scholarly journals Energy Substrates for Neurons during Neural Activity: A Critical Review of the Astrocyte-Neuron Lactate Shuttle Hypothesis

2003 ◽  
Vol 23 (11) ◽  
pp. 1263-1281 ◽  
Author(s):  
Ching-Ping Chih ◽  
Eugene L Roberts
Keyword(s):  
Glucose Metabolism ◽  
Experimental Evidence ◽  
Neural Activity ◽  
Critical Review ◽  
Theoretical Background ◽  
Anaerobic Glycolysis ◽  
Energy Substrates ◽  
Lactate Shuttle ◽  
Theoretical Considerations ◽  
Primary Substrate

Glucose had long been thought to fuel oxidative metabolism in active neurons until the recently proposed astrocyte-neuron lactate shuttle hypothesis (ANLSH) challenged this view. According to the ANLSH, activity-induced uptake of glucose takes place predominantly in astrocytes, which metabolize glucose anaerobically. Lactate produced from anaerobic glycolysis in astrocytes is then released from astrocytes and provides the primary metabolic fuel for neurons. The conventional hypothesis asserts that glucose is the primary substrate for both neurons and astrocytes during neural activity and that lactate produced during activity is removed mainly after neural activity. The conventional hypothesis does not assign any particular fraction of glucose metabolism to the aerobic or anaerobic pathways. In this review, the authors discuss the theoretical background and critically review the experimental evidence regarding these two hypotheses. The authors conclude that the experimental evidence for the ANLSH is weak, and that existing evidence and theoretical considerations support the conventional hypothesis.

Electrochemical behavior of aqueous acid perrhenate-containing solutions on noble metals: critical review and new experimental evidence

2003 ◽  
Vol 263 (1) ◽  
pp. 119-132 ◽  
Author(s):  
Eduardo Méndez ◽  
Marı́a F. Cerdá ◽  
Ana M. Castro Luna ◽  
Carlos F. Zinola ◽  
Carlos Kremer ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Electrochemical Behavior ◽  
Critical Review ◽  
Noble Metals ◽  
Aqueous Acid

scholarly journals Regiospecificty in the heterocyclization of β-oxonitriles to 5-substituted 4-oxothiazolidine derivatives

2003 ◽  
Vol 68 (4-5) ◽  
pp. 383-390 ◽  
Author(s):  
Rade Markovic ◽  
Zdravko Dzambaski ◽  
Milovan Stojanovic ◽  
Peter Steel ◽  
Marija Baranac
Keyword(s):  
Experimental Evidence ◽  
Reasonable Explanation ◽  
Theoretical Considerations ◽  
Derivatives Of

Astudy on the regiospecificity of the base-catalyzed reaction of activated ?-oxonitriles 1 with diethyl mercaptosuccinate affording the title compounds 3 is reported. Other competitive heterocyclic products, that is 4-oxo-1,3-thiazinanes 4, derivatives of tetrahydrothiophene 5 and/or thiacyclohexane 6 which on the grounds of mechanistic considerations could be formed, were not observed. Spectroscopic and experimental evidence together with theoretical considerations, provides a reasonable explanation for the observed regiospecificity.

Mechanisms of calcium disposal from osteoclastic resorption hemivacuole

2003 ◽  
Vol 176 (1) ◽  
pp. 1-5 ◽  
Author(s):  
HK Datta ◽  
BR Horrocks
Keyword(s):  
Protein Degradation ◽  
Experimental Evidence ◽  
Matrix Protein ◽  
Degradation Products ◽  
Transcellular Transport ◽  
Osteoclastic Resorption ◽  
Osteoclast Function ◽  
Theoretical Considerations ◽  
Simple Link

One of the most remarkable but neglected aspects of osteoclast function is its unique adaptation that allows the cell to function despite its resorbing surface being exposed to extremely high levels of ambient Ca2+. Recently our studies have provided evidence of continuous transcellular Ca2+ disposal, suggesting that osteoclasts are able to prevent Ca2+ accumulation within the resorptive hemivacuole. It has also been shown that matrix protein degradation products that accumulate within the osteoclast resorptive vacuole are also undergoing transcellular transport by transcytosis. However, both experimental evidence and theoretical considerations suggest that transcellular transport of Ca2+ and matrix protein is likely to occur via distinct routes. In light of these considerations, we are able to provide convincing explanations for the apparent anomalies of osteoclast intracellular [Ca2+] responses to a variety of endocrine stimuli. The understanding of the mechanisms involved in Ca2+ handling by osteoclasts indicates the lack of a simple link between osteoclast function and changes in overall cytosolic [Ca2+].

scholarly journals The Competitiveness of Business Groups and Their Affiliates in International Operations

2016 ◽  
Vol 8 (1) ◽  
pp. 251-262
Author(s):  
Roderick Caballero Bugador
Keyword(s):  
Emerging Economies ◽  
Critical Review ◽  
Business Groups ◽  
Business Group ◽  
Emerging Economy ◽  
Theoretical Background ◽  
International Expansion ◽  
Vast Literature ◽  
International Operations ◽  
Managerial Capabilities

AbstractThe discourse on the competitiveness of emerging economy firms continues with globalization. This paper joins the dialogue by providing a framework of the competitiveness of business groups and their affiliates in international operations. The goal is to address the vast literature on emerging economies that remains short in providing the theoretical background on the competitiveness of emerging and transitioning economy firms. To do this, this study used a critical review and analysis of the literature. It offers some propositions to illustrate the applicability of the framework in analyzing the international expansion of business group affiliates across borders. Ultimately, the paper contributes to the literature on managerial capabilities and competitiveness of firms to sustain their operations as the new emerging economy multinationals.

