Acute radiation effect in the brain in infant rats: Neurocognitive and histopathological examination.

PURPOSE: The aim of the present study was to evaluate the radiation-induced cognitive dysfunction and the radioprotective effect of amifostine (AMI) in the brain of infantile rats. METHODS: Thirty 2-week-old rats were randomly assigned into 3 groups of 10 rats each. Group 1: control (CONT), group 2: radiation alone (RT), and group 3: AMI before radiation (AMI+RT). The rats in the RT and AMI+RT groups were irradiated individually with a single dose of 20 Gy. All animals were evaluated by using the Morris water maze test to evaluate of their cognitive functions. Histopathological analyses of the hippocampus were also carried out after euthanasia. RESULTS: The study showed that the place navigational function and the spatial probe test were not significantly different between the groups. CONCLUSION: It can be said that it is very important to determine when the radiation-induced brain injury is formed. From a clinical perspective, the patients can be intervened before irreversible functional deficits are formed and may be amenable to treatment.

Nontraumatic giant fat necrosis of the breast presenting as a rapidly growing tumor.

Nontraumatic rapid growing giant fat necrosis of the breast mimicking breast tumors is a rare clinical manifestation. The imaging features of the fat necrosis which range from benign to malign findings may be better explained with associated aetiology. The present paper reports a 54-year old woman with a rapid growing, fibrous, and hard giant mass originating in the subareolar region of the left breast. Mammography and magnetic resonance imaging demonstrated a heterogeneous, well circumscribed mass in 12 × 12 cm size in the left breast. The lesion was suspected as a malignant tumor and underwent core biopsy. The histopathology examination of the biopsy revealed mononuclear cells, foamy, vacuolated, and bubbly cells containing fat. Excision biopsy of the mass was performed and the final pathological diagnosis was confirmed as fat necrosis. The wide clinical and radiologic manifestations of fat necrosis are still difficult to diagnose even with the new diagnostic modalities and a great proportion of these lesions need a biopsy to diagnose.

Scintigraphic evaluation of small intestinal transit in the streptozotocin induced diabetic rats.

AIM: Small intestine (SI) transit in the streptozotocin (STZ) induced diabetic rats were examined by using 99mTc-mebrofenin scintigraphy. MATERIALS AND METHODS: Wistar albino rats (mean body weight: 220±12 g) were studied for both control (n=10) and diabetes mellitus (DM) (n=10) groups. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg kg(-1) body weight. SI transit time was assessed by measuring arrival times of 99mTc-mebrofenin from duodenum to caecum. RESULTS: The mean transit time of 99mTc- mebrofenin was 67.8±11 min in control group. The mean transit time of SI was prolonged in STZ induced diabetic animals with (111.9±12.5, p=0.01). There was significant correlation between small intestinal transit time and blood glucose level (r: 0.73, p=0.01). CONCLUSION: We observed that SI transit was prolonged in diabetic animals using 99mTc- mebrofenin, and additionally this technique is a readily available method for the detection of transit abnormalities in animal experiment.

Gorham-Stout disease of the humerus.

Gorham-Stout disease is characterized by local proliferation of small vascular or lymphatic channels resulting in progressive destruction and resorption of bone. The etiology and pathogenesis of the disease remains mostly unknown, despite some 175 reported cases. A case of Gorham-Stout disease of the humerus in a 14-year-old boy is described. The patient presented with progressive pain and deformity of the right arm. Although the disease was described in different bones of the body its location in the humerus is rare. We report the natural history and clinical follow-up in a young patient. A fibular graft was performed but 10 months later, resorption and pathological fractures occurred again. This study presents the radiographic and MRI features of Gorham disease.

The effects of taking chronic nitrate by drinking water on thyroid functions and morphology.

