Aortic valve cusp shearing and migration into the left main coronary artery during transcatheter aortic valve implantation

In inoperable or high-risk patients with severe aortic stenosis, transcatheter aortic valve implantation (TAVI) provides an efficacious and safe alternative to surgical aortic valve replacement. In this case report, TAVI resulted in aortic valve cusp shearing and migration into the left main coronary artery, resulting in occlusion of coronary blood flow and cardiac arrest. The patient underwent immediate cardiopulmonary support and surgical intervention with a favourable outcome. With this case report, we illustrate the etiology and management of this complication, which can be recognized nonsurgically only if a high index of suspicion exists.     

Autoimmune thyroid diseases and Helicobacter pylori: the correlation is present only in Graves's disease

AIM: To investigate the correlation between autoimmune thyroid diseases (ATDs) and the prevalence of Cag-A positive strains of Helicobacter pylori (H. pylori) in stool samples.METHODS: Authors investigated 112 consecutive Caucasian patients (48 females and 4 males with Graves’ disease and 54 females and 6 males with Hashimoto’s thyroiditis HT), at their first diagnosis of ATDs. Authors tested for H. pylori in stool samples using an amplified enzyme immunoassay and Cag-A in serum samples using an enzyme-linked immunoassay method (ELISA). The results were analyzed using the two-sided Fisher’s exact test and the respective odds ratio (OR) was calculated.RESULTS: A marked correlation was found between the presence of H. pylori (P ≤ 0.0001, OR 6.3) and, in particular, Cag-A positive strains (P ≤ 0.005, OR 5.3) in Graves’ disease, but not in Hashimoto’s thyroiditis, where authors found only a correlation with Cag-A strains (P ≤ 0.005, OR 8.73) but not when H. pylori was present.CONCLUSION: The marked correlation between H. pylori and Cag-A, found in ATDs, could be dependent on the different expression of adhesion molecules in the gastric mucosa.     

What Do Cytokine Profiles Tell Us About Subsets of Juvenile Idiopathic Arthritis?

Classification of juvenile idiopathic arthritis is an ongoing process and up to now has been predominantly based on clinical manifestations—mainly number of joints at onset of disease. In the meantime, basic studies have advanced our knowledge regarding the disease pathogenesis. Unfortunately, studies of cytokines and cytokine polymorphisms have not followed the predominantly clinical International League of Associations for Rheumatology classification in that no significant biological differences among the different disease categories have been demonstrated with robust associations. Only systemic-onset disease seems to be quite different from other disease categories with regard to biologic mechanisms; indeed, it now seems closer to autoinflammatory than to classic autoimmune diseases. New players in the immunologic basis of juvenile idiopathic arthritis (eg, interleukin-17 and regulatory T cells) are also discussed in this review.     

Adipose-derived stem cells and rabbit bone regeneration: histomorphometric, immunohistochemical and mechanical characterization

Background

In the last few years, several attempts have been made to treat large bone loss, including the use of tissue engineering with osteoinductive scaffolds and cells. This study highlights the role of mesenchymal stem cells from adipose tissue (ASCs; adipose-derived stem cells) in a rabbit bone regeneration model.

Methods

We compared the neoformed bone tissues achieved by treating critical tibial defects with either hydroxyapatite alone (HA, group I) or hydroxyapatite–autologous ASC constructs (ASCs-HA, group II), investigating their histomorphometric, immunohistochemical and biomechanical properties.

Results

After eight weeks of follow-up, we observed advanced maturation and a spatial distribution of new bone that was more homogeneous in the inner parts of the pores in group II, not just along the walls (as seen in group I). The new tissue expressed osteogenic markers, and biomechanical tests suggested that the newly formed bone in group II had a higher mineral content than that in group I. Although variability in differentiation was observed among the different cell populations in vitro, no differences in bone healing were observed in vivo; the variability seen in vitro was probably due to local microenvironment effects.

Conclusions

Tibial defects treated with rabbit ASCs-HA showed an improved healing process when compared to the process that occurred when only the scaffold was used. We suggest that implanted ASCs ameliorate the bone reparative process either directly or by recruiting resident progenitor cells.     

Proton MR spectroscopy in the breast: Technical innovations and clinical applications

Proton magnetic resonance spectroscopy (MRS) is a promising noninvasive diagnostic technique for investigation of breast cancer metabolism. Spectroscopic imaging data may be obtained following contrast‐enhanced MRI by applying the point‐resolved spectroscopy sequence (PRESS) or the stimulated echo acquisition mode (STEAM) sequence from the MR voxel encompassing the breast lesion. Total choline signal (tCho) measured in vivo using either a qualitative or quantitative approach has been used as a diagnostic test in the workup of malignant breast lesions. In addition to tCho metabolites, other relevant metabolites, including multiple lipids, can be detected and monitored. MRS has been heavily investigated as an adjunct to morphologic and dynamic MRI to improve diagnostic accuracy in breast cancer, obviating unnecessary benign biopsies. Besides its use in the staging of breast cancer, other promising applications have been recently investigated, including the assessment of treatment response and therapy monitoring. This review provides guidance on spectroscopic acquisition and quantification methods and highlights current and evolving clinical applications of proton MRS. Level of Evidence 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019.     

Detection of Clostridium difficile toxin: comparison of enzyme immunoassay results with results obtained by cytotoxicity assay

Several kinds of laboratory techniques are available to detect Clostridium difficile toxin in fecal samples. Because questions have been raised about the reliability of immunoassays compared to the accepted standard, cytotoxicity assay, we studied three enzyme immunoassays (EIAs) and one rapid EIA, which demonstrated relatively good sensitivities and specificities compared to cytotoxicity assay.