Multiplicity of cerebrospinal fluid functions: New challenges in health and disease

This review integrates eight aspects of cerebrospinal fluid (CSF) circulatory dynamics: formation rate, pressure, flow, volume, turnover rate, composition, recycling and reabsorption. Novel ways to modulate CSF formation emanate from recent analyses of choroid plexus transcription factors (E2F5), ion transporters (NaHCO3 cotransport), transport enzymes (isoforms of carbonic anhydrase), aquaporin 1 regulation, and plasticity of receptors for fluid-regulating neuropeptides. A greater appreciation of CSF pressure (CSFP) is being generated by fresh insights on peptidergic regulatory servomechanisms, the role of dysfunctional ependyma and circumventricular organs in causing congenital hydrocephalus, and the clinical use of algorithms to delineate CSFP waveforms for diagnostic and prognostic utility. Increasing attention focuses on CSF flow: how it impacts cerebral metabolism and hemodynamics, neural stem cell progression in the subventricular zone, and catabolite/peptide clearance from the CNS. The pathophysiological significance of changes in CSF volume is assessed from the respective viewpoints of hemodynamics (choroid plexus blood flow and pulsatility), hydrodynamics (choroidal hypo- and hypersecretion) and neuroendocrine factors (i.e., coordinated regulation by atrial natriuretic peptide, arginine vasopressin and basic fibroblast growth factor). In aging, normal pressure hydrocephalus and Alzheimer's disease, the expanding CSF space reduces the CSF turnover rate, thus compromising the CSF sink action to clear harmful metabolites (e.g., amyloid) from the CNS. Dwindling CSF dynamics greatly harms the interstitial environment of neurons. Accordingly the altered CSF composition in neurodegenerative diseases and senescence, because of adverse effects on neural processes and cognition, needs more effective clinical management. CSF recycling between subarachnoid space, brain and ventricles promotes interstitial fluid (ISF) convection with both trophic and excretory benefits. Finally, CSF reabsorption via multiple pathways (olfactory and spinal arachnoidal bulk flow) is likely complemented by fluid clearance across capillary walls (aquaporin 4) and arachnoid villi when CSFP and fluid retention are markedly elevated. A model is presented that links CSF and ISF homeostasis to coordinated fluxes of water and solutes at both the blood-CSF and blood-brain transport interfaces

A COMPARATIVE STUDY OF ISLAMIC AND SOUTH AFRICAN LAW ON LIVING AND CADAVERIC ORGAN DONATIONS: CONSENSUS AND DIVERGENCE

Religion plays a pivotal role in people’s attitude to organ donation. Generally, practising Muslims (adherents of the Islamic faith) are unlikely to consent to organ donation because they believe it is not in keeping with the tenets of Islamic law (Sharī`ah). Although there is a wealth of information on organ donation with reference to both South African and Islamic law, there has not been a study comparing the two sets of laws. The purpose of this article is to develop the literature on living and cadaveric organ donation by drawing a comparison between Islamic law and South African law on this issue. Apart from a few minor differences inherent in each set of laws, there is a startling consensus in South African law and Sunnī (mainstream) Islamic law on the issue of organ donation. This research is also significant in that it provides legal and medical professionals, academics and practitioners with an informed position from which to advise clients and/or patients. This may in turn raise awareness among clients and/or patients, which could result in a desirable increase in organ donation rates among Muslims in South Africa. This article makes a number of recommendations in this regard

A COMPARATIVE STUDY OF ISLAMIC AND SOUTH AFRICAN LAW ON LIVING AND CADAVERIC ORGAN DONATIONS: CONSENSUS AND DIVERGENCE

Religion plays a pivotal role in people’s attitude to organ donation. Generally, practising Muslims (adherents of the Islamic faith) are unlikely to consent to organ donation because they believe it is not in keeping with the tenets of Islamic law (Sharī`ah). Although there is a wealth of information on organ donation with reference to both South African and Islamic law, there has not been a study comparing the two sets of laws. The purpose of this article is to develop the literature on living and cadaveric organ donation by drawing a comparison between Islamic law and South African law on this issue. Apart from a few minor differences inherent in each set of laws, there is a startling consensus in South African law and Sunnī (mainstream) Islamic law on the issue of organ donation. This research is also significant in that it provides legal and medical professionals, academics and practitioners with an informed position from which to advise clients and/or patients. This may in turn raise awareness among clients and/or patients, which could result in a desirable increase in organ donation rates among Muslims in South Africa. This article makes a number of recommendations in this regard.</jats:p

Spatial fragmentation of industries by functions

We show that key functions are spatially clustered with, or dispersed from, each other even within manufacturing industries in West Germany, and that these clustering or dispersion patterns have changed significantly during recent decades. Estimating levels and changes (1992\u20132007) of localizations and colocalizations of selected functions (production, headquarter services, R&D) within 27 West German industries by means of K densities, we identify two broad groups of industries. In \u201cfragmenting\u201d industries, which account for half of manufacturing employment, functions were more clustered with each other than the industry as a whole after the fall of the Iron Curtain but have, in accordance with regional theories of spatial fragmentation, been unbundled spatially from each other subsequently. In \u201cintegrating\u201d industries, by contrast, which account for one third of manufacturing employment, functions were initially dispersed from each other but have subsequently been rebundled spatially with each other. This spatial rebundling may be a consequence of offshoring, i.e., international fragmentation