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Biomedical subjects

L Robertson

Publications and source records attributed to L Robertson.

At least 19 recordsLinked to original sources
PubMed2006

Thrombophilia in pregnancy: a systematic review.

Growing evidence suggests that thrombophilia is associated with venous thromboembolism (VTE) and adverse pregnancy outcomes. However, methodological limitations have made it difficult to obtain a clear overview of the overall risks. We conducted a systematic review to determine the risk of VTE and adverse pregnancy outcomes associated with thrombophilia in pregnancy. The effectiveness of prophylactic interventions during pregnancy was also evaluated. Major electronic databases were searched, relevant data abstracted and study quality assessed by two independent reviewers. Odds ratios (ORs) stratified by thrombophilia type were calculated for each outcome. A total of 79 studies were included in our review. The risks for individual thrombophilic defects were determined for VTE (ORs, 0.74-34.40); early pregnancy loss (ORs, 1.40-6.25); late pregnancy loss (ORs, 1.31-20.09); pre-eclampsia (ORs, 1.37-3.49); placental abruption (ORs, 1.42-7.71) and intrauterine growth restriction (ORs, 1.24-2.92). Low-dose aspirin plus heparin was the most effective in preventing pregnancy loss in thrombophilic women (OR, 1.62). Our findings confirm that women with thrombophilia are at risk of developing VTE and complications in pregnancy. However, despite the increase in relative risk, the absolute risk of VTE and adverse outcomes remains low. There is also a lack of controlled trials of antithrombotic intervention to prevent pregnancy complications. Thus, at present, universal screening for thrombophilia in pregnancy cannot be justified clinically.

Female↗
PubMed2006

Screening for thrombophilia in high-risk situations: systematic review and cost-effectiveness analysis. The Thrombosis: Risk and Economic Assessment of Thrombophilia Screening (TREATS) study.

