972 research outputs found

    Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome

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    Background: Platelet-leukocyte gel (PLG) is being used during various surgical procedures in an attempt to enhance the healing process. We studied the effects of PLG on postoperative recovery of patients undergoing open subacromial decompression (OSD). Methods: PLG was produced from platelet-leukocyte-rich plasma (P-LRP), prepared from a unit of whole blood. Forty patients were included in the study. Self-assessed evaluations, using the American Shoulder and Elbow Surgeons scoring system of activities of daily living (ADL), joint instability, pain levels, pain medications, and clinical evaluations for range of motion were conducted. Results: Platelet and leukocyte counts were significantly increased in the P-LRP compared to baseline counts. Treated patients demonstrated decreased visual analog scales for pain and used significantly less pain medication, had an improved range of motion during passive forward elevation, external rotation, external rotation with arm at 90 degrees abduction, internal rotation, and cross body adduction compared to control patients (p < 0.001). No differences in the instability score were observed between the groups. Furthermore, treated patients performed more ADL (p < 0.05). Conclusion: In the PLG-treated group, recovery was faster and patients returned earlier to daily activities and also took less pain medication than control subjects

    Microwave to optical photon conversion via fully concentrated rare-earth-ion crystals

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    Most investigations of rare-earth ions in solids for quantum information have used crystals where the rare-earth ion is a dopant. Here, we analyze the conversion of quantum information from microwave photons to optical frequencies using crystals where the rare-earth ions, rather than being dopants, are part of the host crystal. These concentrated crystals are attractive for frequency conversion because of their large ion densities and small linewidths. We show that conversion with both high efficiency and large bandwidth is possible in these crystals. In fact, the collective coupling between the rare-earth ions and the optical and microwave cavities is large enough that the limitation on the bandwidth of the devices will instead be the spacing between magnon modes in the crystal

    Tissue identification with micro-magnetic resonance imaging in a caprine spinal fusion model

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    Nonunion is a major complication of spinal interbody fusion. Currently X-ray and computed tomography (CT) are used for evaluating the spinal fusion process. However, both imaging modalities have limitations in judgment of the early stages of this fusion process, as they only visualize mineralized bone. Magnetic resonance imaging (MRI) could be of great value as it is able to discriminate between different types of tissue. A feasibility study was performed in nine animals from a goat spinal fusion study, to evaluate the detection capacity of different tissues with micro-MRI. In this study bioresorbable polylactic acid cages were used. Six- and 12-months follow-up specimens were scanned in a 6.3 T micro-MRI scanner. After scanning, the specimens were processed for histology. Different types of tissue as well as the degradable cage material were identified in the fusion zone and designated as regions of interest (ROIs). Subsequently, the location of these ROIs was determined on the corresponding micro- MRI image, and average signal intensities of every individual ROI were measured. An excellent match was seen between the histological sections and micro-MRI images. The micro-MRI images showed quantifiable differences in signal intensity between bone with adipose marrow, bone with hematopoietic marrow, fibrocartilage, fibrous tissue, and degradable implant material. In time the signal intensity of bone with adipose marrow, bone with hematopoietic red marrow, and of fibrous tissue remained relatively constant. On the other hand, the signal intensity of the degradable implant material and the fibrocartilage changed significantly in time, indicating change of structure and composition. In conclusion, in our model using bioresorbable cages the MRI provides us with detailed information about the early fusion process and may therefore, allow early diagnosis of non-union

    Cognitive improvement in patients with carotid stenosis is independent of treatment type

