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Biomedical subjects

M De Ridder

Publications and source records attributed to M De Ridder.

8 recordsLinked to original sources

NF-kappaB inhibition impairs the radioresponse of hypoxic EMT-6 tumour cells through downregulation of inducible nitric oxide synthase.

Hypoxic EMT-6 tumour cells displayed a high level of inducible nitric oxide synthase (iNOS) and an increased radiosensitivity after a 16 h exposure to lipopolysaccharide, a known activator of nuclear factor-kappaB (NF-kappaB). Both iNOS activation and radioresponse were impaired by the NF-kappaB inhibitors phenylarsine oxide and lactacystin. Contrasting to other studies, our data show that inhibition of NF-kappaB may impair the radioresponse of tumour cells through downregulation of iNOS.

Acetylcysteine↗

Chronic hypoxia modulates tumour cell radioresponse through cytokine-inducible nitric oxide synthase.

Chronic hypoxia up-regulated the mRNA and protein expression of inducible nitric oxide synthase (iNOS) in EMT-6 tumour cells exposed to interferon (IFN)-gamma and interleukin (IL)-I beta. Low concentrations of cytokines (1 unit ml(-1)) in 1% but not in 21% oxygen induced a remarkable increase in NO production and a 1.8-fold hypoxic cell radiosensitization. Therefore, chronic hypoxia may potentially be exploited to increase tumour cell radioresponse through the cytokine-inducible iNOS pathway.

Animals↗

Imaging in radiotherapy.

Radiotherapy, more then any other treatment modality, relies heavily and often exclusively on medical imaging to determine the extent of disease and the spatial relation between target region and neighbouring healthy tissues. Radically new approaches to radiation delivery are inspired on CT scanning and treat patients in a slice-by-slice fashion using intensity modulated megavoltage fan beams. For quality assurance of complex 3-D dose distributions, MR based 3-D verificative dosimetry on irradiated phantoms has been described. As treatment delivery becomes increasingly refined, the need for accurate target definition increases as well and sophisticated imaging tools like image fusion and 3-D reconstruction are routinely used for treatment planning. While in the past patients were positioned on the treatment machines based exclusively on surface topography and the well-known skin marks, such approach is no longer sufficient for high-accuracy radiotherapy and special imaging tools like on-line portal imaging are used to verify and correct target positioning. Much of these applications rely on digital image processing, transmission and storage, and the development of standards, like DICOM and PACS have greatly contributed to these applications. Digital imaging plays an increasing role in many areas in radiotherapy and has been fundamental in new developments that have demonstrated impact on patient care.

Diagnostic Imaging↗

Death due to fulminant toxic-shock syndrome: differential diagnosis of a multilayered clinical picture.

Reported is the case study of a 27-year-old top-performance sportswoman who died of a fulminant illness with multiple organ failure. Long-term polypragmatic therapy and pharmacotherapy as well as acute analgesic and non-steroid antirheumatic treatment due to lumbago led to the diagnosis of a "complex toxic-allergic process". Numerous pathologic-anatomical findings, including the absence of septic spleen reaction and the demonstration of hyperacute polyradiculitis, supported this diagnosis. The present article discusses the possible differential diagnoses of the illness with the conclusion that its symptoms, clinical course, laboratory constellation and pathologic-anatomical findings better correspond to infection-caused toxic-shock syndrome (TSS) than to a toxic-allergic process.

Adult↗