Cortical phase

Fig. 74. Delayed CT in apatient with ALPE and a patient with myoglobinuric acute renal failure with a serum creatinine level of 1.5mg/dl. In the patient with ALPE, wedge-shaped contrast enhancement was observed 24 h after the administration of a contrast medium. However, wedge-shaped contrast enhancement could not be confirmed in the cortical phase 20-40 s after the administration, or in the excretory phase 3 min after the administration (see Fig. 17). The patient with myoglobinuric acute renal failure showed diffuse contrast enhancement...

With regard to the development of osteopenia or osteoporosis with hypogonadism in males, lack of androgens is considered as a risk factor from the point of view of the quality of the bone. Anabolic steroids act on the bone probably through the androgen receptors on the osteoblasts, but an inhibitory effect on the osteoclasts is also possible. The condition affects mainly the cortical phase of the bone. When anabolic steroids are applied in females, they are usually combined with estrogens. Their application acts preventively against the loss of bone mass, stimulates osteoformation, and reduces the risk of hip fracture. 

Fig.1.2.1a-f. Normal MR urogram in 3-month-old boy with antenatal hydronephrosis. Images a-c show same slice from each of three separate volume acquisitions, whereas d-f show MIP projections derived from the same three separate time points, a and d show the cortical phase, b and e were acquired 60 s later and demonstrate enhancement of both the cortex and medulla with the signal intensity of the medulla exceeding the cortex, c and f were acquired 115 s after the vascular phase and show excretion into the calyces, renal pelvis and ureters. The renal transit time was 2 min and 20 s bilaterally and the volumetric DRF was 51 49... 

Fig. 25.11 a-c. A 5-year-old boy who was the victim of a motor vehicle accident, a Enhanced CT scan (tubular phase) showing absence of opacification of the anterior part of the right kidney (note the cortex corticis enhancement pattern). b Same examination 2D reformatting in the coronal plane. No surgery was performed, c Four months later, follow-up CT (vascular and cortical phase) showed atrophy of the involved area. The inferred final diagnosis was traumatic lesion of the anterior branch of division of the right renal artery... 

Diagenesis of the inorganic phase of cortical bone. In Price, T.D., ed.. Bone Chemistry and Past Behaviour. Cambridge, Cambridge University Press 211-229. 

The slow (deep sleep) -waves probably originate in the eortex beeause they survive separation from, or lesions of, the thalamus. However, the rhythm and appearanee of spindles in earlier phases of the sleep eyele do depend on links with the thalamus (see Steriade 1999). Unlike stimulation of the specific sensory relay nuclei in the thalamus, which only affects neurons in the appropriate sensory areas of the cortex, the nonspecific nuclei can produce responses throughout the cortex and may not only control, but also generate, cortical activity. Certainly, in vitro studies show that neurons of the non-specific reticular thalamic nucleus (NspRTN) can fire spontaneously at about 8-12 Hz (equivalent to EEG a-rhythm) or lower, and that low-frequency stimulation of this area can induce sleep. 

It is important to emphasise that a lesion of the reticular system disrupts a number of afferent inputs to the cortex. Particularly important in this respect are the mono-aminergic (especially noradrenaline, 5-HT and histamine) and cholinergic pathways. When the ascending inputs from these neurons are destroyed, sleep is passive and not at all like natural sleep which, as detailed above, has distinct phases and depends on brainstem influences on cortical function. How these different neurotransmitters might influence sleep and arousal will be considered next. 

FIG. 1. Timing and morphology of mouse embryos during the first two cleavages. The cortical activity of the one-cell embryo begins during late G2 phase shortly before the entry into the mitotic M phase. Scheme represents shapes of embryos and morphology of their chromatin and microtubule cytoskeleton. 

The entry into the first mitotic M phase at the end of the first embryonic cell cycle requires activation of MPF. In the mouse one-cell embryo this activation is fully autonomous from the nucleus (Ciemerych 1995, Ciemerych et al 1998). It proceeds within the cytoplasts obtained either by enucleation or by bisection of the embryo. Other autonomous phenomena are the cortical activity, or the deformation of the one-cell embryo, directly preceding the entry into first mitosis (Waksmundzka et al 1984) and the cyclic activity of K+ ion channels (Day et al 1998). The role of the cortical activity remains unknown however, the fact that it directly precedes the entry into the first mitotic M phase suggests that it could be linked to the activation... 

However, in interphase delaminating neuroblasts, which are known to have completed S-phase and are at the G2 stage of the cell cycle, this codependence of Baz/Insc/Pins seen in mitotic neuroblasts does not apply. Delaminating neuroblasts possess an apical membrane stalk which retains contact with the epithelial surface and this is where apical cortical localization of Insc is initially seen (see Fig. 2). This initial localization of Insc to the apical stalk occurs... 

SSR-504734 is a potent, selective, and reversible inhibitor (IC50 = 18 nM) that is competitive with glycine [47,51]. The inhibitor rapidly and reversibly blocked the uptake of [14C]glycine in mouse cortical homogenates, which was sustained for up to 7 h. Complete cessation of blockade and return to glycine basal levels occurred prior to 24 h, which is in stark contrast to NFPS (>24 h). SSR-504734 potentiated a nearly twofold increase of NMDA receptor-mediated excitatory postsynaptic currents (EPSCs) in rat hippocampal slices and produced an increase in contralateral rotations in mice when microinjected into the striatum. Microdialysis experiments indicated that the inhibitor induced a rapid and sustained increase in extracellular glycine levels in the PFC of freely moving rats [51]. The compound also demonstrated efficacy in a variety of psychosis models [51-53]. SSR-504734 was reportedly in clinical trials for schizophrenia but discontinued after Phase I (data not disclosed) [54]. 

There has been concern at various times that prolonged oral contraception might cause permanent changes in the genital system. When high-dose products were in use, various studies showed condensation of the superficial cortical layers of the ovary (SEDA-8, 863). Severe atrophy of the endometrium after a period of oral contraception has been described (267), but the report usually quoted is one that dates from a period when high doses were in use, and the incidence is not known, since the endometrium is not usually examined. Certainly, the endometrium will go into a resting phase in women who have amenorrhea, but there is no reason to believe that it will become permanently unresponsive. 

Two vanadium bromoperoxidases that differ in carbohydrate content [26,33] have been isolated from A. nodosum. The most abundant bromoperoxidase, V-BrPO-I, was found in the thallus, and the other bromoperoxidase, V-BrPO-II, was reported to be present on the thallus surface [26], A previous report also concluded that V-BrPO is present in two different locations of A. nodosum, one in the cell walls of the transitional region between the cortex and medulla of the thallus and the other in the cell wall of the thallus surface [34], More recent experiments demonstrate that vanadium-dependent bromoperoxidase activity is present in both the cortical and surface protoplasts of M. pyrifera [35], L. saccharina, and L. digitata [36], The biosynthesis of V-BrPO in the protoplasts of L. saccharina has been shown using [35S]-methionine [36], The vanadium bromoperoxidases are all acidic proteins [26] with very similar amino acid compositions [37], V-BrPO (A. nodosum) has been crystallized, although refined structural data have not been reported yet [38], A different isolation procedure, based primarily on a two-phase extraction system, has been described [39,40], This procedure works well for certain types of algae (e.g., Laminaria) but not for the isolation of V-BrPO from A. nodosum, the principal source of V-BrPO for the mechanistic studies. 

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