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Mann-Whitney U (mann-whitney + u)

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Terms modified by Mann-Whitney U

  • mann-whitney u test
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    Selected Abstracts

    Digital versus Local Anesthesia for Finger Lacerations: A Randomized Controlled Trial

    ACADEMIC EMERGENCY MEDICINE, Issue 10 2006
    Stuart Chale MD
    Abstract Objectives To compare the pain of needle insertion, anesthesia, and suturing in finger lacerations after local anesthesia with prior topical anesthesia with that experienced after digital anesthesia. Methods This was a randomized controlled trial in a university-based emergency department (ED), with an annual census of 75,000 patient visits. ED patients aged ,8 years with finger lacerations were enrolled. After standard wound preparation and 15-minute topical application of lidocaine-epinephrine-tetracaine (LET) in all wounds, lacerations were randomized to anesthesia with either local or digital infiltration of 1% lidocaine. Pain of needle insertion, anesthetic infiltration, and suturing were recorded on a validated 100-mm visual analog scale (VAS) from 0 (none) to 100 (worst); also recorded were percentage of wounds requiring rescue anesthesia; time until anesthesia; percentage of wounds with infection or numbness at day 7. Outcomes were compared by using Mann-Whitney U and chi-square tests. A sample of 52 patients had 80% power to detect a 15-mm difference in pain scores. Results Fifty-five patients were randomized to digital (n= 28) or local (n= 27) anesthesia. Mean age (±SD) was 38.1 (±16.8) years, 29% were female. Mean (±SD) laceration length and width were 1.7 (±0.7) cm and 2.0 (±1.0) mm, respectively. Groups were similar in baseline patient and wound characteristics. There were no between-group differences in pain of needle insertion (mean difference, 1.3 mm; 95% confidence interval [CI] =,17.0 to 14.3 mm); anesthetic infiltration (mean difference, 2.3 mm; 95% CI =,19.7 to 4.4 mm), or suturing (mean difference, 7.6 mm; 95% CI =,3.3 to 21.1 mm). Only one patient in the digital anesthesia group required rescue anesthesia. There were no wound infections or persistent numbness in either group. Conclusions Digital and local anesthesia of finger lacerations with prior application of LET to all wounds results in similar pain of needle insertion, anesthetic infiltration, and pain of suturing. [source]

    Prevalence of personality disorders in patients with eating disorders: a pilot study using the IPDE

    EUROPEAN EATING DISORDERS REVIEW, Issue 4 2004
    Izaskun Marañon
    Abstract Objective The present study aims to determine the comorbidity of personality disorders (PD) with anorexia and bulimia nervosa, and to establish the major personality characteristics of eating disorders subtypes. Method Using the International Personality Disorders Examination (IPDE), the study investigated the personality profiles of 66 outpatients with eating disorders. Statistical analyses were carried out using non-parametric methods such as the Kruskal-Wallis H test and Mann-Whitney U. Results 51.5% of the overall sample met criteria for at least one personality disorder. Purging anorexia nervosa patients were the most affected. The most common personality disorders were obsessive-compulsive, avoidant, dependent, borderline and not otherwise specified. Discussion More than half of the subjects with AN and BN met the criteria for at least one PD. This finding is a challenge for clinical practice. Implications for further research in this area are commented on. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association. [source]

    Adolescent emergency department presentations with alcohol- or other drug-related problems in Perth, Western Australia

    ADDICTION, Issue 7 2001
    Gary K. Hulse
    Aims. To identify the morbidity, type of substance used and the pattern of presentation by adolescents with problems related to alcohol or other drug (AOD) use. Design. A 4-week retrospective review of hospital records. Setting. Four metropolitan hospitals in Perth, Australia. Participants. There were 1064 presentations by people aged 12-19 years of which 160 (15%) were related to AOD use. The median age of the AOD cases was 17 (interquartile range 16-19) of whom 97 (61%) were male and 19 (12%) were Indigenous Australians. Findings. Alcohol was the most frequent precursor to presentation (66, 41%) followed by heroin (24, 15%) and prescription/over-the-counter drugs (24, 15%). Injury was the most common diagnosis at presentation (50, 31%), followed by overdose/drug use (47, 29%). A diagnosis of injury was significantly more likely following the use of alcohol than other categories of substances (,2 = 42.07, df = 3, p < 0.001). Deliberate self-harm (DSH) occurred in more female than male cases (,2 = 7.4, df = 1, p < 0.01). Presentations were more frequent over the weekend (102, 64%) than on weekdays, and the length of stay was significantly shorter for weekend cases (Mann-Whitney U 2132, p < 0.05). Conclusions. Given the small window of opportunity to provide AOD treatment to youth following hospital presentation, a number of suggestions are made. From a harm-minimization perspective the focus of interventions should be on alcohol use by male youth and DSH associated with prescription/over-the-counter drug use by female adolescents. In addition, Indigenous youth are over-represented in hospital presentations, but there is currently a lack of evaluated interventions designed for them. [source]

