multiple linear regression analysis
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This paper deals with the use of multiple linear regression to predict the viscosity of engine oil at 100 °C based on the analysis of selected parameters obtained by Fourier transform infrared spectroscopy (FTIR). The spectral range (4000-650 cm⁻¹), resolution (4 cm⁻¹), and key pre-processing steps such as baseline correction, normalization, and noise filtering applied prior to modeling. A standardized laboratory method was used to analyze 221 samples of used motor oils. The prediction model was built based on the values of Total Base Number (TBN), fuel content, oxidation, sulphation and Anti-wear Particles (APP). Given the large number of potential predictors, stepwise regression was first used to select relevant variables, followed by Bayesian Model Averaging (BMA) to optimize model selection. Based on these methods, a regression relationship was developed for the prediction of viscosity at 100 °C. The calibration model was subsequently validated, and its accuracy was determined using the Root Mean Squared Error (RMSE) metric, it was 0.287. Finally, the obtained model was used to predict the lifetime of engine oil in diesel engines operating under severe conditions.
- Publikační typ
- časopisecké články MeSH
In an attempt to develop predictive relationships, apparent digestible energy (ADE) content (n = 361) as biological dependent variable and dietary contents of crude protein (CP), lipid, ash and gross energy (GE) as independent variables, obtained in 40 studies with 65 different feed ingredients and evaluated with 26 fish species, were subjected to linear correlation and multiple linear regression analysis. With dietary CP and GE contents identified as significant predictors, only 58% of the variation in ADE content could be explained. No improvement in accuracy of regression equations was gained by classification of values according to either feed ingredient (animal proteins, plant proteins, cereals) or fish species (water type, water temperature, feed habit). An R (2)-value of 0.4570 and mean prediction error (MPE) of 0.2085 between predicted and observed ADE values from eight independent studies (n = 37) illustrated the inability of the derived regression equation to accurately predict ADE contents of feed ingredients. Inclusion of dietary crude fibre and nitrogen-free extract (NFE) contents as independent variables did not improve the accuracy of prediction equations. The inadequacy of the use of linear regression to predict DE content from dietary composition across feed ingredients and fish species with high accuracy is discussed.
- MeSH
- dietní proteiny analýza MeSH
- druhová specificita MeSH
- energetický metabolismus fyziologie MeSH
- fyziologie výživy zvířat * MeSH
- krmivo pro zvířata analýza MeSH
- lineární modely MeSH
- lipidy analýza MeSH
- nutriční hodnota MeSH
- ryby fyziologie MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- dietní proteiny MeSH
- lipidy MeSH
BACKGROUND: Based on epidemiological commonalities, multiple sclerosis (MS) and Hodgkin lymphoma (HL), two clinically distinct conditions, have long been suspected to be aetiologically related. MS and HL occur in roughly the same age groups, both are associated with Epstein-Barr virus infection and ultraviolet (UV) light exposure, and they cluster mutually in families (though not in individuals). We speculated if in addition to sharing environmental risk factors, MS and HL were also genetically related. Using data from genome-wide association studies (GWAS) of 1816 HL patients, 9772 MS patients and 25 255 controls, we therefore investigated the genetic overlap between the two diseases. METHODS: From among a common denominator of 404 K single nucleotide polymorphisms (SNPs) studied, we identified SNPs and human leukocyte antigen (HLA) alleles independently associated with both diseases. Next, we assessed the cumulative genome-wide effect of MS-associated SNPs on HL and of HL-associated SNPs on MS. To provide an interpretational frame of reference, we used data from published GWAS to create a genetic network of diseases within which we analysed proximity of HL and MS to autoimmune diseases and haematological and non-haematological malignancies. RESULTS: SNP analyses revealed genome-wide overlap between HL and MS, most prominently in the HLA region. Polygenic HL risk scores explained 4.44% of HL risk (Nagelkerke R(2)), but also 2.36% of MS risk. Conversely, polygenic MS risk scores explained 8.08% of MS risk and 1.94% of HL risk. In the genetic disease network, HL was closer to autoimmune diseases than to solid cancers. CONCLUSIONS: HL displays considerable genetic overlap with MS and other autoimmune diseases.
