Local Biological Reactions and Pseudotumor-Like Tissue Formation in relation to Metal Wear in a Murine In Vivo Model

Metal wear debris and released ions (CoCrMo), which are widely generated in metal-on-metal bearings of hip implants, are also found in patients with metal-on-polyethylene bearings due to the mechanically assisted crevice corrosion of modular taper junctions, including head-neck and neck-stem taper interfaces. The resulting adverse reactions to metal debris and metal ions frequently lead to early arthroplasty revision surgery. National guidelines have since been published where the blood metal ion concentration of patients must consistently be monitored after joint replacement to prevent serious complications from developing after surgery. However, to date, the effect of metal particles and metal ions on local biological reactions is complex and still not understood in detail;the present study sought to elucidate the complex mechanism of metal wear-associated inflammation reactions. The knee joints in 4 groups each consisting of 10 female BALB/c mice received injections with cobalt chrome ions, cobalt chrome particles, and ultra-high-molecular-weight polyethylene (UHMWPE) particles or PBS (control). Seven days after injection, the synovial microcirculation and knee joint diameter were assessed via intravital fluorescence microscopy followed by histological evaluation of the synovial layer. Enlarged knee diameter, enhanced leukocyte to endothelial cell interactions, and an increase in functional capillary density within cobalt chrome particle-treated animals were significantly greater than those in the other treatment groups. Subsequently, pseudotumor-like tissue formations were observed only in the synovial tissue layer of the cobalt chrome particle-treated animals. Therefore, these findings strongly suggest that the cobalt chrome particles and not metal ions are the cause for in vivo postsurgery implantation inflammation

Oral Disposition Index Predicts the Development of Future Diabetes Above and Beyond Fasting and 2-h Glucose Levels

OBJECTIVE—We sought to determine whether an oral disposition index (DIO) predicts the development of diabetes over a 10-year period. First, we assessed the validity of the DIO by demonstrating that a hyperbolic relationship exists between oral indexes of insulin sensitivity and β-cell function

Oral Disposition Index Predicts the Development of Future Diabetes Above and Beyond Fasting and 2-h Glucose Levels

OBJECTIVE—We sought to determine whether an oral disposition index (DIO) predicts the development of diabetes over a 10-year period. First, we assessed the validity of the DIO by demonstrating that a hyperbolic relationship exists between oral indexes of insulin sensitivity and β-cell function

Metabolic Changes Following a 1-Year Diet and Exercise Intervention in Patients With Type 2 Diabetes

Objective—To characterize the relationships among longterm improvements in peripheral insulin sensitivity (glucose disposal rate [GDR]), fasting glucose, and free fatty acids (FFAs) and concomitant changes in weight and adipose tissue mass and distribution induced by lifestyle intervention in obese individuals with type 2 diabetes. Research Design And Methods—We measured GDR, fasting glucose, and FFAs during a euglycemic clamp and adipose tissue mass and distribution, organ fat, and adipocyte size by dual-energy X-ray absorptiometry, CT scan, and adipose tissue biopsy in 26 men and 32 women in the Look-AHEAD trial before and after 1 year of diet and exercise aimed at weight loss. Results—Weight and fasting glucose decreased significantly (P _ 0.0001) and significantly more in men than in women (_12 vs. _8% and _16 vs. _7%, respectively; P _ 0.05), while FFAs during hyperinsulinemia decreased and GDR increased significantly (P _ 0.00001) and similarly in both sexes (_53 vs. _41% and 63 vs. 43%; P _ NS). Men achieved a more favorable fat distribution by losing more from upper compared with lower and from deeper compared with superficial adipose tissue depots (P _ 0.01). Decreases in weight and adipose tissue mass predicted improvements in GDR but not in fasting glucose or fasting FFAs; however, decreases in FFAs during hyperinsulinemia significantly determined GDR improvements. Hepatic fat was the only regional fat measure whose change contributed independently to changes in metabolic variables. Conclusions—Patients with type 2 diabetes undergoing a 1-year lifestyle intervention had significant improvements in GDR, fasting glucose, FFAs and adipose tissue distribution. However, changes in overall weight (adipose tissue mass) and hepatic fat were the most important determinants of metabolic improvements.Jeanine B. Albu, Leonie K. Heilbronn, David E. Kelley, Steven R. Smith, Koichiro Azuma, Evan S. Berk, F. Xavier Pi-Sunyer, Eric Ravussin, and the Look AHEAD Adipose Research Grou

Dipeptidyl peptidase IV inhibitors in diabetes: more than inhibition of glucagon-like peptide-1 metabolism?

