Tension-Compression Loading with Chemical Stimulation Results in Additive Increases to Functional Properties of Anatomic Meniscal Constructs

Objective: This study aimed to improve the functional properties of anatomically-shaped meniscus constructs through simultaneous tension and compression mechanical stimulation in conjunction with chemical stimulation. Methods: Scaffoldless meniscal constructs were subjected to simultaneous tension and compressive stimulation and chemical stimulation. The temporal aspect of mechanical loadingwas studied by employing two separate five day stimulation periods. Chemical stimulation consisted of the application of a catabolic GAG-depleting enzyme, chondroitinase ABC (C-ABC), and an anabolic growth factor, TGF-b1. Mechanical and chemical stimulation combinations were studied through a full-factorial experimental design and assessed for histological, biochemical, and biomechanical properties following 4 wks of culture. Results: Mechanical loading applied from days 10–14 resulted in significant increases in compressive, tensile, and biochemical properties of meniscal constructs. When mechanical and chemical stimuliwere combined significant additive increases in collagen per wet weight (4-fold), compressive instantaneous (3-fold) and relaxation (2-fold) moduli, and tensile moduli in the circumferential (4-fold) and radial (6-fold) directions were obtained. Conclusions: This study demonstrates that a stimulation regimen of simultaneous tension and compression mechanical stimulation, C-ABC, and TGF-b1 is able to create anatomic meniscus constructs replicating the compressive mechanica

Significance of Urinary Full-Length Megalin in Patients with IgA Nephropathy

<div><p>Background and Objectives</p><p>Megalin is highly expressed at the apical membranes of proximal tubular epithelial cells. A urinary full-length megalin (C-megalin) assay is linked to the severity of diabetic nephropathy in type 2 diabetes. This study examined the relationship between levels of urinary C-megalin and histological findings in adult patients with IgA nephropathy (IgAN).</p><p>Design, Setting, Participants, & Measurements</p><p>Urine samples voided in the morning on the day of renal biopsy were obtained from 73 patients with IgAN (29 men and 44 women; mean age, 33 years) and 5 patients with membranous nephropathy (MN). Renal pathologic variables were analyzed using the Oxford classification of IgAN, the Shigematsu classification and the Clinical Guidelines of IgAN in Japan. The levels of urinary C-megalin were measured by sandwich ELISA.</p><p>Results</p><p>Histological analysis based on the Oxford classification revealed that the levels of urinary C-megalin were correlated with mesangial hypercellularity in IgAN patients (OR = 1.76, 95% CI: 1.04–3.27, P<0.05). There was a significant correlation between the levels of urinary C-megalin and the severity of chronic extracapillary abnormalities according to the Shigematsu classification in IgAN patients (β = 0.33, P = 0.008). The levels of urinary C-megalin were significantly higher in all risk levels of IgAN patients requiring dialysis using the Clinical Guidelines of IgAN in Japan than in the control group. The levels of urinary C-megalin were significantly higher in the high risk and very high risk grades than in the low risk grade (P<0.05). The levels of urinary C-megalin were significantly higher in MN patients compared to the control group.</p><p>Conclusions</p><p>The levels of urinary C-megalin are associated with histological abnormalities in adult IgAN patients. There is a possibility that urinary C-megalin is an independent predictor of disease progression of IgAN. In addition, our results suggest that urinary C-megalin is a marker of glomerular abnormalities in various glomerular diseases as well as IgAN.</p></div

Stepwise multiple regression analysis of levels of urinary total protein excretion with relevant factors.

<p>C-megalin, full-length megalin; β₂-MG, β₂-microglobulin; α₁-MG, α₁-microglobulin; NAG, N-acetyl-b-D-glucosaminidase.</p><p>Stepwise multiple regression analysis of levels of urinary total protein excretion with relevant factors.</p

Characteristics of the study subjects.

<p>Unless otherwise noted, the data are given as median (interquartile range).</p><p>eGFR, estimated GFR.</p><p>Characteristics of the study subjects.</p

The levels of urinary C-megalin in patients with membranous nephropathy.

<p>MN: membranous nephropathy. ‡, p<0.001</p

Triple staining for megalin, phalloidin and DAPI in renal biopsy specimens from IgAN patients.

<p>Triple staining for megalin, phalloidin and DAPI in renal biopsy specimens from minor glomerular injury patients (A) and IgAN patients (B, C) showed that megalin was localized in the brush border of proximal tubules.</p

Relationship of risk levels of requiring dialysis to levels of urinary C-megalin.

<p>The numbers on horizontal bars means; control, control subjects (N = 77); I, low risk group (N = 33); II, medium risk group (N = 27); III and IV, high and super high risk group (N = 13). †, p<0.05; ‡, p<0.001.</p

Stepwise multiple regression analysis of histological variables in the Oxford classification with relevant factors.

<p>IgAN: IgA nephropathy.</p><p>Stepwise multiple regression analysis of histological variables in the Oxford classification with relevant factors.</p

Stepwise multiple regression analysis of histological variables in the Shigematsu classification with relevant factors.

<p>Stepwise multiple regression analysis of histological variables in the Shigematsu classification with relevant factors.</p