- MeSH
- celogenomová asociační studie * MeSH
- genetická predispozice k nemoci MeSH
- genové regulační sítě MeSH
- Hodgkinova nemoc genetika MeSH
- jednonukleotidový polymorfismus * MeSH
- lidé MeSH
- lineární modely MeSH
- roztroušená skleróza genetika MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
BACKGROUND: Impairment of cognition and speech are common in multiple sclerosis (MS) patients, but their relationship is not well understood. OBJECTIVE: To describe the relationship between articulation rate characteristics and processing speed and to investigate the potential role of objective speech analysis for the detection of cognitive decline in MS. METHODS: A total of 122 patients with clinically definite MS were included in this cross-sectional pilot study. Patients underwent three speaking tasks (oral diadochokinesis, reading text and monologue) and assessment of processing speed (Symbol Digit Modalities Test [SDMT], Paced Auditory Serial Addition Test-3 s [PASAT-3]). Association between articulation rate and cognition was analyzed using linear regression analysis. We estimated the area under the receiver operating characteristics curves (AUC) to evaluate the predictive accuracy of articulation rate measures for the detection of abnormal processing speed. RESULTS: We observed an association between articulation rate and cognitive measures (rho = 0.45-0.58; p < 0.001). Faster reading speed by one word per second was associated with an 18.7 point (95% confidence interval [CI] 14.9-22.5) increase of the SDMT score and 14.7 (95% CI 8.9-20.4) point increase of PASAT-3 score (both p < 0.001). AUC values of articulation rate characteristics for the identification of processing speed impairment ranged between 0.67 and 0.79. Using a cutoff of 3.10 in reading speed, we were able to identify impairment in both the SDMT and PASAT-3 with 91% sensitivity and 54% specificity. CONCLUSION: Slowed articulation rate is strongly associated with processing speed decline. Objective quantitative speech analysis identified patients with abnormal cognitive performance.
- Klíčová slova
- Articulation, Cognition, Information processing, Multiple sclerosis, Speech,
- MeSH
- dospělí MeSH
- dysartrie etiologie MeSH
- kognitivní poruchy diagnóza etiologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- pilotní projekty MeSH
- průřezové studie MeSH
- regresní analýza MeSH
- ROC křivka MeSH
- roztroušená skleróza komplikace MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The relationship between fatigue impact and walking capacity and perceived ability in patients with multiple sclerosis (MS) is inconclusive in the existing literature. A better understanding might guide new treatment avenues for fatigue and/or walking capacity in patients with MS. OBJECTIVE: To investigate the relationship between the subjective impact of fatigue and objective walking capacity as well as subjective walking ability in MS patients. METHODS: A cross-sectional multicenter study design was applied. Ambulatory MS patients (n = 189, age: 47.6 ± 10.5 years; gender: 115/74 women/men; Expanded Disability Status Scale (EDSS): 4.1 ± 1.8 [range: 0-6.5]) were tested at 11 sites. Objective tests of walking capacity included short walking tests (Timed 25-Foot Walk (T25FW), 10-Metre Walk Test (10mWT) at usual and fastest speed and the timed up and go (TUG)), and long walking tests (2- and 6-Minute Walk Tests (MWT). Subjective walking ability was tested applying the Multiple Sclerosis Walking Scale-12 (MSWS-12). Fatigue impact was measured by the self-reported modified fatigue impact scale (MFIS) consisting of a total score (MFIStotal) and three subscales (MFISphysical, MFIScognitive and MFISpsychosocial). Uni- and multivariate regression analysis were performed to evaluate the relation between walking and fatigue impact. RESULTS: MFIStotal was negatively related with long (6MWT, r = -0.14, p = 0.05) and short composite (TUG, r = -0.22, p = 0.003) walking measures. MFISphysical showed a significant albeit weak relationship to walking speed in all walking capacity tests (r = -0.22 to -0.33, p < .0001), which persisted in the multivariate linear regression analysis. Subjective walking ability (MSWS-12) was related to MFIStotal (r = 0.49, p < 0.0001), as well as to all other subscales of MFIS (r = 0.24-0.63, p < 0.001), showing stronger relationships than objective measures of walking. CONCLUSIONS: The physical impact of fatigue is weakly related to objective walking capacity, while general, physical, cognitive and psychosocial fatigue impact are weakly to moderately related to subjective walking ability, when analysed in a large heterogeneous sample of MS patients.
