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Biomedical subjects

M Campbell

Publications and source records attributed to M Campbell.

At least 145 records · Page 8Linked to original sources
PubMed2001

A candesartan cilexetil/hydrochlorothiazide combination tablet provides effective blood pressure control in hypertensive patients inadequately controlled on monotherapy.

In this double-blind, placebo-controlled, randomised, parallel-group study, a combination tablet of candesartan cilexetil/hydrochlorothiazide (HCTZ), 16/12.5 mg once daily, reduced sitting diastolic blood pressure (DBP) significantly more (p = 0.037) than candesartan cilexetil/placebo, 16 mg once daily, in patients with mild to moderate primary hypertension (n = 328) who had not reached target blood pressure with candesartan cilexetil, 16 mg once daily. At the end of the 8-week double-blind treatment period, the adjusted mean reductions in sitting DBP, 24 h post dose, were 7.5 mm Hg in the candesartan cilexetil/HCTZ treatment group and 5.5 mm Hg in the candesartan cilexetil/placebo treatment group, corresponding to an adjusted mean difference between treatments of 2.0 mm Hg in favour of candesartan cilexetil/HCTZ (95% CI 0.1-3.8 mm Hg, p = 0.037). The adjusted mean reductions in sitting systolic blood pressure, 24 h post dose, were 12.0 mm Hg and 7.5 mm Hg, respectively, corresponding to an adjusted mean difference between treatments of 4.5 mm Hg (95% CI 1.1-8.0, p = 0.01). Consistent with the placebo-like tolerability of candesartan cilexetil reported in other studies, both treatments were very well tolerated, with a similar pattern and low frequency of adverse events in both treatment groups.

Adult↗
PubMed2001

Mitoxantrone and paclitaxel combination chemotherapy in metastatic breast cancer.

This study evaluated mitoxantrone and paclitaxel combination chemotherapy in the treatment of patients with metastatic breast cancer. Thirty-seven patients who had developed progressive disease after prior chemotherapy were treated with mitoxantrone (14 mg/m2) and paclitaxel (150 mg/m2) every 21 days for a maximum of six cycles. The most frequent grade 3 or 4 nonhematological toxicities were fever and nausea. Grade 4 neutropenia occurred in 71% of patients. Cardiotoxicity occurred in 2 patients, both of whom had previously received doxorubicin. Objective response was achieved in 35% of patients (5% complete response and 30% partial response) and 41% had stable disease. Median time to disease progression and median survival were 6 and 12 months, respectively. The percent of patients with an objective response was not different for those who had received prior doxorubicin or had chemotherapy in the preceding 6 months. This regimen appears to be effective and well tolerated as salvage therapy and merits further evaluation.

Adult↗
PubMed2001

Is untargeted outreach visiting in primary care effective? A pragmatic randomized controlled trial.

BACKGROUND: There is increasing evidence that clinical guidelines can lead to improvements in clinical care. However, they are not self-implementing. Outreach visits may improve prescribing behaviour. METHODS: Within a before-and-after pragmatic randomized controlled trial, involving all general practices in one health district, routine methods were used to distribute guidelines for management of Helicobacter pylori eradication. Intervention practices were offered a visit and the conduct of an audit by a pharmacist trained in the techniques of outreach visiting. The intervention was evaluated using level three Prescribing Analysis and Cost (PACT) data for metronidazole and omeprazole for the two 12 month periods around the introduction of the guidelines. RESULTS: Of the 38 intervention practices 19 accepted an outreach visit and three accepted the offer of an audit. There was a significant increase in omeprazole use during the study of 0.24 [95 per cent confidence interval (CI) +0.19 to +0.29] dose units per year but no effect from the offer [-0.02 (95 per cent CI -0.12 to +0.08) dose units] or acceptance of a visit [-0.03 (95 per cent CI -0.15 to +0.08) dose units]. The results for metronidazole were similar, with an increase in use of 0.028 (95 per cent CI +0.018 to +0.038) dose units per year. The effect of the intervention was a non-significant change in prescribing of -0.005 (95 per cent CI -0.025 to +0.015) dose units. Accepting a visit had little effect on prescribing: a change of 0.003 (95 per cent CI -0.021 to +0.027) dose units. CONCLUSIONS: The routine use of untargeted outreach visiting is probably not a worthwhile strategy.

