Kruskal-Wallis Test (Kruskal-Walli + test)

Distribution by Scientific Domains

Selected Abstracts

A comparative analysis of the habitat of the extinct aurochs and other prehistoric mammals in Britain

ECOGRAPHY, Issue 2 2008
Stephen J. G. Hall
The present study tests the hypothesis that the habitat of the globally extinct aurochs Bos primigenius was primarily riverine flat-lands. Landscape features in Britain were analyzed for sites with Late Pleistocene and postglacial finds of aurochs (n=188), and, for comparison, wolf (101), brown bear (96), red deer (73), beaver (68), roe deer (46) and moose (23). Find sites were defined as Ordnance Survey 1 km map squares containing 1 or more finds. For each, spot height above sea level, heights of contour lines, flatness of terrain, total length of watercourses, and presence of woods, rock and water features were noted. Comparisons of find sites among species (Kruskal-Wallis test) show significant differences that accord with knowledge of present-day habitat preferences at the landscape level. Considering the species separately each find site was then compared with a randomly selected control map square within 10 km. Compared with their respective control squares, find sites of beaver have, today, a stronger association with presence of lakes; those of brown bear and wolf with presence of cliffs and rock outcrops; and those of aurochs with absence of woodland and with lower elevation and greater flatness. The concordance of these findings with the present-day habitats of the extant species suggests valid inferences can be made about the habitat preference of the extinct aurochs. On this basis the aurochs appears, as hypothesized, to have selected low-lying, flat ground, which (indicated by its present-day use for purposes other than woodland) was relatively fertile. [source]

Doppler measurement of blood flow velocities in extraocular orbital vessels in patients with obstructive sleep apnea syndrome

C. Zuhal Erdem MD
Abstract Purpose. We used color Doppler sonography to determine blood flow velocities in the extraocular orbital vessels of patients with obstructive sleep apnea syndrome (OSAS) and compared the results with those of healthy control subjects without OSAS. Methods. Patients with OSAS were classified according to the apnea-hypopnea index (AHI) as having mild OSAS (AHI < 20) or severe OSAS (AHI , 20). The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index were measured in the ophthalmic artery (OA), central retinal artery (CRA), lateral short posterior ciliary artery, and medial short posterior ciliary artery using color Doppler sonography. Only 1 eye was measured in each study participant, and right and left eyes were chosen randomly. The blood flow velocities of patients with OSAS and those of control subjects were compared with the Kruskal-Wallis test and Wilcoxon's rank-sum test. Results. The study comprised 30 patients (15 with mild and 15 with severe OSAS) and 20 healthy control subjects. Blood flow velocities were higher in most measured vessels in patients with OSAS than they were in the control subjects. Among patients with mild OSAS, the PSVs and EDVs in the posterior ciliary arteries were statistically significantly higher than those of the control group (p < 0.05), but those in the OA and CRA did not differ significantly between the mild OSAS group and the control group (p > 0.05). However, as the severity of OSAS increased, the PSVs and EDVs of the OA and CRA were also affected (p < 0.05). Conclusions. Color Doppler sonographic measurements of blood flow parameters in the orbital vessels may differ significantly between patients with OSAS and those without the syndrome. Therefore, OSAS should be considered in addition to other conditions when interpreting the results of color Doppler sonography of the extraocular orbital vessels if the clinical history points toward such a diagnosis. © 2003 Wiley Periodicals, Inc. 31:250,257, 2003 [source]

Clinical interest: a study of the influence on general practitioners' prescribing,

Dorte Gilså Hansen MD
Abstract Purpose To analyse the association between general practitioners' clinical interest and prescribing rates in four clinical areas: dyspepsia, depression, headache and diabetes. Methods Data concerning general practitioners' prescribing during 2004 were retrieved from a pharmacy database and linked with data from a physician questionnaire and the National Health Insurance Register. To counterbalance differences in practice populations all 1-year prevalences of prescribing were standardised according to age and gender. Participants were asked ,To what extent do you find the following areas interesting from a professional point-of- view?' Four rating categories were used. The association between clinical interest and standardised prescribing rates was investigated using logistic regression, the Kruskal-Wallis test and a trend test. Results A total of 68 (72%) single-handed general practitioners representative of the total group completed the questionnaire. We observed a two-fold ratio between the 90% and the 10% percentiles of the 1-year prevalences of antisecretory drugs, antidepressants, migraine drugs as well as anti-diabetics. The variation in prescribing of antidepressant and antisecretory drugs was far above chance level. No significant association with clinical interest could, however, be observed for any of the four clinical areas. Conclusion General practitioners' prescribing of the four classes of medical drugs varied considerably. However, only part of this variation was based on chance. This study did not confirm our hypothesis that general practitioners' level of clinical interest in one area corresponds with their prescribing of drugs used within that area. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Multivariate analysis of protein profiles of metal hyperaccumulator Thlaspi caerulescens accessions