- Klíčová slova
- Fatigue, Multiple sclerosis, Walking capacity,
- MeSH
- chůze fyziologie MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- neurologické poruchy chůze etiologie MeSH
- percepce fyziologie MeSH
- posuzování pracovní neschopnosti MeSH
- průřezové studie MeSH
- regresní analýza MeSH
- roztroušená skleróza komplikace psychologie MeSH
- senioři MeSH
- test chůzí MeSH
- únava etiologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
Fingolimod is an oral drug for the escalation of treatment of relapsing-remitting multiple sclerosis in patients with persistent disease activity on first-line drugs or in patients with rapidly progressive severe relapsing-remitting multiple sclerosis. An ultra-high-performance liquid chromatography-tandem mass spectrometry method for determining the concentrations of fingolimod and its active metabolite fingolimod phosphate in whole blood has been developed and validated. The advantages of this method are the easy, fast and cheap sample preparation using protein precipitation from blood with a mixture of acetonitrile-methanol (40:60, v/v). Chromatographic separation was performed on a ultra-high performance liquid chromatography BEH C18 1.7 μm (100 × 2.1 mm) column. Two modes of ionization, electrospray ionization and atmospheric pressure chemical ionization, were tested and compared. For validation, the electrospray ionization mode was chosen. As internal standard, isotopically labeled fingolimod-D4 was used to quantify the analytes. The method was validated according to the rules of the European Medicines Agency. The coefficients of variation for fingolimod were in the range of 1.13-11.88%, and the recovery was 98.80-106.00%. The coefficients of variation for fingolimod phosphate were in the range of 2.73-9.31%, and the recovery was 90.08-107.00%. The method is quite easy and fast and can be used for routine analysis.
- Klíčová slova
- fingolimod, fingolimod phosphate, liquid chromatography, mass spectrometry, multiple sclerosis,
- MeSH
- chromatografie kapalinová metody MeSH
- dospělí MeSH
- fingolimod hydrochlorid * krev farmakokinetika terapeutické užití chemie MeSH
- imunosupresiva krev farmakokinetika MeSH
- lidé MeSH
- limita detekce MeSH
- lineární modely MeSH
- reprodukovatelnost výsledků MeSH
- roztroušená skleróza krev farmakoterapie MeSH
- tandemová hmotnostní spektrometrie * metody MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fingolimod hydrochlorid * MeSH
- imunosupresiva MeSH
Correlations between facial bony structures and soft facial features are fundamental for facial approximation methods The purpose of this study was to assess the strength of the association between craniofacial shape and the shape of the soft-tissue profile and to determine the extent to which it might be possible to predict the latter from the former. Soft-tissue and skeletal facial profile curves were extracted from 86 lateral head cephalograms of a recent Central European population (52 males and 34 females, aged between 19 and 43 years), divided into five parts, segmented automatically and evaluated using geometric morphometrics. The magnitude of the hard-soft shape association was assessed by principal component analysis and subsequent multiple linear regression (Halazonetis, 2007), by partial least square analysis (PLS) (Rohlf and Corti, 2000) and the RV coefficient (Klingenberg, 2009). The greatest amount of association between the skeletal contour and overlying soft tissues was exhibited by the region of the forehead (predictive power: 95.1%, RV=0.91, correlation for PLS1 r=0,96), followed by the region of the nasal root (predictive power: 40.2%, RV=0.42, rPLS1=0.72) and the lower lip and chin (predictive power: 37.3%, RV=0.41, rPLS1=0.65). The smallest statistically significant covariation was displayed by the upper lip and the maxilla (predictive power: 9.6%, RV=0.14, rPLS1=0.43). The shape covariation between the nasal bridge and the tip and lateral border of the nasal aperture was found to be statistically insignificant (predictive power: 5.8%, RV=0.05, rPLS1=0.26). Shape covariation was visualized and described by thin-plate spine grids. These findings correspond with the observation that the shape of the nasal profile and the upper lip contour are difficult to reconstruct or predict reliably in facial approximations. It seems that the shape of soft tissues might not follow underlying structures as closely as expected.