Amoxicillin↗
PubMed2001

The safety and effectiveness of the Le Fort I approach to removing central skull base lesions.

The difficulty of gaining access to the central skull base has led to the development of many surgical approaches to this area during the past decade. Yet we believe that the Le Fort I technique, which has been used for almost 140 years in orthognathic surgery, is still an excellent approach to treating anterior skull base lesions. This procedure, which entails the horizontal sectioning of the dentoalveolar maxillary segment, seemed to fall out of favor with otolaryngologists after a few reports of complications surfaced during the past 10 to 15 years. In this article, we report a series of seven patients whom we treated with a Le Fort I approach during a 3-year period for a variety of benign and malignant anterior skull base lesions. We have encountered no significant complications of surgery or recurrence of disease at a maximum postoperative followup of 3 years.

Adult↗
PubMed2001

[Clinical significance and frequency of the 11q23/MLL genetic molecular alteration in Chilean infants with acute leukemia].

BACKGROUND: Acute leukemia (AL) in infants generally shows distinctive biologic features and has a poor prognosis. AIM: To study the frequency of the cytogenetic alteration of 11q23 chromosome or the recombination of MLL gene in infants less than 18 months old, with acute leukemia. PATIENTS AND METHODS: We analyzed 37 cases of AL in infants less than 18 months of age diagnosed in Chile from 1989 to 1999. The clinical features and cytogenetic/molecular defects of 11q23MLL gene rearrangement and their influence in prognosis were determined. RESULTS: There were 18 cases of acute Lymphoblastic leukemia (ALL) characterized by female sex (67%) high presenting leukocyte count (median 99 x 109/L), blast cells with a CD10 negative phenotype (50%) and 11q23/MLL rearrangement (39%). Molecular abnormalities of 11q23 were significantly associated with adverse prognosis, with an event free survival (EFS) of only 14 +/- 12%. Interestingly, infants with germ line 11q23 had a very good outcome with an EFS of 73 +/- 11% (p < 0.025). There were 19 cases of acute myeloblastic leukemia (AML) characterized by male sex (63%) high leukocyte count (median 93 x 109/L), FAB-MS morphology (53%) and 11q23/MLL rearrangement (53%). EFS was very poor, 20 +/- 9% and 33 +/- 4% for rearranged and germinal group respectively (p = NS), due to a high mortality rate during the first month of diagnosis. CONCLUSIONS: These findings demonstrate that Chilean ALL infants with 11q23 abnormalities have a very poor prognosis. However those with germinal state can enjoy a prolonged disease free survival with the current treatment protocols.

Blotting, Southern↗
PubMed2001

The General Medical Council's Performance Procedures: the development and implementation of tests of competence with examples from general practice.

OBJECTIVE: This paper describes the development of the tests of competence used as part of the General Medical Council's assessment of potentially seriously deficient doctors. It is illustrated by reference to tests of knowledge and clinical and practical skills created for general practice. SUBJECTS AND TESTS: A notional sample of 30 volunteers in 'good standing' in the specialty (reference group), 27 practitioners referred to the procedures and four practitioners not referred but who were the focus of concern over their performance. Tests were constructed using available guidelines and a specially convened working group in the specialty. METHODS: Standards were set using Angoff, modified contrasting group and global judgement methods, as appropriate. RESULTS: Tests performed highly reliably, showed evidence of construct validity, intercorrelated at appropriate levels and, at the standards employed, demonstrated good separation of reference and referred groups. Likelihood ratios for above and below standard performance based on competence were large for each test. Seven of 27 doctors referred were shown not to be deficient in both phases of the performance assessment.

Adult↗
PubMed2000

Ductal growth is impeded in mammary glands of C-neu transgenic mice.

