Disease relevance of Least-Squares Analysis

• The crystal structure of thioredoxin from Escherichia coli has been refined by the stereochemically restrained least-squares procedure to a crystallographic R-factor of 0.165 at 1.68 A resolution [1].
• The crystal structure of the apoenzyme form of GDH from Hyphomicrobium methylovorum has been determined by the method of isomorphous replacement and refined at 2.4 A resolution using a restrained least-squares method [2].
• Comparisons of last 14-day, least-squares means among groups did not reveal differences in data treated by lean body weight [3MH/(kg LBW X d)] or by urinary creatinine excretion [3MH/(kg UCE X d)], but 3MH/(kg LBW X d) excretions were higher for exercise than no-exercise subjects [3].
• Using broken-line least-squares analysis, weight gain reached a plateau (6.8 g/d) at a thiamin concentration of 0.55 +/- 0.07 mg/kg [4].
• Adopting this general approach, we fitted human pulmonary O2 toxicity data to the hyperbolic equation % delta VC = Bs.(PO2 - B1).(time)B3 using a nonlinear least squares analysis [5].

Psychiatry related information on Least-Squares Analysis

• RESULTS: At the end of IM treatment, patients receiving ziprasidone (n=427) showed significantly improved Brief Psychiatric Rating Scale Total (BPRS total) scores compared with those receiving haloperidol (n=138) [least-squares (LS) mean change -6.14 for ziprasidone versus -4.13 for haloperidol, P<0.0018] [6].
• Following this, the eye movements of the longest REM periods (and one long period of pre-sleep wakefulness) were subject to a least-squares spectral analysis [7].
• The conclusion is that the Defense Mechanism Test and Partial Least Squares analysis seem to be powerful methods for personality assessment and potentially for cross-cultural research, and culture-specific norms in the Defense Mechanism Test must be employed [8].

High impact information on Least-Squares Analysis

• A restrained least squares refinement of the solution structure of the double-stranded DNA undecamer 5'd(AAGTGT-GACAT).5'd(ATGTCACACTT) comprising a portion of the specific target site of the cAMP receptor protein in the gal operon is presented [9].
• Selected backbone segments of the model representing regions of prominent sequence similarity between antibodies and TCRs were least-squares superimposed onto the corresponding segments of the crystallographically resolved 4-4-20 antibody complexed with its antigen, fluorescein [10].
• Use of the van't Hoff equation plus least-squares fitting to determine a more probable baseline gives delta H = 1.3 kcal/mol per residue [11].
• The structure of human recombinant interleukin 1 beta (IL-1 beta) has been refined by a restrained least-squares method to a crystallographic R factor of 17.2% to 2.0 A resolution [12].
• The crystal structure of Lys-7-(dinitrophenylene)-Lys-41-cross-linked ribonuclease A has been determined by molecular replacement and refined by restrained least-squares methods to an R factor of 0.18 at 2.0-A resolution [13].

Chemical compound and disease context of Least-Squares Analysis

• Fourier-transform infrared spectroscopy (FT-IR) has been applied to the quantitative study of the dehydration of the phosphatidylserine phosphate group in the presence of Ca2+ exerted by different molecules, such as diacylglycerol, sphingosine and stearylarnine, by using a partial least-squares statistical procedure [14].
• Calf birth weights were correlated with least-squares means for maternal concentrations of prepartum estrone (r = .57), estradiol (r = .59) and estrone sulfate (r = .64) and postpartum maternal concentrations of PGFM (r = .56) [15].
• In the second study increasing education was associated with decrease in smoking, leisure-time physical inactivity, total and LDL cholesterol, and triglycerides and increase in obesity, truncal obesity and hypertension (Least-squares regression p < 0.05) [16].

Biological context of Least-Squares Analysis

• Absolute metabolic fluxes in isolated perfused hearts have been determined by a nonlinear least squares analysis of glutamate labeling kinetics from [1-13C]glucose, [4-13C]beta-hydroxybutyrate, or [2-13C]acetate using 13C NMR spectroscopy [17].
• Partial least squares (PLS) has proven to be a important multivariate analytic tool for positron emission tomographic and, more recently, event-related potential (ERP) data [18].
• The models were refined to R-factors of 0.19 (maleate complex) and 0.18 (2-methylaspartate complex) by molecular dynamics and restrained least squares methods [19].
• Isotope excretion ratios of urinary folates were used as criteria of bioavailability (pooled SE = 0.10): PteGlu (1.53, least squares mean), 10-formyl-H4folate (1.02), 5-methyl-H4folate (0.99), 5-formyl-H4folate (0.1.13), and H4folate (0.71) [20].
• RESULTS: Vildagliptin significantly increased the insulin secretory rate at 7 mmol/liter glucose (secretory tone), calculated from the dose response; the difference in least squares mean (deltaLSM) was 101 +/- 51 pmol.min(-1).m(-2) (P = 0.002) [21].

