Biomedical subjects
Publications and source records attributed to S el-Sayed.
A rare case of frontal sinus carcinoma is reported. The patient developed early recurrence following surgery, and was managed by accelerated hyperfractionated radiation therapy and concurrent cisplatinum-based systemic chemotherapy. The patient has remained disease-free for 30 months following the end of treatment.
Seventeen cases of histiocytosis X are presented (11 children and 6 young adults, with the usual male predominance), having a minimum follow-up of 1 year and a maximum of 20 years. In these age groups, even small doses of radiation should not be given without careful consideration, but fairly low doses carry only a small risk and may be very useful in management. Unlike chemotherapy, radiotherapy can be confined to the affected area, or to the area causing symptoms. All but two of our patients had radiotherapy for bone deposits; only one failed to show a complete response. In addition, the diabetes insipidus of two children responded immediately to radiation of the pituitary. One patient, however, after responding well to radiation for bone deposits, suffered increasing symptoms due to lung involvement and the latter showed no response. This striking contrast in radiosensitivity is hard to explain, given the identical histology obtained by biopsy from each site, but it has been noted many times by others.
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PURPOSE: Daunorubicin is a cytotoxic drug, which, in nontoxic doses, is effective in preventing cellular proliferation in experimental vitreoretinopathy. We studied dose and clearance of daunorubicin in various ocular tissues using fluorophotometry techniques. METHODS: In vitro tests: The emission of fluorescence from the daunorubicin solution having a concentration range of 0.1 to 10 micrograms/mL in phosphate buffer was measured using an excitation wavelength range of 489 +/- 10 nm. The emission of fluorescence was measured at 514 nm; the linearity of the response was determined using linear regression analysis. There is a fluorescence peak of daunorubicin at 485 nm. The validity and reproducibility of the method were examined. In vivo tests: The rabbits were randomized into three groups and daunorubicin concentrations of 4, 6, or 8 micrograms/mL were injected into the vitreous. Fluorophotometry scanning from the retina to the anterior chamber was performed with a commercially available fluorophotometer at various times up to 48 hours after injection to quantify fluorescence emission of daunorubicin. RESULTS: The standard curve of fluorescence versus concentration of daunorubicin was linear in the range of 0.1 to 8 micrograms/mL. It was sensitive up to 0.1 microgram. The daunorubicin time concentration profile showed a dose response relationship over the 48-hour period studied. The half-life of daunorubicin in the vitreous was about 5 hours. CONCLUSION: We performed fluorophotometry using a fluorophotometer whose exciter emits light at 489 nm, which is very close to an absorption peak of daunorubicin. These two values are close enough to obviate the need for modifying the commercial fluorophotometer. Therefore the concentration of daunorubicin in the vitreous cavity can be measured noninvasively.