The physical state of intranuclear water and ions: changes during cell proliferation and chemically induced carcinogenesis

A review on B/A measurement methods with a clinical perspective

The nonlinear parameter of ultrasound B/A has shown to be a useful diagnostic parameter, reflecting medium content, structure, and temperature. Despite its recognized values, B/A is not yet used as a diagnostic tool in the clinic due to the limitations of current measurement and imaging techniques. This review presents an extensive and comprehensive overview of the techniques developed for B/A measurement of liquid and liquid-like media (e.g., tissue), identifying the methods that are most promising from a clinical perspective. This work summarizes the progress made in the field and the typical challenges on the way to B/A estimation. Limitations and problems with the current techniques are identified, suggesting directions that may lead to further improvement. Since the basic theory of the physics behind the measurement strategies is presented, it is also suited for a reader who is new to nonlinear ultrasound.

Electrolyte homeostasis in urothelial neoplasia: the effects of amiloride

OBJECTIVE

To investigate the effect of amiloride preincubation on the intracellular electrolyte levels in neoplastic and non-neoplastic urothelium.

MATERIALS AND METHODS

Samples of papillary transitional cell carcinomas (grades 1 and 2) and non-neoplastic human urothelium were either frozen immediately or after pre-incubation with Krebs saline alone or with Krebs saline containing amiloride. The frozen samples were planed in a cryo-ultramicrotome and then examined by low temperature scanning electron microscopy. Intracellular electrolyte levels were measured using X-ray microanalysis.

RESULTS

In the cells frozen immediately the ratios K+/Na+, K+/P and K+/Cl- were significantly increased in neoplastic compared with non-neoplastic urothelial cells (P < 0.001). This difference was also found in the cells pre-incubated with Krebs saline alone but was not present in the cells pre-incubated with amiloride.

CONCLUSIONS

These results were consistent with the concept that activation of the amiloride-sensitive Na+/H+ membrane exchanger is a primary event in neoplasia.

Electrolyte levels in neoplastic and nonneoplastic human urothelium after ouabain treatment: X-ray microanalysis of bulk hydrated samples

Samples of neoplastic and nonneoplastic human urothelium were immediately frozen, incubated in Krebs' saline and then frozen, or incubated in 10(-5) mol/L ouabain in Krebs' saline and then frozen. The frozen specimens were then planed in a cryoultramicrotome and examined by low-temperature scanning electron microscopy. X-Ray microanalysis was performed on the superficial urothelial cells. Neoplastic cells immediately frozen and those incubated in Krebs' saline had significantly higher K+/Na+, K+/P, and K+/Cl- ratios and lower Na+/P and Cl-/P ratios than nonneoplastic cells. Incubation in ouabain led to a fall in the K+/Na+, K+/P, and K+/Cl- ratios and a rise in the Na+/P and Na+/Cl- ratios in both neoplastic and non-neoplastic cells and effectively nullified the difference between them. These results are consistent with the concept that in neoplasia a primary event is stimulation of Na+/H+ exchange, which leads to secondary stimulation of the ouabain-sensitive Na+/K+ ATPase pump.

X-ray microanalysis of bulk hydrated specimens of neoplastic and non-neoplastic human urothelium

Specimens of neoplastic and non-neoplastic human urothelium were rapidly frozen against a copper block immersed in liquid nitrogen, planed in a cryoultramicrotome and then examined by low-temperature scanning electron microscopy (LTSEM) following coating by aluminium. Energy dispersive X-ray microanalysis (XRMA) was performed on the superficial urothelial cells and on gelatin blocks mounted in parallel which had known concentrations of sodium, potassium, chloride, and phosphorus. The neoplastic urothelial cells had significantly less phosphorus (P less than 0.05) than non-neoplastic cells and the ratios K+/P,K+/Na+, and K+/Cl- were significantly higher in neoplastic cells than in non-neoplastic cells (P less than 0.00001). These results are consistent with those expected in cells with a sustained increase in intracellular pH caused by stimulation of Na+/H+ ion membrane exchange.