Biomedical subjects

David Bartlett

Publications and source records attributed to David Bartlett.

9 recordsLinked to original sources

PubMed2026

Real-World Actionability Analysis of Comprehensive Genomic Profiling Versus Single/Small-Gene Panels.

INTRODUCTION: Comprehensive genomic profiling (CGP) enables identification of patients eligible for targeted treatments, making it essential in the management of advanced cancer. This retrospective real-world study compared actionable mutations in CGP-tested patients with advanced/metastatic solid tumors to those who received single-gene/small-panel (SP) tests. METHODS: Patients aged > 18 years with advanced/metastatic solid tumors (including non-small cell lung cancer (NSCLC), colorectal cancer, prostate cancer, breast cancer, or melanoma) with a CGP or SP test reported between 1 January 2018, and 31 December 2022, were included. OncoKB-derived actionability was compared between the two cohorts. Inverse probability of treatment weighting (IPTW) was used to adjust for baseline characteristics. A weighted generalized linear model with log link was used to report actionability ratio (AR) and 95% confidence intervals (CI). RESULTS: Among 406 patients (CGP-tested cohort: 202, SP-tested cohort: 204), approximately half were diagnosed with NSCLC. After adjusting for baseline characteristics, CGP testing detected more actionable alterations than SP: OncoKB level 1 (50.0% versus 31.4%; AR 1.76 [95% CI: 1.24, 2.51]; p = 0.002), OncoKB level 2 (22.8% versus 10.3%; AR 2.53 [95% CI: 1.17, 5.48]; p = 0.018), and OncoKB level 1 or level 2 or level R1 (55.9% versus 41.2%; AR 1.5 [95% CI: 1.11, 2.01]; p = 0.008). CONCLUSIONS: CGP testing identified more actionable genetic alterations compared with SP testing methods for patients with advanced/metastatic NSCLC, colorectal cancer, prostate cancer, breast cancer, or melanoma. Expanding reimbursement and coverage for CGP testing as well as expanding CGP use can facilitate equitable treatment access for patients with advanced/metastatic cancer.

Actionable mutations↗

PubMed2005

Herbicidal indolizine-5,8-diones: photosystem I redox mediators.

6,7-Disubstituted indolizine-5,8-diones showed activity as herbicides, giving rapid desiccation symptomology in whole-plant tests and bleaching in leaf-disc assays. In isolated chloroplasts, such compounds initiated rapid uptake of oxygen in Photosystem I. A redox mediator mode of action was further supported by electrochemical studies. Several compounds described had low photostability, high volatility, hydrolytic instability or reactivity with glutathione. The detrimental effects that these factors may have had on expression of herbicidal activity are discussed.

Drug Stability↗

PubMed2004

Dental erosion, gastro-oesophageal reflux disease and saliva: how are they related?

AIMS: The purpose of this study was to assess the prevalence of tooth wear, symptoms of reflux and salivary parameters in a group of patients referred for investigation of gastro-oesophageal reflux disease (GORD) compared with a group of control subjects. MATERIALS AND METHODS: Tooth wear, stimulated salivary flow rate and buffering capacity and symptoms of GORD were assessed in patients attending an Oesophageal Laboratory. Patients had manometry and 24-h pH tests, which are the gold standard for the diagnosis of GORD. Tooth wear was assessed using a modification of the Smith and Knight tooth wear index. The results were compared to those obtained from a group of controls with no symptoms of GORD. RESULTS: Patients with symptoms of GORD and those subsequently diagnosed with GORD had higher total and palatal tooth wear (p<0.05). The buffering capacity of the stimulated saliva from the control subjects was greater than patients with symptoms of GORD (p<0.001). Patients with hoarseness had a lower salivary flow rate compared with those with no hoarseness. CONCLUSIONS: Tooth wear involving dentine was more prevalent in patients complaining of symptoms of GORD and those diagnosed as having GORD following 24-h pH monitoring than controls. Patients had poorer salivary buffering capacity than control subjects. Patients complaining of hoarseness had lower salivary flow rate than controls.

Adult↗

PubMed2004

The use of a 3D laser scanner using superimpositional software to assess the accuracy of impression techniques.

OBJECTIVE: Several studies have made comparisons in the dimensional accuracy of different elastomeric impression materials. Most have used two-dimensional measuring devices, which neglect to account for the dimensional changes that exist along a three-dimensional surface. PURPOSE: The aim of this study was to compare the dimensional accuracy of an impression technique using a polyether material (Impregum) and a vinyl poly siloxane material (President) using a laser scanner with three-dimensional superimpositional software. MATERIALS AND METHODS: Twenty impressions, 10 with a polyether and 10 with addition silicone, of a stone master model that resembled a dental arch containing three acrylic posterior teeth were cast in orthodontic stone. One plastic tooth was prepared for a metal crown. The master model and the casts were digitised with the non-contacting laser scanner to produce a 3D image. 3D surface viewer software superimposed the master model to the stone replica and the difference between the images analysed. RESULTS: The mean difference between the model and the stone replica made from Impregum was 0.072mm (SD 0.006) and that for the silicone 0.097mm (SD 0.005) and this difference was statistically significantly, p=0.001. CONCLUSIONS: Both impression materials provided an accurate replica of the prepared teeth supporting the view that these materials are highly accurate.