    High levels of anxiety and depression have a negative effect on quality of life of women with chronic pelvic pain

    INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2009
    A. P. M. S. Romão
    Summary Background:, Chronic pelvic pain (CPP) is a common and complex disease whose cause is often clinically inexplicable, with consequent difficulty in diagnosis and treatment. Patients with CPP have high levels of anxiety and depression, with a consequent impairment of their quality of life. Aims:, The objective of this study was to determine the prevalence of anxiety and depression and their impact on the quality of life of women with CPP. Materials and methods:, A cross-sectional controlled study was conducted on 52 patients with CPP and 54 women without pain. Depression and anxiety were evaluated by the Hospital Anxiety and Depression Scale, and quality of life was evaluated by the World Health Organization Quality of life Whoqol-bref questionnaire. Data were analysed statistically by the Mann-Whitney U -test, the Fisher exact test, chi-square test and Spearman correlation test. Results:, The prevalence of anxiety was 73% and 37% in the CPP and control groups, respectively, and the prevalence of depression was 40% and 30% respectively. Significant differences between groups were observed in the physical, psychological and social domains. Patients with higher anxiety and depression scores present lower quality of life scores. Discussion:, The fact that DPC is a syndromic complex, many patients enter a chronic cycle of search for improvement of medical symptoms. The constant presence of pain may be responsible for affective changes in dynamics, family, social and sexual. Initially the person is facing the loss of a healthy body and active, to a state of dependence and limitations. In this study, patients with higher scores of anxiety and depression scores had lower quality of life and patients with lower scores of anxiety and depression had scores of quality of life. These results show that perhaps the depression and anxiety may be related to the negative impact on quality of life of these patients. Conclusion:, In view of this association, we emphasise the importance of a specific approach to the treatment of anxiety and depression together with clinical treatment to improve the quality of life of these patients. [source]

    Validity and reliability of an inpatient severity of psychiatric illness measure

    INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 2 2005
    Bentson H. McFarland
    Abstract Inpatient psychiatric severity measures are often used but few psychometric data are available. This study evaluated the psychometric properties (reliability and validity) of a measure used to assess severity of psychiatric illness among inpatients. Using the severity measure, minimally trained raters conducted retrospective patient record reviews to assess medical necessity for psychiatric hospitalization. The data analysis compared 135 civilly committed psychiatric inpatients with a heterogeneous group of 248 psychiatric inpatients at a general hospital. The severity measure showed acceptable inter-rater reliability in both populations. Two-way analysis of variance showed that the intra-class correlation coefficient for the total score was 0.65 for general hospital subjects and 0.63 for civilly committed subjects. Differences in mean scores were substantial (15 out of a possible 75 points for general hospital subjects versus 42 for civilly committed subjects, Mann-Whitney U = 562, p < 0.001). As expected, all civilly committed subjects were well above admission cut-off score of 12, versus only 64% of the general hospital patients. The measure is appropriate for retrospective severity assessment and may also be useful for pre-admission screening. Copyright © 2005 Whurr Publishers Ltd. [source]

