Biomedical subjects

Egbert Smit

Publications and source records attributed to Egbert Smit.

8 recordsLinked to original sources

PubMed2006

Erlotinib for frontline treatment of advanced non-small cell lung cancer: a phase II study.

PURPOSE: Erlotinib has proven activity in pretreated patients with advanced non-small cell lung cancer (NSCLC). We evaluated erlotinib in the frontline treatment of advanced NSCLC and assessed biological predictors of outcome. EXPERIMENTAL DESIGN: In this phase II study, chemotherapy-naive patients with stage IIIB/IV NSCLC received oral erlotinib (150 mg/d) until disease progression or unacceptable toxicity occurred. Tumor response was assessed every 6 weeks, and samples were analyzed for potential molecular markers of treatment response and survival. The primary end point was the proportion of patients without disease progression after 6 weeks of treatment. RESULTS: Fifty-three patients were eligible. The overall rate of nonprogression at 6 weeks was 52.8% (28 of 53 patients). Tumor response rate was 22.7%, with 1 complete response, 11 partial responses, and 16 cases of stable disease. Responses were seen across most patient clinical characteristics. The median duration of tumor response was 333 days; median overall survival was 391 days; and median time to disease progression was 84 days. Erlotinib was well tolerated, the main treatment-related adverse events being mild-to-moderate rash and diarrhea. Histologic material for biological studies was available in 29 cases. Four of five responders and one patient with stable disease had a classic epidermal growth factor receptor tyrosine kinase mutation. Two progressing patients exhibited epidermal growth factor receptor point mutations (one with T790M mutation), and K-ras mutations were detected in 10 nonresponders. CONCLUSIONS: Erlotinib shows significant antitumor activity in the first-line treatment of advanced NSCLC and may be a viable alternative to chemotherapy. Patient selection cannot easily be based on clinical or biological variables.

Administration, Oral↗

PubMed2005

A phase II study of paclitaxel in advanced bronchioloalveolar carcinoma (EORTC trial 08956).

PURPOSE: The incidence of bronchioloalveolar carcinoma (BAC) has risen steadily over the last decades along with the increasing frequency of adenocarcinomas. BAC is relatively resistant to commonly used chemotherapy regimens. A phase II study with single agent paclitaxel in patients with stages IIIB, IV or recurrent BAC was performed. EXPERIMENTAL DESIGN: Patients with BAC with at least one target bidimensionally measurable lesion staged as unresectable stages IIIB, IV or recurrent disease, not previously irradiated; ECOG performance status 0-2; life expectancy greater than 3 months; age range between 18 and 75, received paclitaxel at a dose of 200 mg/m2 i.v. as 3h continuous infusion on day 1 every 21 days. Treatment was continued until progression or up to a maximum of six cycles. RESULTS: Nineteen patients were eligible. Median number of cycles was 3 (range 0-6); 35% of patients received the planned six cycles of chemotherapy. One patient died of unrelated cause before the start of treatment. Both hematological and non-hematological toxicities were generally mild. Only one partial response (PR) was observed among the 18 eligible patients who started protocol treatment, with a response rate of 5.6% (95% CI: 0.1-27.3%). After an independent review, two PR were confirmed, for a response rate of 11.1% (95% CI: 1.4-34.7%); nine patients had stable disease (50.0%), three patients had progressive disease (11.1%) and four patients were not assessable (22.2%). Median survival was 8.6 months (95% CI: 5.8-14.5) and 1-year survival was 35.0% (95% CI: 14.1-55.8). Median progression free survival for all patients was 2.2 months (95% CI: 1.5-6.0). The study was terminated due to the low response rate. CONCLUSIONS: Paclitaxel as single agent in stages IIIB-IV BAC was well tolerated and manageable but of limited efficacy. BAC should not be excluded from trials of new forms of chemotherapy.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed2005

Lung cancer.

Explore the source record for details and available documents.

Clinical Trials as Topic↗

PubMed2005

The effects of exercise and adipose tissue lipolysis on plasma adiponectin concentration and adiponectin receptor expression in human skeletal muscle.

OBJECTIVE: It has been suggested that adiponectin regulates plasma free fatty acid (FFA) clearance by stimulating FFA uptake and/or oxidation in muscle. We aimed to determine changes in plasma adiponectin concentration and adiponectin receptor 1 and 2 mRNA expression in skeletal muscle during and after prolonged exercise under normal, fasting conditions (high FFA trial; HFA) and following pharmacological inhibition of adipose tissue lipolysis (low FFA trial; LFA). Furthermore, we aimed to detect and locate adiponectin in skeletal muscle tissue. METHODS: Ten subjects performed two exercise trials (120 min at 50% VO(2max)). Indirect calorimetry was used to determine total fat oxidation rate. Plasma samples were collected at rest, during exercise and during post-exercise recovery to determine adiponectin, FFA and glycerol concentrations. Muscle biopsies were taken to determine adiponectin protein and adiponectin receptor 1 and 2 mRNA expression and to localise intramyocellular adiponectin. RESULTS: Basal plasma adiponectin concentrations averaged 6.57+/-0.7 and 6.63+/-0.8 mg/l in the HFA and LFA trials respectively, and did not change significantly during or after exercise. In the LFA trial, plasma FFA concentrations and total fat oxidation rates were substantially reduced. However, plasma adiponectin and muscle adiponectin receptor 1 and 2 mRNA expression did not differ between trials. Immunohistochemical staining of muscle cross-sections showed the presence of adiponectin in the sarcolemma of individual muscle fibres and within the interfibrillar arterioles. CONCLUSION: Plasma adiponectin concentrations and adiponectin receptor 1 and 2 mRNA expression in muscle are not acutely regulated by changes in adipose tissue lipolysis and/or plasma FFA concentrations. Adiponectin is abundantly expressed in muscle, and, for the first time, it has been shown to be present in/on the sarcolemma of individual muscle fibres.