OBJECTIVES: To assess the risk of clinical complications associated with thrombophilia in three high-risk patient groups: women using oral oestrogen preparations, women during pregnancy and patients undergoing major orthopaedic surgery. To assess the effectiveness of prophylactic treatments in preventing venous thromboembolism (VTE) and adverse pregnancy outcomes in women with thrombophilia during pregnancy and VTE in patients with thrombophilia, undergoing major orthopaedic surgery. To evaluate the relative cost-effectiveness of universal and selective VTE history-based screening for thrombophilia compared with no screening in the three high-risk patient groups. DATA SOURCES: Electronic databases including MEDLINE, EMBASE, and four other major databases were searched up to June 2003. REVIEW METHODS: In order to assess the risk of clinical complications associated with thrombophilia, a systematic review of the literature on VTE and thrombophilia in women using oral oestrogen preparations and patients undergoing major orthopaedic surgery; and studies of VTE and adverse obstetric complications in women with thrombophilia during pregnancy was carried out. Meta-analysis was used to calculate pooled odds ratios (ORs) associated with individual clinical outcomes, stratified by thrombophilia type and were calculated for each patient group. To assess the effectiveness of prophylaxis, a systematic review was carried out on the use of prophylaxis in the prevention of VTE and pregnancy loss in pregnant women with thrombophilic defects and the use of thromboprophylaxis in the prevention of VTE in patients with thrombophilia undergoing major elective orthopaedic surgery. Relevant data were summarised according to the patient groups and stratified according to the types of prophylaxis. A narrative summary was provided; where appropriate, meta-analysis was conducted. An incremental cost-effectiveness analysis was then carried out, from the perspective of the NHS in the UK. A decision analytical model was developed to simulate the clinical consequences of four thrombophilia screening scenarios. Results from the meta-analyses, information from the literature and results of two Delphi studies of clinical management of VTE and adverse pregnancy complications were incorporated into the model. Only direct health service costs were measured and unit costs for all healthcare resources used were obtained from routinely collected data and the literature. Cost-effectiveness was expressed as incremental cost-effectiveness ratios (ICERs); an estimate of the cost per adverse clinical complication prevented, comparing screening with no screening, were calculated for each patient group. RESULTS: In the review of risk of clinical complications, 81 studies were included, nine for oral oestrogen preparations, 72 for pregnancy and eight for orthopaedic surgery. For oral contraceptive use, significant associations of the risk of VTE were found in women with factor V Leiden (FVL); deficiencies of antithrombin, protein C, or protein S, elevated levels of factor VIIIc; and FVL and prothrombin G20210A. For hormone replacement therapy (HRT), a significant association was found in women with FVL. The highest risk in pregnancy was found for FVL and VTE, in particular, homozygous carriers of this mutation are 34 times more likely to develop VTE in pregnancy than non-carriers. Significant risks for individual thrombophilic defects were also established for early, recurrent and late pregnancy loss; preeclampsia; placental abruption; and intrauterine growth restriction. Significant associations were found between FVL and high factor VIIIc and postoperative VTE following elective hip or knee replacement surgery. Prothrombin G20210A was significantly associated with postoperative pulmonary embolism. However, antithrombin deficiency, MTHFR and hyperhomocysteinaemia were not associated with increased risk of postoperative VTE. In the review of the effectiveness of prophylaxis, based on available data from eight studies, low-dose aspirin and heparin was found to be the most effective in preventing pregnancy loss in thrombophilic women during pregnancy, while aspirin alone was the most effective in preventing minor bleeding. All the studies on thrombophilia and major elective orthopaedic surgery included in the review of risk complications were also used in the review of the effectiveness of thromboprophylaxis. However, there were insufficient data to determine the relative effectiveness of different thromboprophylaxis in preventing VTE in this patient group. For the cost-effectiveness analysis, of all the patient groups evaluated, universal screening of women prior to prescribing HRT was the most cost-effective (ICER pound6824). In contrast, universal screening of women prior to prescribing combined oral contraceptives was the least cost-effective strategy (ICER pound202,402). Selective thrombophilia screening based on previous personal and/or family history of VTE was more cost-effective than universal screening in all the patient groups evaluated. CONCLUSIONS: Thrombophilia is associated with increased risks of VTE in women taking oral oestrogen preparations and patients undergoing major elective orthopaedic surgery, and of VTE and adverse pregnancy outcomes in women with thrombophilia during pregnancy. There is considerable difference in the magnitude of the risks among different patient groups with different thrombophilic defects. In women who are on combined oral contraceptives, the OR of VTE among those who are carriers of the FVL mutation was 15.62 (95% confidence interval 8.66 to 28.15). However, in view of the prevalence of thrombophilia and the low prevalence of VTE in non-users of combined oral contraceptives, the absolute risk remains low. Significant risks for VTE and adverse pregnancy outcomes have been established with individual thrombophilic defects. Thrombophilic defects including FVL, high plasma factor VIIIc levels and prothrombin G20210A are associated with the occurrence of postoperative VTE in elective hip or knee replacement therapy. These associations are observed in patients who were given preoperative thromboprophylaxis and are, therefore, of clinical significance. Universal thrombophilia screening in women prior to prescribing oral oestrogen preparations, in women during pregnancy and in patients undergoing major orthopaedic surgery is not supported by current evidence. The findings from this study show that selective screening based on prior VTE history is more cost-effective than universal screening. Large prospective studies should be undertaken to refine the risks and establish the associations of thrombophilias with VTE among hormone users and in patients undergoing orthopaedic surgery. The relative value of a thrombophilia screening programme to other healthcare programmes needs to be established.

Cost-Benefit Analysis↗
PubMed2004

Comparison of chlorproguanil-dapsone with sulfadoxine-pyrimethamine for the treatment of uncomplicated falciparum malaria in young African children: double-blind randomised controlled trial.

