Edward George Gray. 11 January 1924 – 14 August 1999

2002 ◽  
Vol 48 ◽  
pp. 151-165
Author(s):  
R.W. Guillery

George Gray was an early contributor to our knowledge of the electron microscopic appearance of the central nervous system. He was skilful with the difficult techniques for preparing the tissues, worked rapidly, and was an astute observer. Sitting with him in the dark, staring at a dim image that George was moving rapidly as he searched for significant detail, could be an exciting experience. He had clear ideas about features that mattered and could quickly relate the two-dimensional electron microscopic images to the three-dimensional neural structures under investigation. He is best known for his detailed and perceptive description of synaptic junctions in the mammalian neocortex, and his name is still linked to two distinct junctional types (Gray's type 1 and Gray's type 2), now recognized as generally distinguishing excitatory from inhibitory junctions. He studied a wide range of neural tissues, played a significant role in the early isolation of ‘synaptosomes’, contributed greatly to the rapid advance of knowledge that accompanied the early application of the electron microscope to neural tissues, and influenced a great many later fine-structural studies of the nervous system.

1980 ◽  
Vol 58 (12) ◽  
pp. 1414-1420 ◽  
Author(s):  
Maria T. Debanne ◽  
Erwin Regoeczi ◽  
Mark W. C. Hatton

Binding of bovine asialofetuin by rat liver plasma membranes was studied using different techniques for the separation of the free and bound forms of the glycoprotein and also different approaches to measure nonspecific binding. The membrane preparations had the electron microscopic appearance of a mixture of lamellae and vesicles and their lipid:protein ratios and marker enzyme profiles fell within the range of values available from the literature. The binding capacity was approximately 15 pmol of asialofetuin per milligram of membrane protein.Scatchard plots of the values obtained over a wide range of concentrations (4.8–12.6 μg asialofetuin per 30 μg membrane protein) after incubation at 22 °C showed pronounced non-linearity which, in combination with evaluations according to other theoretical models, was referable to heterogeneity of binding. In sharp contrast, after incubation at 4 °C the Scatchard plot was linear. This difference is interpreted as the expression of a functional, rather than a chemical, heterogeneity in asialofetuin binding. The underlying mechanism is thought to be competition of galactose groups for binding sites with the result that the number of bonds varies between the galactose groups of a bound asialofetuin molecule and the hepatic lectin, depending on the concentration of the glycoprotein in the incubation mixture.


2020 ◽  
Vol 21 (15) ◽  
pp. 5475 ◽  
Author(s):  
Manuela Pennisi ◽  
Giuseppe Lanza ◽  
Luca Falzone ◽  
Francesco Fisicaro ◽  
Raffaele Ferri ◽  
...  

Increasing evidence suggests that Severe Acute Respiratory Syndrome-coronavirus-2 (SARS-CoV-2) can also invade the central nervous system (CNS). However, findings available on its neurological manifestations and their pathogenic mechanisms have not yet been systematically addressed. A literature search on neurological complications reported in patients with COVID-19 until June 2020 produced a total of 23 studies. Overall, these papers report that patients may exhibit a wide range of neurological manifestations, including encephalopathy, encephalitis, seizures, cerebrovascular events, acute polyneuropathy, headache, hypogeusia, and hyposmia, as well as some non-specific symptoms. Whether these features can be an indirect and unspecific consequence of the pulmonary disease or a generalized inflammatory state on the CNS remains to be determined; also, they may rather reflect direct SARS-CoV-2-related neuronal damage. Hematogenous versus transsynaptic propagation, the role of the angiotensin II converting enzyme receptor-2, the spread across the blood-brain barrier, the impact of the hyperimmune response (the so-called “cytokine storm”), and the possibility of virus persistence within some CNS resident cells are still debated. The different levels and severity of neurotropism and neurovirulence in patients with COVID-19 might be explained by a combination of viral and host factors and by their interaction.


1962 ◽  
Vol 12 (2) ◽  
pp. 385-410 ◽  
Author(s):  
Sanford L. Palay ◽  
S. M. McGee-Russell ◽  
Spencer Gordon ◽  
Mary A. Grillo

This paper describes in detail a method for obtaining nearly uniform fixation of the nervous system by vascular perfusion with solutions of osmium tetroxide. Criteria are given for evaluating the degree of success achieved in the preservation of all the cellular components of the nervous system. The method permits analysis of the structural relations between cells at the electron microscopic level to an extent that has not been possible heretofore.


2001 ◽  
Vol 82 (10) ◽  
pp. 2319-2326 ◽  
Author(s):  
J. D. Foster ◽  
D. W. Parnham ◽  
N. Hunter ◽  
M. Bruce

This study has examined the distribution of PrPSc in sheep by immunocytochemistry of tissues recovered from terminally affected animals following their experimental infection by the oral route with BSE. Despite a wide range of incubation period lengths, affected sheep showed a similar distribution of high levels of PrPSc throughout the central nervous system. PrPSc was also found in the lymphoid system, including parts of the digestive tract, and some components of the peripheral nervous system. These abundant PrPSc deposits in sheep in regions outside the central nervous system are in direct contrast with cattle infected with BSE, which show barely detectable levels of PrPSc in peripheral tissues. A number of genetically susceptible, challenged animals appear to have survived.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 465 ◽  
Author(s):  
Shoeb Ansari ◽  
Eleonora Ficiarà ◽  
Federico Ruffinatti ◽  
Ilaria Stura ◽  
Monica Argenziano ◽  
...  

Magnetic Nanoparticles (MNPs) are of great interest in biomedicine, due to their wide range of applications. During recent years, one of the most challenging goals is the development of new strategies to finely tune the unique properties of MNPs, in order to improve their effectiveness in the biomedical field. This review provides an up-to-date overview of the methods of synthesis and functionalization of MNPs focusing on Iron Oxide Nanoparticles (IONPs). Firstly, synthesis strategies for fabricating IONPs of different composition, sizes, shapes, and structures are outlined. We describe the close link between physicochemical properties and magnetic characterization, essential to developing innovative and powerful magnetic-driven nanocarriers. In conclusion, we provide a complete background of IONPs functionalization, safety, and applications for the treatment of Central Nervous System disorders.


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