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In Turkey, an average of 24 people die in snow avalanches every year, mainly in the eastern part of Anatolia and in the eastern Black Sea region, where high-mountain ranges are close to the sea. The proportion of people killed in buildings is very high (87%), especially in comparison to other European countries and North America. In this paper we discuss avalanche occurrence, the climatic situation and historical avalanche events in Turkey; in addition, we identify bottlenecks and suggest solutions to tackle avalanche problems. Furthermore, we have applied the numerical avalanche simulation software RAMMS (rapid mass movements simulation) combined with a (digital elevation model) DEM-based potential release zone identification algorithm to analyze the catastrophic avalanche events in the villages of Üzengili (Bayburt province) in 1993 and Yaylaönü (Trabzon province) in 1981. The results demonstrate the value of such an approach for regions with poor avalanche databases, enabling the calculation of different scenarios and the estimation of run-out distances, impact pressure and flow height.

Aim: To investigate the effects of amifostine, a cytoprotective agent, on pathophysiological changes in vasogenic brain edema induced by an experimental cold injury model and to compare these changes with dexamethasone., Material and Methods: A total of 138 rats divided into 6 groups. Brain water content (BWC), malondialdehyde (MDA) concentration and myeloperoxidase (MPO) activity in brain tissue were calculated to evaluate the pathophysiological changes following experimental cold injury. In addition, effects of cold injury on cell structure were assessed with direct light and transmission electron microscopy (TEM)., Results: Extent of edema, MDA and MPO levels were significantly higher in cold injury groups than in controls. Although a decrease was noted in these parameters in both the amifostine and dexamethasone groups, the differences were significant only for MDA concentration in dexamethasone group, and for MPO activity in both groups. In addition, there was a significant difference between the group in which amifostine was administered prior to cold injury and dexamethasone group for MPO activity. Histopathologically, positive effects were observed in treatment groups., Conclusion: Despite several positive effects of amifostine, its superiority to dexamethasone could not be clearly demonstrated. Further experimental and clinical studies are warranted to better delineate the neuroprotective effects of amifostine.

Ectopic intrathyroidal thymus tissue that may be present as a thyroid nodule is rarely reported. We present a case of a 4-year-old boy with a solitary thyroid nodule. Real-time thyroid ultrasound showed a calcified nodule in the right lobe. Complete blood count, serum calcitonin, and thyroglobulin concentration were normal and antithyroid antibodies were negative. Fine-needle aspiration (FNA) biopsy was revealed as inadequate for cytological examination. During his follow-up, nodular enlargement was found, and the patient was subjected to surgical total excision of the right lobe of the thyroid gland. Pathological examination showed an ectopic intrathyroidal thymus tissue. In childhood, ectopic intrathyroidal thymus tissue can present as an enlarging microcalcified thyroid nodule that may mimic thyroid cancer and may grow during follow-up.

The ARHI (aplasia Ras homologue member I, also known as DIRAS3) gene shows 60.0% sequence homology to the Ras proto-oncogene and was the first mater-nally-imprinted tumor suppressor gene identified in the Ras family. It is constitutively expressed from the paternal allele in normal breast, ovary, heart, liver, pancreas, thyroid and brain tissues, and is lost or markedly down-regulated primarily in breast, ovarian, pancreas and thyroid tumor tissues. We have investigated the expression, LOH (loss of heterozygosity) and methylation status of this gene in glial tumors and peripheral blood samples of 21 patients, and in seven normal brain tissue samples. Gene expression by real time reverse transcriptase polymerase chain reaction (RT-PCR) was found to be increased in 14 and decreased in seven of the 21 tumors. The LOH was detected by fragment analysis, using five labeled polymorphic markers specific for the 1p31 region, in two of the tumors. Methylation status of the CpG island I, II and III was evaluated using COBRA (combined bisulfite restriction analysis) and RFLP (restriction fragment length polymorphism) in 21 tumors and also a hypermethylated healthy volunteer as a positive control, revealed that only two tumors had hypermethylation in CpG island I (of which one also had LOH). These results suggest that LOH and hypermethylation may be one mechanism of silencing the ARHI gene expression and development of glial tumor development.