Marjo H. Tuomainen
Abstract Thlaspi caerulescens is increasingly acknowledged as one of the best models for studying metal hyperaccumulation in plants. In order to study the mechanisms underlying metal hyperaccumulation, we used proteomic profiling to identify differences in protein intensities among three T.,caerulescens accessions with pronounced differences in tolerance, uptake and root to shoot translocation of Zn and Cd. Proteins were separated using two-dimensional electrophoresis and stained with SYPRO Orange. Intensity values and quality scores were obtained for each spot by using PDQuest software. Principal component analysis was used to test the separation of the protein profiles of the three plant accessions at various metal exposures, and to detect groups of proteins responsible for the differences. Spot sets representing individual proteins were analysed with the analysis of variance and non-parametric Kruskal-Wallis test. Clearest differences were seen among the Thlaspi accessions, while the effects of metal exposures were less pronounced. The 48,tentatively identified spots represent core metabolic functions (e.g. photosynthesis, nitrogen assimilation, carbohydrate metabolism) as well as putative signalling and regulatory functions. The possible roles of some of the proteins in heavy metal accumulation and tolerance are discussed. [source]

Shoulder Disability After Different Selective Neck Dissections (Levels II,IV Versus Levels II,V): A Comparative Study

Johnny Cappiello MD
Abstract Objectives/Hypothesis: The objective was to compare the results of clinical and electrophysiological investigations of shoulder function in patients affected by head and neck carcinoma treated with concomitant surgery on the primary and the neck with different selective neck dissections. Study Design: Retrospective study of 40 patients managed at the Department of Otolaryngology, University of Brescia (Brescia, Italy) between January 1999 and December 2001. Methods: Two groups of 20 patients each matched for gender and age were selected according to the type of neck dissection received: patients in group A had selective neck dissection involving clearance of levels II,IV, and patients in group B had clearance of levels II,V. The inclusion criteria were as follows: no preoperative signs of myopathy or neuropathy, no postoperative radiotherapy, and absence of locoregional recurrence. At least 1 year after surgery, patients underwent evaluation of shoulder function by means of a questionnaire, clinical inspection, strength and motion tests, electromyography of the upper trapezius and sternocleidomastoid muscles, and electroneurography of the spinal accessory nerve. Statistical comparisons of the clinical data were obtained using the contingency tables with Fisher's Exact test. Electrophysiological data were analyzed by means of Fisher's Exact test, and electromyography results by Kruskal-Wallis test. Results: A slight strength impairment of the upper limb, slight motor deficit of the shoulder, and shoulder pain were observed in 0%, 5%, and 15% of patients in group A and in 20%, 15%, and 15% of patients in group B, respectively. On inspection, in group B, shoulder droop, shoulder protraction, and scapular flaring were present in 30%, 15%, and 5% of patients, respectively. One patient (5%) in group A showed shoulder droop as the only significant finding. In group B, muscle strength and arm movement impairment were found in 25% of patients, 25% showed limited shoulder flexion, and 50% had abnormalities of shoulder abduction with contralateral head rotation. In contrast, only one patient (5%) in group A presented slight arm abduction impairment. Electromyographic abnormalities were less frequently found in group A than in group B (40% vs. 85% [P = .003]), and the distribution of abnormalities recorded in the upper trapezius muscle and sternocleidomastoid muscle was quite different: 20% and 40% in group A versus 85% and 45% in group B, respectively. Only one case of total upper trapezius muscle denervation was observed in group B. In both groups, electroneurographic data from the side of the neck treated showed a statistically significant increase in latency (P = .001) and decrease in amplitude (P = .008) compared with the contralateral side. There was no significant difference in electroneurographic data from the side with and the side without dissection in either group. Even though a high number of abnormalities was found on electrophysiological testing, only a limited number of patients, mostly in group B, displayed shoulder function disability affecting daily activities. Conclusion: The study data confirm that clearance of the posterior triangle of the neck increases shoulder morbidity. However, subclinical nerve impairment can be observed even after selective neck dissection (levels II,IV) if the submuscular recess is routinely dissected. [source]

Clinical optical coherence tomography of early articular cartilage degeneration in patients with degenerative meniscal tears