BACKGROUND: Increasing resistance to sulfadoxine-pyrimethamine is leading to a decline in its effectiveness. We aimed to assess the safety profile of chlorproguanil-dapsone (CD), and to compare the safety and efficacy of this drug with that of sulfadoxine-pyrimethamine (SP) as treatment for uncomplicated falciparum malaria. METHODS: We undertook a double-blind, randomised trial in 1850 consecutively recruited children with uncomplicated falciparum malaria, pooling data from five African countries. Analyses were based on all randomised patients with available data. FINDINGS: CD was significantly more efficacious than SP (odds ratio 3.1 [95% CI 2.0-4.8]); 1313 patients (96%) given CD and 306 (89%) given SP achieved acceptable clinical and parasitological response by day 14. Adverse events were reported in 46% and 50% of patients randomised to CD and SP, respectively (treatment difference -4.4%, [95% CI -10.1 to 1.3]). Haemoglobin in the CD group was significantly lower than in the SP group at day 7, a difference of -4 g/L (95% CI -6 to -2). Mean day 14 haemoglobin (measured only for the small number of patients whose day 7 data caused concern) was 94 g/L (92-96) and 97 g/L (92-102) after CD and SP, respectively. Glucose-6-phosphate dehydrogenase deficient patients on CD had greater odds than those on SP of having a fall of 20 g/dL or more in haemoglobin when baseline temperature was high. Methaemoglobinaemia was seen in the CD group (n=320, mean 0.4% [95% CI 0.4-0.4]) before treatment, 4.2% (95% CI 3.8-4.6) (n=301) at day 3, and 0.6% (0.6-0.7) (n=300) at day 7). INTERPRETATION: CD had greater efficacy than SP in Africa and was well tolerated. Haematological adverse effects were more common with CD than with SP and were reversible. CD is a useful alternative where SP is failing due to resistance.

Africa↗
PubMed2003

Audit of an antibiotic policy and microbiological investigations for treating bacteraemia in a large teaching hospital.

An audit of different approaches to guide empirical therapy in 78 cases of bacteraemia revealed poor utilisation of the antibiotic policy with resulting inadequate (P=0.005) or excessive (P<0.00001) antibiotic treatment and a trend to increased mortality. Eighty-seven percent of blood cultures were positive on Gram-stain within 24 h but streamlined therapy was still judged excessive in 27%. The results show poor utilisation of an up-to-date antibiotic policy but confirm its potential benefits and the ability of traditional culture methods to guide antibiotic therapy in a useful time-scale.

Anti-Bacterial Agents↗
PubMed2003

Rosiglitazone in Type 2 diabetes mellitus: an evaluation in British Indo-Asian patients.

AIMS: To evaluate the effectiveness of rosiglitazone in reducing hyperglycaemia in patients with Type 2 diabetes mellitus (DM) of Indo-Asian origin taking concurrent sulphonylurea therapy. METHODS: A randomized, double-blind, placebo-controlled study of 26 weeks' duration at 31 primary and secondary care centres in areas of the UK with a high Indo-Asian population, including 177 patients aged 28-78 years. Rosiglitazone 8 mg/day or matching placebo was added to existing sulphonylurea therapy. The primary endpoint was change from baseline in glycosylated haemoglobin A1c (HbA1c) at week 26. RESULTS: The mean changes in HbA1c were -1.16% with rosiglitazone (baseline 9.21%) and +0.26% with placebo (baseline 9.06%) (treatment difference P < 0.001; 95% confidence interval (CI) -1.81, -1.08). HbA1c fell below 8% in 55% and 19% of patients, respectively (treatment difference P < 0.001; 95% CI 0.22, 0.51). The greatest improvements occurred in patients whose glycaemic control was initially poor. Improvements in homeostasis model assessment of insulin sensitivity and pancreatic beta-cell function with rosiglitazone were not accompanied by a change in plasma insulin or C-peptide after 26 weeks. Free fatty acids fell by 0.09 mmol/l with rosiglitazone and increased by 0.03 mmol/l with placebo (treatment difference P < 0.001; 95% CI -0.19, -0.07). CONCLUSION: Rosiglitazone improved insulin sensitivity, pancreatic beta-cell function, and glycaemic control in Indo-Asian patients with Type 2 DM who are at greater risk of the complications of Type 2 DM than other ethnic groups.

Adult↗
PubMed2003

Prokaryotic metabolic activity and community structure in Antarctic continental shelf sediments.

