We developed a robust bottom-up approach to construct open-ended, tubular co-culture constructs that simulate the human vascular morphology and microenvironment. By design, these three-dimensional ...artificial vessels mimic the basic architecture of an artery: a collagen-rich extracellular matrix (as the tunica externa), smooth muscle cells (SMCs) (as the tunica media), and an endothelial cell (EC) lining (as the tunica interna). A versatile needle-based fabrication technique was employed to achieve controllable arterial layouts within a PDMS-hosted collagen microchannel scaffold (330 ± 10 μm in diameter): (direct co-culture) a SMC/EC bilayer to follow the structure of an arteriole-like segment; and (encapsulated co-culture) a lateral SMC multilayer covered by an EC monolayer lining to simulate the architecture of a larger artery. Optical and fluorescence microscopy images clearly evidenced the progressive cell elongation and sprouting behavior of SMCs and ECs along the collagen gel contour and within the gel matrix under static co-culture conditions. The progressive cell growth patterns effectively led to the formation of a tubular co-culture with an internal endothelial lining expressing prominent CD31 (cluster of differentiation 31) intercellular junction markers. During a 4-day static maturation period, the artery constructs showed modest alteration in the luminal diameters (i.e. less than 10% changes from the initial measurements). This argues in favor of stable and predictable arterial architecture achieved via the proposed fabrication protocols. Both co-culture models showed a high glucose metabolic rate during the initial proliferation phase, followed by a temporary quiescent (and thus, mature) stage. These proof-of-concept models with a controllable architecture create an important foundation for advanced vessel manipulations such as the integration of relevant physiological functionality or remodeling into a vascular disease-mimicking tissue.
A prospective clinical study.
The purpose of this study was to evaluate prospectively a large group of patients with thoracolumbar burst fractures who were treated with a posterior/anterior combined ...procedure and to report on the surgical outcomes, complications and radiographic results.
A total of 100 consecutive patients were surgically managed with posterior instrumentation, anterior decompression and anterior strut grafting. There were 71 males and 29 females; the mean age was 36 years. Patients with osteoporotic delayed vertebral body collapse were excluded. The mean follow-up period was 30 months. Surgical outcomes such as operative time, blood loss and sagittal alignment were investigated. A neurological assessment was performed by a rating system based on the American Spine Injury Association impairment scale. An interbody fusion was judged using plain X-ray and computed tomographic scans.
The mean operative time was 256 min and the mean operative bleeding was 985 ml. Most of the patients were ambulatory within 3 days after surgery. Of the 76 patients with neurological injury, 54 (71.1%) recovered function following surgery. The mean local kyphosis angle was 12.2° kyphotic preoperatively and 0.8° lordotic at the final observation. The mean correction angle was 15.7° and correction loss was 2.6°. No instrumentation failure was observed and the postoperative fusion rate was 99%.
Posterior/anterior combined surgery with posterior pedicle screws and hooks fixation, and reconstruction by simultaneous strut grafting and anterior decompression, achieved short segment fixation and can be a useful option for surgically treating thoracolumbar burst fractures.
A prospective randomized clinical trial in preemptive analgesia for postoperative pain was conducted.
To compare the efficacy of three preemptive analgesics combined with local anesthesia: continuous ...subcutaneous morphine (SC), continuous epidural morphine (ED), and diclofenac sodium (DS).
Systemic opioids are known to be effective methods of postoperative pain control. The use of epidural morphine for postoperative analgesia has been a standard treatment in spinal surgery. Only a few studies in the literature have investigated the efficacy of preemptive analgesia using morphine. This is the first prospective randomized clinical trial to assess both subcutaneous and epidural continuous administration of opioids for preemptive analgesia.
For this study, 73 patients were assigned randomly to one of three treatment groups: SC, ED, or DS. All patients underwent posterior lumbar interbody fusion with instrumentation. Pain management was assessed using the visual analogue scale (VAS). Usage of supplemental analgesics, the time to first request of them, and side effects were also investigated.
Twenty-two patients were randomized to SC, 23 to ED, and 27 to DS. No baseline variable differences among the three groups were seen. The results showed no significant difference in analgesic effects among those three preemptive analgesics. Only immediately after surgery (at 0 hours), the VAS of the DS group was lowest among three groups. But the DS group took more supplemental analgesic drugs until 72 hours, and the time to first request of this group was shorter than that of the other two groups. High rates of minor side effects were seen in both the ED and DS groups. SC gave moderate analgesic effects as well as the other two groups with few adverse effects.
DS provided a favorable effect immediately after surgery, but the effective time was short and the patient needed more supplemental drugs after that. ED did not give the expected effect, with comparatively high rates of side effects. Continuous epidural anesthesia did not seem to be suitable for preemptive analgesia. Continuous subcutaneous morphine brought some analgesic effects with a low rate of complications. It can be an attractive method for postoperative analgesia with technical ease.