The steroid hormone, estradiol, is essential for both the growth of normal breast and induction of mammary carcinomas. The growth promoting effects of estrogen are presumed to be mediated by growth factors, in particular, epidermal growth factor, which mediates its effects through erbB receptors, erbB1 and erbB2/C-neu. C-neu is amplified and over-expressed in a large number of human cancers and transgenic mice over-expressing C-neu also develop mammary tumors. However, as yet, the impact of C-neu over-expression on estrogen action during normal mammary development and hence, its precise role in carcinogenesis, remains unclear. In the present studies, we demonstrate that estradiol-dependent mammary ductal growth accompanying puberty is impaired in transgenic mice expressing wild type Cneu, and is intrinsic to the tissue. The impairment is not due to an overall impairment in estrogen action, since progesterone receptor expression is unaffected in C-neu mice. It is also not due to an intrinsic inability of the epithelial cells to proliferate, since impeded ductal growth co-exists with alveolar growth during pregnancy. Therefore, we propose that, depending on the physiological state, C-neu may either promote or inhibit the growth of mammary epithelial cells, and discuss its potential significance to carcinogenesis.

Aging↗
PubMed2000

Measurement of J/psi and psi(2S) polarization in pp collisions at sqrt[s] = 1.8 TeV.

We have measured the polarization of J/psi and psi(2S) mesons produced in pp collisions at sqrt[s] = 1.8 TeV, using data collected at the Collider Detector at Fermilab during 1992-1995. The polarization of promptly produced J/psi [psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4 [5.5]<P(T)<20 GeV/c and |y|<0.6. For P(T) greater than or approximately equal 12 GeV/c we do not observe significant polarization in the prompt component.

Journal Article↗
PubMed2000

Search for scalar top and scalar bottom quarks in pp collisions at square root s=1.8 TeV.

We have searched for direct pair production of scalar top and scalar bottom quarks in 88 pb-1 of pp collisions at sqrt[s]=1.8 TeV with the CDF detector. We looked for events with a pair of heavy flavor jets and missing energy, consistent with scalar top (bottom) quark decays to a charm (bottom) quark and a neutralino. The numbers of events that pass our selections show no significant deviation from standard model expectations. We compare our results to the next-to-leading order scalar quark production cross sections to exclude regions in scalar quark-neutralino mass parameter space.

Journal Article↗
PubMed2000

Search for a W' boson via the decay mode W'-->munumu in 1.8 TeV pp collisions.

We report the results of a search for a W' boson produced in pp collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W'-->&munumu and search for anomalous production of high transverse mass munumu lepton pairs. We observe no excess of events above background and set limits on the rate of W' boson production and decay relative to standard model W boson production and decay using a fit of the transverse mass distribution observed. If we assume standard model strength couplings of the W' boson to quark and lepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c2 at 95% confidence level.

Journal Article↗
PubMed2000

Fabrication of photonic crystals for the visible spectrum by holographic lithography

The term 'photonics' describes a technology whereby data transmission and processing occurs largely or entirely by means of photons. Photonic crystals are microstructured materials in which the dielectric constant is periodically modulated on a length scale comparable to the desired wavelength of operation. Multiple interference between waves scattered from each unit cell of the structure may open a 'photonic bandgap'--a range of frequencies, analogous to the electronic bandgap of a semiconductor, within which no propagating electromagnetic modes exist. Numerous device principles that exploit this property have been identified. Considerable progress has now been made in constructing two-dimensional structures using conventional lithography, but the fabrication of three-dimensional photonic crystal structures for the visible spectrum remains a considerable challenge. Here we describe a technique--three-dimensional holographic lithography--that is well suited to the production of three-dimensional structures with sub-micrometre periodicity. With this technique we have made microperiodic polymeric structures, and we have used these as templates to create complementary structures with higher refractive-index contrast.

Journal Article↗
PubMed2000

A double-blind placebo-controlled study of lithium in hospitalized aggressive children and adolescents with conduct disorder.

