Table 2

Mean analyte concentrations in cartilage extracts

Cartilage region

Number

IsoAsp μM/g cartilage ± SEM

Protein μg/g cartilage ± SEM

GAG μg/g cartilage ± SEM

Normal

8

7,092 ± 1,568

65,092 ± 18,017

743 ± 102

Lesioned OA

14

4,942 ± 719

15,281 ± 552^a

4,463 ± 1,053^b

Non-lesioned OA

14

7,439 ± 1,273

17,926 ± 1,134^c

2,911 ± 657^b

Superficial

6

2,453 ± 315^c

11,266 ± 818^c

3,626 ± 921

Deep

6

3,999 ± 665^d

16,894 ± 3,105^c

7,316 ± 1,279^{a, d, e}

^aP < 0.001 compared to normal cartilage; ^bP < 0.01 compared to normal cartilage; ^cP < 0.05 compared to normal cartilage; ^dP < 0.05 compared to superficial cartilage; ^eP < 0.05 compared to osteoarthritis (OA) lesion cartilage. GAG, glycosaminoglycan; IsoAsp, isomerized aspartate; SEM, standard error of the mean.

Catterall et al. Arthritis Research & Therapy 2009 11:R55   doi:10.1186/ar2675