- Klíčová slova
- Craniofacial relationships, Facial approximation, Facial profile, Forensic anthropology, Shape analysis,
- MeSH
- analýza hlavních komponent MeSH
- anatomická značka MeSH
- dospělí MeSH
- kefalometrie metody MeSH
- lebka anatomie a histologie diagnostické zobrazování MeSH
- lidé MeSH
- lineární modely MeSH
- metoda nejmenších čtverců MeSH
- mladý dospělý MeSH
- obličej anatomie a histologie MeSH
- radiografie MeSH
- software * MeSH
- soudní antropologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND OBJECTIVES: Trigeminal neuralgia affects approximately 2% of patients with multiple sclerosis (MS) and often shows higher rates of pain recurrence after treatment. Previous studies on the effectiveness of stereotactic radiosurgery (SRS) for trigeminal neuralgia did not consider the different MS subtypes, including remitting relapsing (RRMS), primary progressive (PPMS), and secondary progressive (SPMS). Our objective was to investigate how MS subtypes are related to pain control (PC) rates after SRS. METHODS: We conducted a retrospective multicenter analysis of prospectively collected databases. Pain status was assessed using the Barrow National Institute Pain Intensity Scales. Time to recurrence was estimated through the Kaplan-Meier method and compared groups using log-rank tests. Logistic regression was used to calculate the odds ratio (OR). RESULTS: Two hundred and fifty-eight patients, 135 (52.4%) RRMS, 30 (11.6%) PPMS, and 93 (36%) SPMS, were included from 14 institutions. In total, 84.6% of patients achieved initial pain relief, with a median time of 1 month; 78.7% had some degree of pain recurrence with a median time of 10.2 months for RRMS, 8 months for PPMS, 8.1 months for SPMS ( P = .424). Achieving Barrow National Institute-I after SRS was a predictor for longer periods without recurrence ( P = .028). Analyzing PC at the last available follow-up and comparing with RRMS, PPMS was less likely to have PC (OR = 0.389; 95% CI 0.153-0.986; P = .047) and SPMS was more likely (OR = 2.0; 95% CI 0.967-4.136; P = .062). A subgroup of 149 patients did not have other procedures apart from SRS. The median times to recurrence in this group were 11.1, 9.8, and 19.6 months for RRMS, PPMS, and SPMS, respectively (log-rank, P = .045). CONCLUSION: This study is the first to investigate the relationship between MS subtypes and PC after SRS, and our results provide preliminary evidence that subtypes may influence pain outcomes, with PPMS posing the greatest challenge to pain management.
- MeSH
- bolest etiologie chirurgie MeSH
- lidé MeSH
- lokální recidiva nádoru chirurgie MeSH
- management bolesti metody MeSH
- neuralgie trigeminu * radioterapie chirurgie MeSH
- radiochirurgie * metody MeSH
- retrospektivní studie MeSH
- roztroušená skleróza * chirurgie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
BACKGROUND: Cognitive impairment is a well-recognized symptom of multiple sclerosis (MS) that can manifest early in the disease course. Deficits in cognitive function can have a major impact on daily life. However, cognitive decline is often under-examined in clinical trials and clinical practice due to lack of adequate data. The objective of this study was to examine the longitudinal effect of ocrelizumab vs interferon beta (IFNβ)-1a on cognitive impairment in 2 phase 3 studies in relapsing MS (RMS). METHODS: The pooled population of participants with RMS (n = 1656) from the OPERA I/II clinical trials received subcutaneous IFNβ-1a (44 μg; n = 829) 3 times weekly or intravenous ocrelizumab (600 mg; n = 827) every 24 weeks. Cognition was assessed with a Symbol Digit Modalities Test (SDMT), administered in written or oral form according to each site investigator's choice, that primarily measured cognitive processing speed at baseline and every 12 weeks until the end of the double-blind treatment (96 weeks). Treatment effects were investigated based on longitudinal linear models for the change from baseline in SDMT and Cox regression for the time to 12- or 24-week confirmed decline of ≥4 points. RESULTS: Among the participants with an SDMT assessment at baseline and ≥1 postbaseline time point (IFNβ-1a, n = 749; ocrelizumab, n = 766), ocrelizumab treatment was associated with a greater mean SDMT improvement over 96 weeks than IFNβ-1a treatment (5.4 [95 % CI, 4.4-6.5] vs 4.0 [95 % CI, 3.0-5.1]; adjusted mean difference, 1.4 [95 % CI, 0.05-2.72]; P = 0.042). The risk of a clinically meaningful SDMT decline (≥4 points) was lower for those treated with ocrelizumab for both ≥12 weeks (IFNβ-1a, 18.4 %; ocrelizumab, 12.7 %; hazard ratio, 0.63 [95 % CI, 0.47-0.85]; P = 0.003) and ≥24 weeks (IFNβ-1a, 12.9 %; ocrelizumab, 7.9 %; HR, 0.57 [95 % CI, 0.39-0.82]; P = 0.003). CONCLUSION: Ocrelizumab treatment resulted in better cognitive outcomes as measured by SDMT in participants with RMS compared with IFNβ-1a treatment. However, methodological limitations need to be considered when interpreting these data. CLINICALTRIALS: gov: NCT01247324, NCT01412333.