Constance R. Chu
Objective Quantitative and nondestructive methods for clinical diagnosis and staging of articular cartilage degeneration are important to the evaluation of potential disease-modifying treatments in osteoarthritis (OA). Optical coherence tomography (OCT) is a novel imaging technology that can generate microscopic-resolution cross-sectional images of articular cartilage in near real-time. This study tested the hypotheses that OCT can be used clinically to identify early cartilage degeneration and that OCT findings correlate with magnetic resonance imaging (MRI) T2 values and arthroscopy results. Methods Patients undergoing arthroscopy for degenerative meniscal tears were recruited under Institutional Review Board,approved protocols. Thirty consecutive subjects completing preoperative 3.0T MRI, arthroscopy, and intraoperative OCT comprised the study group. Qualitative and quantitative OCT results and MRI T2 values were compared with modified Outerbridge cartilage degeneration scores (0,4 scale) assigned at arthroscopy. Results Arthroscopic grades showed cartilage abnormality in 23 of the 30 patients. OCT grades were abnormal in 28 of the 30 patients. Both qualitative and quantitative OCT strongly correlated with the arthroscopy results (P = 0.004 and P = 0.0002, respectively, by Kruskal-Wallis test). Neither the superficial nor the deep cartilage T2 values correlated with the arthroscopy results. The quantitative OCT results correlated with the T2 values in the superficial cartilage (Pearson's r = 0.39, P = 0.03). Conclusion These data show that OCT can be used clinically to provide qualitative and quantitative assessments of early articular cartilage degeneration that strongly correlate with arthroscopy results. The correlation between the quantitative OCT values and T2 values for the superficial cartilage further supports the utility of OCT as a clinical research tool, providing quantifiable microscopic resolution data on the articular cartilage structure. New technologies for nondestructive quantitative assessment of human articular cartilage degeneration may facilitate the development of strategies to delay or prevent the onset of OA. [source]

Mann-Whitney U test and Kruskal-Wallis test should be used for comparisons of differences in medians, not means: Comment on the article by van der Helm-van Mil et al

Bin Zhang ScD
No abstract is available for this article. [source]

Inflammatory cytokine gene expression in the urinary sediment of patients with lupus nephritis

Rebecca Wing-Yan Chan
Objective Lupus nephritis is characterized by intrarenal inflammation and lymphocyte activation. In the present study, the expression of cytokine genes in the urinary sediment of patients with systemic lupus erythematosus (SLE) was examined. Methods We studied 3 SLE patient groups (25 with active lupus nephritis [active group], 25 with inactive SLE and previous renal involvement [remission group], 20 with inactive SLE and no history of renal involvement [nonrenal SLE group]) and 2 control groups (10 patients with noninflammatory renal diseases [non-SLE group] and 10 healthy volunteers [healthy group]). Cytokine gene expression in the urinary sediment was studied by real-time quantitative polymerase chain reaction. Results Expression of interferon-, (IFN,) in urinary sediment was significantly higher in the active group than in all other groups (P < 0.001 by Kruskal-Wallis test). Among the SLE patient groups, there was a close correlation between IFN, expression and the overall SLE Disease Activity Index (SLEDAI) score (Spearman's r = 0.590, P < 0.001) and the SLEDAI renal score (r = 0.642, P < 0.001). Urinary expression of interleukin-2 (IL-2) in the active group was significantly higher than that in the healthy group (P = 0.046) but not in the remission or nonrenal SLE groups. There was no difference in the levels of IL-4 expression among the SLE groups. Conclusion We found a predominance of Th1 cytokine in the urinary sediment of patients with active lupus nephritis. Measurement of cytokine gene expression in urinary sediment may be a useful noninvasive tool for assessing the severity of renal involvement in SLE. [source]

External Validation of the Clinical Dehydration Scale for Children With Acute Gastroenteritis