178 TRANSCRIPTIONAL DIFFERENCES IN GENES RELATED TO GLUCOSE METABOLISM BETWEEN COMPETENT AND INCOMPETENT BOVINE IMMATURE CUMULUS-OOCYTE COMPLEXES SELECTED BY BCB

2017 ◽  
Vol 29 (1) ◽  
pp. 197
Author(s):  
I. Lamas-Toranzo ◽  
D. A. Martínez-Corona ◽  
E. Pericuesta ◽  
P. Bermejo-Álvarez
Keyword(s):  
Glucose Metabolism ◽  
Growth Phase ◽  
In Vitro Maturation ◽  
Cumulus Cells ◽  
Transcriptional Analysis ◽  
Glutathione Metabolism ◽  
Anaerobic Glycolysis ◽  
G6pdh Activity ◽  
Morphological Criteria

In vitro maturation is a key step of in vitro embryo production, being the main factor responsible for the low blastocyst yield. In vitro maturation requires the selection of competent immature cumulus-oocytes complexes (COC), which is usually accomplished based on morphological criteria and follicle size. Competent immature COC have finished their growth phase and show decreased G6PDH activity. Brilliant cresol blue (BCB) is a dye that is degraded by G6PDH and, therefore, can be used to distinguish COC that have finished their growth phase (BCB+) from those that are still growing and are less competent (BCB-). The objective of this study was to determine the metabolic differences between BCB- and BCB+ COC by performing a transcriptional analysis of genes related to glucose metabolism. The COC obtained from slaughterhouse ovaries were selected based on BCB staining. The BCB+ and BCB- COC were fertilized and cultured in vitro to determine the differences in developmental ability. For gene expression analysis, BCB+ and BCB- COC were denuded by vortexing and 5 groups of 10 oocytes; their corresponding cumulus cells per group were snap-frozen until analysis. Messenger RNA was extracted by Dynabeads (Dynal Biotech, Lake Success, NY, USA) and relative mRNA abundance was analysed by quantitative PCR using PPIA1 as housekeeping. Statistical differences were determined based on ANOVA (P < 0.05). The genes analysed were G6PDH, its positive regulator SIRT2, 2 glucose transporters SLC2A1 and SLC2A5, 2 genes involved in anaerobic glycolysis GAPDH and LDHA, 2 genes related with Krebs cycle CS and ATP5A1, and 1 gene related to glutathione metabolism GPX1. As expected, the BCB+ group showed a higher cleavage rate (85.6 ± 1.8 v. 74.2 ± 1.3%, BCB+ v. BCB-; P < 0.05) and blastocyst yield (Day 9: 33.3 ± 3.8 v. 16.1 ± 1.4%, BCB+ v. BCB-; P < 0.05) compared with BCB-. Genes SIRT2, GAPDH, and LDHA were significantly up-regulated in BCB- cumulus cells (SIRT2: 1 ± 0.04 v. 1.45 ± 0.21; GAPDH: 1 ± 0.17 v. 1.46 ± 0.15; LDHA: 1 ± 0.22 v. 1.65 ± 0.12; BCB+ v. BCB-; P < 0.05), whereas no significant differences were found in the other genes and in oocytes. In conclusion, the differences in G6PDH activity between BCB+ and BCB- COC are not controlled by G6PDH transcript abundance, but seem to be mediated by SIRT2 regulation of G6PDH activity. The BCB- cumulus cells showed an up-regulation of GAPDH and LDHA, suggesting a higher activity of anaerobic glycolysis in BCB- COC compared with BCB+.

A Critical review about Haratala ( Orpiment )

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Pranav K. Shah ◽  
L. B. Singh ◽  
P. U. Vaishnav ◽  
Bharat Kalsariya
Keyword(s):  
Experimental Evidence ◽  
Intestinal Absorption ◽  
Critical Review ◽  
Skin Disease ◽  
Powdered Material ◽  
Inorganic Compound ◽  
Burning Sensation ◽  
Toxic Effects ◽  
High Degree

Haratala (Arsenic trisulphide) is an inorganic compound with the formula As2S3. The Haratala is used without proper purification the toxic effects are Daha (burning sensation), Kampaka (tremors), Toda (pricking pain), Kshobha, Pida, Raktadusti (vitiates blood), Kushta (skin disease), Malinikaroti Gatram, Vata Kapha Prakopatamaka Roga, Mrtyusankakara. Coarse powdered material is less toxic because it can be eliminated in faeces before it dissolves, experimental evidence has shown a high degree of gastro-intestinal absorption of both trivalent and pentavalent forms of arsenic. Arsenic is eliminated by many routes (faeces, urine, sweat, hair, skin, lungs) although most is excreted in urine of man.

scholarly journals Prediction of seizure outcome following epilepsy surgery: Asymmetry of thalamic glucose metabolism and cerebral neural activity in temporal lobe epilepsy

Seizure ◽  
2009 ◽  
Vol 18 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Shinichi Sakamoto ◽  
Toshihiro Takami ◽  
Naohiro Tsuyuguchi ◽  
Michiharu Morino ◽  
Kenji Ohata ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Epilepsy Surgery ◽  
Neural Activity ◽  
Seizure Outcome
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