and establishes criteria for biological intervention. It details the pathological cascade that occurs during the acute phase of the injury in which damaged axons swell, excitatory neurotransmitters trigger excitotoxic injury, reactive oxygen species are generated, and inflammation develops, leading to further loss of neurons and glia. It describes the application of agents to impede this cascade and reduce the damage expressed in the finally established lesion. The chapter also reviews the effectiveness of pharmacological agents and neuronal grafts, and provides guidelines for what should be done for a patient with chronic post-traumatic spinal cord injury if neurobiological interventions are available.Less

Cell-Based Therapies: Imaging Outcomes

Paola Piccini and Marios Politis

in Imaging in Parkinson’s Disease

This chapter discusses recent advances in the field of cell therapy for Parkinson’s disease and the utilization of functional imaging to monitor survival and growth of grafted human embryonic ... More

This chapter discusses recent advances in the field of cell therapy for Parkinson’s disease and the utilization of functional imaging to monitor survival and growth of grafted human embryonic dopamine cells. Additionally, studies of long-term treatment outcome are reviewed, including the potential application of preoperative imaging for the selection of transplantation candidates. The chapter also provides valuable new data on imaging changes underlying complications of therapy such as graft-related dyskinesias. Additional data are provided on the use of novel PET tracers to assess the role of serotonergic terminals in grafted tissue as well as MRI methods to evaluate changes in neural circuitry following cell implantation.Less

Scleral Flap Dehiscence

Jeff Maltzman and Silvia D. Orengo-Nania

in Complications of Glaucoma Surgery

Following its introduction by Cairns in 1968, trabeculectomy quickly became the procedure of choice for the management of elevated intraocular pressure ... More

Following its introduction by Cairns in 1968, trabeculectomy quickly became the procedure of choice for the management of elevated intraocular pressure (IOP) inadequately controlled by medications, and it remains the gold standard today. This procedure’s popularity stemmed from dissatisfaction with the existing practices of the time, which typically involved full-thickness sclerectomy. Although quite effective at IOP reduction, an unguarded sclerectomy invited severe and often prolonged hypotony, with the associated risks of a flat anterior chamber, maculopathy, and suprachoroidal hemorrhage, to name but a few. Placement of the sclerectomy beneath a partial thickness scleral flap added much needed control to filtering surgery. Indeed, proper construction and suturing of the scleral flap are vital to preventing scleral flap dehiscence and promoting further surgical success, as the scleral “valve” provides the majority of the resistance to initial aqueous outflow, limiting the risk of early hypotony. There is no consensus on the size or shape of scleral flap required to produce effective IOP control. Surgeon preference is generally what was taught during training, with square, rectangular, trapezoidal, and triangular flaps all commonly employed. Although scleral flap shape is probably unimportant, the flap should be at least one-half to two-thirds scleral thickness to avoid tearing or avulsing the tissue and to prevent “cheese wiring” by sutures. Most surgeons prefer to hinge the flap as far forward as possible to ensure that the sclerectomy is created anterior to the scleral spur, avoiding the ciliary body. Extending the sides of the flap too far beyond the limbus, however, may result in excessive filtration and early hypotony. Recently, some have advocated leaving the sides of the flap short, not extending fully to the limbus, in order to force aqueous posteriorly and create a more diffuse bleb. In this case a wider flap may assist with proper anterior placement of the sclerectomy. In many cases, complications involving the scleral flap can be avoided by attention to risk factors preoperatively and careful handling of tissue intraoperatively. The most important risk factor for scleral complications is previous ocular surgery performed at the intended trabeculectomy site, particularly extracapsular cataract extraction. Less

Ecological Modernity in Shakespeare: an overview

Randall Martin

in Title Pages

The story of how The Globe (1599) was rebuilt from the reused oak timbers of The Theatre (1576) is well known. Less familiar is the environmental crisis that prompted ... More