- Klíčová slova
- Cognitive impairment, DMT, Multiple sclerosis, Ocrelizumab, SDMT,
- MeSH
- dospělí MeSH
- dvojitá slepá metoda MeSH
- humanizované monoklonální protilátky * farmakologie aplikace a dávkování terapeutické užití MeSH
- imunologické faktory * farmakologie aplikace a dávkování terapeutické užití MeSH
- interferon beta 1a * farmakologie terapeutické užití aplikace a dávkování MeSH
- kognitivní dysfunkce * etiologie farmakoterapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- relabující-remitující roztroušená skleróza * farmakoterapie komplikace MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky, fáze III MeSH
- randomizované kontrolované studie MeSH
- Názvy látek
- humanizované monoklonální protilátky * MeSH
- imunologické faktory * MeSH
- interferon beta 1a * MeSH
- ocrelizumab MeSH Prohlížeč
OBJECTIVE: Alveolar concentration (C(A)NO) and bronchial flux (J(aw)NO) of nitric oxide (NO) characterize the contributions of peripheral and proximal airways to exhaled NO. Both parameters can be estimated using a two-compartment model if the fraction of NO in orally exhaled air (FE(NO)) is measured at multiple constant expiratory flow rates (V). The aim of this study was to evaluate how departures from linearity influence the estimates of C(A)NO and J(aw)NO obtained with the help of linear regression analysis of the relationships between FE(NO) and 1/V (method P), and between the NO output (V(NO) = FE(NO) × V) and V (method T). Furthermore, differences between patients with atopic asthma (AA) and allergic rhinitis (AR) and between methods P and T were assessed. DESIGN: Measurements of FE(NO) were performed with a chemiluminiscence analyzer at five levels of V ranging from 50 to 250 ml/sec in school children and adolescents with mild to moderate-severe AA treated by inhaled corticosteroids (N = 42) and AR (N = 20). RESULTS: Violation of the linearity condition at V ≤ 100 ml/sec caused shifts between methods with regard to the partition of exhaled NO into alveolar (C(A)NO: P > T) and bronchial (J(aw)NO: T > P) components. Both methods gave similar results in the linear range of 150-250 ml/sec: The mean ratios P/T and limits of agreement calculated in AA and AR patients were 1.03 (0.49-1.56) and 1.07 (0.55-1.59) for C(A)NO and 1.03 (0.73-1.33) and 0.99 (0.90-1.10) for J(aw)NO, respectively. No significant differences between AA and AR were found in C(A)NO and J(aw)NO calculated in the linear range by the T method {medians (inter-quartile ranges): 1.7 ppb (0.9-3.9) vs. 2.3 ppb (0.8-3.7), P = 0.91; 1,800 pl/sec (950-3,560) vs. 1,180 pl/sec (639-1,950), P = 0.061}. However, the flow-dependency of the estimates was markedly higher in AA than in AR patients: C(A) NO was decreased 2.8-fold vs. 1.5-fold and J(aw) NO was increased 1.5-fold vs. 1.2-fold in the linear range as compared to the range of 50-250 ml/sec. In both groups, the median standard errors (SE) of the J(aw) NO estimates were similar for the metods P and T and small (<15%) regardless of the range for expiratory flows. The precision of C(A) NO estimates was less in all ranges. For both methods, the SE of the estimates obtained in the range of 150-250 ml/sec exceeded 50% in asthmatics and 30% in AR patients, respectively. The results show that FE(NO) has to be measured at several expiratory flows ≥100 ml/sec for the accurate estimation of C(A) NO and J(aw) NO using linear methods P and T in children and adolescents with AA and AR. A stepwise procedure for detecting nonlinearity and evaluating the quality of FE(NO) measurements is suggested.
- MeSH
- alergická rýma MeSH
- biologické modely * MeSH
- bronchiální astma metabolismus patofyziologie MeSH
- bronchy chemie metabolismus patofyziologie MeSH
- celoroční alergická rýma metabolismus patofyziologie MeSH
- dechové testy metody MeSH
- dítě MeSH
- lidé MeSH
- lineární modely MeSH
- mladiství MeSH
- oxid dusnatý analýza metabolismus MeSH
- plicní alveoly chemie metabolismus patofyziologie MeSH
- respirační funkční testy MeSH
- stupeň závažnosti nemoci MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- oxid dusnatý MeSH