Benoit Bailey MD
Abstract Objectives:, The objective was to validate the clinical dehydration scale (CDS) for children with gastroenteritis in a different pediatric emergency department (ED) from where it was initially derived and validated. Methods:, A prospective cohort study was performed in a tertiary care pediatric ED over a 1-year period. A sample of triage nurses were trained in applying the CDS. The CDS consists of four clinical characteristics (general appearance, eyes, mucous membranes, and tears), each of which are scored 0, 1, or 2 for a total score of 0 to 8, with 0 representing no dehydration; 1 to 4, some dehydration; and 5 to 8, moderate/severe dehydration. Children 1 month to 5 years of age with vomiting and/or diarrhea who had the CDS documented at triage and a final diagnosis of gastroenteritis, gastritis, or enteritis were enrolled. Exclusion criteria included a chronic disease, treatment with intravenous (IV) rehydration within the previous 24 hours, visit to the ED for the same illness in the 7 days prior to arrival, and diarrhea of more than 10 days' duration. The primary outcome was the length of stay (LOS) in the ED from the time of seeing a physician to discharge, analyzed with a Kruskal-Wallis test. Results:, From April 2008 to March 2009, 150 patients with a mean (±SD) age of 22 (±14) months (range = 4 months to 4 years) were enrolled. Fifty-six patients had no dehydration, 74 had some dehydration, and 20 had moderate/severe dehydration. The median LOS in the ED after being seen by a physician was significantly longer as children appeared more dehydrated according to the CDS: 54 minutes (interquartile range [IQR] = 26,175 minutes), 128 minutes (IQR = 25,334 minutes), and 425 minutes (IQR = 218,673 minutes) for the no, some, and moderate/severe dehydration groups, respectively (p < 0.001). Conclusions:, The CDS has been further validated in children with gastroenteritis in a different pediatric center than the original one where it was developed. It is a good predictor of LOS in the ED after being seen by a physician. ACADEMIC EMERGENCY MEDICINE 2010; 17:583,588 © 2010 by the Society for Academic Emergency Medicine [source]

Ascorbic acid concentration is reduced in the secondary aqueous humour of glaucomatous patients

Mauro T Leite MD
Abstract Background:, We aimed to evaluate the ascorbic acid concentration in secondary aqueous humour (AH) from glaucomatous patients and to compare it with primary AH from primary open-angle glaucoma patients and non-glaucomatous patients. Methods:, Primary AH samples were prospectively obtained from clinically uncontrolled primary open-angle glaucoma patients and senile cataract patients (controls) prior to trabeculectomy and cataract surgery. Secondary AH samples were obtained from eyes with previous intraocular surgery, prior to trabeculectomy or cataract surgery. AH (0.1 mL) was aspirated by inserting a 26-gauge needle into the anterior chamber just before surgery and then immediately stored at ,80°C. The ascorbic acid concentration was determined in a masked fashion by high-pressure liquid chromatography. Results:, A total of 18 patients with senile cataract, 16 glaucomatous patients with primary AH (no previous intraocular surgery) and 11 glaucomatous patients with secondary AH (previous intraocular surgery) were included. There was no difference in mean age between groups (P = 0.15). The mean ± standard deviation concentration of ascorbic acid in the secondary AH from glaucomatous patients (504 ± 213 µmol/L [95% confidence interval {CI}, 383,624]) was significantly lower than the concentration of ascorbic acid found in the primary aqueous of primary open-angle glaucoma (919 ± 427 µmol/L [95% CI, 709,1128]) and control patients (1049 ± 433 µmol/L [95% CI, 848,1249]; P < 0.01, Kruskal-Wallis test). Conclusions:, The ascorbic acid concentration in secondary AH of glaucomatous patients was approximately twofold lower in comparison with primary AH of glaucomatous and cataract patients. The implications of a reduced concentration of ascorbic acid in the secondary AH deserve further investigation. [source]

The Effects of Brain Natriuretic Peptide on Scar Formation in Incisional Rat Wounds

Breena R. Taira MD
Abstract Background:, Brain natriuretic peptide (BNP) is a peptide that reduces scar formation in the heart by blocking transforming growth factor-, (TGF-,). Although TGF-, is known to play a role in scar formation in the myocardium, little is known about the effects of BNP on cutaneous wound healing. Objectives:, The objective was to determine if the administration of BNP in healing cutaneous wounds reduces the amount of scarring. Methods:, This was a laboratory investigation using 40 wild-strain rats. Three full-thickness 1-cm incisional wounds were created on each animal and randomized to intradermal BNP, saline, or no treatment. Wounds were excised at 3, 7, 14, 31, and 60 days and examined histologically for scar surface area and collagen architecture. Those wounds excised at 30 days were subjected to a measure of tensile strength and those excised at 60 days were evaluated prior to excision for cosmesis using a scar evaluation scale. The proportion of wounds healing without visually apparent scar was the main outcome. Groups were compared with Fisher's exact and Kruskal-Wallis tests. Results:, Wounds treated with BNP were more likely to heal without an apparent scar when compared to those treated with saline or control (37.5% vs. 0%, p = 0.03). There were no between-group differences in the surface area of the scars or the collagen architecture. Incisional tensile strength was also similar across treatments. Conclusions:, Treatment of rat incisions with BNP reduced the number of visually apparent scars but did not affect the histologic appearance of the scars or the incisional tensile strength. [source]