Inhibitors of the protease dipeptidyl peptidase IV (DPP-IV) are promising new drugs for the treatment of type 2 diabetes. They are thought to act by inhibiting the breakdown of glucagon-like peptide-1 and, thereby, selectively enhancing insulin release under conditions when it is physiologically required. These drugs are selective for DPP-IV, but the enzyme itself has a broad range of substrates other than glucagon-like peptide-1. Other high affinity substrates of DPP-IV including peptide YY may also play a role in the regulation of energy homeostasis. Moreover, DPP-IV is also known as CD26 and considered to be a moonlighting protein because it has a wide range of other functions unrelated to energy homeostasis, e.g. in immunity. The potential role of DPP-IV inhibition on substrates other than glucagon-like peptide-1 in diabetes patients remains to be elucidated

Corrigendum to “Randomized phase 2 trial and open-label extension of domagrozumab in Duchenne muscular dystrophy” [Neuromuscular Disorders, Vol. 30 (6) 2020, 492-502] (Neuromuscular Disorders (2020) 30(6) (492–502), (S0960896620301188), (10.1016/j.nmd.2020.05.002))

This article reported on the results from a phase 2 trial of domagrozumab and its open-label extension in patients with Duchenne muscular dystrophy (Clinicaltrials.gov identifiers: NCT02310763 and NCT02907619). The manuscript also provided results on two secondary endpoints for magnetic resonance imaging (MRI), muscle volume and muscle volume index. The authors regret that, following publication of the results and in preparation for a separate publication on MRI results from this trial, the MRI images were reviewed and segmentation errors were identified. As a result, the team worked to (1) Perform a rigorous quality inspection of all analysed data; (2) Identify cases where there were incorrect segmentations; (3) correct segmentation errors; (4) Re-analyse all data with correct segmentation. Using the updated MRI data, the MMRM analysis showed there was a change in the significance of secondary endpoints evaluating Thigh Muscle Volume and Muscle Volume Index. No significant differences between treatment groups in muscle volume measures were found in the original analysis. These results have not altered the overall interpretation of the study results but do necessitate revisions to the article. These data confirm that the trial design and execution adequately tested the hypothesis that myostatin inhibition would slow or delay the loss of function in patients with Duchenne muscular dystrophy (DMD). The increase in muscle volume observed by MRI in patients with DMD treated with domagrozumab is in accordance with mechanism of action for domagrozumab, which targets myostatin, a negative regulator of muscle growth. The increase in muscle volume did not lead to a clinical benefit in patients with DMD. The primary endpoint (4 stair climb) did not meet statistical significance, nor did the other functional tests. The study was terminated due to lack of efficacy. Full details of the needed revisions are as follows: 1. In the results section 3.6 (page 8, second paragraph), we reported no significant differences in mean percent change from baseline between domagrozumab and placebo for both muscle volume and muscle volume index. This paragraph was replaced with the following text: “There was a significant difference between domagrozumab and placebo in the mean percent change from baseline in thigh muscle volume at Week 17 (difference 2.945%, P=0.0087) and Week 49 (differences 4.087%, P=0.0298), and in muscle volume index at Week 33 (difference 2.612%, P=0.0376) and Week 49 (differences3.208%, P=0.0411).” 2. In the discussion (page 9), the following sentence, “Although neither muscle volume nor muscle volume index measures were statistically significant in this study, they are both consistent with a potential anabolic effect.” was replaced with, “The increase in muscle volume observed on MRI in patients with DMD treated with domagrozumab, is in accordance with mechanism of action for this compound which targets myostatin, a negative regulator of muscle growth. However, the increase in muscle volume did not lead to a clinical benefit (improved function) in patients with DMD.” 3. In view of the correction to the Results section, this is now reflected in the abstract which has changed to read: “There were no significant between-group differences in secondary clinical endpoints, except for the thigh muscle volume and muscle volume index measures (P\u3c0.05).” The authors would like to apologise for any inconvenience caused