    Nitric Oxide Metabolites Are Associated with Survival in Older Patients

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2007
    Toshio Hayashi MD
    OBJECTIVES: To assess the efficacy of various vascular endocrinological substances, such as plasma nitric oxide metabolites (NOx), as surrogate markers of survival in older patients. DESIGN: Prospective cohort, observational. SETTING: Nagoya University Hospital and related hospitals, Japan. PARTICIPANTS: One hundred fifty patients aged 70 and older, recruited consecutively from the outpatient clinics of Nagoya University Hospital and related hospitals. MEASUREMENT: Serum biochemical analyses such as albumin and total cholesterol, various prognostic markers, such as tumor necrosis factor (TNF)-,, NOx, activities of daily living (ADLs), and instrumental ADLs (IADLs) were evaluated on enrollment. ADLs, IADLs, and comorbidities, especially depression and impaired cognition, were evaluated on enrollment. The main outcome was survival rate over 2.75 years. RESULTS: Forty-nine patients died during the follow-up period. Mann-Whitney U -test showed that hemoglobin, total protein, serum albumin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high sensitive c-reactive protein, NOx, B-type natriuretic peptide, interleukin-6, and TNF-, levels; ADLs; cognitive impairment; and depressive status were significantly different for subjects who survived and those who died. Of the dependent variables in the Cox proportional hazards regression analyses, only ADLs, NOx, and albumin were significantly different. In the Kaplan-Meier analyses of mortality, the prognosis of patients in the third and fourth quartiles of NOx was significantly worse than that of patients in the first or second quartile. The prognosis of patients with impaired ADLs was worse than that of other patients for the overall period. CONCLUSION: Lower levels of NOx may be associated with survival in older patients. It may be an effective marker, like ADLs, which is a well-known marker. [source]

    Relative effectiveness of powered and manual toothbrushes in elderly patients with implant-supported mandibular overdentures

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 4 2002
    A. Tawse-Smith
    Abstract Aim: The aim of this study was to compare the clinical effectiveness of a powered toothbrush (Braun Oral-B Plaque Remover 3-D) and a manual soft toothbrush (Oral-B Squish-grip brush) for the control of supragingival plaque and soft tissue inflammation around implants supporting mandibular overdentures. Material and methods: The study sample involved 40 edentulous subjects, aged 55,80 years, having 2 unsplinted mandibular implants supporting a complete removable overdenture opposed by a maxillary complete denture. In this single-blinded, randomised, cross-over clinical trial, two 6-week experimental phases were separated by a 2-week wash-out period. 2 weeks prior to each experimental phase (pre-entry visits), implant abutments were polished to remove all plaque and a standardised instruction in the use of the toothbrush was given. Modified plaque and bleeding indices were recorded at the start and end of each experimental period. Mean index scores at each phase were analysed using paired t -test, and the mean number of sites showing a change in plaque or mucositis were compared using the Mann-Whitney U -test. Combined data from 2 different implant systems were considered after controlling for implant type. Results: Only minor changes in plaque and bleeding scores were observed following the two test periods. There were no statistically significant differences between the manual and powered toothbrushes. Conclusion: Manual and powered brushes were found to be of comparable efficacy with regard to improvement in peri-implant bleeding and plaque indices. Zusammenfassung Zielsetzung: Untersuchung der klinischen Effektivität einer elektrischen Zahnbürste (Braun Oral-B Plaque Remover 3-D) im Vergleich zu einer weichen Handzahnbürste (Oral-B Squish-grip brush) zur Kontrolle supragingivaler Plaque und Weichgewebsentzündung an Implantaten, die Unterkiefer-Totalprothesen tragen. Material und Methoden: Das Untersuchungskollektiv bestand aus 40 zahnlosen Patienten im Alter zwischen 55 und 80 Jahren, die 2 unverblockte Unterkiefer-Implantate zur Unterstützung einer Totalprothese aufwiesen. Der Oberkiefer war jeweils mit einer total schleimhautgetragenen Prothese versorgt. In dieser einfach verblindeten, randomisierten klinischen Cross-over-Studie wurden 2 6-wöchige experimentelle Phasen von einer 2-wöchigen Auswaschperiode unterbrochen. 2 Wochen vor jeder experimentellen Phase wurden die supragingivalen Implantatflächen von sämtlicher Plaque gereinigt und die Patienten erhielten eine Instruktion im Gebrauch der Zahnbürsten. Modifizierte Plaque- und Blutungsindizes wurden zu Beginn und am Ende jeder experimentellen Phase erhoben. Die Mittelwerte für die Indizes wurden mittels des paarigen t -Tests und die Zahl der Stellen, die eine Veränderung in Plaque und Mucositis aufwiesen, wurden durch den Mann-Whitney U -Test verglichen. Die Daten für 2 Implantatsysteme wurden zusammengefasst, nachdem der Einfluss des Implantatsystems überprüft worden war. Ergebnisse: Es wurden nur geringe Veränderungen der Plaque- und Blutungsindizes am Ende beider Testphasen beobachtet. Ein statistisch signifikanter Unterschied zwischen elektrischer und Handzahnbürste konnte nicht gezeigt werden. Schlussfolgerungen: Hand- und elektrische Zahnbürsten erwiesen sich als gleich effektiv für die Verbesserung periimplantärer Plaque- und Blutungsindizes. Résumé But: Le but de cette étude était de comparer l'efficacité clinique d'une brosse à dent électrique (Plaque remover 3D de Braun Oral B) et une brosse souple manuelle (squish grip d'oral B) pour le contrôle de la plaque supra-gingivale et l'inflammation des tissus mous autour d'implants supportant des overdentures mandibulaires. Matériaux et méthodes: L'échantillon étudié comprenait 40 sujets édentés, âgés de 55 à 80 ans, ayant 2 implants mandibulaires non reliés supportant une overdenture amovible complète et une prothèse maxillaire antagoniste complète. Dans cet essai clinique croisé en aveugle simple, randomisée, 2 phases expérimentales de 6 semaines encadraient une période d'arrêt de 2 semaines. 2 semaines avant chaque phase expérimentale, (visite de pré-entrée), les piliers implantaires étaient polis afin d'éliminer toute la plaque et des instructions standardisées d'utilisation de la brosse étaient données. On notait les indices, de saignement et de plaque modifié, au début et à la fin de chaque période expérimentale. Les notes d'indices moyens à chaque phase étaient analysées par le test t apparié et le nombre moyen de sites présentant une modification de la plaque ou de la mucosite était comparé par le test U de Mann Whitney. Les données combinées des 2 systèmes implantaires étaient considérées après cotrôle pour chaque type d'implant Résultats: De minimes modifications des notes de plaque et de saignement étaient observées après les deux périodes de test. Il n'y avait pas de différences statistiques significatives entre les brosses manuelles et électriques. Conclusion: Les brosses manuelles et électriques ont une efficacité comparable du point de vue de l'amélioration des indices de saignement et de plaque peri-implantaires. [source]

