Drug-Eluting versus Bare-Metal Stents in Saphenous Vein Grafts Compared to Native Coronary Vessels: The Norwegian Coronary Stent Trial Study.

BACKGROUND: Drug-eluting stents (DES) reduce target lesion revascularization (TLR) with no effect on mortality or myocardial infarction (MI) compared to bare-metal stents (BMS) in native vessels. Randomized stent studies in saphenous vein grafts (SVG) are few and the reported effects are ambiguous. The Norwegian Coronary Stent Trial study is the first to randomize lesions to percutaneous coronary intervention in native vessels and SVG. AIMS: The aim of this study was to compare the rate of mortality, MI, and TLR across stent and vessel types. METHODS: In this substudy, 6,087 patients with a single lesion in native vessels and 164 in SVG were followed for 5 years. RESULTS: MI was more frequent in SVG (subdistributional hazard ratio [SHR] 4.95 (3.75-6.54, p < 0.001), but not affected by stent type. In the first 500 days, DES reduced TLR in native vessels (SHR 0.21 (0.15-0.30) p < 0.001) and SVG (SHR 0.18 (0.04-0.80) p = 0.02). Thereafter, DES and BMS were equivalent in native vessels, but DES had a higher TLR rate than BMS in SVG (SHR 3.31 (1.23-8.94) p = 0.02). After 5 years, the TLR rate was still significantly lower for DES in native vessels (3.2% vs. 7.8%, p < 0.001) but not in SVG (21.4% vs. 18. 4%). CONCLUSION: In SVG, no difference in TLR between DES and BMS was observed after 5 years in contrast to persistent benefit in native vessels. The high rate of TLR and MI in SVG makes treatment of native vessels a preference whenever feasible and better treatment options for SVG are warranted.

Should we individualize training based on force-velocity profiling to improve physical performance in athletes?

The present study aimed to examine the effectiveness of an individualized training program based on force-velocity (FV) profiling on jumping, sprinting, strength, and power in athletes. Forty national level team sport athletes (20 ± 4years, 83 ± 13 kg) from ice-hockey, handball, and soccer completed a 10-week training intervention. A theoretical optimal squat jump (SJ)-FV-profile was calculated from SJ with five different loads (0, 20, 40, 60, and 80 kg). Based on their initial FV-profile, athletes were randomized to train toward, away, or irrespective (balanced training) of their initial theoretical optimal FV-profile. The training content was matched between groups in terms of set x repetitions but varied in relative loading to target the different aspects of the FV-profile. The athletes performed 10 and 30 m sprints, SJ and countermovement jump (CMJ), 1 repetition maximum (1RM) squat, and a leg-press power test before and after the intervention. There were no significant group differences for any of the performance measures. Trivial to small changes in 1RM squat (2.9%, 4.6%, and 6.5%), 10 m sprint time (1.0%, -0.9%, and -1.7%), 30 m sprint time (0.9%, -0.6%, and -0.4%), CMJ height (4.3%, 3.1%, and 5.7%), SJ height (4.8%, 3.7%, and 5.7%), and leg-press power (6.7%, 4.2%, and 2.9%) were observed in the groups training toward, away, or irrespective of their initial theoretical optimal FV-profile, respectively. Changes toward the optimal SJ-FV-profile were negatively correlated with changes in SJ height (r = -0.49, p < 0.001). Changes in SJ-power were positively related to changes in SJ-height (r = 0.88, p < 0.001) and CMJ-height (r = 0.32, p = 0.044), but unrelated to changes in 10 m (r = -0.02, p = 0.921) and 30 m sprint time (r = -0.01, p = 0.974). The results from this study do not support the efficacy of individualized training based on SJ-FV profiling.

Electromyographic comparison of the barbell deadlift using constant versus variable resistance in healthy, trained men.

Variable, external resistance is proposed to increasingly augment the muscular stress throughout a dynamic movement. However, it is uncertain how different levels of variable resistance affect the activation in the deadlift. The aim of the study was to compare the electromyographic activity of the gluteus maximus, biceps femoris, semitendinosus, vastus lateralis and erector spinae muscles during the barbell deadlift with free weights (FW) alone, with two (FW-2EB), and four elastic bands (FW-4EB) to deload some of the constant external resistance. Fifteen resistance-trained men participated in a cross-over design where resistance loadings were matched using two-repetition maximum loadings in the three different conditions. For the whole movement, both repetitions were analyzed. For the phase-specific analysis, the last repetition was divided into six parts, i.e. the lower, middle and upper phase in both the ascending and descending phase of the movement. The mean deloading contributions from FW-2EB and FW-4EB were 21% and 41%, respectively. In FW-4EB, the erector spinae was activated more in the whole movement (8%, ES = 0.31, p = 0.002) compared to FW-2EB. There was also a tendency towards higher activation in FW-4EB versus FW for the whole movement (5%, ES = 0.18, p = 0.072). There were no significant differences between the conditions in any of the other phases or muscles (p = 0.106-0.926). In summary, a high contribution from variable, external resistance seems to activate the back extensors more than a low contribution.