The story of how The Globe (1599) was rebuilt from the reused oak timbers of The Theatre (1576) is well known. Less familiar is the environmental crisis that prompted this thrifty recycling. Shakespeare’s company, the Chamberlain’s Men, were in danger of losing The Theatre because the lease had expired. The landlord, Giles Allen, was threatening to pull down the playhouse and put its wood and timber to other uses. The leaseholders, Richard and Cuthbert Burbage, got there before him because a clause in the original agreement made them owners of the building on Allen’s land. In the lead-up to their stealthy dismantling of The Theatre on the icy morning of 28 December 1598, when Allen was away celebrating Christmas in the country, each side had been eyeing the valuable timber and wood. Its reuse was the lynchpin of a deal between the Burbages and five actor-sharers of the Chamberlain’s Men, including Shakespeare, for building The Globe: the brothers offered to supply the main materials if the sharers contributed to the lesser expenses of construction and maintenance. The Burbages had spent their savings on building an indoor theatre at Blackfriars two years before. Although it had begun to pay them rent, they could not afford to buy new materials because the price of wood and timber had risen 96 per cent over the quarter century since The Theatre had been built. This inflation was the result of southern English woodlands being deforested. Ancient English woodland and forests had been shrinking throughout the middle ages. By Henry VIII’s time the pace began to accelerate. Worried about timber supplies for shipbuilding, the government took the first steps—largely ineffective—to manage depletions. Climactic and demographic pressures aggravated overexploitation, and by the 1590s caused a fuel crisis in south-east England and the country’s first major environmental controversy. Similar to the threat of warming global temperatures today, the stresses on southern English woodland—at that time the country’s most essential but finite natural resource—reached an ecological turning point. A solution was in the offing, but it was a highly ambivalent one. Less

Gunpowder, Militarization, and Threshold Ecologies in Henry IV Part Two and Macbeth

Randall Martin

in Shakespeare and Ecology

The disputed land-uses and cultivation practices represented in As You Like It responded to unprecedented changes in Elizabethan climate, population, and economic ... More

The disputed land-uses and cultivation practices represented in As You Like It responded to unprecedented changes in Elizabethan climate, population, and economic relations. Traditional modes of rural dwelling were no longer protected by virtue of their rural isolation or autonomy, but were becoming inescapably tied to national and global orders of competitive growth and resource exploitation. Perhaps the most disruptive of these modernizing turns was the development of gunpowder technologies and the armament industry. As in other western European countries, military culture became ubiquitous in England by the late sixteenth century as a result of innovations in gunpowder weapons and the formation of national armies. During the Middle Ages, low-tech weaponry and feudal mobilization had limited the social and environmental impacts of war. This situation began to change from the fifteenth century onwards with the development of far more deadly cannons, mines, and firearms. Influenced partly by the Erasmian ethics of his Humanist education (like Queen Elizabeth and King James in their attitudes to war), Shakespeare drew attention to gunpowder’s devastating effects on human and non-human animals and their environments in virtually all his history plays and several of his tragedies, even thoughmost of these references were anachronistic. By layering historical and contemporary viewpoints he registered changing material realities and cultural assumptions about the ecology of war: from self-regulating cycles of martial destruction and agrarian regeneration, to incremental technological mastery reliant on ever-increasing resource consumption. Traditional ideas about redeeming war through cultivation are captured by the Virgilian image of beating swords into ploughshares. It suggests that peacetime cultivation will heal wartime damage, and that periods of war and peace routinely alternate. The swordsinto-ploughshares trope also encodes temporal assumptions that the arc of catastrophe, in its political, ecological, and dramatic senses, is limited in scope and ultimately reversible. In this chapter I want to examine the emerging gunpowder regime putting pressure on this paradigm, and replacing it with modern structures of recoiling environmental risk and planetary push-back, represented in Henry IV Part Two and Macbeth respectively. Less

Transplantation of neuronal and nonneuronal cells into the brain

H. Widner

in Immune Responses in the Nervous System

Transplantation into the central nervous system has the potential to develop into a very powerful therapeutic approach for a variety of neurological disorders. This chapter discusses the principles ... More

Transplantation into the central nervous system has the potential to develop into a very powerful therapeutic approach for a variety of neurological disorders. This chapter discusses the principles of transplantation, the brain as transplantation site, transplantation of neural cells, potential therapies with intracerebral grafts, transplantation of nonneural cells, human trials with neural tissue transplants, immunological risks of transplantation, the use of immunosuppression, transplantation of transfected cells, and direct injection of oligonucleotides, virus vectors, and other noncellular approaches for gene transfer.Less