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    Treatment of carotid artery stenosis decreases the long-term risk of stroke and may enhance cerebral blood flow. It is therefore expected to have the potential to prevent cognitive decline or even improve cognition over the long-term. However, intervention itself can cause peri-interventional cerebral infarcts, possibly resulting in a decline of cognitive performance, at least for a short time. We investigated the long-term effects of three treatment methods on cognition and the emotional state one year after intervention. In this prospective observational cohort study, 58 patients with extracranial carotid artery stenosis (≥ 70%) underwent magnetic resonance imaging and assessment of cognition, mood and motor speed before carotid endarterectomy (n = 20), carotid stenting (n = 10) or best medical treatment (n = 28) (i.e., time-point 1 [TP1]), and at one-year follow-up (TP2). Gain scores, reflecting cognitive change after treatment, were built according to performance as (TP2 -TP1)/TP1. Independent of the treatment type, significant improvement in frontal lobe functions, visual memory and motor speed was found. Performance level, motor speed and mood at TP1 were negatively correlated with gain scores, with greater improvement in patients with low performance before treatment. Active therapy, whether conservative or interventional, produces significant improvement of frontal lobe functions and memory in patients with carotid artery disease, independent of treatment type. This effect was particularly pronounced in patients with low cognitive performance prior to treatment

    No positive effect of autologous platelet gel after total knee arthroplasty: A double-blind randomized controlled trial: 102 patients with a 3-month follow-up

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    Background and purpose Activated platelets release a cocktail of growth factors, some of which are thought to stimulate repair. We investigated whether the use of autologous platelet gel (PG) in total knee arthroplasty (TKA) would improve wound healing and knee function, and reduce blood loss and the use of analgesics. Patients and methods 102 patients undergoing TKA were randomly assigned to a PG group (n 50) or to a control (C) group (n 52). The primary analysis was based on 73 participants (PG: 32; C: 41) with comparison of postoperative wound scores, VAS, WOMAC, knee function, use of analgesics, and the pre- and postoperative hemoglobin values after a follow-up of 3 months. 29 participants were excluded due to insufficient data. Results The characteristics of the protocol-compliant patients were similar to those of the patients who w

    Monte Carlo Simulation of the Heisenberg Antiferromagnet on a Triangular Lattice: Topological Excitations

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    We have simulated the classical Heisenberg antiferromagnet on a triangular lattice using a local Monte Carlo algorithm. The behavior of the correlation length ξ\xi, the susceptibility at the ordering wavevector χ(Q)\chi(\bf Q), and the spin stiffness ρ\rho clearly reflects the existence of two temperature regimes -- a high temperature regime T>TthT > T_{th}, in which the disordering effect of vortices is dominant, and a low temperature regime T<TthT < T_{th}, where correlations are controlled by small amplitude spin fluctuations. As has previously been shown, in the last regime, the behavior of the above quantities agrees well with the predictions of a renormalization group treatment of the appropriate nonlinear sigma model. For T>TthT > T_{th}, a satisfactory fit of the data is achieved, if the temperature dependence of ξ\xi and χ(Q)\chi(\bf Q) is assumed to be of the form predicted by the Kosterlitz--Thouless theory. Surprisingly, the crossover between the two regimes appears to happen in a very narrow temperature interval around Tth0.28T_{th} \simeq 0.28.Comment: 13 pages, 8 Postscript figure

    Commitment to glycolysis sustains survival of NO-producing inflammatory dendritic cells

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    TLR agonists initiate a rapid activation program in dendritic cells (DCs) that requires support from metabolic and bioenergetic resources. We found previously that TLR signaling promotes aerobic glycolysis and a decline in oxidative phosphorylation (OXHPOS) and that glucose restriction prevents activation and leads to premature cell death. However, it remained unclear why the decrease in OXPHOS occurs under these circumstances. Using real-time metabolic flux analysis, in the present study, we show that mitochondrial activity is lost progressively after activation by TLR agonists in inflammatory blood monocyte–derived DCs that express inducible NO synthase. We found that this is because of inhibition of OXPHOS by NO and that the switch to glycolysis is a survival response that serves to maintain ATP levels when OXPHOS is inhibited. Our data identify NO as a profound metabolic regulator in inflammatory monocyte–derived DCs

