Isolation of Acanthamoeba spp. from Different Environmental Sources

Background: Acanthamoeba spp. are free-living amebas found in a wide variety of natural habitats. The high percentage of Acanthamoeba in different environmental sources represents a sanitary risk for public health especially contact lens users and immunocompromised patients. The aim of this study was to determine the presence of Acanthamoeba spp. in different environments such as water, soil, dust and ophthalmology wards. Methods: From March to November 2007, 80 samples were collected from numerous localities in Tehran city including university campus, Laleh park and ophthalmology center. Sample types were water, soil, dust, cow faeces and medical in­strument. Each sample was filtered through nitrate membrane and cultured on 1% non-nutrient agar. These plates were fol­lowed up daily for 2 weeks. Monitoring continued for two months on a weekly basis.  Results: Overall, 46.25% of samples contained Acanthamoeba spp. All of the soil samples had shown positive culture in contrast to tap water. Of 61 dust samples, 28 were positive. Interestingly, we were able to isolate Acanthamoeba in treat­ment unit of an ophthalmology center in Tehran. It should be mentioned that two cow faeces showed positive culture as well.Conclusion: The widespread distribution of Acanthamoeba spp. across the environmental sources and increasing numbers of HIV+ patients and contact lens wearers, as well as its ability as a pathogen carrier for humans, demands  more awareness and knowledge for public as a risk for human health

Amoebic keratitis in Iran (1997-2007)

Background: Amoebic keratitis introduced as a painful corneal infection which sometimes lead to poor vision and blind-ness. The main goal of this study was to report amoebic keratitis during ten years from 1997-2007 in patients who was sus-pected to have amoebic keratitis and referred to Parasitology laboratory, School of Public Health, Tehran Univer¬sity of Medical Sciences, Iran. Other aim was to assess the major risk factor for developing this sight-threatening disease. Comparison of lens culture and corneal scrapes culture also was performed. "nMethods: During 1997-2007, 142 patients referred to Dept. of Medical Parasitology, School of Public Health, Tehran Uni-versity of Medical Sciences, Iran. Details of each patient such as age, sex, history of contact lens wear, type of contact lens, clinical symptoms were recorded in questioners. Keratitis was diagnosed on the basis of culture of lenses and/or corneal scrapes on non-nutrient agar overlaid with Escherichia coli and direct microscopy of lenses and/or corneal scrapes. "nResults: Among 142 patients, 49 (34.5%) had amoebic keratitis. 73.46% of these patients were from Tehran but there were a few cases from other cities. The commonest age was between 15-25 yr (75.5%) and more female (37:12) were identified then male. It is worth to mention that 44 patients (89.79%) were contact lens wearers who among them 41 patients (93.18%) wore soft contact lens and only three patients suffer from amoebic keratitis because of wearing hard contact lens. Other finding of this study demonstrated that the most common sign of the patients was severe pain combined with photophobia. "nConclusion: This study indicates that Acanthamoeba keratitis continue to rise in Iran. This is due to increase frequency of lens wearers as well as consideration of ophthalmologist to Acanthamoeba as an agent of keratitis and improvement of labo¬ratory methods. Another finding of this research was the confirmation of soft contact lens as a major risk factor. It is rec¬ommended to educate contact lens wearers for regular disinfection. Besides, culture of corneal scrapes was negative in most of cases, so lens culture were performed which had a much better result

Molecular Characterization and Sequencing of a Gene Encoding Mannose Binding Protein in an Iranian Isolate of Acanthamoeba castellanii as a Major Agent of Acanthamoeba Keratitis

Background: Acanthamoeba castellanii is the important cause of amoebic keratitis in Iran. The key molecule in pathogenesis of Acanthamoeba keratitis is Mannose Binding Protein (MBP) led to adhesion of amoeba to corneal epithelium. Subsequent to adhesion other cytopathic effects occur. The goal of this study was to identify the molecular characterization of a gene encoding MBP in an Iranian isolate of A.castellanii in order to pave the way for further investigations such as new therapeutic advances or immunization. Methods: A.castellanii was cultured on non nutrient agar. Extraction of DNA was performed by phenol-chloroform method. After designing a pair of primer for the gene encoding MBP, PCR analysis was performed. Finally, the PCR product has been sequenced and the result submitted to the gene data banks. Results: An MBP gene of 1081 nucleotides was sequenced. This fragment contained three introns and encodes a protein with 194 amino acids. Homology search by Blast program showed a significant homology with the MBP gene in gene data banks (96%). Besides, the identity of amino acids with the other MBPs in gene data banks was about 86%. Conclusion: We isolated and sequenced a gene fragment encoding MBP in an Iranian isolate of A.castellanii. Molecular characterization of this important gene is the first step in pursuing researches such as developing better therapeutic agents, immunization of population at risk or even developing a diagnostic tool by PCR techniques

Stereotactic body radiotherapy

Stereotactic body radiation therapy (SBRT) consists of the delivery of precise, conformal, hypofractionated, and ablative therapy in a single or a small number of fractions to extracranial regions. Over the last decade, it is rapidly being integrated into mainstream radiation oncology practices. The indications for SBRT continue to grow, as does the technology associated with its delivery. This chapter presents a detailed overview of clinically relevant topics including patient selection and outcomes, and the technological aspects of planning and delivery of SBRT. The tumor streams covered in this chapter are lung, liver, spine, pancreas, renal cell carcinoma, adrenal, prostate, and head and neck. The chapter concludes by highlighting two novel areas, cardiac arrhythmias and pediatric oncology, in which the use of SBRT is emerging