Anatomical Effects Integration

The near isotropic imaging obtained by spiral CT allows not only the accurate evaluation of anatomic details on native images, but even the reconstruction of oblique planes (MPR, multiplanar reconstructions) (Ali et al. 1993 Hermans et al. 1995). MPRs are well known since the introduction of CT in the clinical practice. Initial applications of MPR to the study of the middle ear were carried out with conventional CT (Haas and Kahle 1988 Grevers et al. 1989), and such experiences addressed to MPR an effective integrative role in CT imaging of the middle ear. With the advent of spiral CT, MPRs have been made available for most users, and the frequency of their application in the clinical routine has increased. 

The goal of this chapter is to review recent morphologic studies in which current anatomic me ods have been used to characterize the neurotoxic effects of psychoactive amphetamine derivatives. Several strategies combining anatomic with biochemical data have been employed to analyze the effects of selected drugs in this class. These studies show that psychoactive drugs that have selective neurotoxic effects can be useful experimental tools to study the neural mechanisms of elusive brain functions such as affective state control and perceptual integration. 

There is really only one, whole, integrated nervous system. However, for the purposes of understanding the effects of drugs and poisons on the system, we will subdivide it anatomically and functionally. Afferent nerves... 

Figure 4.1. The vascular blood-brain barrier three levels of complexity. The upper panel illustrates the brain endothelial cell. This is the functional and anatomical site of both barrier function and of saturable and non-saturable mechanisms of passage. The major modifications allowing both barrier function and selective penetration of substances are indicated. The middle panel illustrates other ceU types and structures important in BBB function. Pericytes are embedded in a basement membrane and astrocytes form a net-like structure over the capillary bed. Both cell types are in paracellular communication with the brain endothelial cells. Pericytes and astrocytes to some extent oppose each others effects on BBB fnnctions. The lower panel illnstrates the neurovascnlar nnit, a concept, that emphasizes integration of peripheral, BBB, and central interactions.

Techniques have been developed for study of the renal microcirculation. These techniques have distinct advantages over in vitro endothelial and vascular smooth muscle cell preparations. They allow study of important anatomic and physiologic relationships that are lost in isolated cell systems. For example, the effects of both pressure and flow can be determined and the spatial relahonship between the endothelium and smooth muscle is maintained. These techniques permit functional assessment of the resistance micro-vasculature without destroying vessel integrity while eliminating the confounding influence of undetected circulating, neural and parenchymal factors. The techniques are demonstrated in Table 8. 

Bourges et al. studied the kinetics of polylactide (PLA) nanoparticle (NP) localization within the intraocular tissues and to evaluate their potential to release encapsulated material. Environmental scanning electron microscopy (ESEM) showed the flow of the NPs from the site of injection into the vitreous cavity and their rapid settling on the internal limiting membrane. Histology demonstrated the anatomic integrity of the injected eyes and showed no toxic effects. A mild inflammatory cell infiltrate was observed in the ciliary body 6 h after the injection and in the posterior vitreous and retina at 18-24 h. The intensity of inflammation decreased markedly by 48 h. Confocal and fluorescence microscopy and immunohistochemistry showed that a transretinal movement of the NPs was... 

Today, PET has an important role in the management of patients with liver metastases from various primaries. It provides functional information that can be used to detect hepatic metastases, to predict their response to therapy, and to follow-up them effectively. PET-CT has the unique advantage of combining functional and anatomic imaging in an integrated scanner and allows for a comprehensive evaluation of patients with liver metastases. 

As reviewed in Chapter 7 with a focus on the issue of insolubility, extensive phenomenological correlations exist between muscle contraction and contraction by model proteins capable of inverse temperature transitions of hydrophobic association. As we proceed to examination of muscle contraction at the molecular level, a brief restatement of those correlations follows with observations of rigor at the gross anatomical level and with related physiological phenomena at the myofibril level. Each of the phenomena, seen in the elastic-contractile model proteins as an integral part of the comprehensive hydrophobic effect, reappear in the properties and behavior of muscle. More complete descriptions with references are given in Chapter 7, sections 7.2.2, and 7.2.3. 

Anatomical characteristics and physiological mechanisms protect the eye against toxic external effects. These mechanisms include the specific structure of the cornea, blinking, baseline and reflex lachiymation, drainage, tear film composition and the corneal sensitivity. The combination of aU mechanistic, anatomical and physiological characteristics maintains the integrity of the eye, together... 

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