Effect of anterior wedging of L1 on the measurement of lumbar lordosis: comparison of two roentgenological methods.

Objective: To determine whether the choice of either the superior or inferior endplate of the L1 vertebra as the proximal landmark for the measurement of lumbar lordosis could significantly affect the categorization (i.e., hypo- or hyperlordotic or normal) of that lordosis in subjects where the L1 vertebra is wedged anteriorly.

The use of backscattered electron imaging, X-ray microanalysis and X-ray microscopy in demonstrating physiological cell death.

The cytochemical localization of enzymatic activity by means of backscattered electron imaging (BEI) is reviewed and the application of BEI to changes in acid phosphatase and ATPase distribution during physiological (programmed) cell death in Heliothis midgut is explored. Programmed cell death entails the release of nascent free acid phosphatase as extracisternal hydrolase. This shift can readily be detected by means of the atomic number contrast imparted by BEI of the lead phosphatase reaction product, thus enabling the distribution of dying cells to be mapped.