The prokaryote community activity and structural characteristics within marine sediment sampled across a continental shelf area located off eastern Antarctica (66 degrees S, 143 degrees E; depth range, 709 to 964 m) were studied. Correlations were found between microbial biomass and aminopeptidase and chitinase rates, which were used as proxies for microbial activity. Biomass and activity were maximal within the 0- to 3-cm depth range and declined rapidly with sediment depths below 5 cm. Most-probable-number counting using a dilute carbohydrate-containing medium recovered 1.7 to 3.8% of the sediment total bacterial count, with mostly facultatively anaerobic psychrophiles cultured. The median optimal growth temperature for the sediment isolates was 15 degrees C. Many of the isolates identified belonged to genera characteristic of deep-sea habitats, although most appear to be novel species. Phospholipid fatty acid (PLFA) and isoprenoid glycerol dialkyl glycerol tetraether analyses indicated that the samples contained lipid components typical of marine sediments, with profiles varying little between samples at the same depth; however, significant differences in PLFA profiles were found between depths of 0 to 1 cm and 13 to 15 cm, reflecting the presence of a different microbial community. Denaturing gradient gel electrophoresis (DGGE) analysis of amplified bacterial 16S rRNA genes revealed that between samples and across sediment core depths of 1 to 4 cm, the community structure appeared homogenous; however, principal-component analysis of DGGE patterns revealed that at greater sediment depths, successional shifts in community structure were evident. Sequencing of DGGE bands and rRNA probe hybridization analysis revealed that the major community members belonged to delta proteobacteria, putative sulfide oxidizers of the gamma proteobacteria, Flavobacteria, Planctomycetales, and Archaea. rRNA hybridization analyses also indicated that these groups were present at similar levels in the top layer across the shelf region.

Antarctic Regions↗
PubMed2002

A novel approach to promoting change in SHO training in a dental teaching hospital.

An action research study using a series of staged focus groups with senior house officers (SHOs) and educational supervisors (ES) was used to identify the perceptions of the strengths and challenges in the SHO training programme and to indicate areas for improvement. The basic findings were not entirely surprising, with SHOs wanting more detailed feedback from educational supervisors and educational supervisors challenged (by time constraints and competing clinical and research responsibilities) in meeting the expectations of the SHOs. However the novel approach of using staged focus groups enhanced the educational supervisors' perception of the SHOs' view of their training and the SHOs' perception'of the challenges faced by educational supervisors. Thus a culture of dialogue was created which supported change and innovation. This process was able to directly inform and influence the development of a new induction programme for SHOs and provide valuable insight into the use of the portfolio of learning and the provision of study opportunities. These findings may only be of local interest, however the method employed can be transferred to other contexts to support a grass roots approach to change. Indeed, since this study has been completed, the method has been replicated in a medical setting.

Communication↗
PubMed2001

Final results of a randomized trial comparing the MULTI-LINK stent with the Palmaz-Schatz stent for narrowings in native coronary arteries.

The MULTI-LINK (ML) stent is a novel second generation coronary stent. The ACS MultiLink Stent Clinical Equivalence in De Novo Lesions Trial (ASCENT) randomized 1,040 patients with single, de novo native vessel lesions to treatment with the ML stent or the benchmark Palmaz-Schatz (PS) stent, to demonstrate that the ML stent was not inferior to (i.e., equivalent or better than) the PS stent in terms of target vessel failure by 9 months. Successful stent delivery was achieved in 98.8% versus 96.9% of patients, with a slightly lower postprocedural diameter stenosis (8% vs 10%, p = 0.04), and no difference in 30-day major adverse cardiac events (5.0% vs 6.5%) for the ML stent versus the PS stent. The primary end point of target vessel failure at 9 months was seen in 15.1% of ML-treated patients versus 16.7% of PS-treated patients, with the ML proving to be equal or superior to the PS stent (p <0.001 by test for equivalency). In a prespecified subset, angiographic restudy showed a nonsignificant trend for reduced ML restenosis (16.0% vs 22.1%). Thus, the ML stent showed excellent deliverability and acute results, with 9-month clinical and 6-month angiographic outcomes that were equivalent or better than the PS stent.

Aged↗
PubMed2001

Identification of predominant human and animal anaerobic intestinal bacterial species by terminal restriction fragment patterns (TRFPs): a rapid, PCR-based method.

