Drugs may have a significant effect on postoperative bone healing by reducing the function of human mesenchymal stromal cells (hMSC) or mature osteoblasts. Although cefazolin is one of the most commonly used antibiotic drugs in arthroplasty to prevent infection worldwide, there is a lack of information regarding how cefazolin affects hMSC and therefore may have an effect on early bone healing. We studied the proliferation and migration capacity of primary hMSC during cefazolin treatment at various doses for up to 3 days, as well as the reversibility of the effects during the subsequent 3 days of culture without the drug. We found a time- and dose-dependent reduction of the proliferation rate and the migratory potential. Tests of whether these effects were reversible revealed that doses ≥ 250 μg/mL or treatments longer than 24 h irreversibly affected the cells. We are the first to show that application of cefazolin irreversibly inhibits the potential of hMSC for migration to the trauma site and local proliferation. Cefazolin should be administered only at the required dosage and time to prevent periprosthetic infection. If long-term administration is required and delayed bone healing is present, cefazolin application must be considered as a cause of delayed bone healing.
To evaluate the feasibility of delayed gadolinium-enhanced magnetic resonance (MR) imaging of the cartilage of metacarpophalangeal (MCP) joints in patients with rheumatoid arthritis (RA) compared with that in control subjects.Institutional review board approval and informed consent were obtained. Thirty-one MCP joints in 10 patients with RA (mean age, 59 years; range, 35-77 years) and six healthy volunteers (mean age, 51 years; range, 30-71 years) were examined with delayed gadolinium-enhanced MR imaging of cartilage. Sagittal images of the second and third MCP joints (hereafter, MCP II and MCP III) were acquired with a three-dimensional dual-flip-angle gradient-echo sequence at 3.0 T. B(1) field inhomogeneity-corrected T1 maps were calculated, and delayed gadolinium-enhanced MR imaging of cartilage values for phalangeal and metacarpal cartilage were determined. In addition, cartilage thickness was measured. A nonparametric Mann-Whitney U test was used to assess differences between groups.Phalangeal and metacarpal delayed gadolinium-enhanced MR imaging of cartilage values in patients with RA (MCP II: 388 msec ± 105 [standard deviation] and 342 msec ± 79, respectively; MCP III: 409 msec ± 96 and 371 msec ± 89, respectively) were significantly lower than in control subjects (MCP II: 598 msec ± 62 and 560 msec ± 51, respectively; MCP III: 586 msec ± 57 and 561 msec ± 80, respectively). Cartilage thickness of both joints was comparable in patients with RA (MCP II: 1.28 mm ± 0.50, MCP III: 1.17 mm ± 0.24) and control subjects (MCP II: 1.42 mm ± 0.33, MCP III: 1.18 mm ± 0.26).Delayed gadolinium-enhanced MR imaging of cartilage of the MCP joints is feasible at 3.0 T. Delayed gadolinium-enhanced MR imaging of cartilage may help to assess cartilage degeneration in morphologically normal-appearing MCP II and III cartilage in patients with RA.
Background Aim of this study was to assess the glycosaminoglycan content in hip joint cartilage in mature hips with a history of Legg-Calvé-Perthes (LCPD) disease using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). Methods Thirty one hips in 27 adults (mean age: 30.5±10.9 y) with LCPD in childhood were included. Mean follow-up after diagnosis was 24.5±11.4 years. Clinical symptoms and standard radiographic parameters were evaluated. dGEMRIC indices were calculated as T1Gd mean values in four coronal MRI slices medially, centrally, and laterally. For comparison, the morphologically normal appearing contra-lateral hips (21 hips) were assessed. Results The following T1Gd values for the LCPD group were noted: medial (507±100 ms), central (543±104 ms), and lateral (553±105 ms). The total T1Gd mean value was 534±104 ms. The difference between LCPD and normal hips was statistically significant only for the medial compartment (P=0.018). Conclusions Hip joint cartilage after LCPD shows a significant glycosaminoglycan loss in the medial compartment while this decrease is less apparent centrally and laterally. dGEMRIC allows direct assessment of cartilage matrix biochemistry and may depict the complex damage pattern of hip joint cartilage after LCPD spatially and qualitatively better than other radiographic methods. Level of Evidence Prognostic study, Level II-1 (retrospective study).