    Secular trend of age-specific prevalence of hepatitis B surface and e antigenemia in pregnant women in Taiwan

    JOURNAL OF MEDICAL VIROLOGY, Issue 4 2003
    Ho-Hsiung Lin
    Abstract To elucidate the impact of aging of hepatitis B carrier women on their viral replicative markers in a hepatitis B endemic area, all the parturients admitted to the Hospital were studied from 1985 to 2000. Serum hepatitis B surface (HBsAg) and hepatitis B e antigen (HBeAg) were tested by radioimmunoassay. Mann-Whitney U and Student's t -tests were used for statistical analysis. The results showed the yearly prevalence rate of HBsAg in pregnant women seemed stable with a mean of 12.0,±,1.1% during the period. The yearly positive rate of HBeAg among HBsAg-positive pregnant women varied between 30.4% and 42.6% from 1985 to 1992 and declined from 29.6% in 1993 to 18.1% in 2000. The mean ratio of HBeAg/HBsAg in carrier parturients was 24.7% [intraquantile range (IQR) 20.5,28.4] from 1993 to 2000, which was significantly lower than that of 32.4% (IQR 31.0,39.0) from 1985 to 1992 (P,< 0.0001). The mean age of HBeAg-positive primiparas from 1993 to 2000 was 29.1,±,3.9 years and significantly higher than that of 28.0,±,3.7 years from 1985 to 1993 (P,<,0.001), as well as in secundiparas 31.2,±,3.8 years vs. 30.1,±,3.4 years (P,< 0.001) and in total parturients 30.3,±,4.2 years vs. 29.3,±,3.8 years (P,<,0.001). Thus, no significant decrease of HBsAg carriage was observed in the past 16 years, whereas a decreased ratio of HBeAg/HBsAg was noted in carrier parturients in the past 8 years and the elderly HBeAg-positive parturients from 1993 to 2000 may be the cause. J. Med. Virol. 69:466,470, 2003. © 2003 Wiley-Liss, Inc. [source]

    Influence of Matrix Type on Surface Roughness of Three Resins for Provisional Crowns and Fixed Partial Dentures