    Rapid sulfation of 3,3',5'-triiodothyronine in native Xenopus laevis oocytes

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    Sulfation is an important metabolic pathway facilitating the degradation of thyroid hormone by the type I iodothyronine deiodinase. Different human and rat tissues contain cytoplasmic sulfotransferases that show a substrate preference for 3,3'-diiodothyronine (3,3'-T2) > T3 > rT3 > T4. During investigation of the expression of plasma membrane transporters for thyroid hormone by injection of rat liver RNA in Xenopus laevis oocytes, we found uptake and metabolism of iodothyronines by native oocytes. Groups of 10 oocytes were incubated for 20 h at 18 C in 0.1 ml medium containing 500,000 cpm (1-5 nM) [125I]T4, [125I]T3, [125I]rT3, or [125I]3,3'-T2. In addition, cytosol prepared from oocytes was tested for iodothyronine sulfotransferase activity by incubation of 1 mg cytosolic protein/ml for 30 min at 21 C with 1 microM [125I]T4, [125I]T3, [125I]rT3, or [125I]3,3'-T2 and 50 microM 3'-phosphoadenosine-5'-phosphosulfate. Incubation media, oocyte extracts, and assay mixtures were analyzed by Sephadex LH-20 chromatography for production of conjugates and iodide. After 20-h incubation, the percentage of added radioactivity present as conjugates in the media and oocytes amounted to 0.9 +/- 0.2 and 1.0 +/- 0.1 for T4, less than 0.1 and less than 0.1 for T3, 32.5 +/- 0.4 and 29.3 +/- 0.2 for rT3, and 3.8 +/- 0.3 and 2.3 +/- 0.2 for 3,3'-T2, respectively (mean +/- SEM; n = 3). The conjugate produced from rT3 was identified as rT3 sulfate, as it was hydrolyzed by acid treatment. After injection of oocytes with copy RNA coding for rat type I iodothyronine deiodinase, we found an increase in iodide production from rT3 from 2.3% (water-injected oocytes) to 46.2% accompanied by a reciprocal decrease in rT3 sulfate accumulation from 53.7% to 7.1%. After 30-min incubation with cytosol and 3'-phosphoadenosine-5'-phosphosulfate, sulfate formation amounted to 1.8% for T4, less than 0.1% for T3, 77.9% for rT3, and 2.9% for 3,3'-T2. These results show that rT3 is rapidly metabolized in native oocytes by sulfation. The substrate preference of the sulfotransferase activity in oocytes is rT3 >> 3,3'-T2 > T4 > T3. The physiological significance of the high activity for rT3 sulfation in X. laevis oocytes remains to be established

    Cognitive and emotional effects of carotid stenosis.

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    PRINCIPLES: Patients with carotid artery stenosis (CAS) are at risk of ipsilateral stroke and chronic compromise of cerebral blood flow. It is under debate whether the hypo-perfusion or embolism in CAS is directly related to cognitive impairment. Alternatively, CAS may be a marker for underlying risk factors, which themselves influence cognition. We aimed to determine cognitive performance level and the emotional state of patients with CAS. We hypo-thesised that patients with high grade stenosis, bilateral stenosis, symptomatic patients and/or those with relevant risk factors would suffer impairment of their cognitive performance and emotional state. METHODS: A total of 68 patients with CAS of ≥70% were included in a prospective exploratory study design. All patients underwent structured assessment of executive functions, language, verbal and visual memory, motor speed, anxiety and depression. RESULTS: Significantly more patients with CAS showed cognitive impairments (executive functions, word production, verbal and visual memory, motor speed) and anxiety than expected in a normative sample. Bilateral and symptomatic stenosis was associated with slower processing speed. Cognitive performance and anxiety level were not influenced by the side and the degree of stenosis or the presence of collaterals. Factors associated with less co-gnitive impairment included higher education level, female gender, ambidexterity and treated hypercholesterolemia. CONCLUSIONS: Cognitive impairment and increased level of anxiety are frequent in patients with carotid stenosis. The lack of a correlation between cognitive functioning and degree of stenosis or the presence of collaterals, challenges the view that CAS per se leads to cognitive impairment