Background Biochemical alterations such as glycosaminoglycan (GAG) depletion occur early in the course of osteoarthritis, but cannot be detected with standard magnetic resonance techniques. With glycosaminoglycan chemical exchange saturation transfer (gagCEST), a biochemical imaging technique, it is feasible to detect biochemical components in knee joint cartilage. Purpose To establish baseline values for gagCEST magnetic resonance imaging (MRI) in knee joint cartilage at 3 Tesla (T). Material and Methods Twenty volunteers (8 women, 12 men; mean age, 24.55 ± 2.35 years;age range, 21–29 years) with no history or clinical findings indicative of knee joint pathologies underwent MRI at 3T. The imaging protocol included three-dimensional (3D) double-echo steady-state sequence for morphological cartilage assessment and a prototype 3D CEST pulse sequence to evaluate the CEST effects in six cartilage regions of the knee joint: (i) lateral femoral condyle; (ii) medial femoral condyle; (iii) lateral tibial plateau; (iv) medial tibial plateau; (v) patella; and (vi) trochlea. We used the asymmetry of the magnetization transfer ratio (MTR asym ) parameter to quantify the gagCEST effects in these regions. Results Regional differences revealed high MTR asym values in the patellar (1.62% ± 1.19%) and the trochlear (1.17% ± 1.29%) cartilages, and low MTR asym values in the medial femoral condyle (0.41% ± 0.58%) and the lateral tibial plateau (0.52% ± 0.53%) cartilages. Conclusion Regional differences in the gagCEST values must be considered when conducting gagCEST imaging of knee joint cartilage. In the future gagCEST imaging may be an additional feature in the evaluation of the biochemical composition of knee joint cartilage.
Introduction: The purpose of the present study was to evaluate the feasibility of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) in the detection of cartilage changes versus morphologic imaging in the long-term course of Legg–Calvé–Perthes disease (LCPD). Methods: A total of 31 hips in 26 patients (mean age, 30.0 years; range, 18–54 years) who were diagnosed with LCPD in childhood were included. Twenty-one radiographically normal contralateral hips served as controls. dGEMRIC indices of femoral and acetabular cartilage in the weight-bearing zone. Cartilage morphology was classified on radial PD-weighted images according to the modified Outerbridge classification. Results: Mean dGEMRIC values of cartilage were significantly lower in hips after LCPD than in the radiographically normal contralateral hips (513 ± 100 ms vs. 579 ± 103 ms; P = 0.026). In 24 out of 31 LCPD hips and in 4 out of 21 radiographically normal contralateral hips, morphological cartilage changes were noted. Analysis of variance analysis revealed a significant influence of Outerbridge grading on decreased T1-values (P = 0.031). Conclusion: Our results suggest that dGEMRIC at 1.5 T is suitable to assess cartilage quality changes in the long-term follow-up after LCPD. The evaluation of biochemical cartilage quality with dGEMRIC may provide additional information about early cartilage changes occurring without visible alterations of cartilage morphology.
To the Editor: Finding a way to diagnose myelodysplastic syndromes (MDS) using proteins of the peripheral blood serum instead of morphologic characteristics of bone marrow (BM) cells would be a large improvement by minimizing invasiveness of the diagnostic procedure and reviewer dependent variability. The key challenge in studying the serum proteome is its extraordinary wide dynamic range of protein concentrations spanning more than 10 orders of magnitude that makes discovery of a potential biomarker almost impossible. This makes pre-fractionation of the serum sample essential to decrease its range of protein concentrations and enrich the low-abundant proteins. We have previously demonstrated that affinity-chromatography-based combinatorial hexapeptide ligand libraries (CPLL) for serum pretreatment are a highly reproducible fractionation method enabling analysis of low abundance proteins in complex mixtures and presented an efficient and reliable workflow for deep serum proteome analysis by combining CPLL with mass spectrometric profiling of low molecular weight proteins and peptides on ProteinChips 1, 2. Here, we used this experimental set-up to analyze the deep serum proteome of 75 patients with MDS and 30 age-matched controls (Table 1). Using 56 sera as learning set (40 MDS and 16 controls), the peak detection and clustering analysis of m/z 2,000–15,000 detected 98 peptides in CM10, 80 in Q10, and 117 in IMAC30 spectra meaning 40% more peaks in an eighth of the m/z range than previous studies 3, 4. Different proteomic profiles were tested as prediction models to distinguish between MDS and controls. Their performance was calculated and the best predictive profile (peptides FC>2.5, P < 0.01) was applied to the independent validation set comprising 49 sera (35 MDS and 14 controls). Needing only one measurement per patient, less predictive peaks and no mix of different ProteinChips we observed better performances (Table 2) and area under the curve (AUC) data (Fig. 1A–C) than previous studies 3, 4. We further used our experimental set-up to classify different MDS subtypes and stages (RCMD/del(5q) = early, RAEBI/II = advanced). Using 11 IMAC30 peptides of the learning set that met our minimal criteria (FC>1.6, P < 0.05), we again acquired good performance data in the validation set with very high accuracy and without false positives (Table 2, Fig. 1D,E). Despite very good predictions of our proteome profiles a more elegant way to diagnose MDS from blood would be an immunoassay against an appropriate serum biomarker