BACKGROUND: A subgroup of children and adolescents with conduct disorder are characterized by severe and persistent aggression. Although there is no agreed on treatment for such aggression, lithium carbonate has shown promise in some studies involving children. Our study was designed to critically assess the efficacy of lithium in the treatment of aggression in children and adolescents using a measure specific for aggression. METHODS: Subjects were inpatients with conduct disorder hospitalized because of severe and chronic aggression. A parallel-groups design was used in this double-blind, placebo-controlled trial with randomization to lithium or placebo. Only those who met the aggression criterion during the 2-week placebo-baseline period were randomized to 4 weeks of treatment. Outcome measures included Clinical Global Impressions, the Global Clinical Judgements (Consensus) Scale, and the Overt Aggression Scale. RESULTS: Eighty-six inpatients enrolled in the study; 40 (33 male and 7 female; median age, 12.5 years) entered and completed the treatment phase. Lithium was statistically and clinically superior to placebo. Sixteen of 20 subjects in the lithium group were responders on the Consensus ratings vs 6 of 20 in the placebo group (P=.004). Ratings on the Overt Aggression Scale decreased significantly for the lithium group vs the placebo group (P=.04). More than half of the subjects in the lithium group experienced nausea, vomiting, and urinary frequency. CONCLUSIONS: Lithium is a safe and effective short-term treatment for aggression in inpatients with conduct disorder, although its use is associated with adverse effects.

Adolescent↗
PubMed2000

Evidence-based medicine and health economics: a case study of end stage renal disease.

This paper explores the potential for use of an economic evaluation framework alongside systematic reviews. Clinical issues in dialysis therapy for end stage renal disease are used as case studies. The effectiveness data required were obtained from a systematic review of randomized controlled trials. Resource use and cost data were obtained from three sources; the identified randomized controlled trials, a separate review of observational studies and primary data collection. The results of the case studies show that, although simple economic evaluations were possible, issues arose, such as how transferable results are between settings and how appropriate it is to focus on the average patient. The interface between economic evaluation and systematic reviews needs to be further developed in order to ensure that the best available evidence can be used to inform future policy and research.

Chi-Square Distribution↗
PubMed2000

Fas-independent apoptosis in T-cell tumours induced by the CD2-myc transgene.

Depending on the cellular context, the Myc oncoprotein is capable of promoting cell proliferation or death by apoptosis. These observations suggest that apoptosis in response to deregulated gene expression may represent a natural brake to tumour development. The pathways by which Myc induces apoptosis are as yet poorly characterised although recent observations on rat fibroblasts over-expressing Myc have demonstrated a requirement for the Fas pathway. To investigate the role of Fas in Myc-induced lymphomagenesis we backcrossed CD2-myc mice onto an lpr background. Rates of tumour development and phenotypic properties, including levels of apoptosis were indistinguishable from CD2-myc controls. Further, tumour cell lines derived from mice expressing a regulatable form of Myc showed inducible apoptosis at similar rates regardless of their lpr genotype. These results show that activation of c-myc and loss of Fas do not collaborate in T lymphoma development and that Myc-induced apoptosis in T-cells occurs by Fas-independent pathways.

Animals↗
PubMed2000

Effects of interleukin-15 on in vitro human T cell proliferation and activation.

Interleukin-15 (IL-15) has been reported to have many activities on T cell populations, including a potential role in improving antigen-specific proliferation in HIV-1 disease. We tested this response in healthy adults by studying the response of T cell populations after stimulation with medium, tetanus, cytomegalovirus (CMV) antigens in cultures from 21 volunteers. IL-15 caused a dose-dependent increase in medium and antigen-induced proliferation. The expansion was due to CD8>natural killer (NK)>CD4 lymphocytes and memory > naive cells. The IL-15-stimulated CD8 cells had increased levels of the activation markers CD69 and DR. The published CMV-induced expression of CD57 on CD8+ cells was increased in CMV seronegative and seropositive subjects by IL-15. IL-15 appears to be a stimulator of T cell populations in healthy adults and may be useful in settings to enhance nonspecific NK activity or antigen-specific CD8 activity.

Adult↗