Search PubMed⌕ Search

Biomedical subjects

K Anderson

Publications and source records attributed to K Anderson.

At least 163 records · Page 9Linked to original sources
PubMed1997

Multicenter comparative study of the efficacy and safety of sotalol in the prophylactic treatment of patients with paroxysmal supraventricular tachyarrhythmias.

We performed a randomized, double-blind, placebo-controled, parallel-group comparison study of the efficacy and safety of sotalol in the prophylaxis of paroxysmal supraventricular tachyarrhythmias (PSVTs) (including paroxysmal atrial fibrillation and paroxysmal reentrant SVTs). The frequency of PSVT episodes while not receiving drug therapy was monitored during a baseline phase, the length of which depended on the frequency of PSVT events. In the double-blind phase, the duration of which depended on the baseline frequency of episodes of PSVT, patients received placebo, sotalol 80 mg twice daily, or sotalol 160 mg twice daily. PSVT events were documented by electrocardiogram and diary. The time to recurrence of PSVT was significantly less compared with placebo when receiving sotalol 80 mg (p = 0.018) and sotalol 160 mg (p = 0.0009). On subanalysis, sotalol was shown to be effective in the prophylaxis of both paroxysmal atrial fibrillation and paroxysmal reentrant arrhythmias. Sotalol was well tolerated, with no deaths, proarrhythmia, or cardiac failure. Because of adverse effects, drug therapy was discontinued in six patients.

Adult↗
PubMed1997

Gamma delta T cells: their immunobiology and role in malaria infections.

The status of research on gamma delta T cells is reviewed. Recent research shows that gamma delta T cells may see antigens in an immunoglobulin-like manner and that non-peptidic substance can be antigens for these cells. Considerable advances have been made in defining the immunobiology of gamma delta T cells, with evidence for sentinel, protective and immunoregulatory roles. Research on gamma delta T cells in malaria infections suggests that gamma delta T cells are mediators of protective immunity, most probably through the production of Th1 cytokines such as TNF alpha, TNF delta and IFN gamma and that excessive production of such cytokines may contribute to pathology. Our data on the features of the peripheral blood gamma delta T cells response in humans infected with Plasmodium falciparum show that there is considerable variation between individuals in the relative expansion of gamma delta T lymphocytes following primary or secondary infection. They confirm that activation of gamma delta T cells occurs during P. falciparum infection and that activated cells can persist for many weeks after treatment. The possibility that gamma delta T cells have an immunoregulatory function in malaria infections is proposed.

Cytokines↗
PubMed1997

A cross-sectional study of private psychiatric practices under a single-payer health care system.

OBJECTIVES: To examine current concerns that in the Canadian single-payer mental health care system, the "rich worried well" (that is, wealthy individuals who are worried yet mentally well) may overuse psychiatric services, while low-income, uninsured mentally ill individuals may remain undertreated. The current study focuses on the mental health care in the Canadian region of Ottawa-Carleton, where a single-payer system provides universal access to mental health services, to assess how psychiatric services are provided by psychiatrists in private practice. METHOD: One hundred and seven private psychiatrists working in the region of Ottawa-Carleton completed a questionnaire which contained questions about the sociodemographic characteristics and background of the psychiatrists themselves and which asked the psychiatrists specific questions about the sociodemographic status, diagnosis, and treatment of each patient seen on November 10, 1994. RESULTS: Approximately 93% of the patients seen met criteria for one or more Axis I disorders, of which mood and anxiety disorders were the most common. Wealthier patients were relatively underrepresented among the patients treated by the private psychiatrists. In addition, we found no significant differences in the distribution of Axis I, Axis II, and Axis III disorders between patients earning below $30,000 per year compared with patients earning above $60,000 per year. CONCLUSIONS: Our results suggest that outpatient psychiatric care delivered by private psychiatrists in a Canadian single-payer system targets primarily individuals with major psychiatric disorders and does not seem to favour "the worried well." Larger epidemiological studies with independent assessments of psychiatric populations are necessary to confirm our findings.

Adolescent↗
PubMed1997

Incidence and prevalence of diabetes in children aged 0-14 years in Manitoba, Canada, 1985-1993.

OBJECTIVE: To estimate the incidence and prevalence of type I diabetes among Manitoba children aged 0-14 years from 1985-1993. RESEARCH DESIGN AND METHODS: The Manitoba Diabetes Database (a population-based database of individuals diagnosed with diabetes based on Manitoba's health insurance system) was used to estimate the annual incidence of diabetes for the years 1985-1993 and the point prevalence of diabetes at 31 March 1993 for Manitoba children aged 0-14 years. The Diabetes Education Resource for Children and Adolescents program database was used to correct incidence and prevalence rates for ascertainment using the two-source capture-recapture method. RESULTS: The overall ascertainment rate of the Manitoba Diabetes Database was 95% for incident cases and 93% for prevalent cases. The average annual incidence was 20.4 per 100,000 for children aged 0-14 years. The annual incidence appears to be stable for all age-groups 0-14 years over the past decade. The point prevalence of diabetes among children was 120.4 per 100,000. CONCLUSIONS: The incidence of type I diabetes in children aged 0-14 years in Manitoba is higher than reported previously in other urban regions of Canada, but similar to population-based estimates from Prince Edward Island. The incidence appears stable in Manitoba over the past decade even in the 0-4 year age-group. The Manitoba Diabetes Database appears to be a highly accurate population-based source of data on the epidemiology of diabetes in children.

