METHODS: The osteogenic potential of the OPG-chitosan gel was evaluated in rabbits. Critical-sized defects were created in the calvarial bone, which were either left unfilled (control; group I), or filled with chitosan gel (group II) or OPG-chitosan gel (group III), with rabbits sacrificed at 6 and 12 weeks. Bone samples from the surgical area were decalcified and treated with routine histological and immunohistochemical protocols using OC, OPN, and cathepsin K (osteoclast marker) antibodies. The toxicity of the OPG-chitosan gel was evaluated by biochemical assays (liver and kidney function tests).
RESULTS: The mean bone growth in defects filled with the OPG-chitosan gel was significantly higher than those filled with the chitosan gel or the unfilled group (p functional tests indicated no signs of harmful systemic effects of treatment. In conclusion, the OPG-chitosan gel has many characteristics that make it suitable for bone repair and regeneration, highlighting its potential benefits for tissue engineering applications.
METHODS: This cross-sectional study was performed at Hue Central Hospital from 2012-2016 on 176 CKD and 64 control subjects. ADMA levels were measured by using the enzyme linked immunosorbent assay (ELISA) method.
RESULTS: Mean ADMA level was markedly higher (p<0.001) in all patients combined (0.73±0.24μmol/L) than in control subjects (0.47±0.13μmol/L). Mean ADMA levels in advanced kidney disease were higher than control subjects. ADMA levels correlated inversely and relatively strictly to estimated glomerular filtration rate (eGFR) (r = -0.689; p<0.001), haemoglobin (r = -0.525; p<0.001) and haematocrit (r = - 0.491; p<0.001); correlated favourably and relatively strictly to serum creatinine (r = 0.569; p<0.001) and serum urea (r = 0.642; p<0.001). ADMA elevation was predicted simultaneously by eGFR<60 mL/min/1.73m2 (p<0.001), anaemia (p=0.002), body mass index (BMI) (p=0.011) and high sensitivity C-reactive protein (hs-CRP) (p=0.041). Cutoff of ≥0.68μmol/L, ADMA levels predict reduction of eGFR<60 mL/min/1.73m2, sensitivity of 86.9 %, specificity of 82.6%, area under ROC 92.4% (95%CI: 88.6-96.1%).
Methods: One hundred and fifty hard-working agricultural farmers from high-prevalence area for CKDu (Madawachchiya) were screened three times for proteinuria; 66 proteinuric and 21 non-proteinuric were identified as the baseline classification. Selected individuals were analysed further for creatinine, protein and cystatin C in urine and creatinine, cystatin C in serum. Urine protein-to-creatinine ratio (UP/UC) was calculated.
Results: Based on creatinine and cystatin C cut-off levels in serum, individuals were classified as high or normal. Diagnosis of two functional markers (creatinine and cystatin C) were evaluated using receiver operating characteristic (ROC) curve and in terms of sensitivity and specificity using UP/UC as the baseline. Creatinine and cystatin C-based eGFR (estimated Glomerular filtration rate) levels were calculated, and Pearson's correlation coefficient was determined between different eGFR measurements using UP/UC. Mean (SD) UP/UC ratio, serum creatinine, and serum cystatin C levels of the proteinuric subjects were 129.0 (18.4) mg/mmol, 1.35 (0.39) mg/dL, 1.69 (0.58) mg/L. For non-proteniuric individuals, the results were found to be 14.4 (2.28), 1.22 (0.40) mg/dL, 0.82 (0.25) mg/L. The ROC analysis showed excellent accuracy in using cystatin C for identifying proteinuric patients than creatinine area under the curve (AUC): 0.9675, P < 0.001). Cut-off points were identified as 1.015 mg/dL for serum creatinine and 0.930mg/L for cystatin C. Furthermore, cystatin C based Hoek formula showed the better correlation (0.635, P < 0.001) with UP/UC compared with creatinine based modification of diet in renal disease (MDRD) formula.
Conclusion: The study showed elevated serum cystatin C in patients with persisting proteinuria compared with non-responding serum creatinine. Moreover, cystatin C-based eGFR equations were more accurate to determine the kidney function than serum creatinine in proteinuric patients who are vulnerable for CKDu in high-prevalence areas.