296 research outputs found
Detection of longitudinal waves in resonance with capillary waves at the air-water interface by energy transfer.
Capillary (transverse) ripples are generated at a monolayer-covered air-water interface. Compression of the monolayer changes the surface dilatational modulus ε and the reduced elasticity ε/σ of the monolayer. When the reduced elasticity reaches a particular value, resonance between the capillary wave and the longitudinal wave should occur. Longitudinal waves (lateral oscillations, modulation of the average distances of the molecules) are detected by using energy transfer (Förster type) between dye molecules incorporated in the monolayer. Capillary ripples are detected by specular reflection of a laser beam from the water surface. The dependence of the longitudinal and the transverse wave characteristics on the area per molecule was investigated, and the resonance phenomenon was observed near the theoretical value of ε/σ for the resonance condition
Combination of celecoxib with percutaneous radiotherapy in patients with localised prostate cancer – a phase I study
BACKGROUND: Current approaches for the improvement of bNED for prostate cancer patients treated with radiotherapy mainly focus on dose escalation. However molecularly targeted approaches may also turn out to be of value. In this regard cyclooxygenase (COX)-2 inhibitors have been shown to exert some anti-tumour activities in human prostate cancer in vivo and in vitro. Although in vitro data indicated that the combination of COX-2 inhibition and radiation was not associated with an increased toxicity, we performed a phase I trial using high dose celecoxib together with percutaneous radiation therapy. METHODS: In order to rule out any increases of more than 20% incidence for a given side effect level 22 patients were included in the trial. Celecoxib was given 400 mg twice daily with onset of the radiation treatment. Risk adapted radiation doses were between 70 and 74 Gy standard fractionation. RTOG based gastrointestinal (GI) and genitourinary (GU) acute toxicity scoring was performed weekly during radiation therapy, at six weeks after therapy and three month after completing radiation treatment. RESULTS: Generally no major increase in the level and incidence of side effects potentially caused by the combined treatment was observed. In two cases a generalised skin rash occurred which immediately resolved upon discontinuation of the drug. No grade 3 and 4 toxicity was seen. Maximal GI toxicity grade 1 and 2 was observed in 85% and 10%, respectively. In terms of GU toxicity 80 % of the patients experienced a grade 1 toxicity and 10 % had grade 2 symptoms. CONCLUSION: The combination of irradiation to the prostate with concurrent high dose celecoxib was not associated with an increased level of side effects
Irradiation specifically sensitises solid tumour cell lines to TRAIL mediated apoptosis
BACKGROUND: TRAIL (tumor necrosis factor related apoptosis inducing ligand) is an apoptosis inducing ligand with high specificity for malignant cell systems. Combined treatment modalities using TRAIL and cytotoxic drugs revealed highly additive effects in different tumour cell lines. Little is known about the efficacy and underlying mechanistic effects of a combined therapy using TRAIL and ionising radiation in solid tumour cell systems. Additionally, little is known about the effect of TRAIL combined with radiation on normal tissues. METHODS: Tumour cell systems derived from breast- (MDA MB231), lung--(NCI H460) colorectal--(Colo 205, HCT-15) and head and neck cancer (FaDu, SCC-4) were treated with a combination of TRAIL and irradiation using two different time schedules. Normal tissue cultures from breast, prostate, renal and bronchial epithelia, small muscle cells, endothelial cells, hepatocytes and fibroblasts were tested accordingly. Apoptosis was determined by fluorescence microscopy and western blot determination of PARP processing. Upregulation of death receptors was quantified by flow cytometry. RESULTS: The combined treatment of TRAIL with irradiation strongly increased apoptosis induction in all treated tumour cell lines compared to treatment with TRAIL or irradiation alone. The synergistic effect was most prominent after sequential application of TRAIL after irradiation. Upregulation of TRAIL receptor DR5 after irradiation was observed in four of six tumour cell lines but did not correlate to tumour cell sensitisation to TRAIL. TRAIL did not show toxicity in normal tissue cell systems. In addition, pre-irradiation did not sensitise all nine tested human normal tissue cell cultures to TRAIL. CONCLUSIONS: Based on the in vitro data, TRAIL represents a very promising candidate for combination with radiotherapy. Sequential application of ionising radiation followed by TRAIL is associated with an synergistic induction of cell death in a large panel of solid tumour cell lines. However, TRAIL receptor upregulation may not be the sole mechanism by which sensitation to TRAIL after irradiation is induced
Management of radiation dermatitis in patients receiving cetuximab and radiotherapy for locally advanced squamous cell carcinoma of the head and neck: proposals for a revised grading system and consensus management guidelines
Background: Radiation dermatitis developing in patients receiving cetuximab concomitantly with radiotherapy for locally advanced squamous cell carcinoma of the head and neck (LA SCCHN) is now recognized to have different pathophysiological and clinical characteristics to the radiation dermatitis associated with radiotherapy or concomitant chemotherapy and radiotherapy. Current grading tools were not designed to grade this type of radiation dermatitis; their use may lead to misclassification of reactions and inappropriate management strategies, potentially compromising cancer treatment. Patients and methods: An advisory board of seven leading European specialists (three medical oncologists, three radiation oncologists and a dermatologist) with extensive experience of the use of cetuximab plus radiotherapy produced consensus guidelines for the grading and management of radiation dermatitis in patients receiving cetuximab plus radiotherapy. Results: Modifications to the current, commonly used National Cancer Institute—Common Terminology Criteria for Adverse Events version 4.3 for grading radiation dermatitis were proposed. Updated management guidelines, building on previously published guidelines from 2008, were also proposed. Conclusions: The proposed revisions to the grading system and updated management guidelines described here represent important developments toward the more appropriate grading and effective management of radiation dermatitis in patients receiving cetuximab plus radiotherapy for LA SCCH
Severe skin reaction secondary to concomitant radiotherapy plus cetuximab
The therapeutic use of monoclonal antibodies against the epidermal growth factor receptor (EGFR) is specifically associated with dermatologic reactions of variable severity. Recent evidence suggests superiority of the EGFR inhibitor (EGFRI) cetuximab plus radiotherapy compared to radiotherapy alone in patients with squamous cell carcinoma of the head and neck. Although not documented in a study population, several reports indicate a possible overlap between radiation dermatitis and the EGFRI-induced skin rash. We here present a case of severe skin reaction secondary to the addition of cetuximab to radiotherapy
Severe cutaneous toxicity following treatment with radiotherapy and cetuximab: a case report
While the addition of cetuximab to radiotherapy improves clinical outcomes in locoregionally advanced head and neck squamous cell cancers, there are a small number of reports of severe radiation dermatitis occurring with this therapeutic combination. We present the case of a 69 year old male who developed severe radiation dermatitis following treatment with cetuximab and radiotherapy for a locoregionally advanced head and neck squamous cell cancer
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