PubMed Health⌕ Search

Biomedical subjects

T Dexter

Publications and source records attributed to T Dexter.

12 recordsLinked to original sources
PubMed2006

Microarray-based comparative genomic hybridisation of breast cancer patients receiving neoadjuvant chemotherapy.

We analysed the molecular genetic profiles of breast cancer samples before and after neoadjuvant chemotherapy with combination doxorubicin and cyclophosphamide (AC). DNA was obtained from microdissected frozen breast core biopsies from 44 patients before chemotherapy. Additional samples were obtained before the second course of chemotherapy (D21) and after the completion of the treatment (surgical specimens) in 17 and 21 patients, respectively. Microarray-based comparative genome hybridisation was performed using a platform containing approximately 5800 bacterial artificial chromosome clones (genome-wide resolution: 0.9 Mb). Analysis of the 44 pretreatment biopsies revealed that losses of 4p, 4q, 5q, 12q13.11-12q13.12, 17p11.2 and 17q11.2; and gains of 1p, 2p, 7q, 9p, 11q, 19p and 19q were significantly associated with oestrogen receptor negativity. 16q21-q22.1 losses were associated with lobular and 8q24 gains with ductal types. Losses of 5q33.3-q4 and 18p11.31 and gains of 6p25.1-p25.2 and Xp11.4 were associated with HER2 amplification. No correlations between DNA copy number changes and clinical response to AC were found. Microarray-based comparative genome hybridisation analysis of matched pretreatment and D21 biopsies failed to identify statistically significant differences, whereas a comparison between matched pretreatment and surgical samples revealed a statistically significant acquired copy number gain on 11p15.2-11p15.5. The modest chemotherapy-driven genomic changes, despite profound loss of cell numbers, suggest that there is little therapeutic selection of resistant non-modal cell lineages.

Adult↗
PubMed2002

Efficacy of microfiltration in decreasing propofol-induced pain.

In a randomised, double-blinded, two-centre trial we evaluated the effect of a microbiological filter (Supor, Pall Life Sciences) on propofol injection pain. We studied 336 unpremedicated adult patients, who graded pain experienced during induction of anaesthesia with propofol on a 4-point verbal rating scale. Use of the microfilter reduced both the incidence and severity of propofol injection pain (p < 0.001). Incidence of severe pain in the filter group was 2.4% compared with 16.6% in the control group. Overall, 33.7% in the filter group experienced pain compared with 62.1% in the control group. A microbiological filter may provide a non-pharmacological alternative to a lidocaine/propofol mixture for reducing injection pain. It would also reduce the risk of any glass and bacterial contamination.

Adolescent↗
PubMed2000

Pretreatment with ketorolac and venous occlusion to reduce pain on injection of propofol.

We performed a randomised, double-blind, prospective trial to discover whether intravenous ketorolac 10 mg made up to 2 ml with saline, with or without venous occlusion for 2 min, reduces the pain on injection of propofol. In 90 patients, pain scores were obtained during injection of propofol following pretreatment of the vein with saline, ketorolac or ketorolac with venous occlusion. Pain on injection of ketorolac was more common than with saline (p = 0.02). The incidence of severe pain following propofol was reduced by ketorolac with venous occlusion (p = 0.019) compared with saline or ketorolac without venous occlusion. There was no difference in venous sequelae at 7 days postoperatively between the groups. Our results suggest that pain on injection of propofol may be related to release of local kininogens and that nonsteroidal anti-inflammatory drugs may have a role in reducing that pain.

Adolescent↗
PubMed2000

An accessible analytical approach for investigating what happens between the rounds of a Delphi study.

The Delphi method is used to investigate consensus amongst a panel of experts using repeated rounds of a questionnaire, often in healthcare settings. However, many Delphi studies do not report any investigation into what happens to the stability of consensus or the convergence of agreement between the rounds in the study, which may be of importance. In this paper an accessible analytical approach is outlined using graphical presentations of means and standard deviations to identify what happens between rounds. For Delphi studies where the scale upon which experts are expressing their opinions can be considered to be interval, the mean will represent the group opinion whilst the standard deviation will represent the level of agreement. An example Delphi study from a healthcare setting is used to illustrate the methodology.

Attitude of Health Personnel↗
PubMed1999

Protection of committed murine haemopoietic progenitors against BCNU toxicity does not predict protection of primitive, multipotent spleen colony-forming cells - implications for chemoprotective gene therapy.

The effect of expression of an O6-benzylguanine (O6-beG)-resistant mutant (hATPA/GA) of human O6-alkylguanine-DNA alkyltransferase (ATase) on the in vivo toxicity and clastogenicity of the anti-tumour agent N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU) to murine bone marrow has been investigated. When compared with control animals, the bipotent granulocyte-macrophage colony-forming (GM-CFC) progenitor population of the hATPA/GA transduced mice were somewhat more resistant to BCNU (1.4-fold, P = 0.047) and this effect was more significant in the presence of the ATase inactivator O6-beG (3. 5-fold, P = 0.001). The polychromatic erythrocytes were also significantly protected against BCNU-induced clastogenicity both in the presence (P < 0.001) and absence of O6-beG (P < 0.05). The primitive, multipotent spleen colony-forming cells (CFU-S) in these animals also showed moderate (1.6-fold, P = 0.034) protection in the absence of O6-beG but in the presence of the inactivator they remained as sensitive to BCNU toxicity as those in the control animals (P = 0.133). This result contrasts with previous findings demonstrating significant hATPA/GA-mediated, O6-beG-resistant protection against the toxicity and clastogenicity of a number of O6-alkylating agents, including temozolomide, fotemustine and chlorozotocin. The possibility that our strategy for protective gene therapy may be highly agent and cell-type specific is unexpected and has possible implications for clinical trials of this approach using BCNU or related agents.

Animals↗
PubMed1999

Relationship between sport knowledge, sport performance and academic ability: empirical evidence from GCSE Physical Education. General Certificate of Secondary Education.

The literature concerning links between sport knowledge, sport performance and academic ability is reviewed and related to empirical evidence obtained from a GCSE examination in Physical Education, together with GCSE Mathematics and GCSE English grades. For most sports examined, there was a small but significant positive correlation between sport performance and GCSE Mathematics and English grades, confirming the findings of most previous research. Using a multilevel multivariate model, average sport performance, academic ability and sex were important explanatory variables for sport knowledge, yet only academic ability was an important explanatory variable for the concept of physical education knowledge. Ability in game sports, rather than athletics, were related to sport knowledge. Males scored higher for sport knowledge than females, after taking into account sport performance and academic ability. The effects of sport performance and academic ability on sport knowledge were stable across schools, but there was some evidence that the effect of sex varied across schools. These findings support theories of a role for sport knowledge in sport performance; that such a role should be greater in game sports; that academic ability is important for gaining such knowledge; and they highlight differences in sport knowledge between the sexes.

Achievement↗