Nitrate incorporation in humans takes place via drinking water and food. The water used for drinking and cooking in the goitrous areas is high in nitrate content. The aim of the present study was to evaluate both chronic effects and the dose-response relationship of nitrate on thyroid functions. A total of rats were divided into 5 work groups and sodium nitrate was added to their drinking water in different concentrations (0, 50, 100, 250 and 500 mg/l) over a 30-week period. The radioiodine uptake of thyroid was decreased in the 50 mg/l nitrate group, whereas it was increased in the 250 and 500 mg/l nitrate groups as compared to control. All hormones of thyroid gland except total thyroxine and thyroid-stimulating hormone were decreased in the 50, 250 and 500 mg/l nitrate groups. However, the level of total thyroxin was increased in the 100 mg/l nitrate group. Thyroid gland weights were increased in all experimental groups. Histomorphological changes were observed in the 250 and 500 mg/l nitrate groups. These findings suggest that nitrate impairs thyroid function involving the hypothalamo-hypophysio-thyroid axis. This observation could contribute to the current discussion about the acceptable daily intake of nitrate, as well as drinking water nitrate standard safety margins.

Prevention of cyclophosphamide-induced ovarian damage by concomitant administration of GnRHa in mice: a dose-dependent relationship?

OBJECTIVE(S): This experimental study investigates the dose-related effects of cyclophosphamide (Cy) on primordial follicular reserve in young mice, and examines whether the concomitant administration of a gonadotropin-releasing hormone agonist (GnRHa) may protect gonadal reserve, even at different doses of Cy. METHODS: Forty sexually mature virginal Balb/c mice aged five to six weeks were administered different doses (0, 50, 75,100 mg/kg) of Cy. Another 40 animals were treated with increasing doses (0, 50, 75, 100 mg/kg) of Cy in combination with GnRHa. GnRHa treatment was initiated one week prior to chemotherapy and also continued after chemotherapy for one week. The ovaries were removed seven days after Cy administration and the total number of primordial follicles in both ovaries was counted. RESULTS: Primordial follicular destruction occurred at all levels of Cy exposure. There was a positive correlation between increasing doses of Cy and higher proportion of follicular loss (p < 0.0001). GnRHa was not able to protect against the chemotherapy-induced negative effect on primordial follicular count at low doses (50 mg/kg and 75 mg/kg). Mean +/- SD primordial follicle count in the 100 mg/kg Cy-treated group was significantly lower than in the 100 mg/kg Cy + GnRHa treatment group (73.9 +/- 33.1 vs 89 +/- 17.9, p = 0.047). CONCLUSION: Our data suggest a possible ovarian protective effect of GnRHa cotreatment only at high doses of Cy treatment. However, in spite of co-administration of GnRHa, loss of primordial follicular reserve occurred at all doses of Cy in mice.

Dynamic MRI in indirect estimation of microvessel density, histologic grade, and prognosis in colorectal adenocarcinomas.

The relations of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters to microvessel density (MVD), histologic grade, and presence of metastasis were evaluated to establish new prognostic indicators in colorectal cancer (CRC). Fast-low angle shot DCE-MRI parameters (time-intensity curves, TICs; maximal relative enhancement within the first minute, E(max/1); maximal relative enhancement of the entire study, Emax; steepest slope of the contrast enhancement curve; and time to peak enhancement) of 21 CRCs (seven Duke stage B, 12 Duke stage C, and two Duke stage D) were retrospectively evaluated and correlated with corresponding postoperative MVD measurements, histologic grades, and presence of metastasis at 2 years. TICs were classified as type A in nine (43%), type B in seven (33%), and type C in five cases (24%). There was a significant difference between TIC types with regard to MVD (p < 0.05-0.001). Time to peak enhancement, steepest slope of TIC, and E(max/1) were strongly correlated with MVD (r = -0.765, p < 0.01; r = 0.681, p < 0.01; r = 0.634, p < 0.01; respectively). MVD, steepest slope of the enhancement curve, E(max/1), and Emax strongly correlated with histologic grade (r = 0.475, p < 0.05; r = 0.683, p < 0.01; r = 0.687, p < 0.01; r = 0.791, p < 0.01; respectively). There was a significant difference between groups of patients with and without metastasis with regard to histologic grade (p < 0.05) and two of the DCE-MRI parameters (p < 0.005 for E(max/1) and p < 0.05 for time to peak enhancement). Discriminant analysis correctly predicted the metastatic occurrence at 2 years in 90.5% of cases using E(max/1) (p < 0.001). Histologic grade resulted in lower rates of discrimination (66.7%; p < 0.05). DCE-MRI parameters may help in the prediction of MVD and histologic grade in CRC and may be used to predict therapeutic outcome.

