Destructive Index

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paper reviewed: Saetta, M, Shiner, R.J., Angus, G.E., Kim, W.K., Wang, N., King, M., Ghezzo, H., and M.G. Cosio (1985) Destructive Index: A Measurement of Lung Parenchymal Destruction in Smokers. Am.Rev. Respir. Dis., 131, 764-769

In this paper the authors want to see how much alveoli have changed size and how much of the alveoli wall has been destroyed in cigarette smokers. They compare what they are calling destructive index to Lm. Destructive index is the ratio of damaged to healthy tissue in the alveoli/duct space. The Lm is the mean linear intercept (also called chord length) of the alveoli.

Random sampling is used in the paper (Saetta et al., 1985, Preparation of Lungs or Lobes). We recommend systematic random sampling instead. Thin sections (6 microns) are used.

To estimate the destructive index please use the area fraction fractionator probe. It is set up to use systematic random sampling and you will get a volume to volume ratio of damaged to healthy tissue.

The authors do a good job in the paper describing what is damaged tissue (Saetta et al., Destructive Index). They count the points at high magnification (63x objective). They use a graticule in the eyepiece but there are software programs available today that will put the graticule (grid) of points down for you. The area fraction fractionator probe calculates the volume fraction the same way as the destructive index in the paper:

DI = D/(D + N) X 100

DI = destructive index

D = number of points counted over damaged tissue

N = number of points counted over normal tissue

 

Saetta, M, Shiner, R.J., Angus, G.E., Kim, W.K., Wang, N., King, M., Ghezzo, H., and M.G. Cosio (1985) Destructive Index: A Measurement of Lung Parenchymal Destruction in Smokers. Am.Rev. Respir. Dis., 131, 764-769