Bio-nanocomposites with non-cellulosic biofillers

Peter R. Chang, Jin Huang, and Ning Lin

in Nanocomposites with Biodegradable Polymers: Synthesis, Properties, and Future Perspectives

Among the components of bio-nanocomposites, the nanometer sized biofillers from biomass show unique advantages over traditional inorganic nanoparticles by virtue of their biodegradability and ... More

Among the components of bio-nanocomposites, the nanometer sized biofillers from biomass show unique advantages over traditional inorganic nanoparticles by virtue of their biodegradability and biocompatibility. Currently, biomass-based nanofillers include the rod-like whiskers of cellulose and chitin, the platelet-like nanocrystals of starch, the self-organized nanophase of supramolecular lignin complexes, and many artificial nanofillers derived from biomass. Biofillers that do not have a cellulose origin are defined as noncellulosic biofillers. Besides the inherent biodegradability and biocompatibility of biomass-based polymers, these nanometer sized noncellulosic biofillers have the following predominant advantages over inorganic nanoparticles: (1) Biofiller materials are abundant, renewable, and easily available; (2) Application of the biofiller can improve the bioeconomy; (3) The as-prepared biofillers are low density, and thus can not severely increase, and may even decrease, the specific gravity of nanocomposites; (4) Biofillers have high specific strength and modulus, i.e. high rigidity, that contribute a reinforcing function; (5) Biofillers have comparatively easy processability due to their nonabrasive nature, which allows high fill levels and hence a significant cost savings; (6) The relatively reactive surface of biofillers, covered with many hydroxyl groups, provides a great opportunity for chemical modification and grafting; (7) Recycling by combustion of noncellulosic biofiller-filled composites is easier in comparison with inorganic filler systems; (8) The self-organized arrangement of biofillers in nanocomposites may regulate electronic, optical, magnetic, and superconductive properties. As a result, the possibility of using noncellulosic biofillers in bio-nanocomposites has received considerable interest.Less

Gelatine-based bio-nanocomposites

Francisco M. Fernandes, Margarita Darder, Ana I. Ruiz, Pilar Aranda, and Eduardo Ruiz-Hitzky

in Nanocomposites with Biodegradable Polymers: Synthesis, Properties, and Future Perspectives

Gelatine is a well-known structural protein widely used in the daily life, as well as in the scientific and technological areas for the preparation of a great variety of composite materials. But in ... More

Gelatine is a well-known structural protein widely used in the daily life, as well as in the scientific and technological areas for the preparation of a great variety of composite materials. But in spite of its abundance and common use, gelatine presents itself as a complex biopolymer with a mixed character between a protein, since it is derived from collagen, and a synthetic linear polymer with random spatial arrangement above certain temperature. For numerous applications, mainly in biomedicine, the biocompatible and biodegradable properties of gelatine are crucial, and usually the reinforcement of biopolymer matrix by assembling to inorganic or hybrid nanoparticles is also required to improve its mechanical stability. Alternative treatments such as chemical crosslinking may also contribute to reduce water swelling and enhance the mechanical properties as well as thermal stability. The incorporation of inorganic solids into the proteinous matrix allows tailoring both the mechanical and functional properties of the resulting gelatine-based composites. Many strategies may be followed to tune the functional properties: selection of inorganic solids offering the desired functionalities, grafting of suitable functional groups to the gelatine hybrids, or combination of additional polymers or fillers in ternary composites. In this way, advanced functional materials of increasing complexity are developed from the basis of a very common biopolymer, opening the way for a wide range of applications of the gelatine-based nanocomposites.Less

Biospheric Ecologies in Cymbeline

Randall Martin

in Shakespeare and Ecology

Cymbeline makes a theatrical virtue of continually echoing dialogue and scenarios from Shakespeare’s previous plays. Earlier critics were doubtful about this ... More

