A Computational Fluid Dynamics Investigation on the Drag Coefficient Measurement of an AUV in a Towing Tank

The accuracy of experimental procedure used to calculate the drag coefficient of an Autonomous underwater vehicle (AUV) in a towing tank is investigated using computational fluid dynamics. Effects of struts, used to connect the AUV model to towing carriage, on the hydrodynamics coefficient of the AUV at various relative submergence depths, at AUV speeds of 1.5 and 2.5 m/s are numerically simulated. Various numerical modeling are performed to investigate the effects of free surface with and without presence of struts on the drag coefficient of the AUV. Volume of fluid (VOF) model is used to solve the two phase flow RANS equations. The drag coefficients obtained from two phase flow simulations are compared with those obtained from single phase flow at corresponding velocities. The results obtained from experiments conducted in the towing tank of the Subsea Science and Technology centre, on a full-scale model of the AUV developed in this Centre, agreed well with those obtained by numerical simulations

Effect of the Sera of Patients with Multiple Sclerosis on Apoptosis and Nitric Oxide Production of Endothelial Cells

Abstract: Background & Aims: Multiple sclerosis (MS) is one of the chronic autoimmune diseases of the central nervous system with unknown etiology. The present study aimed to investigate the apoptosis and nitric oxide (NO) production of endothelial cells treated with serum of patients with MS and response to interferon beta (IFN-?) therapy. Methods: Human umbilical vein endothelial cells were treated with sera from patients with active MS (in relapse), MS in remission, or sera from healthy volunteers (each n = 10). Nitric oxide (NO) levels were determined in culture supernatants by Greiss method and endothelial cell apoptosis was assessed by annexin V-propidium iodide staining. Effects of IFN-beta-1b on endothelial cell apoptosis and NO production were tested at increasing doses (10, 100, and 1000 U/ml). Results: Compared with healthy people, only apoptosis of endothelial cells treated with serum of patients with relapsing phase increased, P<0.01; while there was no significant difference between apoptosis of endothelial cells treated with serum of patients in remission phase and healthy controls. Apoptosis of endothelial cells treated with sera of patients in relapse was decreased by IFN-beta-1b at 10 U/ml, P<0.05. The same dose also led to a significant increase in nitric oxide production. Conclusion: The results suggest that endothelial cells injury and apoptosis may play a role in MS etiology and represents a potential therapeutic mechanism of action for IFN-beta-1b in MS therapy. Keywords: Multiple sclerosis, Interferon beta-1b (IFN-beta-1b), Endothelial cell apoptosis, Nitric oxid

Interleukin-10 and Transforming Growth Factor-β in Early and Late Lesions of Patients with Leishmania major Induced Cutane­ous Leishmaniasis

Background: Cutaneous leishmaniasis is a neglected parasitic disease, which imposes massive human distress and financial costs to the endemic countries. Better understanding of host immune response to the parasite leads to helpful strategies for disease control. Interleukin (IL)-10 and transforming growth factor (TGF)-&beta; are important immune regulatory cytokines, which appear to develop non-healing forms of leishmaniasis. However, there is little information about the function of IL-10 and TGF-&beta; in old world cutaneous leismaniasis. The aim of this study was to analyze the role of IL-10 and TGF-&beta; in human cutaneous leishmaniasis due to Leishmania major infection. Methods: Biopsies were obtained from lesions of twenty proven cases of L. major induced cutaneous leishmaniasis. IL-10 and TGF-&beta; positive cells were detected by immunofluorescence staining of frozen sections and compared between two groups of patients with early and late lesions. Results: The mean percentage of IL-10 positive cells were significantly (P= 0.035) higher in late lesions (0.51&plusmn;0.24) than early ones (0.15&plusmn;0.07). Similar results were obtained for TGF-&beta; with mean percentages of 0.16&plusmn;0.05 and 0.53&plusmn;0.28 in early and late lesions respectively (P= 0.008). Conclusion: IL-10 and TGF-&beta; are present in lesions of L. major induced cutaneous leishmaniasis and contribute to the pathogenesis of long lasting disease forms

THYROID FUNCTION IN MALIGNANT PEDIATRIC PATIENTS AFTER RADIOTHERAPY

Introduction. Malignancy is seen in pediatrics, frequently. Radiotherapy as a common procedure in malignancy management may has many side effects and complications, especially about endocrine system. In this study, we evaluate the incidence of post radiotherapy hypothyroidism In malignant pediatric patients.&#13; Methods. In a cross sectional study one hundred and eighty children between 1 to 20 years old that survived of malignancy were selected. They have been treated in Sayyed-Alshohada hospital (affiliated to Isfahan University of Medical Sciences) from 1993 Sep. until 1998 Sep. by radiotherapy.&#13; Baseline characteristics (e.g. sex, age, dose, location and number of radiotherapy fraction, type of malignancy) were derived from medical records. Subjects were invited by letters to evaluate their thyroid functions in 1999. Serum T4 and FT4 concentrations assayed by RIA and TSH by IRMA methods.&#13; Results. The incidence of hypothyroidism was 13.3 percent (1.2 percent secondary hypothyroidism and 12.1 percent primary hypothyroidism). There was no statistical difference in age and sex distribution between patients with or without hypothyroidism. History of cervical region radiotherapy was taken in 45.8 percent of hypothyroid patients. There was no significant difference in dose and number of radiotherapy fraction between hypothyroid and euthyroid patients.&#13; Discussion. Radiotherapy may have a role in developing hypothyroidism in patients who received radiotherapy. This role has no relation to age and sex, dose and number of radiation fraction in development of hypothyroidism. Region of radiotherapy is important. It is suggested that this study continues and data will be collected during several years in future. Of course, many of hypothyroid patients will become euthyroid spontaneously

An unusual Case of Transitional Cell Carcinoma of Renal Pelvis Presenting with Brain Metastases

ABSTRACT: Introduction & Objective: Transitional cell carcinoma of renal pelvis presenting with brain metastases is a very rare case which should be diagnosed and treated in order to prevent further damages. Case: We report a rare case, who had presented with a constellation of neurological symptoms (due to multiple brain metastases), but without any urological symptoms. During evaluation of patient, we found transitional cell carcinoma (TCC) of left renal pelvis, for which palliative radical nephroureterectomy was performed . Conclusion: Although transitional cell carcinoma of renal pelvis presenting with brain metastases is a very rare case, but the patient was managed with gamma knife stereotactic radiosurgery for the metastatic lesions. Afterward he received four cycles of paclitaxel and carboplatin chemotherapy. The patient is alive with stable disease at 32- months’ follow-up