Manipulating cytoplasmic pH under anoxia: A critical test of the role of pH in the switch from aerobic to anaerobic metabolism

Planta ◽  
1995 ◽  
Vol 195 (3) ◽  
Author(s):  
G.G. Fox ◽  
N.R. McCallan ◽  
R.G. Ratcliffe
2000 ◽  
Author(s):  
Michael S. Sacks ◽  
Sanjay Kaushal ◽  
John E. Mayer

Abstract The need for improved heart valve prostheses is especially critical in pediatric applications, where growth and remodeling are essential. Tissue engineered heart valves (TEHV) have functioned in the pulmonary circulation of growing lambs for up to four months [1], and thus can potentially overcome limitations of current bioprosthetic heart valves. Despite these promising results, significant questions remain. In particular, the role of scaffold mechanical properties in optimal extra-cellular matrix development, as well as TEHV durability, are largely unexplored. We have previously demonstrated flexure testing as a sensitive and critical test for BHV tissue mechanical property evaluation [2]. The following study was conducted to determine the feasibility of using this technique to provide fundamental information required for optimizing TEHV scaffold designs.


1989 ◽  
Vol 3 (2) ◽  
pp. 163-166 ◽  
Author(s):  
N. Takasu ◽  
I. Komiya ◽  
Y. Nagasawa ◽  
T. Asawa ◽  
Y. Shimizu ◽  
...  

ABSTRACT The role of calcium in cytoplasmic pH (pHi) changes was studied using 2′,7′-bis(2-carboxyethyl)-5-(and 6-)carboxyfluorescein, an internalized fluorescent pH indicator, in cultured porcine thyroid cells. The Ca2+ ionophores A23187 and ionomycin stimulated thyroid cell alkalinization. An increase in cytoplasmic free calcium resulted in activation of Na+/H+ exchange which alkalinized the cells.


1985 ◽  
Vol 248 (3) ◽  
pp. C379-C386 ◽  
Author(s):  
S. Grinstein ◽  
B. Elder ◽  
W. Furuya

Cytoplasmic pH homeostasis was studied in intact and granule-free porcine neutrophils following activation with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). In intact cells, TPA activated at least two separate processes: a Na+-independent and amiloride-insensitive acidification, and a compensatory acid extrusion. The latter is Na+ dependent and blocked by amiloride and is likely to represent Na+-H+ exchange. Enucleated and degranulated neutrophils (cytoplasts) were prepared by sedimentation of cytochalasin B-treated neutrophils through a discontinuous density gradient. Cytoplasts responded to an artificially imposed acid load with activation of an amiloride-sensitive Na+-H+ exchange. TPA also activated both acid production and Na+-dependent acid extrusion in cytoplasts. The magnitude of the responses was comparable in intact neutrophils and in cytoplasts. These data suggest that 1) the nucleus and the secretory granules are not involved in the acidifying response to TPA, and 2) exocytosis of secretory vesicles is not required for activation of Na+-H+ exchange during acid loading or following treatment with the phorbol ester TPA.


2004 ◽  
Vol 107 (1) ◽  
pp. 7-17 ◽  
Author(s):  
Anita Scipioni ◽  
Sabrina Pisano ◽  
Claudio Anselmi ◽  
Maria Savino ◽  
Pasquale De Santis

2021 ◽  
Vol 71 (4) ◽  
pp. 158-160
Author(s):  
Arifah Nur Shadrina ◽  
Irene Yuniar

Shock in children remains public health importance and causes significant morbidity and mortality worldwide. Hypoperfusion in shock results in decreased oxygen delivery to the tissues, causing a shift from more efficient aerobic pathways to anaerobic metabolism, which results in lactate as the end product. Unlike blood lactate measurement, near-infrared spectroscopy (NIRS) monitoring system is safe and easy to use in measuring tissue oxygenation non-invasively. However, NIRS monitoring has yet to be validated against a standard measure of regional oxygenation. The primary objective of this article is to review the role of cerebral oxygen saturation (rSO2) measured by NIRS in evaluating the outcome of pediatric shock resuscitation.


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