Adiponectin↗

PubMed2003

Multi-institutional randomized phase II trial of gefitinib for previously treated patients with advanced non-small-cell lung cancer (The IDEAL 1 Trial) [corrected].

PURPOSE: To evaluate the efficacy and tolerability of two doses of gefitinib (Iressa [ZD1839]; AstraZeneca, Wilmington, DE), a novel epidermal growth factor receptor tyrosine kinase inhibitor, in patients with pretreated advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: This was a randomized, double-blind, parallel-group, multicenter phase II trial. Two hundred ten patients with advanced NSCLC who were previously treated with one or two chemotherapy regimens (at least one containing platinum) were randomly assigned to receive either 250-mg or 500-mg oral doses of gefitinib once daily. RESULTS: Efficacy was similar for the 250- and 500-mg/d groups. Objective tumor response rates were 18.4% (95% confidence interval [CI], 11.5 to 27.3) and 19.0% (95% CI, 12.1 to 27.9); among evaluable patients, symptom improvement rates were 40.3% (95% CI, 28.5 to 53.0) and 37.0% (95% CI, 26.0 to 49.1); median progression-free survival times were 2.7 and 2.8 months; and median overall survival times were 7.6 and 8.0 months, respectively. Symptom improvements were recorded for 69.2% (250 mg/d) and 85.7% (500 mg/d) of patients with a tumor response. Adverse events (AEs) at both dose levels were generally mild (grade 1 or 2) and consisted mainly of skin reactions and diarrhea. Drug-related toxicities were more frequent in the higher-dose group. Withdrawal due to drug-related AEs was 1.9% and 9.4% for patients receiving gefitinib 250 and 500 mg/d, respectively. CONCLUSION: Gefitinib showed clinically meaningful antitumor activity and provided symptom relief as second- and third-line treatment in these patients. At 250 mg/d, gefitinib had a favorable AE profile. Gefitinib 250 mg/d is an important, novel treatment option for patients with pretreated advanced NSCLC [corrected]

Administration, Oral↗

PubMed2003

Lung cancer.

Explore the source record for details and available documents.

Antineoplastic Agents↗

PubMed2002

Structural and functional analysis of the S-layer protein crystallisation domain of Lactobacillus acidophilus ATCC 4356: evidence for protein-protein interaction of two subdomains.

The structure of the crystallisation domain, SAN, of the S(A)-protein of Lactobacillus acidophilus ATCC 4356 was analysed by insertion and deletion mutagenesis, and by proteolytic treatment. Mutant S(A)-protein synthesised in Escherichia coli with 7-13 amino acid insertions near the N terminus or within regions of sequence variation in SAN (amino acid position 7, 45, 114, 125, 193), or in the cell wall-binding domain (position 345) could form crystalline sheets, whereas insertions in conserved regions or in regions with predicted secondary structure elements (positions 30, 67, 88 and 156) destroyed this capacity. FACscan analysis of L.acidophilus synthesising three crystallising and one non-crystallising S(A)-protein c-myc (19 amino acid residues) insertion mutant was performed with c-myc antibodies. Fluorescence was most pronounced for insertions at positions 125 and 156, less for position 45 and severely reduced for position 7. By cytometric flow sorting a transformant harbouring the mutant S(A)-protein gene (position 125) was isolated that showed an increased fluorescense signal. Immunofluorescence microscopy suggested that the transformant synthesized mutant S(A)-protein only. PCR analysis of the transformant grown in the absence of selection pressure indicated that the mutant allele was stably integrated in the chromosome. Proteolytic treatment of S(A)-protein indicated that only sites near the middle of SAN are susceptible, although potential cleavage sites are present through the entire molecule. Expression in E.coli of DNA sequences encoding the two halves of SAN yielded peptides that could oligomerize. Our results indicate that SAN consists of a approximately 12kDa N and a approximately 18kDa C-terminal subdomain linked by a surface exposed loop. The capacity of S(A)-protein of L.acidophilus to present epitopes, up to approximately 19 amino acid residues in length, at the bacterial surface in a genetically stable form, makes the system, in principle, suitable for application as an oral delivery vehicle.

Alleles↗

PubMed2002

One repeat of the cell wall binding domain is sufficient for anchoring the Lactobacillus acidophilus surface layer protein.

The N-terminal repeat (SAC1) of the S-protein of Lactobacillus acidophilus bound efficiently and specifically to cell wall fragments (CWFs) when fused to green fluorescent protein, whereas the C-terminal repeat (SAC2) did not. Treatment of CWFs with hydrofluoric acid, but not phenol, prevented binding. Apparently, SAC1 is necessary and sufficient for cell wall binding. Our data suggest that SAC anchors the S-protein to a cell wall teichoic acid.

Bacterial Proteins↗