Dental Impression Materials↗

PubMed2004

Cosmic radiation exposure of aircraft crew: compilation of measured and calculated data.

The aim of the working group has been to bring together, in particular from European research groups, the available, preferably published, experimental data and results of calculations, together with detailed descriptions of the methods of measurement and calculation. The purpose is to provide a dataset for all European Union Member States for the assessment of individual doses and/or to assess the validity of different approaches, and to provide an input to technical recommendations by the Article 31 group of experts and the European Commission. The radiation protection quantity of interest is effective dose, E (ISO), but the comparison of measurement results obtained by different methods or groups, and comparison of measurement results and the results of calculations, is done in terms of the operational quantity ambient dose equivalent, H*(10). The final report giving the results of the investigations will be published by the European Commission Directorate General Transport and Energy. This paper gives a preview of the report.

Aircraft↗

PubMed2004

Editorial.

Explore the source record for details and available documents.

Medical Records↗

PubMed2003

Complications of medical management of dental erosion.

This article reports the case of a patient presenting with dental erosion as a result of asymptomatic gastro-oesophageal reflux disease (GORD). The management of this patient is discussed, in particular the use of proton pump inhibitors. The advantages and disadvantages of the use of medication are discussed, especially in the light of the symptoms of GORD, which developed after taking omeprazole.

Adult↗

PubMed2003

Crowns revisited.

This paper overviews recent changes to making crowns. For the most part it presents clinically relevant information using examples where necessary. The paper will act as a useful reminder for the techniques involved with crown preparations and the choices of materials available.

Cementation↗

PubMed2002

A phase II trial of combination chemotherapy and surgical resection for the treatment of metastatic adrenocortical carcinoma: continuous infusion doxorubicin, vincristine, and etoposide with daily mitotane as a P-glycoprotein antagonist.

BACKGROUND: Adrenocortical carcinoma (ACC) is rare, nearly always fatal, and to the authors' knowledge has few nonsurgical treatment options. Based on in vitro studies demonstrating the efficacy of mitotane as a P-glycoprotein (Pgp) antagonist, and expression of high levels of Pgp in ACC, the authors conducted a study of infusional doxorubicin, vincristine, and etoposide with oral mitotane +/- surgical resection in patients with metastatic ACC. METHODS: Thirty-six patients with metastatic ACC received daily oral mitotane (mean, 4.6 g/day) and 96-hour infusional doxorubicin (10 mg/m(2)/day), etoposide (75 mg/m(2)/day), and vincristine (0.4 mg/m(2)/day). Four responding patients (11%) underwent surgery. RESULTS: Thirty-five patients were evaluable; all had metastatic disease. Eleven patients had not undergone resection of the primary tumor. Approximately 53% of patients had functional tumors. A total of 190 cycles were administered to 36 patients. Responses were observed in 8 patients (22%): 1 complete, 4 partial, and 3 minor responses. The mean duration of response was 12.4 months. Using a landmark method, the median survival of patients who did not respond to chemotherapy was 11.6 months from a point 4 months after the initiation of therapy, whereas that of 8 patients who demonstrated a response to chemotherapy was 34.3 months from that same landmark. High levels of Pgp expression were documented in nine of nine tumors. Mitotane levels > 10 microg/mL, previously shown to antagonize Pgp in vitro, were achieved in 25 of 36 patients (69%). However, rhodamine efflux from CD56-positive cells was not impaired, suggesting poor in vivo Pgp inhibition. The predominant Grade 3/4 toxicity (according to the Common Toxicity Criteria of the National Cancer Institute) was neutropenia in 66% of cycles; however, fever occurred in only 3% of cycles. Daily mitotane was associated with Grade 1/2 nausea, diarrhea, fatigue, and neuropsychiatric changes in 31 of 36 patients (86%). CONCLUSIONS: Using a combination regimen of daily mitotane with infusional doxorubicin, vincristine, and etoposide in patients with metastatic ACC, responses were observed in 22% of patients. The superiority of this combination over single-agent mitotane is uncertain. The side effects of mitotane made treatment difficult. More effective Pgp antagonists are needed.

ATP Binding Cassette Transporter, Subfamily B, Mem↗