    JOURNAL OF PROSTHODONTICS, Issue 2 2009
    Raul Ayuso-Montero DDS
    Abstract Purpose: This study evaluated the effect of matrix type on the surface roughness of resins for provisional crowns and fixed partial dentures. Materials and Methods: Ninety specimens of two acrylic resins (Trim II, Tab2000) and one bis-acryl composite (Protemp II Garant) were fabricated using one of three matrices: irreversible hydrocolloid (Cavex CA37), poly(vinyl siloxane) (Aquasil) or vacuum-formed matrix (Bio-flow Hard). The sample size for each resin-matrix combination was 10. The vestibular face of one natural maxillary central incisor was used as a model to fabricate all the specimens, following the custom fabrication technique. The average roughness measurements, Ra (,m), were obtained using a profilometer, and the data were analyzed using Kruskal-Wallis and Mann-Whitney U- tests. The results were contrasted against the surface roughness of the tooth using a one-sample t- test. Results: Aquasil and vacuum-formed matrix had a smoother surface than Cavex CA37 regardless of the resin tested (p < 0.05). Protemp II Garant had the smoothest surface regardless of the matrix used, with no significant differences when polymerized against the three different matrices. Trim II polymerized against Cavex CA37 had a rougher (p < 0.05) surface than Aquasil or vacuum-formed matrix. Tab2000 had the smoothest surface (p < 0.05) when polymerized against a vacuum-formed matrix. Conclusions: There is no universal matrix that produces the smoothest surface: this depends on the compatibility between the resin and the matrix. Protemp II Garant polymerized against Cavex CA37 matrix yields a surface that is smooth enough not to require polishing unless this surface is adjusted. [source]

    Occupational performance in older stroke wheelchair users living at home

    OCCUPATIONAL THERAPY INTERNATIONAL, Issue 4 2001
    Dr Denise T Reid Professor, Faculty of Medicine
    Abstract This research aimed to identify problems in occupational performance experienced by survivors of stroke who used a wheelchair, both from their perspective and from the perspective of their caregivers. Sixteen stroke survivors over the age of 65 years who had used a prescribed wheelchair for at least one year, who lived in their own home, who were able to participate in a conversational interview and who had a caregiver willing to participate comprised the sample. The Canadian Occupational Performance Measure (COPM) was used to identify occupational performance problems and to measure stroke survivors' and caregivers' perceptions of performance. The Functional Autonomy Measurement System (SMAF) was also used to evaluate the functional performance of stroke survivors from the caregivers' perspective. The frequency and type of problems identified by the COPM were descriptively analysed and compared for both groups. The results of Mann-Whitney U tests showed no differences in the frequency of self-care, productivity and leisure problems reported between the two groups. Within-group comparisons using the Wilcoxon Signed Ranks Test showed that stroke survivors identified significantly more self-care problems than productivity-type problems (p=0.001), and more leisure problems than productivity problems (p=0.013). Caregivers identified significantly more self-care problems than productivity problems (p=0.001). The most common self-care problems reported by both stroke survivors and caregivers were dressing and bathing. Results suggest a high level of functional disability among the stroke survivors. There was a significant correlation between the score on the SMAF Instrumental Activities of Daily Living subscale and the frequency of caregiver assistance (r=0.747, p=0.001). Addressing the perspectives of both stroke survivors who are wheelchair users and their caregivers in identifying occupational performance problems at home is important for occupational therapists for planning home-based intervention. Copyright © 2001 Whurr Publishers Ltd. [source]

    The behavioral importance of dynamically activated descending inhibition from the nucleus reticularis gigantocellularis pars alpha. (University Hospital of Wales, Cardiff, United Kingdom) Pain 2001;92:53,62.

