Conjunctival melanoma in a six-year-old female.
Conjunctival melanoma (CM) is a highly malignant tumor that derives from melanocytes and is rarely seen in children. This report describes a 6-year-old female diagnosed with CM.
Child↗
Biomedical subjects
Neşe Demirkan
Publications and source records attributed to Neşe Demirkan.
PCNA expression in chronic gastritis due to Helicobacter pylori*.
BACKGROUND/AIMS: It has been reported that cases of Helicobacter pylori (H. pylori) gastritis, those with epithelial hyperproliferation, have potential for malignant transformation. This study was planned to determine the effects of H. pylori on gastritis and the gastric epithelial cell proliferation. METHODS: In this study, we re-evaluated biopsy samples obtained from 331 cases of chronic gastritis according to Sydney criteria, retrospectively. We examined the gastric epithelial cell proliferation with proliferating cell nuclear antigen in the proliferating zone, in the whole mucosa of intestinal metaplasia and in areas of regenerative atypia, separately. RESULTS: The relationship between H. pylori colonization density and chronic active gastritis was statistically significant. We did not see any relationship between the presence and density of H. pylori in gastric mucosa via proliferating cell nuclear antigen indices. In the presence of lymphoid follicles, we noted a significant expression of proliferating cell nuclear antigen in the areas of whole gastric mucosa and regenerative atypia. CONCLUSIONS: In the presence of lymphoid follicles, proliferating cell nuclear antigen expression was observed in the areas of whole gastric mucosa and regenerative atypia, but we did not see any relationship between the presence and density of H. pylori in gastric mucosa via proliferating cell nuclear antigen indices. This observation suggests the role of chronic inflammatory cells in gastric epithelial cell proliferation rather than the bacterium itself.
Adolescent↗
The preventive effect of vitamin D3 on radiation-induced hair toxicity in a rat model.
Our aim is to investigate the protective effect of vitamin D3 especially from radiation-induced hair toxicity. A model of skin radiation injury was developed and a single fraction of 20 Gy Gamma irradiation was applied to the right dorsal skin of fourteen rats. All animals were randomly divided into 2 groups: Group I: irradiation alone (n = 7) and Group II: irradiation and 0.2 microg vitamin D3 given IM (n = 7). Fifty days after post-irradiation rats were sacrificed. The outcomes were evaluated on the basis of histopathological findings and immunohistochemical staining for Vitamin D receptor (VDR) in skin and hair follicles. The number of hair follicles in the radiation field for the group of animals irradiated without pretreatment was significantly lower than outside of the irradiated area (p = 0.016) as it is expected. Contrarily the number of hair follicles did not show significant difference in the pretreated group between the irradiated field and outside of the fields (p = 0,14). Skin of the vitamin D3 pretreated group demonstrated stronger immunoreactivity for VDR compared to irradiation alone group. These results indicate that administration of vitamin D3 may protect hair follicles from radiation toxicity. Further clinical trials should be conducted to prove the preventive effect of vitamin D3 as well as dosing and timing of the agent on radiation-induced alopecia.
Alopecia↗
Experimental sinusitis in a rhinogenic model.
OBJECTIVES/HYPOTHESIS: The objectives were to determine the optimal sinusitis induction period and to examine microbiological and histopathological changes of sinusitis recovery stage in a rhinogenic sinusitis model. METHODS: A synthetic sponge was inserted into the right-side nasal cavities of rabbits. The sponge was impregnated with a Streptococcus pneumoniae strain in group 1 and with sterile saline solution in groups 2 and 3. After the fourth day of sponge insertion, sinuses were examined by coronal computed tomography scans at two-day intervals until any radiological evidence of sinusitis was observed. When sinusitis was detected radiologically, five rabbits each from groups 1 and 2 were killed for histological examination. To determine the recovery period of sinusitis, sponges were removed from the rest of the rabbits in groups 1 and 2. Rabbits were selected randomly and killed on the 15th and the 30th days of the recovery period, immediately after radiological examinations. Group 3 was considered a sham group. RESULTS: Sinusitis induction was performed in all rabbits in groups 1 and 2 until the 8th day. After the sponges were removed, inflammation persisted until the 30th day of the study. CONCLUSION: In a rhinogenic sinusitis model, although histological features of sinusitis were demonstrated, further studies are required to standardize this model and to examine whether or not the studied bacterial strain spreads from nasal cavity into sinus.
Animals↗
[A review on experimental sinusitis models in rabbits].
Experimental animal models are instrumental to study the pathogenesis of diseases and to examine the results of treatment. The great size and ease of accessibility have made rabbit sinuses popular in the investigation of experimental sinusitis. Microbiologic, histopathologic, and radiologic aspects of this model have been well-described and the effects of medical and surgical treatments on sinusitis have been examined. Ongoing research may provide further data to find more simple and non-invasive methods to induce sinusitis in rabbits that may more closely simulate sinusitis pathogenesis in humans. This article reviews the most recent data on technical, surgical, microbiologic, histopathologic, and radiologic aspects, and complications of sinusitis models in rabbits.
Animals↗