Goal of the Study?
In this case-control study from the Journal of Investigative Surgery 1 the authors’ goal was to determine if a correlation exists between proteolytic enzymes and micro angiogenesis in degenerative intervertebral disc nucleus.
Why are they doing this study?
Current pathological studies of intervertebral disc degeneration reveal apoptosis of nucleus pulposus cells in the intervertebral disc. This leads to matrix reduction, conversion of type II collagen into type I and type III collagen, fibroblast proliferation, nerve fibre ingrowth and micro angiogenesis. However, there is little information about pleiotropic enzymes associated with degenerative changes in vertebral disc herniation and angiogenesis. This study was designed to assess how much the severity of the tissue generation was related to the level of pleiotropic enzymes in neovascularization and lumbar disc herniation.
What was done?
Forty patients with degenerative disc nucleus who had clear clinical symptoms of lumbar degenerative disease and cervical stenosis were selected as the case group. Twenty patients that had cervical and lumbar vertebra injury caused by trauma and with matching demographics (age, gender, etc.) were selected as the control group. Three-milliliter venous blood was taken from the patients in each group and nucleus pulposus tissue was obtained. The embedded tissue wax block was dried, sliced and hematoxylin and eosin (H&E) dye used. Various endothelial markers, proteolytic enzymes and content of type i/II/III collagen were measured and statistical correlations were calculated.
What did they find?
A statistically significant multiple linear relationships was found between the two independent endothelial markers; Alanine Aminopeptidase (APN) and Leucyl Aminopeptidase(LAP) with the dependent variable Microvessel Density (MVD). It was also determined that individually the effects of APN and LAP on MVD were statistically similar.
Why do these findings matter?
Protrusion of the disc to the epidural space appears to result in disintegration of inflammatory cells, granular tissue formation, neovascularization and activation of proteolytic enzymes. Correlation studies, such as this one attempt to find various relationships between independent and dependent variables. This study examined the relationship between various endothelial markers to enhance our knowledge base and ultimately improve our clinical diagnosis ability.
At Dynamic Disc Designs, we create models with both an annulus and a nucleus so relevant research can be translated in educational and inter-professional circles. Patient education has been our priority but we are finding educational institutions are purchasing our models for the purpose of student learning.