Skip header and navigation

Refine By

12 records – page 1 of 2.

Empirical estimation of a distribution function with truncated and doubly interval-censored data and its application to AIDS studies.

https://arctichealth.org/en/permalink/ahliterature214497
Source
Biometrics. 1995 Sep;51(3):1096-104
Publication Type
Article
Date
Sep-1995
Author
J. Sun
Author Affiliation
Department of Statistics and Actuarial Science, University of Waterloo, Ontario Canada.
Source
Biometrics. 1995 Sep;51(3):1096-104
Date
Sep-1995
Language
English
Publication Type
Article
Keywords
Acquired Immunodeficiency Syndrome - mortality - transmission
Algorithms
Biometry
Bisexuality
Cohort Studies
Drug Contamination
HIV Seropositivity - epidemiology
HIV-1
Hemophilia A - therapy
Homosexuality, Male
Humans
Male
Mathematics
Models, Statistical
Ontario
Probability
Survival Analysis
Survival Rate
Time Factors
Abstract
In this paper we discuss the non-parametric estimation of a distribution function based on incomplete data for which the measurement origin of a survival time or the date of enrollment in a study is known only to belong to an interval. Also the survival time of interest itself is observed from a truncated distribution and is known only to lie in an interval. To estimate the distribution function, a simple self-consistency algorithm, a generalization of Turnbull's (1976, Journal of the Royal Statistical Association, Series B 38, 290-295) self-consistency algorithm, is proposed. This method is then used to analyze two AIDS cohort studies, for which direct use of the EM algorithm (Dempster, Laird and Rubin, 1976, Journal of the Royal Statistical Association, Series B 39, 1-38), which is computationally complicated, has previously been the usual method of the analysis.
PubMed ID
7548693 View in PubMed
Less detail

Survival from primary breast cancer after routine clinical use of mammography.

https://arctichealth.org/en/permalink/ahliterature189464
Source
Breast J. 2002 Jul-Aug;8(4):199-208
Publication Type
Article
Author
J. Sun
J. Chapman
R. Gordon
R. Sivaramakrishna
M. Link
E. Fish
Author Affiliation
Department of Public Health Sciences, Faculty of Medicine, University of Toronto, Ontario, Canada.
Source
Breast J. 2002 Jul-Aug;8(4):199-208
Language
English
Publication Type
Article
Keywords
Adult
Age Distribution
Age Factors
Aged
Breast Neoplasms - mortality - radiography - therapy
Canada - epidemiology
Cohort Studies
Diagnostic Tests, Routine - standards
Female
Health Services Accessibility
Humans
Mammography - standards
Middle Aged
Multivariate Analysis
Neoplasm Staging
Predictive value of tests
Risk factors
Survival Analysis
Abstract
Clinical trials indicate that mammography provides a substantial breast cancer survival benefit; however, there is a need to demonstrate that this benefit extends to clinical practice and to determine the extent that current reductions in mortality are attributable to regular screening or adjuvant systemic therapy. Mammography was used routinely at our institution across a broad age range, in an era when most patients received no adjuvant systemic therapy. We examined breast cancer survival for a cohort of 678 stage I-III primary invasive breast cancer patients accrued from 1971 to 1990, and followed to 1996; 18% received adjuvant hormonal therapy and 15% received adjuvant chemotherapy. There were 61 women less than 40 years old; 136, 40-49 years; 341, 50-69 years; 140, > or =70 years. Factors available for multivariate investigations were age (years), tumor size (cm), nodal status (N-, Nx, N+), ER (fmol/mg protein), PgR (fmol/mg protein), adjuvant radiotherapy (no, yes), adjuvant hormonal therapy (no, yes), and adjuvant chemotherapy (no, yes). Forward stepwise multivariate regression with log-normal survival analysis was used to examine the effects of these factors on disease-specific survival. Ten-year survival by tumor size was adjusted for the effects of other significant factors. For women less than 40 years of age, 10-year survival at the T1a, T1b, T1c, and T2 cut-points for tumor size is, respectively, 0.77, 0.74, 0.67, 0.44; for 40-49 years it is 0.92, 0.90, 0.85, 0.62; for 50-69 years it is 0.81, 0.79, 0.75, 0.62; for > or =70 years it is 0.84, 0.81, 0.73, 0.44. With routine use of clinical mammography and up to 26 years of follow-up, we found breast cancer survival to be significantly better (p
Notes
Comment In: Breast J. 2002 Jul-Aug;8(4):185-612100108
PubMed ID
12100111 View in PubMed
Less detail

Airway hyperresponsiveness, elevation of serum-specific IgE and activation of T cells following allergen exposure in sensitized Brown-Norway rats.

