Outcomes of arthroscopy of the hip for femoroacetabular impingement based on intraoperative assessment using the Outerbridge classification.

Aims: Hip arthroscopy (HA) has become the treatment of choice for femoroacetabular impingement (FAI). However, less favourable outcomes following arthroscopic surgery are expected in patients with severe chondral lesions. The aim of this study was to assess the outcomes of HA in patients with FAI and associated chondral lesions, classified according to the Outerbridge system. Methods: A systematic search was performed on four databases. Studies which involved HA as the primary management of FAI and reported on chondral lesions as classified according to the Outerbridge classification were included. The study was registered on PROSPERO. Demographic data, patient-reported outcome measures (PROMs), complications, and rates of conversion to total hip arthroplasty (THA) were collected. Results: A total of 24 studies were included with a total of 3,198 patients (3,233 hips). Patients had significantly less improvement in PROMs if they had Outerbridge grade III and IV lesions (p = 0.012). Compared with microfracture, autologous matrix-induced chondrogenesis (AMIC) resulted in significantly reduced rates of conversion to THA (p = 0.042) and of revision arthroscopy (p = 0.038). Chondral repair procedures in these patients also did not significantly reduce the rates of conversion to THA (p = 0.931), or of revision arthroscopy (p = 0.218). However, compared with microfracture, AMIC significantly reduced the rates of conversion to THA (p = 0.001) and of revision arthroscopy (p = 0.011) in these patients. Those with Outerbridge grade III and IV lesions also had significantly increased rates of conversion to THA (p = 0.029) and of revision arthroscopy (p = 0.023) if they had associated lesions of the acetabulum and femoral head. Those who underwent labral debridement had a significantly increased rate of conversion to THA compared with those who underwent labral repair (p = 0.015). Conclusion: There is universal improvement in PROMs following HA in patients with FAI and associated chondral lesions. However, those with Outerbridge grade III and IV lesions had significantly less improvement in PROMs and a significantly increased rate of conversion to THA than those with Outerbridge grade I and II. This suggests that the outcome of HA in patients with FAI and severe articular cartilage damage may not be favourable.

Fibroelastic Tissue Ring Causing ECMO Catheter Obstruction: An Unusual Complication of Avalon Elite Catheter Insertion.

The Avalon Elite catheter (Maquet Cardiopulmonary, Rastatt, Germany) is a bicaval catheter for single-site cannulation that can be used in the initiation of venovenous extracorporeal membrane oxygenation (ECMO) or as a transition from venoarterial ECMO. We report a unique complication of tissue obstructing the outflow aperture during insertion. (Level of Difficulty: Advanced.).

Relationship between ganglion cell layer thickness and estimated retinal ganglion cell counts in the glaucomatous macula.

PURPOSE: To investigate the relationship between macular ganglion cell-inner plexiform layer (mGCIPL) thickness and estimated macular retinal ganglion cell (RGC) counts in glaucoma. DESIGN: Observational cohort study. PARTICIPANTS: Cross-sectional study of 77 healthy, 154 glaucoma suspect, and 159 glaucomatous eyes from the Diagnostic Innovations in Glaucoma Study. METHODS: All eyes underwent 24-2 standard automated perimetry (SAP) and optic nerve and macular imaging using high-definition optical coherence tomography (OCT). The total number of RGCs was estimated using a previously described model that uses SAP and OCT circumpapillary retinal nerve fiber layer (cpRNFL) measurements. The number of macular RGCs was estimated from the temporal cpRNFL and SAP test points within the central 10°. MAIN OUTCOME MEASURES: The correlation between mGCIPL thickness and estimates of macular RGC counts. RESULTS: The average estimated macular RGC count in glaucomatous eyes was 306 010 ± 109 449 cells, which was significantly lower than the estimate of 520 678 ± 106 843 cells in healthy eyes (P < 0.001). Glaucomatous eyes had 41% fewer estimated macular RGCs than healthy eyes and suspects had 21% fewer estimated macular RGCs. There was strong correlation between estimated macular RGC counts and mGCIPL thickness (R(2) = 0.67; P < 0.001). Macular RGC counts performed better than average mGCIPL thickness in discriminating healthy and glaucomatous eyes with receiver operating characteristic curve areas of 0.873 and 0.775, respectively (P = 0.015). CONCLUSIONS: The strong association between estimated macular RGC counts and mGCIPL thickness and the better diagnostic performance of the macular RGC counts compared with mGCIPL thickness provides further evidence that estimates of RGC number from cpRNFL thickness and SAP sensitivity can be used to assess neural losses in glaucoma.

Genomics applications to biotech traits: a revolution in progress?

Twenty years since the inception of the agricultural biotechnology era, only two products have had a significant impact in the market place: herbicide-resistant and insect-resistant crops. Additional products have been pursued but little success has been achieved, principally because of limited understanding of key genetic intervention points. Genomics tools have fueled a new strategy for identifying candidate genes. Primarily thanks to the application of functional genomics in Arabidopsis and other plants, the industry is now overwhelmed with candidate genes for transgenic intervention points. This success necessitates the application of genomics to the rapid validation of gene function and mode of action. As one example, the development of C-box binding factors (CBFs) for enhanced freezing and drought tolerance has been rapidly advanced because of the improved understanding generated by genomics technologies.

Overexpression analysis of plant transcription factors.

Transcription factors (TFs) play important roles in plant development and its response to the environment. A variety of reverse genetics tools have been developed to study TF function, the two most commonly used ones being knockout and overexpression. Because of the unique characteristics and modes of action of TFs, the overexpression strategy has been particularly effective in revealing TF function. Thus, a number of overexpression-based methodologies - constitutive expression, tissue-specific expression, chemically inducible expression and overexpression of modified TFs - have been developed and are used in the analysis of TF function.

Transcription factor CBF4 is a regulator of drought adaptation in Arabidopsis.

In plants, low temperature and dehydration activate a set of genes containing C-repeat/dehydration-responsive elements in their promoter. It has been shown previously that the Arabidopsis CBF/DREB1 transcription activators are critical regulators of gene expression in the signal transduction of cold acclimation. Here, we report the isolation of an apparent homolog of the CBF/DREB1 proteins (CBF4) that plays the equivalent role during drought adaptation. In contrast to the three already identified CBF/DREB1 homologs, which are induced under cold stress, CBF4 gene expression is up-regulated by drought stress, but not by low temperature. Overexpression of CBF4 in transgenic Arabidopsis plants results in the activation of C-repeat/dehydration-responsive element containing downstream genes that are involved in cold acclimation and drought adaptation. As a result, the transgenic plants are more tolerant to freezing and drought stress. Because of the physiological similarity between freezing and drought stress, and the sequence and structural similarity of the CBF/DREB1 and the CBF4 proteins, we propose that the plant's response to cold and drought evolved from a common CBF-like transcription factor, first through gene duplication and then through promoter evolution.