    PAIN PRACTICE, Issue 4 2001
    J. Azami
    This study demonstrates the effects of nucleus reticularis gigantocellularis pars alpha (GiA) on the behavioral response during application of standardized noxious stimuli. As this system is activated in response to noxious stimulation, it is possible that chronic pain states may also activate GiA. Therefore, this study investigated this possibility in animals following partial sciatic nerve ligation (an animal model of chronic pain). Male Wistar rats (280,310 g) were anesthetized with halothane (0.5% to 2% in O2). Guide cannulae for microinjections were stereotaxically placed above GiA. In one group of animals the sciatic nerve was partially litigated. Animals were allowed to recover for 4,6 days. The responses of each animal during the formalin test and the tail flick test were recorded on different days. Microinjections (0.5 ,l) of either ,-aminobutyric acid (GABA, 200 mM), D-L homocysteic acid (DLH, 25 mM), or 0.9% saline (as control) into GiA were preformed during these tests in a randomized, blind manner. In animals without sciatic nerve ligation, microinjection of GABA to GiA did not significantly affect the animal's response during the tail flick test. However, microinjection of DLH significantly increased the latency of tail flick from 6.2 ± 0.8 to 8.4 ± 0.5 seconds for up to 15 minutes. Microinjection of GABA to GiA increased the behavioral response to formalin between 10 and 20 minutes postinjection, while microinjection of DLH reduced this response at all time points except 10 minutes postinjection (n = 8, p < 0.05, Mann-Whitney U -test). In animals with sciatic nerve ligation, microinjections (0.5 ,l) of either GABA (200 mM), or saline (as control) into GiA contralateral to the partial sciatic ligation were performed during these tests in a randomized, blind manner. Partial sciatic ligation significantly reduced the behavioral response to contralaterally applied formalin from 15 minutes postinjection onwards, compared to controls without sciatic nerve ligation. Microinjection of GABA GiA significantly increased the behavioral response to formalin from 20 to 50 minutes postinjection. The inactivation of GiA only causes behavioral effects in nociceptive tests of a long enough duration to activate the system (ie, the formalin test but not the tail flick test). Chemical activation of the system affects both tests. Conclude that these data strongly support the concept of an important analgesic system that is activated in response to noxious stimulation, and subsequently acts to reduce behavioral responses to noxious stimuli. Comment by Leland Lou, M.D. This is a rat study that looked at the presence of inhibitory spinal multireceptive cells modifying and decreasing the behavioural response to noxious stimuli. While no direction was given as to the source of noxious stimuli inhibition in chronic pain, great effort was made to report a possible differential response of the C-fiber pain system versus the large sensory fibers. After review it seems that the authors believed that the nucleus reticularis gigantocellularis pars alpha maybe a central processor of the inhibitory response. It is still too early to assess the clinical impact of this study. [source]

    Does professional-centred training improve consultation outcomes?

    PRACTICAL DIABETES INTERNATIONAL (INCORPORATING CARDIABETES), Issue 6 2006
    FETC Senior Lecturer in Dietetic Practice, Mrs T Parkin BSc(Hons)
    Abstract This study aimed to examine whether professional-centred training improves consultation outcomes. Using a pre- and post-data collection design, immediately after consultations, professionals and patients completed a consultation review sheet which was coded for the level of agreement on issues discussed and decisions made. Patients also completed the Health Care Climate Questionnaire (HCCQ). Pre-training results were fed back to the professionals to provide an objective measure of current practice. Training day one comprised 10 minutes' observation of videoed consultations of each professional in order to identify strengths and training needs. Each professional identified key areas of their consultation that they felt needed further development. Training day two centred on goal setting and negotiating agendas as these were identified as priority areas requiring more skills. Data from 110 baseline and 73 follow-up consultations were collected. The HCCQ showed no significant difference between baseline and follow up. Non-parametric tests indicated that the level of agreement on decisions had improved (Mann-Whitney U = 951; p = 0.002; ,2 = 3.67; df = 2; p = 0.026). The number of consultations where complete disagreement occurred between the patient and professional, on decisions made, reduced from 17% at baseline to 11% at follow up. It was concluded that professional-centred training can be effective in improving patients' perceptions of the consultation, and in increasing patient/professional agreement on recall of decisions made. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Tutorials in Clinical Research: Part VII.