https://arctichealth.org/en/permalink/ahliterature15906
Source
Immunology. 1995 Aug;85(4):598-603
Publication Type
Article
Date
Aug-1995
Author
A. Haczku
K F Chung
J. Sun
P J Barnes
A B Kay
R. Moqbel
Author Affiliation
Department of Allergy and Clinical Immunology, National Heart and Lung Institute, London, UK.
Source
Immunology. 1995 Aug;85(4):598-603
Date
Aug-1995
Language
English
Publication Type
Article
Keywords
Allergens - immunology
Animals
Bronchial Hyperreactivity - immunology
Bronchial Provocation Tests
Bronchoalveolar Lavage Fluid - immunology
Female
Immunoglobulin E - blood
Lymphocyte Activation - immunology
Ovalbumin - immunology
Rats
Rats, Inbred BN
Research Support, Non-U.S. Gov't
T-Lymphocyte Subsets - immunology
Abstract
T lymphocytes may play a regulatory role in the development of allergic airway hyperresponsiveness (AHR). We have studied the relationship between airway responsiveness and a number of immunological changes in Brown-Norway rats sensitized intraperitoneally and repeatedly exposed to ovalbumin (OVA) aerosol. Acetylcholine provocation concentration (PC)150 (the concentration of acetylcholine causing a 150% increase of base-line lung resistance) was measured and peripheral blood and bronchoalveolar lavage (BAL) cells were collected 18-24hr after the final exposure. Total and OVA-specific IgE in serum was measured by enzyme-linked immunosorbent assay (ELISA). Mononuclear cells were analysed by flow cytometry after labelling with monoclonal antibodies against CD2 (pan T-cell marker), CD4, CD8 (T-cell subsets) or CD25 (interleukin-2 receptor). There were significant differences in PC150 (P
PubMed ID
7558155 View in PubMed
Less detail

Contribution of intercellular-adhesion molecule-1 in allergen-induced airway hyperresponsiveness and inflammation in sensitised brown-Norway rats.

https://arctichealth.org/en/permalink/ahliterature15953
Source
Int Arch Allergy Immunol. 1994 Jul;104(3):291-5
Publication Type
Article
Date
Jul-1994
Author
J. Sun
W. Elwood
A. Haczku
P J Barnes
P G Hellewell
K F Chung
Author Affiliation
Department of Thoracic Medicine, National Heart and Lung Institute, London, UK.
Source
Int Arch Allergy Immunol. 1994 Jul;104(3):291-5
Date
Jul-1994
Language
English
Publication Type
Article
Keywords
Allergens - immunology
Animals
Asthma - immunology - prevention & control
Bronchial Hyperreactivity - immunology - prevention & control
Bronchial Provocation Tests
Bronchoalveolar Lavage Fluid - cytology
Cell Adhesion Molecules - immunology
Eosinophils - immunology
Female
Inflammation - pathology
Intercellular Adhesion Molecule-1
Leukocyte Count
Lymphocytes - immunology
Ovalbumin
Rats
Rats, Inbred BN
Research Support, Non-U.S. Gov't
Abstract
We investigated the potential role of intercellular-adhesion molecule-1 (ICAM-1) in allergen-induced bronchial hyperresponsiveness (BHR) and inflammation in sensitised Brown-Norway rats. Rats were sensitised with ovalbumin (OA) intraperitoneally and 21 days later they were either exposed to 0.9% NaCl or 1% OA aerosol for 15 min. Rats exposed to OA aerosol were pretreated either with ICAM-1 antibody (3 mg/kg i.p. and i.v., 45 min prior to OA exposure) or with the diluent for the antibody. Eighteen to twenty-four hours after OA or 0.9% NaCl exposure, rats were anaesthetised, tracheostomised and mechanically ventilated, and airway responsiveness to acetylcholine (ACh) aerosol was measured as the provocative concentration of ACh needed to increase pulmorary resistance by 100% (PC100). Mean -log PC100 was increased in rats exposed to OA but pretreated with diluent (2.75 +/- 0.06) compared to rats treated with ICAM-1 antibody (2.51 +/- 0.08;
PubMed ID
7913357 View in PubMed
Less detail

Anti-PF4/heparin antibodies and venous graft occlusion in postcoronary artery bypass surgery patients randomized to postoperative unfractionated heparin or fondaparinux thromboprophylaxis.