Identification of predominant human and animal intestinal tract anaerobes by conventional methods is cumbersome, time-consuming and less sensitive as compared to molecular methods. We have developed a molecular technique to identify most of the abundant intestinal microflora by polyermase chain reaction (PCR) amplification of a 16S rRNA gene fragment using a pair of universal PCR primers. The forward PCR primer was labelled with 6-carboxyfluorescein amino hexy (6-FAM) fluorescent dye to detect the terminal fragment of the PCR products after digestion with restriction enzymes. The PCR products were purified and digested with restriction enzymes and were analysed by capillary electrophoresis using an automated DNA sequencer. The data was analysed with GeneScan software 2.1. Eleven bacteria (Eubacterium biforme, E. limosum, Peptostreptococcus productus, Lactobacillus acidophilus, Bacteroides thetaiotaomicron, B. vulgatus, B. distasonis, Clostridium clostridiiforme, C. leptum, C. perfringens and Escherichia coli) that are predominant in human and animal intestinal tract were successfully identified by this rapid molecular technique. This protocol is rapid, accurate, sensitive and capable of identifying multiple organisms in a single sample.

Animals↗
PubMed2001

Anterior cingulate metabolism correlates with stroop errors in paranoid schizophrenia patients.

UNLABELLED: Using [O-15]-H(2)O PET Carter et al. (1997) reported that medicated patients with schizophrenia performing computerized single trial Stroop (1935) showed a reduction in the anterior cingulate activation response to the more attention demanding, incongruent Stroop condition. In that study, both patients and controls also showed a direct correlation between anterior cingulate activation and errors committed during incongruent trials of the task. In this study we follow up with an examination of paranoid schizophrenia outpatients and controls with very high resolution positron emission tomography (PET) and the longer half-life tracer [F-18]-fluorinated deoxyglucose (FDG) (Valk et al. 1990). All subjects (10 controls and 9 paranoid schizophrenia patients) were studied with FDG-PET while performing a computerized trial-by-trial version of the Stroop task during the uptake phase of the tracer (Carter et al. 1992). RESULTS: As in previous studies using the single trial Stroop, patients were able to perform the task but made more color-naming errors during incongruent trials than controls. The patients in the present study showed a trend towards increased metabolic activity in the right anterior cingulate cortex. In the patient group, but not in controls, the anterior cingulate glucose metabolic rate correlated positively with the total incongruent trial errors. CONCLUSION: These results are consistent with the hypothesis that the anterior cingulate plays a performance-monitoring role during human cognition. This study does not rule out a reduction in error sensitivity in this region of the brain in schizophrenia, as other studies have suggested, however the data show that in unmedicated patients with the paranoid subtype this function is preserved to some extent.

Adult↗
PubMed2000

Prognostic significance of the metastasis-inducing protein S100A4 (p9Ka) in human breast cancer.

The calcium-binding protein S100A4 is capable of inducing metastasis in rodent models for breast cancer. We now show that rabbit antibodies to recombinant rat S100A4 recognize specifically human S100A4 using Western blotting techniques and use them to assess the prognostic significance of S100A4 in primary tumors from a group of 349 patients treated between 1976 and 1982 for stage I and stage II breast cancer. The antibody stains normal breast tissue heterogeneously, but stains positively 41% of the carcinomas, leaving the remaining 59% as negatively stained. In addition to the carcinoma cells, some host stromal cells and lymphocytes are also stained, but these have been discounted in subsequent analyses. There is an association of staining of carcinomas for S100A4 with some tumor variables considered to be associated with poor prognosis for patients: tumor present in axillary lymph nodes (borderline P = 0.058), staining for c-erbB-3 (P = 0.002), cathepsin D (P = 0.024), and c-erbB-2 (P = 0.048). The association of staining for S100A4 with patient survival has been evaluated using life tables and analyzed using generalized Wilcoxon statistics. Eighty percent of the S100A4-negative patients but only 11% of the S100A4-positive patients are alive after 19 years of follow-up, and this association is highly significant (P < 0.0001); the former have a median survival of >228 months and the latter 47 months. The other tumor variables that show significant association with survival time are nodal status (P < 0.0001), tumor size (P = 0.0035), histological grade (P = 0.013), staining for c-erbB-2 (P = 0.0015), estrogen receptor (P = 0.028), and p53 (P = 0.032). Analysis of the association of patients with carcinomas staining for S100A4 and their survival in subgroups defined by these other tumor variables shows that in each subgroup, staining for S100A4 is associated with poorer survival. Patients whose tumors stain for S100A4 and possess involved lymph nodes (P < 0.0001), which are fixed to the chest wall (P = 0.015) or which stain for c-erbB-2 (P = 0.050), show a significant reduction in survival times over those with only S100A4-staining tumors. Patients with involved lymph nodes, or staining for c-erbB-2 in the S100A4-negative group fail to show any significant reduction in survival times. Multivariate regression analysis for 137 patients shows that staining for S100A4 is most highly correlated with patient deaths (P < 0.0001), but involved lymph nodes (P = 0.001), fixed tumors (P = 0.0002), and high histological grade (P = 0.022) are also significant independent prognostic variables. These results suggest that in this group of patients, the metastasis-inducing protein S100A4 is most tightly correlated with patient demise.