    THE LARYNGOSCOPE, Issue 9 2003
    Part A: General Concepts of Statistical Significance, Understanding Comparative Statistics (Contrast)
    Abstract Objectives/Hypothesis The present tutorial is the seventh in a series of Tutorials in Clinical Research. The specific purpose of the tutorial (Part A) and its sequel (Part B) is to introduce and explain three commonly used statistical tools for assessing contrast in the comparison between two groups. Study Design Tutorial. Methods The authors met weekly for 10 months discussing clinical research studies and the applied statistics. The difficulty was not in the material but in the effort to make the report easy to read and as short as possible. Results The tutorial is organized into two parts. Part A, which is the present report, focuses on the fundamental concepts of the null hypothesis and comparative statistical significance. The sequel, Part B, discusses the application of three common statistical indexes of contrast, the ,2, Mann-Whitney U, and Student t tests. Conclusions Assessing the validity of medical studies requires a working knowledge of research design and statistics; obtaining this knowledge need not be beyond the ability of the busy surgeon. The authors have tried to construct an accurate, easy-to-read, easy-to-apply, basic introduction to comparing two groups. The long-term goal of the present tutorial and others in the series is to facilitate basic understanding of clinical research, thereby stimulating reading of some of the numerous well-written research design and statistical texts. This knowledge may then be applied to the continuing educational review of the literature and the systematic prospective analysis of individual practices. [source]

    Dendritic Cell Deficiency in the Blood of Kidney Transplant Patients on Long-Term Immunosuppression: Results of a Prospective Matched-Cohort Study

    AMERICAN JOURNAL OF TRANSPLANTATION, Issue 12 2005
    Holger Hackstein
    Evidence from in vitro studies suggests that immunosuppressive drugs interfere with key functions of dendritic cells (DCs), but the in vivo relevance of these findings is elusive. We prospectively analyzed the major DC precursor subsets in the blood of kidney transplant recipients on long-term immunosuppression (,1 year). A total of 87 patients were compared to 87 age- and sex-matched controls. Total DC numbers and the precursor subsets, myeloid type 1 DCs, myeloid type 2 DCs (mDC1, mDC2) and plasmacytoid DCs (pDCs) were identified by four color flow cytometry. Long-term immunosuppression was associated with significant reduction of all major DC subsets in comparison to healthy controls (mDC1 p < 0.001; mDC2 p < 0.0001; two-tailed Mann-Whitney U -test) with the strongest negative impact on pDCs (p < 0.00001). In contrast, total leukocyte numbers were not significantly affected. Analysis of the relative impact of different agents revealed a significant impact of prednisolone on pDCs (p = 0.009) and mDCs2 (p = 0.006). The functional relevance of pDC deficiency was confirmed independently by Interferon-alpha analysis after Toll-like receptor 7 (p , 0.001) and 9 (p < 0.05) stimulation. These results indicate for the first time a profound negative impact of long-term immunosuppression on major DC subsets in kidney transplant recipients. DC deficiency may have important implications with respect to viral infections and tumor development. [source]

    Decreased lymphatic vessel counts in patients with systemic sclerosis: Association with fingertip ulcers

    ARTHRITIS & RHEUMATISM, Issue 5 2010
    Alfiya Akhmetshina
    Objective Systemic sclerosis (SSc) is a connective tissue disease that is characterized by microvascular disease and tissue fibrosis. Progressive loss and irregular architecture of the small blood vessels are well characterized, but the potential involvement of the lymphatic vessel system has not been analyzed directly in SSc. This study was undertaken to assess whether the lymphatic vascular system is affected in SSc, and whether changes to the lymphatic vessels are associated with dystrophic changes and tissue damage in patients with SSc. Methods Lymphatic endothelial cells in skin biopsy samples from patients with SSc and age- and sex-matched healthy volunteers were identified by staining for podoplanin and prox-1, both of which are specifically expressed in lymphatic endothelial cells but not in blood vascular endothelial cells. CD31 was used as a pan,endothelial cell marker. Statistical analyses were performed using Kruskal-Wallis, Mann-Whitney U, and Spearman's rank correlation tests. Results The numbers of podoplanin- and prox-1,positive lymphatic vessels were significantly reduced in patients with SSc as compared with healthy individuals. The number of podoplanin-positive lymphatic precollector vessels was significantly lower in SSc patients with fingertip ulcers than in SSc patients without ulcers. Moreover, the number of lymphatic vessels correlated inversely with the number of fingertip ulcers at the time of biopsy and with the number of fingertip ulcers per year. The inverse correlation between lymphatic precollector vessel counts and fingertip ulcers remained significant after statistical adjustment for the blood vessel count, age, and modified Rodnan skin thickness score. Conclusion These results demonstrate a severe reduction in the number of lymphatic capillaries and lymphatic precollector vessels in patients with SSc. Patients with decreased lymphatic vessel counts may be at particularly high risk of developing fingertip ulcers. [source]