Adolescent↗
PubMed1997

CD6+ T cell depleted allogeneic bone marrow transplantation from genotypically HLA nonidentical related donors.

The widespread use of allogeneic bone marrow transplantation (BMT) is limited by the availability of suitable donors. Recent attempts to expand the donor pool by employing HLA matched unrelated marrow have been partially successful. However, severe graft-versus-host disease (GVHD) and graft failure remain obstacles and contribute to the substantial morbidity and mortality associated with matched unrelated BMT. The use of genotypically nonidentical related or unrelated donor marrow could have wider application if problems associated with GVHD could be overcome. Based upon the low incidence of GVHD in recipients of HLA-matched related donor marrow depleted of T cells with T12, an anti-CD6 monoclonal antibody, we applied this approach to 27 adult recipients of HLA mismatched related bone marrow. Ten patients received marrow mismatched at 2 HLA loci, 13 received 1 antigen mismatched marrow, and 4 received phenotypically identical marrow from a non-sibling. Immediately prior to admission, patients were treated with total lymphoid irradiation (750-1050 cGy) to suppress host derived. T lymphocytes capable of mediating graft rejection. The ablative regimen consisted of cyclophosphamide (60 mg/kg x 2 days) followed by total body irradiation (1400 cGy in 7 fractions over 4 days). Patients then received marrow depleted of T cells with T12 (CD6) plus complement. No immune suppressive medications were administered to prevent GVHD. Twenty-four of 27 patients displayed stable hematologic engraftment, achieving an absolute neutrophil count of 0.5 x 10(9)/L at a median of 19 days post-BMT. Degree of HLA disparity did not influence engraftment. Among engrafting patients, grades 2-4 acute GVHD occurred in 40% and grade 3-4 GVHD in 8%. Chronic GVHD developed in 5 patients. Patients mismatched at 2 loci were more likely to develop GVHD than those mismatched at 0-1 loci (logrank, p = .04). Disease relapse has occurred in only 3 patients receiving mismatched marrow. Estimated overall survival for mismatched patients is 56% at 2 years and is independent of HLA disparity. Among the patients transplanted for chronic myelogenous in stable phase or acute leukemia in first remission, estimated event free survival is 69% at 2 years compared to 20% for patients with more advanced disease. Our results suggest that transplantation of mismatched related marrow using modalities designed to reduce GVHD without immune suppressive medication (CD6 depletion) is feasible and should prompt wider investigation into the extended families of patients in the search for potential marrow donors. This approach also merits investigation in recipients of matched unrelated marrow as a potential means of reducing transplant-related toxicity.

Adolescent↗
PubMed1997

Managing TMD.

Explore the source record for details and available documents.

Chronic Disease↗
PubMed1996

The association of maternal psychopathology and family socioeconomic status with psychological problems in obese children.

In an earlier study we found parental psychiatric symptoms to be a better correlate of behavioral problems in obese children than either child or parental obesity. This study sought to extend this research by assessing the association of general maternal distress, specific maternal psychopathology, family socioeconomic status and child obesity with the psychological problems of 152 children seeking treatment for obesity in two cohorts. Child psychological problems were measured using the Child Behavior Checklist/4-18 (CBCL) in each cohort. In sample 1 maternal general psychiatric symptoms were measured using the Cornell Medical Index (psychiatric subscales) and the Inventory of Interpersonal Problems whereas specific psychopathology was assessed with the Beck Depression Inventory and the Bulimia Test. In sample 2 the Symptom Checklist-90 and Binge Eating Scale provided general and specific measures of psychopathology. In the combined sample, 58% percent of the boys and 44% of the girls met criteria on at least one CBCL behavioral problem scale, with Social Problems the most prevalent problem in both boys and girls. For both samples, child obesity did not account for any variance in child psychosocial problems beyond that accounted for by maternal psychopathology and family SES. Family SES accounted for a significant increment in variance in child behavioral problems in only two scales. This study systematically replicates previous research, adding support for a broader conceptualization of factors that influence psychological problems in obese treatment-seeking children than one which focuses on child obesity.

Adult↗
PubMed1996

Actin and the coordination of protrusion, attachment and retraction in cell crawling.

To crawl over a substrate a cell must first protrude in front, establish new attachments to the substrate and then retract its rear. Protrusion and retraction utilise different subcompartments of the actin cytoskeleton and operate by different mechanisms, one involving actin polymerization and the other myosin-based contraction. Using as examples the rapidly locomoting keratocyte and the slowly moving fibroblast we illustrate how over expression of one or the other actin subcompartments leads to the observed differences in motility. We also propose, that despite these differences there is a common coordination mechanism underlying the genesis of the actin cytoskeleton that involves the nucleation of actin filaments at the protruding cell front, in the lamellipodium, and the relocation of these filaments, via polymerization and flow, to the more posterior actin filament compartments.