https://arctichealth.org/en/permalink/ahliterature118371
Source
J Thromb Haemost. 2013 Feb;11(2):253-60
Publication Type
Article
Date
Feb-2013
Author
T E Warkentin
J I Sheppard
J C J Sun
H. Jung
J W Eikelboom
Author Affiliation
Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada. twarken@mcmaster.ca
Source
J Thromb Haemost. 2013 Feb;11(2):253-60
Date
Feb-2013
Language
English
Publication Type
Article
Keywords
Antibodies - blood
Anticoagulants - adverse effects - immunology
Coronary Artery Bypass - adverse effects
Cross Reactions
Graft Occlusion, Vascular - etiology - immunology
Heparin - adverse effects - immunology
Humans
Immunoenzyme Techniques
Immunoglobulin G - blood
Logistic Models
Odds Ratio
Ontario
Pilot Projects
Platelet Factor 4 - immunology
Polysaccharides - adverse effects - immunology
Risk assessment
Risk factors
Thrombocytopenia - etiology - immunology
Time Factors
Treatment Outcome
Abstract
Anti-PF4/heparin antibodies are frequently generated after coronary artery bypass grafting (CABG) surgery, with platelet-activating IgG implicated in heparin-induced thrombocytopenia (HIT). It is controversial whether non-platelet-activating antibodies are associated with thrombosis.
To determine in post-CABG patients whether thromboprophylaxis using fondaparinux vs. unfractionated heparin (UFH) reduces the frequency of anti-PF4/heparin antibodies, and whether anti-PF4/heparin antibodies are associated with early graft occlusion.
In a pre-planned secondary analysis of a randomized control trial (RCT) comparing fondaparinux vs. UFH thromboprophylaxis post-CABG, we determined the frequency of anti-PF4/heparin antibody formation by solid-phase enzyme-immunoassay (EIA) and of platelet-activating antibodies by serotonin-release assay (SRA); the SRA and fluid-phase EIA were used to assess fondaparinux cross-reactivity. We also examined whether anti-PF4/heparin antibodies were associated with early arterial or venous graft occlusion (6-week CT angiography).
We found no significant difference in the frequency of antibody formation between patients who received fondaparinux vs. UFH (65.3% vs. 46.0%; P = 0.069), and no significant fondaparinux cross-reactivity. Venous graft occlusion(s) occurred in 6/26 patients who formed 'strong' IgG antibodies (= 1.0 optical density [OD] units and = 2? baseline) vs. 3/66 who did not (P = 0.0139). In both unadjusted and adjusted analyses, strong postoperative (but not pre-operative) anti-PF4/heparin IgG responses were associated with a markedly increased risk of early venous (but not arterial) graft occlusion (adjusted OR, 9.25 [95% CI, 1.73, 49.43]; P = 0.0093); notably, none of the three SRA-positive patients developed a venous graft occlusion.
Fondaparinux vs. UFH thromboprophylaxis postCABG does not reduce anti-PF4/heparin antibody formation. Non-platelet-activating anti-PF4/heparin IgG antibodies generated post operatively are associated with early venous graft occlusion.
PubMed ID
23216710 View in PubMed
Less detail

Clonotypic heterogeneity in experimental interstitial nephritis. Restricted specificity of the anti-tubular basement membrane B cell repertoire is associated with a disease-modifying crossreactive idiotype.

https://arctichealth.org/en/permalink/ahliterature57819
Source
J Exp Med. 1988 Apr 1;167(4):1296-312
Publication Type
Article
Date
Apr-1-1988
Author
M D Clayman
M J Sun
L. Michaud
J. Brill-Dashoff
R. Riblet
E G Neilson
Author Affiliation
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
Source
J Exp Med. 1988 Apr 1;167(4):1296-312
Date
Apr-1-1988
Language
English
Publication Type
Article
Keywords
Animals
Antibodies, Anti-Idiotypic - therapeutic use
Antibodies, Monoclonal - genetics - immunology
Antigens - immunology
Autoantibodies - genetics - immunology
Autoimmune Diseases - immunology - pathology - therapy
B-Lymphocytes - pathology
Basement Membrane - immunology
Clone Cells - pathology
Immunoglobulin G - genetics - immunology - therapeutic use
Immunoglobulin Heavy Chains - genetics
Immunoglobulin Idiotypes - immunology
Immunoglobulin Variable Region - genetics
Kidney Tubules - immunology
Nephritis, Interstitial - immunology - pathology - therapy
Rats
Rats, Inbred BN
Rats, Inbred Lew
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.
Abstract
Experimental anti-tubular basement membrane (anti-TBM) disease is an autoimmune interstitial nephritis elicited in susceptible rodents after immunization with renal tubular antigen. The nephritogenic antigen in the immunizing preparation is 3M-1, a 48,000 Mr noncollagenous glycoprotein. The hallmarks of the renal lesion are the presence of anti-TBM antibodies (anti-TBM-Ab) and a dense mononuclear cell infiltrate. The anti-TBM B cell repertoire in this disease was analyzed using a library of 22 anti-TBM mAbs generated in a prototypically susceptible Brown Norway rat. These anti-TBM mAbs were all demonstrated to be 3M-1 specific and their characterization formed the basis for the following observations: (a) The size of the anti-TBM B cell population is estimated at 58 distinct clones; (b) by competitive inhibition criteria, all anti-TBM mAbs recognize the same (or spatially close) epitope(s) on 3M-1. This focused recognition was maintained in spite of considerable variability in affinity. Epitopic dominance could also be demonstrated in human polyclonal anti-TBM antisera from a patient with anti-TBM disease; and (c) a crossreactive idiotype was documented, and antisera directed toward this set of variable region determinants was shown to be effective as a prophylactic regimen to abrogate disease, and as a therapeutic modality to arrest the progression of disease; (d) analysis of VH gene families suggested biased usage of Q52- and 7183-like families, although at least three gene families are used in the anti-TBM-Ab response. Thus, the anti-TBM B cell compartment in BN rats is moderately large, but is primarily focused to a single epitope on the nephritogenic antigen and is associated with a disease-modifying crossreactive idiotype.
PubMed ID
3128629 View in PubMed
Less detail

