ABSTRACT
PURPOSE: Radiation-induced pneumonitis and subsequent pulmonary fibrosis are important dose-limiting complications of radiotherapy. Their pathogenesis is known only in part. T-lymphocytes comprise a significant part of the infiltrating cells but little is known about their role. The aim of this study was to define the function of T-lymphocytes during development of postirradiation pneumonitis and pulmonary fibrosis. MATERIALS AND METHODS: Rats received a unilateral lung irradiation of 20 Gy. Kinetics of T-lymphocytes isolated from irradiated and non-irradiated lungs were analysed. Subsequent CD4 depletion experiments were performed to affirm the importance of CD4+ T-cells in the development of lung fibrosis. Finally, the T helper-cell subtype of the T-lymphocytes was analysed by determining the cytokine mRNA by RT-PCR. RESULTS: A selective increase of CD4+ T-cells was observed peaking 4 weeks after irradiation in the irradiated lungs. When rats were depleted of these cells, the postirradiation thickening of parenchyma was significantly reduced as determined by morphometric analysis of lung tissue sections. In addition, it was found that IL-4 mRNA was selectively increased in the CD4+ T-cells isolated from irradiated lungs, which indicates a lymphocyte reactivity dominated by Th2 cells. CONCLUSION: The results suggest a critical role for Th2 CD4+ T-lymphocytes in the pathogenesis of radiation-induced pneumonitis preceding lung fibrosis.
Subject(s)
Lung/radiation effects , Th2 Cells/physiology , Animals , Interferon-gamma/genetics , Interleukin-4/genetics , Male , Pneumonia/etiology , Pulmonary Fibrosis/etiology , RNA, Messenger/analysis , Rats , Rats, Inbred F344ABSTRACT
PROBLEM: Pharmacological doses of 17 beta-estradiol increase epidermal growth factor binding to uterine membranes. METHODS: To determine whether physiological elevated E2 concentrations in the preimplantation phase of rabbits and preovulatory phase of women cause epidermal growth factor (EGF) receptor expression, we performed radioligand binding studies of endometrial membranes with [125I]-EGF. RESULTS: Unmated rabbits revealed a binding maximum (Bmax) of 514 +/- 197 fmol/mg protein for [125I]-EGF. The Bmax values increased significantly to 1424 +/- 430 fmol/mg on day 1 and to 2244 +/- 224 fmol/mg on day 2 after mating. On day 3 the Bmax values decreased to 1409 +/- 238 fmol/mg and on days 4 to 8 the binding maxima were not significantly different from the Bmax values of unmated rabbits. In ovariectomized rabbits a significant increase of [125I]-EGF-binding could be mimicked 12 and 18 h after the intramuscular injection of estradiol (40 micrograms/kg). The estradiol-induced increase of [125I]-EGF Bmax values was blocked by the parallel application of the antiestrogen tamoxifen. Progesterone (2 mg/kg) did not influence [125I]-EGF-binding to endometrial membranes. Membrane preparations of the human endometrium from the periovulatory phase bound significantly more [125I]-EGF compared to endometrium of the early proliferative phase. The expression of EGF receptor mRNA was localized in the epithelial cells of the human endometrium by in situ hybridization technique. CONCLUSIONS: These results provide insight into the regulation of the autocrine and paracrine factor EGF in the endometrium during the preimplantation period.
Subject(s)
Embryonic Development/physiology , Endometrium/cytology , ErbB Receptors/biosynthesis , Estradiol/physiology , Adult , Animals , Endometrium/metabolism , Epidermal Growth Factor/metabolism , ErbB Receptors/isolation & purification , Female , Follicular Phase/physiology , Humans , In Situ Hybridization , In Vitro Techniques , Iodine Radioisotopes , Pregnancy , RNA, Messenger , Rabbits , Radioligand AssayABSTRACT
Statistical methods of survival-analysis were applied to investigate the "life-time" of three types of class II amalgam restorations: 1355 F3-, 355 F4-amalgam filling, 108 TMS-pin-retained extensive amalgam restorations and 222 single crowns of a total of 630 patients of a private dental office. After 8 years of service about 50% of the extensive amalgam fillings, but 12% of the single crowns were still under risk.
Subject(s)
Dental Amalgam , Dental Restoration, Permanent , Adolescent , Adult , Child , Crowns , Equipment Failure , Female , Humans , Male , Middle Aged , Proportional Hazards Models , Risk FactorsABSTRACT
Dental treatment can only be successful in the long run if the patient cooperates with the dentist. A sound dentist-patient relationship is the basic prerequire for patient compliance. This will influence the organisation in the dental office as well as the course of treatment. Each patient should be seen as an individual and not as a treatment case. The resulting additional work can be only be coped with if qualified dental staff is available.
