The mechanical properties of a reconstruction of the anterior cruciate ligament (ACL) using an augmented substitute were investigated in rabbits' knees. After total resection of the ACL, 25 knees were reconstructed with a patellar tendon alone (nonaugmented group) and 25 with a patella tendon augmented by a Leeds-Keio artificial ligament (augmented group) . The rabbits were sacrificed for biomechanical testing at 0, 4, 8, 12 and 24 weeks, respectively, after operation.
In the augmented group, the mean ultimate load was 48.8% of the original ACL load at 4 weeks, and this gradually increased to 65.6% at 8 weeks. That of the twenty-four-week specimens was restored to 71% of the original ACL load.
In the nonaugmented group, the mean ultimate load decreased to 9.3% at 8 weeks, but increased to 37.5% at 24 weeks. The mean static stiffness in the augmented group was higher than in the nonaugmented group at all time periods. The differences between the augmented and nonaugmented groups were statistically significant in the 8 to 12 week period (p<0.01).
Tan δ values, exhibiting the magnitude of viscosity in a viscoelastic material, in the augmented group were significantly higher than those in the nonaugmented group at 8 weeks (p<0.05) and 12 weeks (p<0.01) . The mean tan δ in the augmented group decreased to 0.08±0.04 at 24 weeks, but the values were higher than those of the original ACL.
The mean dynamic elastic modulus in the augmented group was higher than in the nonaugmented group at all time periods. The difference between the augmented and nonaugmented groups was statistically significant in the 8th week (p<0.05).
The values of dynamic elastic modulus in both groups were increased at 24 weeks: 96.4 MPa in the augmented group, and 77, 5 MPa in the nonaugmented group.
It was demonstrated that the augmented ligaments used for anterior cruciate ligament reconstruction had greater strength and static stiffness than the patellar tendon autograft. As for dynamic properties, the augmented group showed higher viscosity group than ACL.

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Zinc protoporphyrin (ZPP) is generated in the erythrocytes of patients with lead toxication and iron deficiency anemia by the incorporation of zinc instead of ferrous iron into protoporphyrin. Although the measurement of ZPP has been thought to be a potential screening test for evaluating iron deficiency, no simple and reliable ZPP assay method has been available until recently. A newly developed hematofluorometer allows us to quickly determine the level of ZPP in a drop of unprocessed whole blood. In this study, we measured the concentration of ZPP in 732 children including 22 patients with iron deficiency anemia using this hematofluorometer. The cut off value of whole blood ZPP in children was determined to be 38.2 μg ZPP/dl whole blood. The level of ZPP showed a good negative correlation with the concentration of hemoglobin. The specificity and the sensitivity of this assay were 97.2% and 81.8%, respectively. These results indicate that this ZPP assay using the newly-developed hematofluorometer is a practical way to screen for iron deficiency anemia.

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