Neither insufficiency nor overexpression of sac1 affects the accumulation of Aß42 in Drosophila expressing Ab42.

https://arctichealth.org/en/permalink/ahliterature263111
Source
Eur Rev Med Pharmacol Sci. 2015 May;19(9):1700-5
Publication Type
Article
Date
May-2015
Author
M. Han
J-K Huang
H-Y Liu
W-A Wang
X-J Sun
F-D Huang
Source
Eur Rev Med Pharmacol Sci. 2015 May;19(9):1700-5
Date
May-2015
Language
English
Publication Type
Article
Abstract
We investigated the effects of genetic down- and up-regulation of sac1 expression on Aß42 accumulation and the associated neural deficits in flies with direct expression of arctic mutant Aß42 (Aßarc) in the neurons of GF pathway.
We genetically down-regulated and up-regulated the level of sac1, encoding a major phosphoinositide phosphatases in a disease model, in which arctic mutant Aß42 is directly expressed in the neurons of a neural pathway of adult fruit flies.
We conducted a time-course analysis of Aß42 level in the model and found an age-dependent elevation of Aß42 accumulation, closely correlated to the age-dependent decline of climbing ability in the model flies. Neither sac1 insufficiency nor sac1 over-expression significantly changed the three phenotypes.
We found that the alterations of sac1 expression did not change Aß42 accumulation and neural deficits in the model.
PubMed ID
26004612 View in PubMed
Less detail

The value of inter-professional education: a comparative study of dental technology students' perceptions across four countries.

https://arctichealth.org/en/permalink/ahliterature278700
Source
Br Dent J. 2015 Apr 24;218(8):481-7
Publication Type
Article
Date
Apr-24-2015
Author
J. Evans
A J Henderson
J. Sun
H. Haugen
T. Myhrer
C. Maryan
K N Ivanow
A. Cameron
N W Johnson
Source
Br Dent J. 2015 Apr 24;218(8):481-7
Date
Apr-24-2015
Language
English
Publication Type
Article
Keywords
Adolescent
Adult
Attitude of Health Personnel
Australia
Cross-Cultural Comparison
Curriculum
Education, Dental - methods - organization & administration
England
Female
Humans
Male
Norway
Patient care team
Students, Dental - psychology
Surveys and Questionnaires
Sweden
Technology, Dental - education
Young Adult
Abstract
The ability to function as an effective member of a dental care team is a highly desirable--frequently mandated--attribute of dental technology (DT) graduates. Currently, there is little rigorous examination of how the learning of team-working skills might best be structured in a DT curriculum. This research compares DT curricula, and students' attitudes and perceptions regarding collaboration in practice, from four countries. Students (n=376) were invited to complete an education profile questionnaire, and the standardised measure--the shared learning scale. There were 196 (52%) responses. Students given opportunities to engage with others had better perceptions of inter-professional learning (IPL). Most believed that team-work and collaborative skills were best acquired by learning together with other dental care professionals, preferably sharing cases for real patients. Curricula should maximise opportunities for dental technology students to experience authentic IPL. Collaboration and team-work needs to be embedded through the whole undergraduate programme.
PubMed ID
25908364 View in PubMed
Less detail

Pulmonary artery catheters: evolving rates and reasons for use.