Background: Experimental models of traumatic brain injury (TBI), using a variety of techniques and species, have been devised with the aim of producing repeatable lesions resembling those found in head injuries. There are various TBI models mentioned in the literature. In experimental head trauma models, emphasis has been placed on the severe head injuries. There are only a few models developed to study mild traumatic brain injury (MTBI). In fact, MTBI is as important a problem as severe head injuries for neurosurgeons., Methods: Fifty-six male Sprague-Dawley rats were subjected to MTBI with a weight-drop device, which was described by Marmarou et al. The said model was used in its original form as well as in modified forms by employing different weights dropped from the same height. Animals were divided into four groups of 14 rats as follows: Group I (n=14), head injury was induced using 450 g-1 m weight-height impact; Group II (n=14), head injury was induced using 350 g-l m weight-height impact; Group III (n=14), head injury was induced using 300 g-1 m weight-height impact; Group IV (n=14), control group, no injury was applied. Animals were evaluated neurologically, physiologically, electrophysiologically, and histopathologically., Results: Group I and II animals (450 and 350 g-1m weight-height impact, respectively) showed the symptoms of severe head injury, whereas Group III animals (300 g-l m) showed more MTBI symptoms., Conclusion: We recommend the application of the modified MTBI model used for group III (300 g-l m weight-height impact) as the most appropriate and the simplest model for future MTBI studies.

Objectives: The aim of this study was to investigate the effects of environmental light-dark changes on the outcome of mild traumatic brain injury (MTBI) using an experimental rodent model. The functions of endogenous and exogenous melatonin on the outcome of injury were also investigated, Methods: Mild traumatic brain injury was experimentally induced in 56 male Sprague-Dawley rats using a weight-drop device. Animals were divided into four groups of 14 each as follows: (i) sham-operated (trauma only, normal day-night cycle), (ii) treated with melatonin (trauma+melatonin, normal day-night cycle), (iii) darkness-induced (trauma+48 h constant dark), and (iv) treated with melatonin and darkness-induced (trauma+48 h constant dark+melatonin). Melatonin (50 mg/kg) was administered, intraperitoneally, immediately after trauma. EEG recordings were taken at three time periods (pretrauma, immediately after trauma, and 48 h after trauma). Motor functions were tested pretrauma, 24 and 48 h post-trauma. Serum melatonin levels were determined pretrauma and 48 h post-trauma. Tissue samples from right frontal area were taken 48 h after trauma for light and electron microscopic examinations., Conclusion: Following MTBI light deprivation alone and light deprivation in combination with exogenously administered melatonin indicated significant neuroprotective effects. Although there may be other important pathways, darkness-induced elevation in endogenous melatonin secretion appears to play an important role in this neuroprotective outcome.

Background: At present, the prevalence of Helicobacter pylori (H. pylori) in complicated peptic ulcer and the effect of H. pylori eradication on complicated peptic ulcer have not been fully established. In this study, we report the prevalence of H. pylori in peptic ulcer patients complicated with gastric outlet obstruction, effectiveness of oral eradication therapy on these patients, and their long-term follow up., Patients and Methods: Ten consecutive patients presenting with clinically and endoscopically significant obstructed peptic ulcers were included in this study. During each endoscopy, seven gastric biopsy specimens were obtained and analyzed for H. pylori colonization., Results: The antral mucosal biopsy specimens were positive for H. pylori in nine patients. H. pylori infection was eradicated and complete ulcer healing was observed in all patients. The mean follow-up period was 14 (7-24) months. One patient had duodenal perforation and underwent surgical intervention following medical treatment, despite the eradication of H. pylori. Ulcer recurrence was noted in two (22.2%) of nine patients, and in one of them the recurrent ulcer was complicated with obstruction (11. 1%). The mean time to ulcer recurrence was 17 months (range, 10-24 months). The biopsies and CLOtests were H. pylori negative at the time of ulcer or erosion recurrence in two patients., Conclusion: We suggest that H. pylori eradication may improve the resolution in obstructive ulcer cases with colonization.