Inflammatory pseudotumor of the spleen with EBV positivity: report of a case.

Inflammatory pseudotumor (IPT) of the spleen is a rare benign tumor with unknown etiology. It causes problems in the diagnosis because of mimicking some hematopoetic malignancies. Here we report the case of a 36-yr-old woman complaining of nausea and insomnia. Laboratory investigations were limited to increase of leukocyte and thrombocyte count. Ultrasonography and magnetic resonance (MR) imaging showed circumscribed solid lobulated mass, measuring about 6.5 cm in diameter, located in the dorsal region of the spleen. Splenectomy was performed with the differential diagnosis including hamartoma and lymphoma of the spleen. Histological examination of the sharply demarcated splenic mass consisted of myofibroblasts and admixture of inflammatory cells. Immunohistochemistry and in situ hybridization were performed. IPT of the spleen was diagnosed. Epstein-Barr virus (EBV) was detected in the tumor by in situ hybridization. This rare entity is presented because of its clinical, radiological and pathological difficulties in the differential diagnosis.

Metastatic squamous cell carcinoma of the skin in chronic myeloid leukaemia: complication of hydroxyurea therapy.

Hydroxyurea is a ribonucleotide diphosphate reductase inhibitor used in the treatment of patients with myeloproliferative disorders. Hydroxyurea has some dermatological side-effects. It has recently been recognized that hydroxyurea can induce squamous cell and basal cell carcinomas of skin. We present the case of an elderly man with chronic myeloid leukaemia who was treated with hydroxyurea for 4 years, with good control of his disease. However, in addition to the appearance of various skin lesions and cutaneous squamous cell carcinoma after 3 years of therapy, he was found to have a metastatic squamous cell carcinoma after 4 years. Hydroxyurea was discontinued, and he underwent surgery and radiotherapy. The patient subsequently died of ventricular fibrillation. We present this case to draw attention to the association between hydroxyurea and secondary skin cancers and to emphasize the need for dermatological examination before and during the course of hydroxyurea therapy.

Nebulized surfactant as a treatment choice for otitis media with effusion: an experimental study in the rabbit.

Exogenous surfactant can improve eustachian tube function in experimentally induced otitis media with effusion (OME). Performing tympanometric recordings, the efficacy of inhaled nebulized surfactant, as compared with inhaled nebulized physiological saline was investigated, for the treatment of OME experimentally induced in the rabbit by intrabullar inoculation of heat-killed Streptococcus pneumoniae. In addition, the histological changes in middle ears after the treatment were investigated in order to establish whether the pathological findings correlated with the results. Middle-ear pressure values before, and after, treatment were analyzed by the Wilcoxon statistical method, and the Mann-Whitney U test was used to compare the post-treatment values between groups. In all ears with OME in the affected animals, which were treated with nebulized surfactant inhalation, a positively significant (p<0.05) increase of pressure more than 20 daPa was recorded. In the control group, after inhalation of nebulized physiological saline, there was no positive increase in the affected middle-ear pressures; on the contrary, more negative pressure changes were recorded. In the histological evaluation, middle-ear epithelia and sub-epithelial space were normal in surfactant-treated ears with OME, whereas mucosal thickening with an oedematous sub-epithelial space containing occasional inflammatory cells and increases in connective tissue and vascularity, and effusions on the epithelial surface were present in the ears with OME in the control group. The significant improvement in the negative middle-ear pressure after nebulized surfactant treatment and the histological findings shown in our study can support the theory that surface-active agents are of importance in eustachian tube function even under pathologic conditions, such as OME.

Supercomputer analysis of sedimentary basins.

Geological processes of fluid transport and chemical reaction in sedimentary basins have formed many of the earth's energy and mineral resources. These processes can be analyzed on natural time and distance scales with the use of supercomputers. Numerical experiments are presented that give insights to the factors controlling subsurface pressures, temperatures, and reactions; the origin of ores; and the distribution and quality of hydrocarbon reservoirs. The results show that numerical analysis combined with stratigraphic, sea level, and plate tectonic histories provides a powerful tool for studying the evolution of sedimentary basins over geologic time.