Cymbeline makes a theatrical virtue of continually echoing dialogue and scenarios from Shakespeare’s previous plays. Earlier critics were doubtful about this recycling, wondering whether Shakespeare was not falling back on re-runs to make up for failing inventiveness towards the end of his career. These opinions tended to overlook his return to writers such as Boccaccio and Holinshed for fresh material, as well as his projection of personal conflict into new geographic contexts, in the manner of All’s Well That Ends Well and his other late romances. Modern stage productions have capitalized on these signs of imaginative vigour, however, by embracing Cymbeline’s retrospective recreation as cheeky, knowing humour, particularly in the final scene of over-packed revelations and entwining narratives. Cymbeline’s multiple storylines create a polygeneric experience characteristic of Shakespeare’s plays in general and his romances in particular. Steve Mentz has observed that Cymbeline and other ‘polyglot’ romances are well suited to staging modern narratives about the natural world’s tendencies to interdependence, adaptation, and biodiversity. Every main character in Cymbeline has his or her own environmental attachments (e.g. Innogen and Britain, Giacomo and Italy, Lucius and the Roman empire, Cymbeline and ‘Lud’s Town’, Belarius, Arviragus, Guiderius and Wales, Posthumus and Milford Haven). Each of these place-identities represents a different physical and cultural worldview, so when they shift and/or interweave, they suggest dynamic networks operating at multiple levels of planetary space and time. These webbed relations raise modern questions of environmental ethics and practice. Which plane of ecological relations suggests the best way of dwelling responsibly in the world? Which life-challenge might analogize a resolve to reduce excessive consumption and reverse human harm? (e.g. cultivating the local allotment garden? travelling to fewer conferences? preserving boreal forests?). Following trends in postmodern and postcolonial studies, ecotheorists observe that environmentalism has tended to privilege local attachments and modes of dwelling as the common ground for resistance to degrading forces of economic globalization. Pioneering ecocritic Jonathan Bate, for example, celebrated regional and village-focused writers such as William Wordsworth and John Clare. Less

Reconstruction of the Lower Eyelid

D.J. John Park and Andrew Harrison

in Surgery of the Eyelid, Lacrimal System, and Orbit

The lower eyelid, tethered medially and laterally by the canthal tendons, is normally suspended at the level of the inferior limbus with the aid of ... More

The lower eyelid, tethered medially and laterally by the canthal tendons, is normally suspended at the level of the inferior limbus with the aid of orbicularis tone counterbalanced by the force of the lower eyelid retractors and gravity. The lower eyelid is apposed to the globe because of the posterior position of the canthal tendon insertions relative to the projection of the globe. Disruption of the normal anatomic relationships from trauma or inflammatory disease or as a result of surgical resection of tumors can result in a poorly functioning lower eyelid with poor cosmesis. The lower eyelid has been conceptualized as consisting of three layers or lamellae. The anterior lamella is composed of skin and orbicularis muscle; the middle lamella is composed of the lower eyelid retractor (capsulopalpebral fascia) and fat; and the posterior lamella is composed of tarsus and conjunctiva. One or more of the lamellae may be disrupted following trauma or tumor resection, and each layer must be addressed in order to reconstruct a normal-appearing and -functioning lower eyelid. Imbalance of tension at the anterior and posterior lamellae, especially in the setting of lower eyelid laxity, can result in malrotation of the eyelid margin, causing entropion or ectropion. For example, inflammation and scarring of the conjunctiva from Stevens-Johnson syndrome or ocular cicatricial pemphigoid will produce entropion, whereas contraction of vertical cutaneous scar or ichthyosis will cause ectropion. A balance of tension of the lamellae must be maintained during reconstruction of the lower eyelid in order to prevent secondary malrotation. Disruption of normal anatomy as often seen following trauma can be addressed by reapproximation of the disrupted segments to their normal anatomic positions. Only rarely will trauma to the lower eyelid result in loss of tissue. Reconstruction with local flaps or free grafts is occasionally needed in traumatic cases that present in a delayed fashion. Local flaps and free grafts are needed to fill and reconstruct a defect in the lower eyelid, a situation that most often presents following resection of tumor. Less

Transplant Surgery

Richard G. Molloy, Graham J. MacKay, Campbell S. Roxburgh, and Martha M. Quinn (eds)

in SBAs and EMIs for the General Surgery FRCS