https://arctichealth.org/en/permalink/ahliterature135270
Source
Crit Care Med. 2011 Jul;39(7):1613-8
Publication Type
Article
Date
Jul-2011
Author
Karen K Y Koo
Jack C J Sun
Qi Zhou
Gordan Guyatt
Deborah J Cook
Stephen D Walter
Maureen O Meade
Author Affiliation
Department of Medicine, University of Western Ontario, London, Canada. karen.koo@lhsc.on.ca
Source
Crit Care Med. 2011 Jul;39(7):1613-8
Date
Jul-2011
Language
English
Publication Type
Article
Keywords
Adult
Aged
Aged, 80 and over
Catheterization, Swan-Ganz - trends - utilization
Female
Humans
Intensive Care Units - trends
Logistic Models
Longitudinal Studies
Male
Middle Aged
Ontario
Physician's Practice Patterns - trends
Retrospective Studies
Abstract
Randomized trials have demonstrated risks and failed to establish a clear benefit for the use of the pulmonary artery catheter. We assessed rates of pulmonary artery catheter use in multiple centers over 5 yrs, variables associated with their use, and how these variables changed over time (2002-2006).
A multicenter longitudinal study using the Hamilton Regional Critical Care Database. A two-level multiple logistic regression analysis was used to determine significant variables associated with pulmonary artery catheter use and whether these varied over time.
Academic intensive care units in Hamilton, Canada.
We identified patients from five intensive care units who received a pulmonary artery catheter within the first 2 days of intensive care unit admission.
Pulmonary artery catheter use over a 5-yr period.
Among 15,006 patients, 1,921 (12.8%) had a pulmonary artery catheter. Adjusted rates of pulmonary artery catheter use decreased from 16.4% to 6.5% over 5 yrs. Determinants of pulmonary artery catheter use included Acute Physiology and Chronic Health Evaluation II score (odds ratio [OR], 1.05; confidence interval [CI], 1.04-1.06; p 50% reduction in the rate of pulmonary artery catheter use over 5 yrs. Patient factors predicting pulmonary artery catheter use were illness severity, specific diagnoses, and the need for advanced life support. Nonpatient factors predicting pulmonary artery catheter use were intensive care unit and the attending physician's base specialty.
Notes
Comment In: Crit Care Med. 2011 Jul;39(7):1820-221685743
PubMed ID
21494107 View in PubMed
Less detail

Transmission network analysis in tuberculosis contact investigations.

https://arctichealth.org/en/permalink/ahliterature160302
Source
J Infect Dis. 2007 Nov 15;196(10):1517-27
Publication Type
Article
Date
Nov-15-2007
Author
Victoria J Cook
Sumi J Sun
Jane Tapia
Stephen Q Muth
D Fermin Arguello
Bryan L Lewis
Richard B Rothenberg
Peter D McElroy
Author Affiliation
Department of Medicine, University of British Columbia, 655 W. 12th Avenue, Vancouver, BC, Canada. mailvictoria.cook@bccdc.ca
Source
J Infect Dis. 2007 Nov 15;196(10):1517-27
Date
Nov-15-2007
Language
English
Publication Type
Article
Keywords
Adult
British Columbia - epidemiology
California - epidemiology
Contact Tracing - statistics & numerical data
Demography
Female
Genotype
Georgia - epidemiology
Humans
Male
Middle Aged
Mycobacterium tuberculosis - genetics - isolation & purification
Outcome Assessment (Health Care)
Prospective Studies
Questionnaires
Tuberculosis, Pulmonary - epidemiology - etiology - prevention & control - transmission
Abstract
Social network analysis (SNA) is an innovative approach to the collection and analysis of infectious disease transmission data. We studied whether this approach can detect patterns of Mycobacterium tuberculosis transmission and play a helpful role in the complex process of prioritizing tuberculosis (TB) contact investigations.
We abstracted routine demographic and clinical variables from patient medical records and contact interview forms. We also administered a structured questionnaire about places of social aggregation to TB patients and their contacts. All case-contact, contact-contact, case-place, and contact-place dyads (pairs and links) were considered in order to analyze the structure of a social network of TB transmission. Molecular genotyping was used to confirm SNA-detected clusters of TB.
TB patients not linked through conventional contact-investigation data were connected through mutual contacts or places of social aggregation, using SNA methods. In some instances, SNA detected connected groups prior to the availability of genotyping results. A positive correlation between positive results of contacts' tuberculin skin test (TST) and location in denser portions of the person-place network was observed (P
PubMed ID
18008232 View in PubMed
Less detail

12 records – page 1 of 2.