being less time-consuming and reaching higher inter-laboratory reproducibility. Using only one chromatographic enrichment step (H50, Bio-Rad Laboratories) before matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) fragment ion analysis (Ultraflex III, Bruker Daltonics), we identified the two peaks dominating the MDS deep serum proteome (m/z 3,818 and 3,971, >20-times higher than in controls) by SwissProt database comparison directly from the IMAC30 ProteinChip. Peptide m/z 3,971 was sequenced as DAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQC, identified as 34 amino acid long N-terminal fragment of human serum albumin with its C-terminal cysteine (Cys34) sulfonated (HSA[1-34]-SO3H) while m/z 3,818 was identified as the same HSA fragment with Cys34 removed and its C-terminal glutamine amidated (HSA[1-33]-NH2). Both are part of the so-called serum fragmentome containing thousands of proteolytically derived peptides, mostly of high-abundant serum proteins, pointing toward an altered protease activity in MDS, such as previously shown for matrix metalloproteinases, their inhibitors and tryptase 5-7. In line with this are also the unusual modifications at the breakpoints before and after Cys34 as albumin is proposed to counteract oxidative stress by radical scavenging that is mainly attributed to the redox state of its free thiol at Cys34. An irreversible modification to sulfonic acid as in HSA[1-34]-SO3H causes loss of function and protein degradation and is considered a suicide function of proteins involved in antioxidation in several diseases 8. Using median split Kaplan–Meyer survival analyses, we evaluated the prognostic effect of our predictive peptides and found m/z 7,835, previously identified as stromal cell-derived factor-1 (CXCL12/SDF-1α) 9, to show highly significant differences in overall survival (P < 0.001, Fig. 2A). We confirmed this by measuring the SDF-1α concentration in sera of 56 MDS patients and 18 normal donors (Table 1) by Quantikine®ELISA (R&D Systems) revealing significantly decreased levels in MDS (P < 0.05) and significantly prolonged survival of the MDS patients with higher SDF-1α expression (P < 0.05, Fig. 2B). That may be explained by disturbed transforming growth factor-β (TGF-β)/Smad signaling in MDS 10 transcriptionally modulating SDF-1α gene expression and causing down-regulated SDF-1α production of MDS mesenchymal stromal cells of 11, 12. Furthermore, a higher expression of CXCR4, the SDF-1α receptor on hematopoietic cells, was recently identified to be a prognostic factor for overall and progression-free survival in MDS patients 13, which might be an attempt to compensate the reduced SDF-1α levels. ROC analyses of predictive deep serum proteome profiles with AUC used on the validation set distinguishing MDS patients and controls (A–C), different MDS stages (D) as well as MDS del(5q) and other MDS subtypes (E). Kaplan–Meyer plots of m/z 7,835 (A) and SDF-1α (B) categorized by median split show that survival of MDS patients with higher cluster intensities and serum concentrations (black line) is significantly longer than that of patients with lower values (gray line). The authors would like to thank Waltraud Paßlack and Sabine Lensing-Höhn for excellent technical assistance. Julia Fröbel,1,2,3* Sonja Hartwig,1 Sabine Jourdain,4 Johannes C. Fischer,5 Christoph Zilkens,3 Andrea Kündgen,2 Detlev Suckau,4 Ulrich Germing,2 Akos Czibere,2 and Stefan Lehr1 1Department of Clinical Biochemistry and Pathobiochemistry, Leibniz Center for Diabetes Research, Heinrich-Heine-University, 40225 Düsseldorf, Germany; 2Department of Hematology, Oncology and Clinical Immunology, Heinrich-Heine-University, 40225 Düsseldorf, Germany; 3Department of Orthopedic Surgery, Heinrich-Heine-University, 40225 Düsseldorf, Germany; 4Bruker Daltonics, 28359 Bremen, Germany; 5Institute for Transplantation Diagnostics and Cell Therapeutics, Heinrich-Heine-University, 40225 Düsseldorf, Germany
Objective To evaluate the diagnostic accuracy of T2*-mapping for detecting acetabular cartilage damage in patients with symptomatic femoroacetabular impingement (FAI). Design A total of 29 patients (17 females, 12 males, mean age 35.6 ± 12.8 years, mean body mass index 25.1 ± 4.1 kg/m 2 , 16 right hips) with symptomatic FAI underwent T2* MRI and subsequent hip arthroscopy. T2* values were obtained by region of interest analysis in seven radially reformatted planes around the femoral neck (anterior, anterior-superior, superior-anterior, superior, superior-posterior, posterior-superior, posterior). Intraoperatively, a modified Outerbridge classification was used for assessment of the cartilage status in each region. T2* values and intraoperative data were compared, and sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV) as well as the correlation between T2*-mapping and intraoperative findings, were determined. The mean time interval between MRI and arthroscopy was 65.7 ± 48.0 days. Results Significantly higher T2* values were noted in arthroscopically normal evaluated cartilage than in regions with cartilage degeneration (mean T2* 25.6 ± 4.7 ms vs. 19.9 ± 4.5 ms; P < 0.001). With the intraoperative findings as a reference, sensitivity, specificity, NPV and PPV were 83.5%, 67.7%, 78.4% and 74.4%, respectively. The correlation between T2*-mapping and intraoperative cartilage status was moderate (ρ = −0.557; P < 0.001). Conclusions T2*-mapping enabled analysis of acetabular cartilage with appropriate correlation with intraoperative findings and promising results for sensitivity, specificity, PPV, and NPV in this cohort. Our results emphasize the value of T2*-mapping for the diagnosis of hip joint cartilage pathologies in symptomatic FAI.
