Citations

Tendon disuse, or stress deprivation, frequently accompanies clinical disorders and treatments, yet the metabolism of tendons subject to stress deprivation has rarely been investigated systematically. The effects of stress deprivation on canine flexor tendon were investigated in this study. One adult canine forepaw was suspended for 21 or 42 days. Control forepaws were collected from dogs that had no intervention on their limbs and paws. The expression of collagen I and III was not significantly altered in the tendons disused for 21 days but was significantly decreased at 42 days ( P < 0.03). The expression of collagen II, aggrecan, decorin, and fibronectin was significantly decreased in the tendons in the suspended limbs at 21 days ( P < 0.002) and further reduced at 42 days. With stress deprivation, the expression of matrix metalloproteinase 2 (MMP2) was significantly increased ( P < 0.004) at 21 and 42 days. The expression of MMP3 was significantly decreased at 21 and 42 days ( P < 0.03). The expression of MMP13 was not altered with stress deprivation at 21 and 42 days. The expression of MMP14 was significantly increased at 21 days ( P = 0.0015) and returned to the control level at 42 days. Tissue inhibitor of metalloproteinase 1 (TIMP1) expression was decreased after the limbs were suspended for 42 days ( P = 0.0043), but not 21 days. However, TIMP2 expression was not significantly different from control at 21 or 42 days. Furthermore, the cross-sectional area of the stress-deprived tendons at 42 days was decreased compared with the control group ( P < 0.01). The intervention method in this study did not result in any alteration of stiffness of the tendon. Our study demonstrated that stress deprivation decreases the anabolic process and increases the catabolic process of extracellular matrix in flexor tendon.

Insulin resistance is highly prevalent in Asian Indians and contributes to worldwide public health problems, including diabetes and related disorders. Surrogate measurements of insulin sensitivity/resistance are used frequently to study Asian Indians, but these are not formally validated in this population. In this study, we compared the ability of simple surrogate indices to accurately predict insulin sensitivity as determined by the reference glucose clamp method. In this cross-sectional study of Asian-Indian men ( n = 70), we used a calibration model to assess the ability of simple surrogate indices for insulin sensitivity [quantitative insulin sensitivity check index (QUICKI), homeostasis model assessment (HOMA2-IR), fasting insulin-to-glucose ratio (FIGR), and fasting insulin (FI)] to predict an insulin sensitivity index derived from the reference glucose clamp method (SIClamp). Predictive accuracy was assessed by both root mean squared error (RMSE) of prediction as well as leave-one-out cross-validation-type RMSE of prediction (CVPE). QUICKI, FIGR, and FI, but not HOMA2-IR, had modest linear correlations with SIClamp(QUICKI: r = 0.36; FIGR: r = −0.36; FI: r = −0.27; P < 0.05). No significant differences were noted among CVPE or RMSE from any of the surrogate indices when compared with QUICKI. Surrogate measurements of insulin sensitivity/resistance such as QUICKI, FIGR, and FI are easily obtainable in large clinical studies, but these may only be useful as secondary outcome measurements in assessing insulin sensitivity/resistance in clinical studies of Asian Indians.

Background— Health status is a key outcome for comparing treatments, particularly when mortality does not differ significantly. Methods and Results— Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) randomized 2368 patients with type 2 diabetes mellitus and stable ischemic heart disease to (1) prompt revascularization versus medical therapy and (2) insulin sensitization versus insulin provision. Randomization was stratified by the intended method of revascularization, coronary artery bypass graft surgery or percutaneous coronary intervention. The Duke Activity Status Index and RAND Energy, Health Distress, and Self-Rated Health scales were assessed at study entry and annually thereafter; linear mixed models were used to evaluate the effect of randomized treatment on these measures. Health status improved significantly from baseline to 1 year ( P <0.001) in each randomized treatment group. Compared with medical therapy, prompt revascularization was associated with significantly greater improvements in Duke Activity Status Index (1.32 points; P <0.001), Energy (1.36 points; P =0.02), and Self-rated Health (1.77 points; P =0.007) but not Health Distress (−0.47; P =0.46). These treatment effects were largely maintained over 4 years of follow-up. The effect of revascularization on the Duke Activity Status Index was significantly larger in the subgroup of patients intended for coronary artery bypass graft surgery compared with the subgroup intended for percutaneous coronary intervention. Health status did not differ significantly on any of the 4 measures between the insulin provision and insulin sensitization strategies. Conclusions— Prompt coronary revascularization was associated with small yet statistically significant improvements in health status compared with initial medical therapy among patients with diabetes mellitus and stable ischemic heart disease. Clinical Trial Registration— http://www.clinicaltrials.gov . Unique identifier: NCT00006305.

The Fanconi anemia (FA) network is important for the repair of interstrand DNA cross-links. A key event in FA pathway activation is the monoubiquitylation of the FA complementation group I (FANCI)–FANCD2 (ID) complex by FA complementation group L (FANCL), an E3 ubiquitin ligase. In this study, we show that RAD18, another DNA damage–activated E3 ubiquitin ligase, also participates in ID complex activation by ubiquitylating proliferating cell nuclear antigen (PCNA) on Lys164, an event required for the recruitment of FANCL to chromatin. We also found that monoubiquitylated PCNA stimulates FANCL-catalyzed FANCD2 and FANCI monoubiquitylation. Collectively, these experiments identify RAD18-mediated PCNA monoubiquitination as a central hub for the mobilization of the FA pathway by promoting FANCL-mediated FANCD2 monoubiquitylation.

Adverse events such as deaths following telephone triage calls are rare, suggesting that the process is basically safe. However, if calls tend to concern mostly minor illnesses, then adverse events following calls would be uncommon even if the triage process itself was flawed. We investigated hospitalization rates following triage calls and compared them to hospitalization following two other types of medical access, emergency department (ED) visits and office visits. For the Ask Mayo Clinic telephone triage centre, hospitalization rates for adult calls concerning chest pain and abdominal pain were each 13%. Based on national survey data, hospitalization for adult ED visits concerning the same symptoms were 33% (chest pain) and 19% (abdominal pain). Office visits had hospitalization rates significantly lower than triage calls in all age groups, while ED visits had higher hospitalization rates than triage calls in all age groups. There are both qualitative and quantitative similarities between triage calls and ED visits and, using hospitalization as an indicator, some subgroups of triage calls are nearly as serious as ED visits.