P2X7Rs are involved in cell death, growth and cellular signaling in primary human osteoblasts.

The ionotropic ATP-gated P2X7 receptor (P2X7R) is involved in the regulation of many physiological functions including bone metabolism. Several studies on osteoblasts from rodents and human osteoblast-like cell lines have addressed the expression and function of P2X7R on these bone-forming cells however; its role in human primary osteoblasts has not yet been reported. The aim of this study was to assess the expression of the P2X7R in bone marrow-derived stromal cells and in primary human trabecular osteoblasts and to determine the function in bone formation and cell signaling. We report that osteoblasts derived from human trabecular explants express a functional P2X7R capable of agonist-induced increase in intracellular calcium concentration and a positive permeability to fluorescent dyes. These osteoblasts are fully differentiated cells with alkaline phosphatase activity and the ability to form mineralized nodules. We show that the transcriptional regulation of osteoblastic markers can be modulated by P2X7R activity or blockade thereby influencing the differentiation, proliferation and bone matrix formation by these primary human osteoblasts. Finally, we demonstrate that the P2X7R is involved in propagation of mechanically-induced intercellular signaling in addition to the known mechanisms involving calcium signaling via P2Y2 receptors and gap junction.

Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty: a randomized, double-blind study.

BACKGROUND AND OBJECTIVES: Femoral nerve block (FNB), a commonly used postoperative pain treatment after total knee arthroplasty (TKA), reduces quadriceps muscle strength essential for mobilization. In contrast, adductor canal block (ACB) is predominately a sensory nerve block. We hypothesized that ACB preserves quadriceps muscle strength as compared with FNB (primary end point) in patients after TKA. Secondary end points were effects on morphine consumption, pain, adductor muscle strength, morphine-related complications, and mobilization ability. METHODS: We performed a double-blind, randomized, controlled study of patients scheduled for TKA with spinal anesthesia. The patients were randomized to receive either a continuous ACB or an FNB via a catheter (30-mL 0.5% ropivacaine given initially, followed by a continuous infusion of 0.2% ropivacaine, 8 mL/h for 24 hours). Muscle strength was assessed with a handheld dynamometer, and we used the percentile change from baseline for comparisons. The trial was registered at clinicaltrials.gov (Identifier: NCT01470391). RESULTS: We enrolled 54 patients, of which 48 were analyzed. Quadriceps strength as a percentage of baseline was significantly higher in the ACB group compared with the FNB group: (median [range]) 52% [31-71] versus 18% [4-48], (95% confidence interval, 8-41; P = 0.004). There was no difference between the groups regarding morphine consumption (P = 0.94), pain at rest (P = 0.21), pain during flexion of the knee (P = 0.16), or adductor muscle strength (P = 0.39); neither was there a difference in morphine-related adverse effects or mobilization ability (P > 0.05). CONCLUSIONS: Adductor canal block preserved quadriceps muscle strength better than FNB, without a significant difference in postoperative pain.

Multimodal analgesia with gabapentin, ketamine and dexamethasone in combination with paracetamol and ketorolac after hip arthroplasty: a preliminary study.

BACKGROUND AND OBJECTIVE: It has been hypothesized that combinations of analgesics with different mechanisms of action may reduce or even prevent postoperative pain. We, therefore, investigated the analgesic effect of gabapentin, dexamethasone and low-dose ketamine in combination with paracetamol and ketorolac as compared with paracetamol and ketorolac alone after hip arthroplasty. METHODS: In this double-blind study, 42 patients were randomly assigned to either a combination group [gabapentin 1200 mg+dexamethasone 8 mg+ketamine (0.15 mg kg(-1))+paracetamol 1 g+ketorolac 15 mg] or a control group (placebo+paracetamol 1 g+ketorolac 15 mg). The medication was given preoperatively except for ketorolac, which was given at the end of surgery. Postoperative pain treatment was paracetamol 1 gx3; ketorolac 15 mgx3; and patient-controlled intravenous morphine. Morphine consumption, pain intensity at rest and during mobilization, nausea and vomiting, sedation, dizziness, hallucination and consumption of ondansetron were recorded 2, 4 and 24 h after operation. A P value of less than 0.05 was considered statistically significant. RESULTS: Morphine consumption was not significantly different between groups (P=0.085). Overall pain scores were improved in the combination group as compared with the control group both at rest (P=0.042) and during mobilization (P=0.027). In the combination group, individual pain score above 30 mm on a 100 mm visual analogue scale was almost eliminated. The incidence of side effects did not differ between the groups. CONCLUSION: Preoperative gabapentin, dexamethasone and ketamine combined with paracetamol and ketorolac reduced overall pain scores in patients after hip arthroplasty as compared with paracetamol and ketorolac alone. Morphine consumption was not reduced.