Adult↗
PubMed2000

Life skills programmes for chronic mental illnesses.

BACKGROUND: Most people with schizophrenia have a pattern of illness characterised by remission and relapses. The illness can become chronic and disabling. The social disability can require a variety of psychological, nursing and occupational therapies. Life skills programmes, addressing the needs associated with independent functioning, are often a part of the rehabilitation process. OBJECTIVES: To compare the effectiveness of life skills programmes with standard care for people with chronic mental health problems. SEARCH STRATEGY: CINAHL (1982-1997), The Cochrane Library (Issue 2, 1997), The Cochrane Schizophrenia Group's Register of Trials (April 1998), EMBASE (1980-1997), MEDLINE (1966-1997) and PsycLIT (1974-1997) were methodically searched. Hand searches and scrutiny of references supplemented this process. SELECTION CRITERIA: All relevant randomised or quasi-randomised controlled trials for life skills programmes versus standard care involving those with serious mental illnesses. DATA COLLECTION AND ANALYSIS: Searches were inspected by two reviewers (LR, MN) with a third (JC) acting as arbitrator. Data were extracted in the same way. Where possible an intention-to-treat analysis was undertaken on dichotomous data and normally distributed continuous data. MAIN RESULTS: Two randomised controlled trials were included with a total of 38 participants. Data were sparse and no clear effects were demonstrated. REVIEWER'S CONCLUSIONS: If life skills training is to continue as part of rehabilitation programmes a large, well designed, conducted and reported pragmatic randomised trial is an urgent necessity. There may even be an argument for stating that maintenance of current practice, outside of a randomised trial, is unethical.

Activities of Daily Living↗
PubMed2000

Vertebral fracture definition from population-based data: preliminary results from the Canadian Multicenter Osteoporosis Study (CaMos).

The Canadian Multicenter Osteoporosis Study is a large population-based prospective study of osteoporosis in the Canadian population. The study involves 9424 subjects, both male and female, from nine centers and seven regions of Canada. Each subject completed an extensive interview to obtain medical, demographic and lifestyle information, and was examined by dual-energy X-ray absorptiometry of the spine and hip, ultrasound of the heel and, for subjects over 50 years of age, lateral spine radiographs. Spinal morphometry of the initial radiographs was performed to determine the prevalence of vertebral deformity. A method is utilized to extract reference norms for vertebral shape from a subset of the population data, which is then used to categorize any deformity within the whole data set. Using 3 standard deviations (SD) as a limit of normality', the male prevalence of 21.5% was similar to the female prevalence of 23.5%. Using 4 SD this reduced to 7.3% and 9.3% respectively. The younger men (50-59 years) showed a higher prevalence of deformity than the women and a lower increase of prevalence with age. In the older age group (over 80 years) the female prevalence of 45% compared with 36% for the men using 3 SD (grade 1) to define the limit of normality. The female group presented with more severe deformities on average than the male group. This continuing study will provide longitudinal information regarding the development of osteoporosis and associated risk factors which will eventually be of use to develop public health policies.

Absorptiometry, Photon↗