Although clinical trials of autologous whole bone marrow for cardiac repair demonstrate promising results, many practical and mechanistic issues regarding this therapy remain highly controversial. Here, we report the results of a randomized study of bone-marrow-derived mesenchymal stem cells, administered to pigs, which offer several new insights regarding cellular cardiomyoplasty. First, cells were safely injected by using a percutaneous-injection catheter 3 d after myocardial infarction. Second, cellular transplantation resulted in long-term engraftment, profound reduction in scar formation, and near-normalization of cardiac function. Third, transplanted cells were preprepared from an allogeneic donor and were not rejected, a major practical advance for widespread application of this therapy. Together, these findings demonstrate that the direct injection of cellular grafts into damaged myocardium is safe and effective in the periinfarct period. The direct delivery of cells to necrotic myocardium offers a valuable alternative to intracoronary cell injections, and the use of allogeneic mesenchymal stem cells provides a valuable strategy for cardiac regenerative therapy that avoids the need for preparing autologous cells from the recipient.
The Canadian Galactic Plane Survey (CGPS) is a project to combine radio, millimetre and infrared surveys of the Galactic Plane to provide arc-minute scale images of all major components of the interstellar medium over a large portion of the Galactic disk. We describe in detail the observations for the low-frequency component of the CGPS, the radio surveys carried out at the Dominion Radio Astrophysical Observatory (DRAO), and summarize the properties of the merged database of surveys that comprises the CGPS.The DRAO Synthesis Telescope surveys have imaged a 73 • section of the Galactic Plane, using ∼85% of the telescope time between April 1995 and June 2000. The observations provide simultaneous radio continuum images at two frequencies, 408 MHz and 1420 MHz, and spectralline images of the λ21-cm transition of neutral atomic hydrogen. In the radio continuum at 1420 MHz dual-polarization receivers provide images in all four Stokes parameters. The surveys cover the region 74.2 • < < 147.3 • , with latitude extent of −3.6 • < b < +5.6 • at 1420 MHz and −6.7 • < b < +8.7 • at 408 MHz. By integration of data from single-antenna observations, the survey images provide complete information on all scales of emission structures down to the resolution limit, which is just below 1 × 1 cosec(δ) at 1420 MHz, and 3.4 × 3.4 cosec(δ) at 408 MHz. The continuum images have dynamic range of several thousand, yielding essentially noise-limited images with rms of ∼0.3 mJy/beam at 1420 MHz and ∼3 mJy/beam at 408 MHz. The spectral-line data are noise limited with rms brightness temperature ∆T B ∼ 3 K in a 0.82 km s −1 channel.The complete CGPS data set, including the DRAO surveys and data at similar resolution in 12 CO (1-0) and in infrared emission from dust, all imaged to an identical Galactic co-ordinate grid and map projection, are being made publicly available through the Canadian Astronomy Data Centre.
Chiral symmetry breaking in stirred crystallization of sodium chlorate ( NaClO3) occurs via the production of secondary crystals from a single "mother crystal." Martin, Tharrington, and Wu [Phys. Rev. Lett. 77, 2826 (1996)] investigated this phenomenon and concluded that it was mechanical crushing of a crystal by the stir bar, not convection, that produces secondary crystals from a single crystal. Here we report the generation of secondary crystals of sodium chlorate when a saturated solution of sodium chlorate is simply made to flow over a sodium bromate ( NaBrO3) crystal. This clearly shows that fluid flows alone can generate and disperse secondary nuclei.
In hypertensive patients with chronic renal failure enalapril slows progression towards end stage renal failure compared with beta blockers. This effect was probably not mediated through controlling blood pressure.
Correolide is a novel immunosuppressant that inhibits the voltage-gated potassium channel K(v)1.3 [Felix et al. (1999) Biochemistry 38, 4922-4930]. [(3)H]Dihydrocorreolide (diTC) binds with high affinity to membranes expressing homotetrameric K(v)1.3 channels, and high affinity diTC binding can be conferred to the diTC-insensitive channel, K(v)3.2, after substitution of three nonconserved residues in S(5) and S(6) with the corresponding amino acids present in K(v)1.3 [Hanner et al. (1999) J. Biol. Chem. 274, 25237-25244]. Site-directed mutagenesis along S(5) and S(6) of K(v)1.3 was employed to identify those residues that contribute to high affinity binding of diTC. Binding of monoiodotyrosine-HgTX(1)A19Y/Y37F ([(125)I]HgTX(1)A19Y/Y37F) in the external vestibule of the channel was used to characterize each mutant for both tetrameric channel formation and levels of channel expression. Substitutions at Leu(346) and Leu(353) in S(5), and Ala(413), Val(417), Ala(421), Pro(423), and Val(424) in S(6), cause the most dramatic effect on diTC binding to K(v)1.3. Some of the critical residues in S(6) appear to be present in a region of the protein that alters its conformation during channel gating. Molecular modeling of the S(5)-S(6) region of K(v)1.3 using the X-ray coordinates of the KcsA channel, and other experimental constraints, yield a template that can be used to dock diTC in the channel. DiTC appears to bind in the water-filled cavity below the selectivity filter to a hydrophobic pocket contributed by the side chains of specific residues. High affinity binding is predicted to be determined by the complementary shape between the bowl-shape of the cavity and the shape of the ligand. The conformational change that occurs in this region of the protein during channel gating may explain the state-dependent interaction of diTC with K(v)1.3.
OBJECTIVE
The purposes of this review are to describe the principles and method of MR spectroscopy, summarize current published data on musculoskeletal lesions, and report additional cases that have been analyzed with recently developed quantitative methods.
CONCLUSION
Proton MR spectroscopy can be used to identify key tissue metabolites and may serve as a useful adjunct to radiographic evaluation of musculoskeletal lesions. A pooled analysis of 122 musculoskeletal tumors revealed that a discrete choline peak has a sensitivity of 88% and specificity of 68% in the detection of malignancy. Modest improvements in diagnostic accuracy in 22 of 122 cases when absolute choline quantification was used encourage the pursuit of development of choline quantification methods.
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