Prospective analysis of anatomic features predisposing patients to intraoperative floppy iris syndrome.

PURPOSE To aid preoperative risk assessment by identifying anatomic parameters corresponding with a higher risk of intraoperative floppy iris syndrome (IFIS) during cataract surgery. METHODS Prospective cohort study of 55 patients with α1-adrenergic receptor antagonist (α1-ARA) treatment and 55 controls undergoing cataract surgery. Anterior segment optical coherence tomography (AS-OCT), video pupilometer, and biometry measurements were performed preoperatively and analyzed regarding anatomic parameters that corresponded with a higher rate of IFIS. Those statistically significant parameters were evaluated with logistic regression analysis and receiver operating characteristic (ROC) curve. RESULTS Pupil diameter was significantly smaller in patients who developed IFIS compared to those who did not develop IFIS (AS-OCT 3.29 ± 0.85 vs. 3.63 ± 0.68, p = 0.03; Pupilometer 3.56 ± 0,87 vs. 3.95 ± 0.67, p = 0.02). Biometric evaluation revealed shallower anterior chambers in the IFIS group (ACD 3.12 ± 0.40 vs. 3.32 ± 0.42, p = 0.02). Cutoff values for 50% IFIS probability (p = 0.5) were PD = 3.18 mm for pupil diameter and ACD = 2.93 mm for anterior chamber depth. ROC curves of combined parameters were calculated for α1-ARA medication with pupil diameter and anterior chamber depth, which yielded an AUC of 0.75 for all IFIS grades. CONCLUSION The combination of biometric parameters with history of α1-ARA medication can improve assessment of risk stratification for IFIS incidence during cataract surgery

Magnetic Resonance Imaging of Cartilage Repair: A Review

Articular cartilage lesions are a common pathology of the knee joint, and many patients may benefit from cartilage repair surgeries that offer the chance to avoid the development of osteoarthritis or delay its progression. Cartilage repair surgery, no matter the technique, requires a noninvasive, standardized, and high-quality longitudinal method to assess the structure of the repair tissue. This goal is best fulfilled by magnetic resonance imaging (MRI). The present article provides an overview of the current state of the art of MRI of cartilage repair. In the first 2 sections, preclinical and clinical MRI of cartilage repair tissue are described with a focus on morphological depiction of cartilage and the use of functional (biochemical) MR methodologies for the visualization of the ultrastructure of cartilage repair. In the third section, a short overview is provided on the regulatory issues of the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) regarding MR follow-up studies of patients after cartilage repair surgeries

Redifferentiation of aged human articular chondrocytes by combining bone morphogenetic protein-2 and melanoma inhibitory activity protein in 3D-culture

<div><p>Melanoma inhibitory activity (MIA) affects the differentiation to hyaline cartilage and can inhibit the osteogenic potential of bone morphogenetic protein (BMP)-2 in mesenchymal stem cells (MSC). The aim of this study was to investigate if MIA also inhibits the osteogenic potential of BMP-2 in human articular chondrocytes during redifferentiation, which may lead to a higher grade of differentiation without calcification. HAC of four female patients (mean age: 73.75 ±6.98) were seeded into 3D culture for 28 days; after adding the recombinant proteins, four groups were formed (Control, BMP-2, MIA, BMP-2+MIA). Samples were analysed for gene expression, glycosaminoglycan (GAG) content and histology on day 0, 14 and 28. Collagen type 2 (<i>COL2A1</i>) was significantly increased in the BMP-2 containing groups on day 28; BMP-2 (100-fold, p = 0.001), BMP-2+MIA (65-fold, p = 0.009) and similar to the level of native cartilage. Higher aggrecan (<i>Agg</i>) levels were present in the BMP-2 (3-fold, p = 0.007) and BMP-2+MIA (4-fold, p = 0.002) group after 14 days and in the BMP-2 (9-fold, p = 0.001) group after 28 days. Collagen type 10 (<i>COL10A1</i>) was increased in the BMP-2 containing groups (6-fold, p = 0.006) but these levels were significantly below native cartilage. Alkaline phosphatase (<i>ALP</i>), collagen type 1 (<i>COL1A1</i>) and the glycosaminoglycan (GAG) content did not reveal any relevant differences between groups. BMP-2 is a potent inducer for differentiation of HAC. A significant enhancement of this effect in combination with MIA could not be observed. Furthermore no significant reduction of osteogenic markers during re-differentiation of chondrocytes was present combining BMP-2 and MIA.</p></div

In‐depth interrogation of protein thermal unfolding data with MoltenProt

Protein stability is a key factor in successful structural and biochemical research. However, the approaches for systematic comparison of protein stability are limited by sample consumption or compatibility with sample buffer components. Here we describe how miniaturized measurement of intrinsic tryptophan fluorescence (NanoDSF assay) in combination with a simplified description of protein unfolding can be used to interrogate the stability of a protein sample. We demonstrate that improved protein stability measures, such as apparent Gibbs free energy of unfolding, rather than melting temperature T$_m$, should be used to rank the results of thermostability screens. The assay is compatible with protein samples of any composition, including protein complexes and membrane proteins. Our data analysis software, MoltenProt, provides an easy and robust way to perform characterization of multiple samples. Potential applications of MoltenProt and NanoDSF include buffer and construct optimization for X‐ray crystallography and cryo‐electron microscopy, screening for small‐molecule binding partners and comparison of effects of point mutations

Relative gene expression of <i>COL10A1</i>.

<p>Relative gene expression of <i>COL10A1</i> normalised to native cartilage in log scale. Comparison of native cartilage (native), dedifferentiated cells—prior to 3D cultivation (cells), control on day 0 (CO d0), control and treated groups on day 14 and 28. * (p<0.05), ** (p<0.01).</p

Relative gene expression of <i>COL2A1</i>.

<p>Relative gene expression of <i>COL2A1</i> normalised to native cartilage in log scale. Comparison of native cartilage (native), dedifferentiated cells—prior to 3D cultivation (cells), control on day 0 (CO d0), control and treated groups on day 14 and 28. * (p<0.05), ** (p<0.01).</p

Relative gene expression of <i>COL1A1</i>.

<p>Relative gene expression of <i>COL1A1</i> normalised to native cartilage in log scale. Comparison of native cartilage (native), dedifferentiated cells—prior to 3D cultivation (cells), control on day 0 (CO d0), control and treated groups on day 14 and 28. * (p<0.05), ** (p<0.01).</p

Glycosaminoglycan content in relation to DNA content.

<p>Comparison of control on day 0 (CO d0), control and treated groups on day 14 and 28. * (p<0.05), ** (p<0.01).</p

Alcian blue staining of alginate beads in 10 and 20 times magnification.

<p>Scale in each slide corresponds to 100μm. (A) Control on day 14; (B) BMP-2 on day 14 (C) MIA on day 14; (D) BMP-2+MIA on day 14; (E) Control on day 28; (F) BMP-2 on day 28; (G) MIA on day 28; (H) BMP-2+MIA on day 28.</p