The effect of alterations in extracellular pH on cellular and humoral immune function is reviewed. Because acidic pH predominates at inflammatory loci and other sites of immune activity, most studies to date focus on the effect of acidic rather than alkaline pH. Investigations on polymorphonuclear leukocytes demonstrate mainly inhibition of chemotaxis, respiratory activity, and bactericidal cap...

The effect of pH adjusted by aeration with carbon dioxide (CO(2)) on the growth of two species of blue-green algae, Microcystis aeruginosa and Anabaena spiroides, was investigated. Three conditions (pH 5.5, 6.0 and 6.5) were found to have significant inhibitory effects on the growth of the two algae species when acidification treatment was conducted during the logarithmic phase. Differences in ...

Ocean acidification (OA) is the reduction in seawater pH due to the absorption of human-released CO2 by the world's oceans. The average surface oceanic pH is predicted to decline by 0.4 units by 2100. However, kelp metabolically modifies seawater pH via photosynthesis and respiration in some temperate coastal systems, resulting in daily pH fluctuations of up to ±0.45 units. It is unknown how th...

The effect of the external pH in the range of 5.5 to 8.0 on the activity of three PSII herbicides (diuron, atrazine and dinoseb) was studied in isolated thylakoid membranes by means of prompt and delayed fluorescence induction kinetics. Well-expressed pH dependence was established for prompt fluorescence parameters (Fv/Fm, Fi/Fm) as well as for delayed fluorescence parameters (I1, I2). Two type...

Low pH has a strong stabilising effect on the fibrillar assembly of amyloid β, which is associated with Alzheimer's disease. The stabilising effect is already pronounced at pH 6.0, suggesting that protonation of histidines might mediate this effect. Through the systematic substitution of the three native histidines in Aβ for alanines, we have evaluated their role in fibril stability. Using surf...

This investigation was undertaken to ascertain the effect of simulated acid rain (SAR) on growth, yield and physiological parameters of tomato. SAR exposure (pH 3.0 and 4.0) caused white-to-tan spots on the abaxial and adaxial surface of tomato leaves. SAR exposure at pH 3.0 and 4.0 significantly suppressed pigment synthesis, shoot and root dry weights and yield of tomato. The effects were more...

In this study, the effect of metabolic inhibition (MI) by glucose substitution with 2-deoxyglucose (2-DOG) and/or application of antimycin A on ovine rumen epithelial cells (REC) vacuolar-type H(+)-ATPase (vH(+)-ATPase) activity was investigated. Using fluorescent spectroscopy, basal pH(i) of REC was measured to be 7.3 +/- 0.1 in HCO(3) (-)-free, glucose-containing NaCl medium. MI induced a str...