Regulation of immune cell entry into the central nervous system

The central nervous system (CNS) has long been regarded as an immune privileged organ implying that the immune system avoids the CNS to not disturb its homeostasis, which is critical for proper function of neurons. Meanwhile, it is accepted that immune cells do in fact gain access to the CNS and that immune responses can be mounted within this tissue. However, the unique CNS microenvironment strictly controls these immune reactions starting with tightly controlling immune cell entry into the tissue. The endothelial blood-brain barrier (BBB) and the epithelial blood-cerebrospinal fluid (CSF) barrier, which protect the CNS from the constantly changing milieu within the bloodstream, also strictly control immune cell entry into the CNS. Under physiological conditions, immune cell migration into the CNS is kept at a very low level. In contrast, during a variety of pathological conditions of the CNS such as viral or bacterial infections, or during inflammatory diseases such as multiple sclerosis, immunocompetent cells readily traverse the BBB and likely also the choroid plexus and subsequently enter the CNS parenchyma or CSF spaces. This chapter summarizes our current knowledge of immune cell entry across the blood CNS barriers. A large body of the currently available information on immune cell entry into the CNS has been derived from studying experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. Therefore, most of this chapter discussing immune cell entry during CNS pathogenesis refers to observations in the EAE model, allowing for the possibility that other mechanisms of immune cell entry into the CNS might apply under different pathological conditions such as bacterial meningitis or stroke.

Overview of analytical approaches

The general model The aim of this chapter is to introduce a structured overview of the different possibilities available to display and analyze brain electric scalp potentials. First, a general formal model of time-varying distributed EEG potentials is introduced. Based on this model, the most common analysis strategies used in EEG research are introduced and discussed as specific cases of this general model. Both the general model and particular methods are also expressed in mathematical terms. It is however not necessary to understand these terms to understand the chapter. The general model that we propose here is based on the statement made in Chapter 3, stating that the electric field produced by active neurons in the brain propagates in brain tissue without delay in time. Contrary to other imaging methods that are based on hemodynamic or metabolic processes, the EEG scalp potentials are thus “real-time,” not delayed and not a-priori frequency-filtered measurements. If only a single dipolar source in the brain were active, the temporal dynamics of the activity of that source would be exactly reproduced by the temporal dynamics observed in the scalp potentials produced by that source. This is illustrated in Figure 5.1, where the expected EEG signal of a single source with spindle-like dynamics in time has been computed. The dynamics of the scalp potentials exactly reproduce the dynamics of the source. The amplitude of the measured potentials depends on the relation between the location and orientation of the active source, its strength and the electrode position.

Foundations of stochastic geometry and theory of random sets

The first section of this chapter starts with the Buffon problem, which is one of the oldest in stochastic geometry, and then continues with the definition of measures on the space of lines. The second section defines random closed sets and related measurability issues, explains how to characterize distributions of random closed sets by means of capacity functionals and introduces the concept of a selection. Based on this concept, the third section starts with the definition of the expectation and proves its convexifying effect that is related to the Lyapunov theorem for ranges of vector-valued measures. Finally, the strong law of large numbers for Minkowski sums of random sets is proved and the corresponding limit theorem is formulated. The chapter is concluded by a discussion of the union-scheme for random closed sets and a characterization of the corresponding stable laws.

Typology of the Tools of EC Communications Regulation

The present article is an abridged version of a chapter to the book EC Electronic Communications and Competition Law (London: Cameron May 2007). It explores in a neutral manner the pros and cons of the currently applied toolkit of European Community communications law, i.e. the generic competition law rules and the sector specific regulatory framework. A number of criteria are introduced and these tools are then tested as to their efficiency and efficacy.

The effects of legal involvement on crime victims' psychological adjustment

The purpose of this chapter is to examine the effects of legal involvement of crime victims on their psychological adjustment. First, causes of possible effects are described, which may be located within the procedure or the outcome of the legal process. Then, the available evidence is reviewed, most of it suggesting that legal involvement does not strongly affect the victims' psychological adjustment, neither negatively nor positively. The chapter continues with a discussion of whether victims should be advised to report the assault to the police or not, and it describes relevant decision criteria, such as victim adjustment retributive justice, victim compensation, victim security and societal security. Finally, suggestions for future research are outlined, pointing to necessary methodological improvements in the design of future studies on legal involvement.

Ultrastructure and Pathoanatomy of the Rotator Cuff

The rotator cuff is a complex musculotendinous unit, which plays a major role in glenohumeral joint stability and mobilization. Tears of the rotator cuff tendon and its subsequent changes of the rotator cuff muscle are common, and the incidence increases with age. Several structures such as the muscle, tendon, and bone may contribute to the development of a tear as well as on the outcome following a rotator cuff repair. Knowledge of these structures may help to improve rotator cuff healing after rotator cuff tear. The goal of this chapter is to discuss the evidence which exists with regard to the pathophysiological changes in the muscle, tendon, and bone that lead to a rotator cuff rupture as well as the changes that occur in these structures after a tear has occurred.

Scalp field maps and their characterization

The present chapter gives a comprehensive introduction into the display and quantitative characterization of scalp field data. After introducing the construction of scalp field maps, different interpolation methods, the effect of the recording reference and the computation of spatial derivatives are discussed. The arguments raised in this first part have important implications for resolving a potential ambiguity in the interpretation of differences of scalp field data. In the second part of the chapter different approaches for comparing scalp field data are described. All of these comparisons can be interpreted in terms of differences of intracerebral sources either in strength, or in location and orientation in a nonambiguous way. In the present chapter we only refer to scalp field potentials, but mapping also can be used to display other features, such as power or statistical values. However, the rules for comparing and interpreting scalp field potentials might not apply to such data. Generic form of scalp field data Electroencephalogram (EEG) and event-related potential (ERP) recordings consist of one value for each sample in time and for each electrode. The recorded EEG and ERP data thus represent a two-dimensional array, with one dimension corresponding to the variable “time” and the other dimension corresponding to the variable “space” or electrode. Table 2.1 shows ERP measurements over a brief time period. The ERP data (averaged over a group of healthy subjects) were recorded with 19 electrodes during a visual paradigm. The parietal midline Pz electrode has been used as the reference electrode.

[Imaging for hepato-pancreatico-biliary diseases - a short review]

The purpose of this chapter is to give a practical and clinically-orientated overview over the best radiological imaging for the most frequent diseases of the hepato-pancreatico-biliary system. For this purpose the liver parenchyma, the biliary tree, the pancreas and the hepatic vasculature are dealt with separately. According to the presumed pathology, the most cost-saving and time-efficient radiological imaging can then be chosen.