Actins↗
PubMed1996

Abstaining and carousing: substance use among adolescents in the Western Isles of Scotland.

An account is presented of a survey of self-reported substance use among 839 adolescents in the Western Isles (Outer Hebrides) of Scotland. The study group was aged 13-16. The drinking habits of those surveyed were extremely polarised. Results showed that while only 81.2% had ever used alcohol, nearly 40% of males and a third of females reported having consumed at least 11 units of alcohol on their last drinking occasion. Levels of tobacco and illicit drug use were less striking: 21.4% considered themselves current smokers, while fewer than one-quarter had ever used illicit drugs or solvents. Results are related to recent UK surveys of adolescents and to the distinctive culture of the study area. It is concluded that the polarisation of youthful drinking in the Western Isles poses special problems in relation to the provision of alcohol education.

Adolescent↗
PubMed1996

Experimental human Plasmodium falciparum infections: longitudinal analysis of lymphocyte responses with particular reference to gamma delta T cells.

The kinetics of the gamma delta T-cell response was analysed in the context of the overall haematological response in subjects experimentally infected with sporozoites of Plasmodium falciparum. Numbers of gamma delta and alpha beta T cells and NK cells declined markedly during infection to reach minimum values 12-13 days post-infection when the patients were ill. This decline commenced from the beginning of the erythrocytic cycle and well before parasites could be detected microscopically and clinical symptoms developed. Platelet numbers also declined. In vivo activation of gamma delta T cells was evident with sequential up-regulation of the activation markers CD69 and HLA-DR. gamma delta T cell numbers were highest after treatment with the majority being CD4-CD8-, HLA-DR+ and showing reduced CD45RA expression. Contrary to some published observations gamma delta T-cell percentages remained within the normal range. Little evidence of upregulation of activation or memory markers was observed in the alpha beta T-cell population. In vitro proliferative responses to malaria antigen which involve gamma delta T cells were lost as the infection progressed and the lymphocyte count declined but these could be restored with the addition of exogenous IL-2 to cultures. The authors findings are consistent with a protective and/or immunomodulatory role for gamma delta T cells in malaria.

Adult↗
PubMed1996

Determinants of physical activity in obese children assessed by accelerometer and self-report.

Previous research has shown that predictors of activity in adults depend upon the method of measurement. This study is designed to assess the predictors of activity in a sample of 59 obese children. Activity was measured using self-reported and TriTrac accelerometer METs. Self-report and TriTrac accelerometer measures were moderately correlated, r = 0.46, with the self-reported activity (2.3 METs) significantly greater than TriTrac (1.6 METs). Hierarchical regression analysis examined the influence of socioeconomic level, body composition, fitness, hedonics of child and adult activity behaviors, and decisional balance on self-reported and accelerometer-measured activity, controlling for child and parent psychopathology. Child and parent psychological symptoms accounted for 8.3% and 3.4% of the variance in accelerometer and self-reported METs, respectively. The model for accelerometer-measured activity showed socioeconomic level and parent self-report of activity accounted for 14.8% of the incremental variance in child activity. The model for self-report of child activity found that child fitness accounted for 23.5% of the incremental variance in child activity. These results suggest that the predictors of activity level are different based upon the method of measurement, consistent with research in adults.

Activities of Daily Living↗
PubMed1996

BDNF down-regulates neurotrophin responsiveness, TrkB protein and TrkB mRNA levels in cultured rat hippocampal neurons.

Regulation of Trk receptors by their ligands, the neurotrophins, was investigated in dissociated cultures of embryonic day 18 rat hippocampal neurons. Cultures were exposed to brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) or NT-4/5 for 24 h upon plating followed by factor washout. As determined by immunohistochemical staining and phosphotyrosine blotting, the functional responses to acute stimulation with BDNF, NT-3 and NT-4/5, including c-Fos induction and phosphorylation of Trk and extracellular signal-regulated kinase (ERK) proteins, were significantly decreased after 6 days in culture by prior exposure to BDNF. As determined by Western and Northern blot analysis respectively, there was a parallel down-regulation of TrkB protein as well as of trkB and trkC mRNA levels in BDNF-pretreated cultures. Exposure to NT-3 or NT-4/5 at the same concentrations as BDNF did not down-regulate any of the measured cellular responses or TrkB protein and/or trkB and trkC mRNA levels. Regulation of hippocampal neuronal Trkb protein does not appear to be just a development phenomenon, as infusion of BDNF into the hippocampus of adult rats for 6 days produced an 80% decrease in levels of full-length TrkB protein. We thus show that exposure of hippocampal neurons to BDNF, both in culture and in the adult brain, results in down-regulation of TrkB. At least in vitro, this leads to long-term functional desensitization to BDNF, NT-3 and NT-4/5, as well as down-regulation of trkB and trkC mRNA.

Animals↗