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Biomedical subjects

C Staff

Publications and source records attributed to C Staff.

5 recordsLinked to original sources
PubMed2001

[Clinical effectiveness of m-THPC-PEG in a new xenogenic animal tumor model for human squamous epithelial carcinomas].

BACKGROUND: Animal tumor models are still essential for the development of new medication and therapy concepts. For the field of oropharyngeal cancer only few reliable xenogeneic tumor models are available. In a two-part experiment a new xenogeneic tumor model was established. PART 1 OF THE STUDY: The growth rates of two different tumor cell lines were compared in the RAG-2 mouse, the SCID mouse and the Swiss nude mouse. Cells from a lymph-node metastasis of an oral squamous cell carcinoma (XF-354) showed a better growth rate and clearer histology than cells from a primary squamous cell carcinoma of the floor of the mouth (UM-SCC-14C). The tumor growth rate was highest on the RAG-2 mouse, followed by the SCID mouse. The Swiss nude mouse showed no tumor growth at all. The combination of the XF-354 tumor cell line and the RAG-2 mouse was the most successful, with a tumor growth rate of 95%. The animal model is very reliable and robust and enables manipulations under anaesthesia outside the sterile barrier for up to 30 min. The single steps for cell cultivation and tumor implantation are described and discussed in detail. PART 2 OF THE STUDY: The second part of this study investigated the clinical efficacy of the macromolecular linked photosensitizer--mTHPC-PEG compared with the free photosensitizer mTHPC. Macromolecular linked photosensitizers have theoretical advantages owing to their pharmacokinetics and tumor selectivity. For the animal experiment, the photosensitizer mTHPC showed significantly better results than the macromolecular linked photosensitizer mTHPC-PEG. The reasons for these in vivo results are discussed in detail.

Animals↗
PubMed1999

Photodynamic therapy of primary nonmelanomatous skin tumours of the head and neck.

BACKGROUND AND OBJECTIVES: Nonmelanomatous skin tumours are the most frequent tumours in the white population and mainly caused by cumulative exposure to ultraviolet B radiation. On account of this origination about 80% of all nonmelanomatous skin tumours are located on the arms or the head and neck. Standard treatment for most tumours is surgical resection, with often only moderate cosmetic outcome. STUDY DESIGN/MATERIALS AND METHODS: In a prospective clinical trial the effect of photodynamic therapy on primary nonmelanomatous skin tumours of the head and neck (basal cell cancer, squamous cell cancer) was tested. In this study Foscan (meta-Tetrahydroxyphenylchlorin/mTHPC), a systemic photosensitizer of the second generation, was applied. Patients were injected 0.15 mg/kg or 0.10 mg/kg Foscan intravenously 96 hours prior to laser light exposure. Light was delivered via fibres by an argon-dye laser at 652 nm, 100 mW/cm(2) and a light dose of 5-20 J/cm(2). RESULTS: Eighteen patients with a total of 97 nonmelanomatous skin tumours and a mean follow up of 15 months (ranging 3-24 months) were treated. Within several days tumour necrosis appeared followed by wound healing within 4-8 weeks, leaving only minor scars behind. Ninety tumours (92.7%) showed a complete response with an excellent cosmetic outcome and only seven tumours responded by partial success due to low light dosage. The cosmetic outcome was very good and the therapy was supported by a high degree of patient satisfaction. CONCLUSION: By choosing the correct drug and light dosage, a selective tumour necrosis can be obtained. Photodynamic therapy (PDT) using Foscan seems to be a promising new and safe treatment modality for the treatment of primary nonmelanomatous skin tumours of the head and neck that can substitute surgical therapy, offering an even better cosmetic outcome.

Adult↗
PubMed1996

Decompressive craniectomy in a rat model of "malignant" cerebral hemispheric stroke: experimental support for an aggressive therapeutic approach.

Acute ischemia in the complete territory of the carotid artery may lead to massive cerebral edema with raised intracranial pressure and progression to coma and death due to uncal, cingulate, or tonsillar herniation. Although clinical data suggest that patients benefit from undergoing decompressive surgery for acute ischemia, little data about the effect of this procedure on experimental ischemia are available. In this article the authors present results of an experimental study on the effects of decompressive craniectomy performed at various time points after endovascular middle cerebral artery (MCA) occlusion in rats. Focal cerebral ischemia was induced in 68 rats using an endovascular occlusion technique focused on the MCA. Decompressive craniectomy was performed in 48 animals (in groups of 12 rats each) 4, 12, 24, or 36 hours after vessel occlusion. Twenty animals (control group) were not treated by decompressive craniectomy. The authors used the infarct volume and neurological performance at Day 7 as study endpoints. Although the mortality rate in the untreated group was 35%, none of the animals treated by decompressive craniectomy died (mortality 0%). Neurological behavior was significantly better in all animals treated by decompressive craniectomy, regardless of whether they were treated early or late. Neurological behavior and infarction size were significantly better in animals treated very early by decompressive craniectomy (4 hours) after endovascular MCA occlusion (p < 0.01); surgery performed at later time points did not significantly reduce infarction size. The results suggest that use of decompressive craniectomy in treating cerebral ischemia reduces mortality and significantly improves outcome. If performed early after vessel occlusion, it also significantly reduces infarction size. By performing decompressive craniectomy neurosurgeons will play a major role in the management of stroke patients.

Animals↗