Anatomical context of Least-Squares Analysis

• Computer simulation studies showed that RLS analysis yielded k(3) with almost the same accuracy as the standard nonlinear least squares (NLS) analysis in brain regions with low (such as neocortex and hippocampus) and moderately high (thalamus) k(3) values [22].
• Enhanced synchronous spectrofluorometric determination of tetracycline in blood serum by chemometric analysis. Comparison of partial least-squares and hybrid linear analysis calibrations [23].
• The algorithms presented here are used to perform nonlinear least-squares analyses of ST-EPR spectra of the anion exchange protein of the human erythrocyte membrane, band 3, which has been affinity spin-labeled with a recently developed dihydrostilbene disulfonate derivative, [15N,2H13]-SL-H2DADS-MAL [24].
• The pharmacology of the receptors was studied using computerized, non-linear least-squares regression analysis of [3H]flunitrazepam displacement by flunitrazepam, CL218,872 and ethyl beta-carboline-3-carboxylate binding to membranes [25].
• The accumulation of choline into PC12 cells proceeded through two uptake systems with high (Km = 3.20 microM) and low (Km = 65.2 muM) affinities as revealed by least-squares iterative fitting of a substrate-velocity curve to the data [26].

Associations of Least-Squares Analysis with chemical compounds

• The slope of the regression line obtained by a least squares method was steepest for all the treatment groups, followed by the heat plus 5 g/kg glucose and heat plus 3 g/kg glucose groups [27].
• Urinary 15N-nitrogen excretion as ammonia and urea was measured during the 210-min infusion period, and urea synthesis and ammonia conversion to amino acids were analyzed with a three-compartment model using the nonlinear least-squares method [28].
• At a late stage of the refinement, atomic parameters for only the Fe4S4 cluster plus the 4 associated cystein S-gamma atoms were adjusted by least squares methods and kept fixed during the rest of the refinement [29].
• The structure of cytoplasmic malate dehydrogenase has been partially refined by crystallographic least squares methods [30].
• Nonlinear least squares fitting of these data to the model gave nonrandomly distributed residuals for the 13C fractional enrichments of glutamate C-4, suggesting an incomplete model, but a well determined cycle flux of 11.9 mumol/g dry weight X min for an oxygen uptake of 35 mumol/g dry weight X min [31].

Gene context of Least-Squares Analysis

• Dissociation constants determined by least-squares non-linear regression indicated that the affinity of UCP2 for these fluorescently tagged nucleotides was 3-5 microM or perhaps an order of magnitude stronger, depending on the model used [32].
• Metabolic profiles from (1)H nuclear magnetic resonance spectroscopy have been used to describe both one and two protein systems in four mouse models related to Duchenne muscular dystrophy using the pattern recognition technique partial least squares [33].
• The crystal structure of human glutathione reductase has been established at 1.54 A resolution using a restrained least-squares refinement method [34].
• The structure of a Y35G mutant of bovine pancreatic trypsin inhibitor (BPTI) was solved by molecular replacement and was refined by both simulated annealing and restrained least-squares at 1.8 A resolution [35].
• The oncomodulin backbone is closely related to that of parvalbumin; however, some differences are found after a least-squares fit of the two backbones, with root-mean-square (r.m.s.) deviations of 1 to 2 A in residues 2 to 6, 59 to 61 of the CD loop, 87, 90 and 108 [36].

Analytical, diagnostic and therapeutic context of Least-Squares Analysis

• RESULTS: Least-squares analysis of the FTIR data of native BNC yielded a collagen content of 54 +/- 13% and a CS content of 37 +/- 16% (mean +/- SD) [37].
• Using multifrequency phase and modulation fluorometry and a nonlinear least-squares analysis of lifetime data, we were able to determine the complex decay of 1,6-diphenyl-1,3,5-hexatriene (DPH) in synthetic phospholipid bilayers [38].
• X-ray powder diffraction with Rietveld refinement, infrared spectroscopy, thermogravimetric analysis, (23)Na MAS NMR, and (1)H MAS NMR were used to determine how the framework anionic charge is cation-balanced over a range of framework compositions [39].
• Crystallization, structure determination and least-squares refinement to 1.75 A resolution of the fatty-acid-binding protein isolated from Manduca sexta L [40].
• Calibration standardization algorithm for partial least-squares regression: application to the determination of physiological levels of glucose by near-infrared spectroscopy [41].

References