Search results for "chiasm"
showing 10 items of 42 documents
Circadian Rhythm Variations and Nutrition in Children
2018
AbstractCircadian rhythms are the changes in biological processes that occur on a daily basis. Among these processes are reactions involved in metabolic homeostasis. Circadian rhythms are structured by the central clock in the suprachiasmatic nucleus of the hypothalamus via the control of melatonin expression. Circadian rhythms are also controlled by the peripheral clocks, which are intracellular mechanisms composed of the clock genes, whose expression follows a circadian pattern. Circadian rhythms are impacted by signals from the environment called zeitgebers, or time givers, which include light exposure, feeding schedule and composition, sleeping schedule and pattern, temperature, and phy…
A case of intrasellar aneurysm simulating a pituitary adenoma
1959
A case of intrasellar aneurysm simulating a pituitary adenoma has been reported. The literature on the subject has been reviewed. The diagnostic difficulties related to intrasellar aneurysms and the role that arteriography should play in the study of chiasmatic lesions have been discussed.
Contralateral and ipsilateral microsurgical approaches to carotid-ophthalmic aneurysms.
1997
Objective The vicinity of carotid-ophthalmic aneurysms to the roof of the cavernous sinus, to the anterior clinoid process, and to the optic nerve or the optic chiasm requires well-defined surgical techniques. Although microsurgical techniques with ipsilateral direct approaches to these aneurysms have been described in detail, studies about contralateral strategies for the microsurgical treatment of carotid-ophthalmic aneurysms are rare and are mainly confined to case reports. The aim of this study is to describe how to decide on the ipsilateral and contralateral microsurgical approaches to such aneurysms and to demonstrate the surgical techniques for the ipsilateral and contralateral expos…
Biportal neuroendoscopic microsurgical approaches to the subarachnoid cisterns. A cadaver study.
1996
A preclinical cadaver study was performed to develop the technique of biportal neuroendoscopic dissection in the subarachnoid space of the basal cisterns and to test the feasibility, utility, and safety of this new technique. In 23 fresh post-mortem adult human cadavers and 2 formalin-fixed adult human head specimen a total of 33 biportal endomicrosurgical dissections into and within the basal cisterns were carried out. Following suction of cerebrospinal fluid from the subarachnoid space 0 degree-, 30 degrees-, and 70 degrees-lens-scopes (Aesculap AG, Tuttlingen, Germany) with outer diameters of 4.2 mm and trochars with outer diameters of 5 to 6.5 mm were introduced into the surgical field.…
Inferior altitudinal hemianopia associated with a tumor in the posterior fossa: report of a case
1984
Altitudinal hemianopias may be related to chiasmatic involvement. A case in which horizontal inferior hemianopia is associated with a tumor in the posterior fossa producing a triventricular hydrocephalus is described. The visual field defect is interpreted as a consequence of the pressure by a dilated third ventricle upon the chiasmatic area.
Prophecy and Apocalypse among the Oromo-Borana: The Power of Chiasmus
2018
This chapter bridges the rhetoric culture and anticipation theoretical domains for reinterpreting the prophetic and apocalyptic texts on the Oromo-Borana (Ethiopia). The analysis qualifies prophecy as a practice of anticipation, a rational and collective exercise of criticism to current social trends, facilitated by creative individuals that make full use of the cognitive potential of chiasmus and other rhetorical devises.
Intracranial pathology of the visual pathway.
2004
Intracranial pathologies involving the visual pathway are manifold. Aligning to anatomy, the most frequent and/or most important extrinsic and intrinsic intracranial lesions are presented. Clinical symptoms and imaging characteristics of lesions of the sellar region are demonstrated in different imaging modalities. The extrinsic lesions mainly consist of pituitary adenomas, meningeomas, craniopharyngeomas and chordomas. In (asymptomatic and symptomatic) aneurysms, different neurological symptoms depend on the location of aneurysms of the circle of Willis. Intrinsic tumors as astrocytoma of any grade, ependymoma and primary CNS-lymphoma require the main pathology in the course of the visual …
Microsporogenesis in three wild species of the genusAntirrhinumL. (A. litigiosumPau,A. pulverulenthumLazaro andA. subbaeticumGüemes, Sánchez and Mate…
2010
The diploid chromosome number (2n = 2x = 16) in three wild species A. litigiosum Pau, A. pul- verulenthum Lazaro and A. subbaeticum Guemes, Sanchez & Mateu, belonging to the genus Antirrhinum was cytologically observed. Genetic stability of the simultaneous meiotic division type was found in these natural growing snapdragons. The synchronicity at the initial meiotic stages and at tetrad and pollen creation was high and disappeared with the diakinesis initiation. Refl ecting the systematic position of the studied species into Antirrhinum, the performed investigation mani- fested similarity: in the presence of univalents and quadrivalent confi gurations parallel with bivalents at the early me…
Vergleich der Wertigkeit von Magnetresonanztomographie und Computertomographie bei Patienten mit Nelson-Syndrom
1992
The hypophyses of 13 patients with Nelson syndrome following bilateral adrenalectomy were examined by MRI and CT. Diffuse enlargement of the hypophysis was demonstrated in 8 patients by CT and in 9 by MRI. Compared with CT, MRI provides better demonstration of tumour development, such as abnormal convexity of the cranial margin of the hypophysis (MRI 4/13, CT 1/13), displacement of the infundibulum (MRI 4/13, CT 0/13) or optic chiasm (MRI 2/13, CT 0/13). MRI also provides diagnostically important differentiation between scar tissue and recurrence of tumour following hypophysectomy (MRI 1/3, CT 0/3) and more accurate demonstration of infiltration of the cavernous sinus (MRI 4/13, CT 2/13). C…
A geographical note about the journey
2022
This paper summarizes the contents of the in print monographic volume entitled About the journey. Stasis, chiasmus and interruptions. A geography essay. It aims at being part of the epistemological debate on the role of the journey intended as a complex action through which relationships between man and space are strengthened and the fundamental cognitive processes are activated. In the first chapter, we want to foster a consideration on the tripartite scan that has the journey as the terminal outcome: stasis, trigger, experience. The paper has its roots in the international and national debates of New Cultural Geography, an essential theoretical prerequisite for setting up a theoretically …