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M Column (m + column)
Selected AbstractsPhysical Medicine and Rehabilitation (87)PAIN PRACTICE, Issue 1 2001A.J. Haig Paraspinal electromyography in high lumbar and thoracic lesions. (University of Michigan, Ann Arbor, MI) Am J Phys Med Rehabil 2000;79:336,342. This study aimed to use needle electromyography in the paraspinal muscles to localize the root level of a radiculopathy. Nine cases of clinically proven, isolated high lumbar or thoracic disk herniations of patients who underwent MiniPM were collected. Four were from a prospective study of 114 persons with low back pain (MiniPM had 100% sensitivity to magnetic resonance imaging-documented high disks). In the most medial "S" column, mean MiniPM scores were 0.7 for the level above the radiologically documented lesion (3.1 at the lesion and 1.6, 1.6, and 1.1 at the 3 spinous processes below the lesion). Similar numbers were obtained in the "M" column (slightly lateral), with no significant differences between S and M. Differences were significant between and at the level of the lesion for S (P < 0.06) and M (P < 0.01), and between the lesion level and 3 levels below for the M column (P < 0.01). Conclude that paraspinal electromyography has a higher than previously reported sensitivity for high lumbar lesions. Electromyography using MiniPM can localize some radiculopathies. The individual cases suggest that, consistent with the anatomy of the caudi equina, thoracic lesions and lateral lumbar lesions denervate only at 1 level, but more central lumbar lesions also denervate distally innervated paraspinal muscles. Comment by Miles Day, MD. This study is designed to assess the sensitivity of many MiniPM for higher-level rediculopathies, ie, lower thoracic and high lumbar, and to determine if findings are specific to the root level involved. The MiniPM is thought to assess the multifidus portion of the paraspinal muscles that are innervated from L2 to the sacrum. The clinical protocol tests the paraspinal extensively and provides a numerica score, thus eliminating some subjectivity of the EMG. The study demonstrates that MiniPM has good sensitivity for high lumbar and thoracic lesions and provides information on the level of the lesion independent of limb EMG. After reviewing the study, I agree with the authors that MiniPM is in itself not diagnostic for radiculopathy, but is only an additional test to help support other neuro physiological studies when evaluating for radiculopathy. It is not specific for diagnosing radiculopathy. [source] The two-median problem on Manhattan meshesNETWORKS: AN INTERNATIONAL JOURNAL, Issue 3 2007Mordecai J. Golin Abstract We investigate the two-median problem on a mesh with M columns and N rows (M , N), under the Manhattan (L1) metric. We derive exact algorithms with respect to m, n, and r, the number of columns, rows, and vertices, respectively, that contain requests. Specifically, we give an O(mn2 log m) time, O(r) space algorithm for general (nonuniform) meshes (assuming m , n). For uniform meshes, we give two algorithms both using O(MN) space. One is an O(MN2) time algorithm, while the other is an algorithm running in O(MN log N) time with high probability and in O(MN2) time in the worst case assuming the weights are independent and identically distributed random variables satisfying certain natural conditions. These improve upon the previously best-known algorithm that runs in O(mn2r) time. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(3), 226,233 2007 [source] HPLC-DAD in identification and quantification of selected coumarins in crude extracts from plant cultures of Ammi majus and Ruta graveolensJOURNAL OF SEPARATION SCIENCE, JSS, Issue 14 2003Marian Kami Abstract This paper describes a method for the separation and determination of selected coumarins and furanocoumarins in the crude extracts from plant tissue cultures of Ammi majus hairy roots and Ruta graveolens cell suspensions, cultured in vitro, separately or together as co-cultures. The usefulness of the three main components of the eluent used in reversed-phase high performance liquid chromatographic analysis, namely: methanol (MeOH), acetonitrile (ACN), and tetrahydrofuran (THF), and different elution programs, was assessed. In the optimal analytical method a Lichrospher® RP-18e 5-,m column, a THF-MeOH elution gradient, and a UV/VIS DAD detector were used. Due to the presence of many different compounds in the investigated plant extracts, the use of a UV/VIS DAD detector was essential. Coumarins