Steady-state levels of pro-dynorphin-related end-products from the brain of the amphibian, Xenopus laevis

1989 ◽  
Vol 479 (1) ◽  
pp. 162-166 ◽  
Author(s):  
Catherine A. Sei ◽  
Robert Richard ◽  
Robert M. Dores
Keyword(s):  
Steady State ◽  
Xenopus Laevis ◽  
End Products ◽  
Steady State Levels ◽  
The Brain

Distribution of pro-opiomelanocortin and its peptide end products in the brain and hypophysis of the aquatic toad, Xenopus laevis

1998 ◽  
Vol 292 (2) ◽  
pp. 251-265 ◽  
Author(s):  
R. Tuinhof ◽  
R. Ubink ◽  
S. Tanaka ◽  
C. Atzori ◽  
F. J. C. van Strien ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
End Products ◽  
The Brain

scholarly journals Proteomic analysis of mouse models of Niemann-Pick C disease reveals alterations in the steady-state levels of lysosomal proteins within the brain

PROTEOMICS ◽  
2012 ◽  
Vol 12 (23-24) ◽  
pp. 3499-3509 ◽  
Author(s):  
David E. Sleat ◽  
Jennifer A. Wiseman ◽  
Istvan Sohar ◽  
Mukarram El-Banna ◽  
Haiyan Zheng ◽  
...  
Keyword(s):  
Steady State ◽  
Mouse Models ◽  
Proteomic Analysis ◽  
Steady State Levels ◽  
Niemann Pick ◽  
The Brain ◽  
Lysosomal Proteins

Continuous Intratumoral Infusion of Methotrexate for Recurrent Glioblastoma: A Pilot Study

Neurosurgery ◽  
1991 ◽  
Vol 28 (5) ◽  
pp. 752-761 ◽  
Author(s):  
David Nierenberg ◽  
Robert Harbaugh ◽  
Herbert L. Maurer ◽  
Teddi Reeder ◽  
Gregory Scott ◽  
...  
Keyword(s):  
Steady State ◽  
Serum Levels ◽  
Recurrent Glioblastoma ◽  
Tumor Bed ◽  
Methotrexate Concentration ◽  
Liquefactive Necrosis ◽  
Methotrexate Dose ◽  
Steady State Levels ◽  
Csf Levels ◽  
The Brain

Abstract Five patients with documented recurrences of glioblastoma multiforme were given continuous infusions of methotrexate delivered intratumorally using implantable catheters and subcutaneous refillable pumps. A continuous infusion of methotrexate (1 mg/d) was begun with concomitant oral administration of folinic acid. The methotrexate dose was increased every 2 weeks to 3, 10, 30, and, ultimately, 75 mg/d in two patients. Samples of serum and ventricular cerebrospinal fluid (CSF) were obtained to determine the levels of methotrexate and total bioactive folates, and brain tissue was obtained from two patients for determination of methotrexate concentration. The patients survived from 7 to 49 weeks after the implantation of the infusion device. Neither the clinical examination nor sequential radiological studies gave clear evidence of reduction in tumor size. Pneumonia developed in one patient, and mild hepatitis and increased seizure frequency in another. Methotrexate was stable in the delivery system over 12 days, and ventricular CSF reached steady-state levels by 5 days. Steady-state ventricular CSF levels of methotrexate were higher than serum levels in some patients, while the reverse was true in others. Levels of total bioactive folates in the CSF did not increase above the normal range. Methotrexate concentrations were highest at the center of the tumor, but measurable amounts of methotrexate were detectable in all areas of the brain. At autopsy in four patients, variable liquefactive necrosis of the brain tumors was seen, and viable tumor was found at the periphery of the tumor bed. These preliminary results suggest that it is technically feasible to infuse methotrexate into brain tumor cavities, and show that little central nervous system or systemic toxicity was encountered in five patients. Better delineation of the safety and efficacy of this therapeutic approach will require further clinical trials.

scholarly journals Modules or Mean-Fields?

Entropy ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 552 ◽  
Author(s):  
Thomas Parr ◽  
Noor Sajid ◽  
Karl J. Friston
Keyword(s):  
Steady State ◽  
Message Passing ◽  
Mean Field Theory ◽  
Functional Anatomy ◽  
Mean Field ◽  
State Density ◽  
Stochastic Dynamical Systems ◽  
Conditional Independency ◽  
The Brain ◽  
Non Equilibrium

The segregation of neural processing into distinct streams has been interpreted by some as evidence in favour of a modular view of brain function. This implies a set of specialised ‘modules’, each of which performs a specific kind of computation in isolation of other brain systems, before sharing the result of this operation with other modules. In light of a modern understanding of stochastic non-equilibrium systems, like the brain, a simpler and more parsimonious explanation presents itself. Formulating the evolution of a non-equilibrium steady state system in terms of its density dynamics reveals that such systems appear on average to perform a gradient ascent on their steady state density. If this steady state implies a sufficiently sparse conditional independency structure, this endorses a mean-field dynamical formulation. This decomposes the density over all states in a system into the product of marginal probabilities for those states. This factorisation lends the system a modular appearance, in the sense that we can interpret the dynamics of each factor independently. However, the argument here is that it is factorisation, as opposed to modularisation, that gives rise to the functional anatomy of the brain or, indeed, any sentient system. In the following, we briefly overview mean-field theory and its applications to stochastic dynamical systems. We then unpack the consequences of this factorisation through simple numerical simulations and highlight the implications for neuronal message passing and the computational architecture of sentience.

scholarly journals The critical role of T cells in glucocorticoid-induced osteoporosis

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Lin Song ◽  
Lijuan Cao ◽  
Rui Liu ◽  
Hui Ma ◽  
Yanan Li ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Steady State ◽  
Side Effects ◽  
Critical Role ◽  
Wild Type ◽  
Receptor Activator ◽  
Steady State Levels ◽  
Induced Apoptosis

AbstractGlucocorticoids (GC) are widely used clinically, despite the presence of significant side effects, including glucocorticoid-induced osteoporosis (GIOP). While GC are believed to act directly on osteoblasts and osteoclasts to promote osteoporosis, the detailed underlying molecular mechanism of GC-induced osteoporosis is still not fully elucidated. Here, we show that lymphocytes play a pivotal role in regulating GC-induced osteoporosis. We show that GIOP could not be induced in SCID mice that lack T cells, but it could be re-established by adoptive transfer of splenic T cells from wild-type mice. As expected, T cells in the periphery are greatly reduced by GC; instead, they accumulate in the bone marrow where they are protected from GC-induced apoptosis. These bone marrow T cells in GC-treated mice express high steady-state levels of NF-κB receptor activator ligand (RANKL), which promotes the formation and maturation of osteoclasts and induces osteoporosis. Taken together, these findings reveal a critical role for T cells in GIOP.

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