We studied ocular surface pH in 161 subjects. The mean pH for 133 normal volunteers was 7 . 11, SD 1 . 5. We found that older women had a more alkaline pH than other subjects, that the pH shifted from acid to alkaline during the day, that one hour of eyelid closure caused an acid shift in pH, and that pH recovered to baseline values within 40 minutes after acid drop instillation. We explored th...

The effects of salt-alkaline mixed stress on switchgrass were investigated by evaluating seed germination and the proline, malondialdehyde (MDA) and soluble sugar contents in three switchgrass (Panicum virgatum L.) cultivars in order to identify which can be successfully produced on marginal lands affected by salt-alkaline mixed stress. The experimental conditions consisted of four levels of sa...

Earlier studies in this laboratory (1) and by other workers (Z-4) have suggested that the effect of alkaline pH and urea on myosin resulted in major structural alterations in the molecule. Many of these studies were concerned with the attempt at the isolation of subunits or small polypeptide fragments by the treatment of myosin with high urea concentrations for long periods of time or by exposu...

The determinants of the oesophageal alkaline pH environment are poorly understood. Saliva (pH 6.4-7.8) may be a major contributor, although some argue the importance of refluxed alkaline duodenal contents. Acid and alkaline reflux parameters were studied over 2 days in 30 subjects (control, oesophagitis and Barrett's patients; 10 each) using glass pH electrodes. In phase 1, one pH electrode was...

OBJECTIVE To determine the effect of pH, and exposure time over the inactivation of aflatoxin B1 (AFB1) during the tortilla making process as well as the degradative molecules generated. MATERIALS AND METHODS Inactivation of AFB1 in maize-dough with alkaline pH and in alkaline methanolic solutions was determined by HPLC. Kinetics of time exposure of AFB1 in methanolic solution and the degrada...

Alkaline soils comprise 30% of the earth and have low plant-available iron (Fe) concentration, and can cause iron deficiency chlorosis (IDC). IDC causes soybean yield losses of $260 million annually. However, it is not known whether molecular responses to IDC are equivalent to responses to low iron supply. IDC tolerant and sensitive soybean lines provide a contrast to identify specific factors ...

The responses of the vascular beds in skeletal muscle and skin to changes in blood pH on the acid and alkaline sides of the physiologic range were compared. Dilatation occurred in both cutaneous and muscular beds when the blood pH was shifted to the acid range. Dilatation also occurred in the muscle beds when the blood pH was shifted to the alkaline range but such change in blood pH caused vaso...

In this paper, the effect of pH on in vitro cell growth and naphthoquinone pigment production in cell suspension cultures of Arnebia euchroma (Royle) Johnston was evaluated under a two-stage culture system. Friable callus derived from leaves of in vitro established shoots was maintained on MS medium supplemented with BAP (10 μM) and IBA (5 μM) and the same medium was used for raising cell suspe...

The effects of external pH (7.0-8.0) on intracellular Ca(2+) signals (Ca(2+) sparks and Ca(2+) waves) were examined in smooth muscle cells from intact pressurized arteries from rats. Elevating the external pH from 7.4 to 7.5 increased the frequency of local, Ca(2+) transients, or "Ca(2+) sparks," and, at pH 7.6, significantly increased the frequency of Ca(2+) waves. Alkaline pH-induced Ca(2+) w...

The ability to respond to ambient pH is critical to the growth and virulence of the fungal pathogen Candida albicans. This response entails the differential expression of several genes affecting morphogenesis. To investigate the mechanism of pH-dependent gene expression, the C. albicans homolog of pacC, designated PRR2 (for pH response regulator), was identified and cloned. pacC encodes a zinc ...