were identified by comparison of their UV spectra with those of the analytical standards, and characterization of peak purity. [source] Determination of chlorpheniramine in human plasma by HPLC-ESI-MS/MS: application to a dexchlorpheniramine comparative bioavailability studyBIOMEDICAL CHROMATOGRAPHY, Issue 7 2010Ronilson Agnaldo Moreno Abstract In the present study a fast, sensitive and robust validated method to quantify chlorpheniramine in human plasma using brompheniramine as internal standard (IS) is described. The analyte and the IS were extracted from plasma by LLE (diethyl ether,dichloromethane, 80:20, v/v) and analyzed by HPLC-ESI-MS/MS. Chromatographic separation was performed using a gradient of methanol from 35 to 90% with 2.5,mm NH4OH on a Gemini Phenomenex C8 5,,m column (50 × 4.6,mm i.d.) in 5.0,min/run. The method fitted to a linear calibration curve (0.05,10,ng/mL, R > 0.9991). The precision (%CV) and accuracy ranged, respectively: intra-batch from 1.5 to 6.8% and 99.1 to 106.6%, and inter-batch from 2.4 to 9.0%, and 99.9 to 103.1%. The validated bioanalytical procedure was used to assess the comparative bioavailability in healthy volunteers of two dexchlorpheniramine 2.0,mg tablet formulations (test dexchlorpheniramine, Eurofarma, and reference Celestamine®, Schering-Plough). The study was conducted using an open, randomized, two-period crossover design with a 2 week washout interval. Since the 90% confidence interval for Cmax and AUC ratios were all within the 80,125% interval proposed by ANVISA and FDA, it was concluded that test and reference formulations are bioequivalent concerning the rate and the extent of absorption. Copyright © 2009 John Wiley & Sons, Ltd. [source] HPLC of basic drugs using non-aqueous ionic eluents: evaluation of a 3,,m strong cation-exchange materialBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010Phillip E. Morgan Abstract HPLC columns packed with 3,,m particle size HPLC Technology Techsphere SCX (propylsulfonic acid-modified) silica offer considerable advantages over 5,,m SCX packings in the analysis of basic drugs using 100% methanol eluents containing an ionic modifier such as ammonium perchlorate. The basic drugs studied included clozapine and norclozapine, olanzapine, quinine and quinidine, and amitriptyline, nortriptyline, imipramine and desipramine. The 3,,m column was not only more efficient for a given column length compared with 5,,m materials, but also elution times were less, a phenomenon observed in reversed-phase systems. The high efficiencies and excellent peak shapes obtained with the 3,,m SCX-modified packing together with the relatively low back-pressures attained show that such materials deserve serious consideration by laboratories involved in the analysis of basic drugs. Manufacturers should offer such packings as a matter of routine. Alternative ionic modifiers such as ammonium acetate are available for use with mass spectrometric detection if required. Copyright © 2009 John Wiley & Sons, Ltd. [source] Determination of ibudilast in human serum by high-performance liquid chromatography for pharmacokinetic studyBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010Hwa Yoon Abstract A simple, accurate, precise and cost effective reversed-phase HPLC method was developed to determine the concentration of ibudilast in human serum. Ibudilast and an internal standard, butyl 4-hydroxybenzoate, were extracted by liquid,liquid extraction with methyl tert -butyl ether. HPLC analysis was carried out under the following conditions: a Luna C18(2) 5,,m column, a mobile phase of acetonitrile,0.02% phosphoric acid (50,:,50, v/v, adjusted to pH 6.0 with triethylamine) and a UV detector at 319,nm. The chromatograms showed good resolution and sensitivity as well as no interference from the human serum. The calibration curves were linear over the concentration range, 1,100,ng/mL, for serum with correlation coefficients >0.999. The intra- and inter-day assay precision as well as the accuracy fulfilled the international requirements. The mean absolute recovery for human serum was 101.7 ± 6.1%. The lower limit of quantitation in human serum was 1,ng/mL, which is sensitive enough for pharmacokinetic studies. Stability studies revealed that ibudilast in human serum was stable during storage as well as during the assay procedure. This method was applied successfully to an examination of the pharmacokinetics of ibudilast in human subjects following a single oral dose of an ibudilast (10,mg) capsule. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||