Analgesic efficacy of selective tibial nerve block versus partial local infiltration analgesia for posterior pain after total knee arthroplasty: a randomized, controlled, triple-blinded trial.

BACKGROUND: The adductor canal block provides pain relief on the anterior aspect of the knee after arthroplasty. Pain on the posterior aspect may be treated either by partial local infiltration analgesia of the posterior capsule or by a tibial nerve block. This randomized, controlled, triple-blinded trial tests the hypothesis that a tibial nerve block would provide superior analgesia compared to posterior capsule infiltration in patients scheduled for total knee arthroplasty under spinal anesthesia with an adductor canal block. METHODS: Sixty patients were randomized to receive either infiltration of the posterior capsule by the surgeon with ropivacaine 0.2%, 25 mL, or a tibial nerve block with 10 mL of ropivacaine 0.5%. Sham injections were performed to guarantee proper blinding. The primary outcome was intravenous morphine consumption at 24 h. Secondary outcomes included intravenous morphine consumption, pain scores at rest and on movement, and different functional outcomes, measured at up to 48 h. When necessary, longitudinal analyses were performed with a mixed-effects linear model. RESULTS: The median (interquartile range) of cumulative intravenous morphine consumption at 24 h was 12 mg (4-16) and 8 mg (2-14) in patients having the infiltration or the tibial nerve block respectively (p = 0.20). Our longitudinal model showed a significant interaction between group and time in favor of the tibial nerve block (p = 0.015). No significant differences were present between groups in the other above-mentioned secondary outcomes. CONCLUSION: A tibial nerve block does not provide superior analgesia when compared to infiltration. However, a tibial nerve block might be associated with a slower increase in morphine consumption over time.

A randomised controlled trial of intravenous dexmedetomidine added to dexamethasone for arthroscopic rotator cuff repair and duration of interscalene block.

Prolongation of peripheral nerve blockade by intravenous dexamethasone may be extended by intravenous dexmedetomidine. We randomly allocated 122 participants who had intravenous dexamethasone 0.15 mg.kg-1 before interscalene brachial plexus block for day-case arthroscopic rotator cuff repair to intravenous saline (62 participants) or intravenous dexmedetomidine 1 µg.kg-1 (60 participants). The primary outcome was time from block to first oral morphine intake during the first 48 postoperative hours. Fifty-nine participants reported taking oral morphine, 25/62 after placebo and 34/60 after dexmedetomidine, p = 0.10. The time to morphine intake was shorter after dexmedetomidine, hazard ratio (95%CI) 1.68 (1.00-2.82), p = 0.049. Median (IQR [range]) morphine doses were 0 (0-12.5 [0-50]) mg after control vs. 10 (0-30 [0-50]) after dexmedetomidine, a difference (95%CI) of 7 (0-10) mg, p = 0.056. There was no effect of dexmedetomidine on pain at rest or on movement. Intra-operative hypotension was recorded for 27/62 and 50/60 participants after placebo vs. dexmedetomidine, respectively, p < 0.001. Other outcomes were similar, including durations of sensory and motor block. In conclusion, dexmedetomidine shortened the time to oral morphine consumption after interscalene block combined with dexamethasone and caused intra-operative hypotension.

Myeloid differentiation primary response gene (MyD) 88 signalling is not essential for intestinal fibrosis development.

Dysregulation of the immune response to microbiota is associated with inflammatory bowel disease (IBD), which can trigger intestinal fibrosis. MyD88 is a key component of microbiota signalling but its influence on intestinal fibrosis has not been clarified. Small bowel resections from donor-mice were transplanted subcutaneously into the neck of recipients C57BL/6 B6-MyD88tm1 Aki (MyD88-/-) and C57BL/6-Tg(UBC-green fluorescence protein (GFP))30Scha/J (GFP-Tg). Grafts were explanted up to 21 days after transplantation. Collagen layer thickness was determined using Sirius Red stained slides. In the mouse model of fibrosis collagen deposition and transforming growth factor-beta 1 (TGF-ß1) expression was equal in MyD88+/+ and MyD88-/-, indicating that MyD88 was not essential for fibrogenesis. Matrix metalloproteinase (Mmp)9 expression was significantly decreased in grafts transplanted into MyD88-/- recipients compared to MyD88+/+ recipients (0.2 ± 0.1 vs. 153.0 ± 23.1, respectively, p < 0.05), similarly recruitment of neutrophils was significantly reduced (16.3 ± 4.5 vs. 25.4 ± 3.1, respectively, p < 0.05). Development of intestinal fibrosis appears to be independent of MyD88 signalling indicating a minor role of bacterial wall compounds in the process which is in contrast to published concepts and theories. Development of fibrosis appears to be uncoupled from acute inflammation.

A DEFICIENS homologue is down-regulated during apomictic initiation in ovules of Hieracium.

Hieracium is a member of the Asteraceae family, and contains sexual species in addition to apomictic species that reproduce by apospory and produce seed without fertilization. A homologue of the floral organ-identity gene DEFICIENS (DEF) was isolated from an apomictic line of Hieracium piloselloides (Vill.) following differential display between mature ovules and those initiating autonomous embryogenesis. The gene termed HPDEF has 93% amino acid identity with GDEF2, a DEF homologue isolated from Gerbera hybrida (D. Yu et al., 1999, Plant J. 17: 51-62), another member of the Asteraceae. In-situ analysis showed that early in floral development HPDEF is expressed in stamen and petal primordia, indicating expected B-function activity, according to the ABC model of floral organ identity (J. L. Bowman et al., 1991, Development 112: 1-20; E. S. Coen and E. M. Meyerowitz, 1991, Nature 353: 31-37). However, HPDEF expression was also observed in ovule primordia and expression continued in developing ovules until anthesis, indicating that this gene may have a role in ovule development. Expression of HPDEF was not detected in megaspore mother cells, or in sexual or aposporous embryo sacs. In sexual Hieracium, HPDEF was uniformly expressed throughout the ovule integument until anthesis. In most ovules of the apomict, however, HPDEF expression was transiently down-regulated in a specific zone in the chalazal region where cells initiating aposporous embryo sac formation differentiate. Uniform low-level HPDEF expression was subsequently observed prior to anthesis in ovules from sexual and apomictic plants. HPDEF may be down-regulated as a consequence of apomictic initiation and/or its down-regulation may facilitate progression of apomictic events.