Recent results from CANGAROO-III Yukawa, Y; Collaboration, the CANGAROO
Journal of physics. Conference series,
07/2008, Letnik:
120, Številka:
6
Journal Article
Recenzirano
Odprti dostop
The CANGAROO-III telescope system for very-high-energy γ-ray astrophysics consists of four 10-m atmospheric Cherenkov telescopes located near Woomera, South Australia. We have been observing ...southern-sky objects since March 2004. Here we report on the status of the system and some recent results from CANGAROO-III observations.
Because accretion and merger shocks in clusters of galaxies may accelerate particles to high energies, clusters are candidate sites for the origin of ultra-high-energy (UHE) cosmic rays. A prediction ...was presented for gamma-ray emission from a cluster of galaxies at a detectable level with the current generation of imaging atmospheric Cherenkov telescopes. The gamma-ray emission was produced via inverse Compton upscattering of cosmic microwave background photons by electron-positron pairs generated by collisions of UHE cosmic rays in the cluster. We observed two clusters of galaxies, Abell 3667 and Abell 4038, searching for very high energy gamma-ray emission with the CANGAROO-III atmospheric Cherenkov telescope system in 2006. The analysis showed no significant excess around these clusters, yielding upper limits on the gamma-ray emission. From a comparison of the upper limit for the northwest radio relic region of Abell 3667 with a model prediction, we derive a lower limit for the magnetic field of the region of ~0.1 Delta *mG. This shows the potential of gamma-ray observations in studies of the cluster environment. We also discuss the flux upper limit from cluster center regions using a model of gamma-ray emission from neutral pions produced in hadronic collisions of cosmic-ray protons with the intracluster medium. The derived upper limit of the cosmic-ray energy density within this framework is an order of magnitude higher than that of our Galaxy.
We report the detection, with the CANGAROO-III imaging atmospheric Cherenkov telescope array, of a very high energy gamma-ray signal from the unidentified gamma-ray source HESS J1614--518, which was ...discovered in the H.E.S.S. Galactic plane survey. Diffuse gamma-ray emission was detected above 760 GeV at the 8.9 Delta *s level during an effective exposure of 54 hr from 2008 May to August. The spectrum can be represented by a power law: (8.2 ? 2.2stat ? 2.5sys) X 10--12 X (E/1 TeV)-- Delta *g cm--2 s--1 TeV--1 with a photon index Delta *g of 2.4 ? 0.3stat ? 0.2sys, which is compatible with that of the H.E.S.S. observations. By combining our result with multiwavelength data, we discuss the possible counterparts for HESS J1614--518 and consider radiation mechanisms based on hadronic and leptonic processes for a supernova remnant (SNR), stellar winds from massive stars, and a pulsar wind nebula (PWN). Although a leptonic origin from a PWN driven by an unknown pulsar remains possible, hadronic-origin emission from an unknown SNR is preferred.
We have observed the giant radio galaxy Centaurus A and the globular cluster omega Centauri in the TeV energy region using the CANGAROO III stereoscopic system. The system has been in operation since ...2004 with an array of four Imaging Atmospheric Cerenkov Telescopes (IACT) with similar to 100 m spacings. The observations were carried out in 2004 March and April. In total, approximately 10 hr of data were obtained for each target. No statistically significant gamma-ray signal has been found above 420 GeV over a wide angular region (a 1 degree radius from the pointing center), and we derive flux upper limits using the wholefield of view. Implications for the total energy of cosmic rays and the density of the cold dark matter are considered.
The five kinds of ferroelectric z-cut LiNbO3 crystals with different thicknesses of 0.3, 0.5, 1.0, 2.0, and 2.2 mm were employed to reveal the effects of frequency in thickness extension mode ...resonance oscillation (TERO) of acoustic waves on the catalytic properties of a 100 nm thick Ag film deposited onto the crystals. The different thicknesses of the crystals provided 11.2, 7.3, 3.6, 1.8, and 1.6 MHz as the primary resonance frequency, respectively. In ethanol decomposition producing ethylene and acetaldehyde, the characteristics of the TERO that caused significant increases in catalytic activity for ethylene production were observed for the five frequencies, but the extent of activity increments depended on the frequency: a maximum appeared at a medium frequency of 7.3 MHz. Remarkably large decreases in the activation energy for ethylene production occurred with 1.6−1.8 MHz, compared to those of the rest of the frequencies. Laser Doppler measurements showed the different distributions of lattice displacement among the five frequencies. The frequency dependence of catalytic activity enhancement was associated with both the magnitudes of lattice displacement and the density of sites causing lattice displacement. Markedly large distortion due to lattice displacement was observed for 1.6−1.8 MHz, compared to the high frequencies, and is considered to be responsible for large activation energy decreases with the lower frequency. The frequency effects of different crystal thicknesses on catalytic behavior are discussed.
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