Publications by authors named "Ahmad Shafiee"

3 Publications

  • Page 1 of 1

Recombination and phenotype evolution dynamics of Helicobacter pylori in colonized hosts.

Int J Syst Evol Microbiol 2016 Jul 15;66(7):2471-2477. Epub 2016 Apr 15.

Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

The ample genetic diversity and variability of Helicobater pylori, and therefore its phenotypic evolution, relate not only to frequent mutation and selection but also to intra-specific recombination. Webb and Blaser applied a mathematical model to distinguish the role of selection and mutation for Lewis antigen phenotype evolution during long-term gastric colonization in infected animal hosts (mice and gerbils). To investigate the role of recombination in Lewis antigen phenotype evolution, we have developed a prior population dynamic by adding recombination term to the model. We simulate and interpret the new model simulation's results with a comparative analysis of biological aspects. The main conclusions are as follows: (i) the models and consequently the hosts with higher recombination rate require a longer time for stabilization; and (ii) recombination and mutation have opposite effects on the size of H. pylori populations with phenotypes in the range of the most-fit ones (i.e. those that have a selective advantage) due to natural selection, although both can increase phenotypic diversity.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
July 2016

Drug-induced toxic reactions in the eye: an overview.

J Infus Nurs 2004 Nov-Dec;27(6):386-98

Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Iran.

Every drug can produce untoward consequences, even when used according to standard or recommended methods of administration. Adverse drug reactions can involve every organ and system of the body, even the eye, and frequently are mistaken for signs of underlying disease. Reactions in the eye may involve the eyelids, periorbital tissues, lacrimal apparatus, conjunctiva, cornea, lens, iris, ciliary body, intraocular pressure, retina, optic nerve, and ocular movement. In addition, fetal abnormalities can be caused by the use of eye drugs during pregnancy. Topical ophthalmic therapies or the use of ophthalmic dyes may cause systemic reactions. This article reviews drugs used systemically or topically that may cause adverse effects in the eye and related structures. Adverse ocular reactions to medications create an important health problem, and nursing professionals in close contact with patients inside and outside the hospital must assume a role in detecting them early, identifying them, educating the patient about them, and treating them.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
February 2005

Antioxidant, antidiabetic, antihyperlipidemic,reproduction stimulatory properties and safety of essential oil of Satureja Khuzestanica in rat in vivo: a oxicopharmacological study.

Med Sci Monit 2003 Sep;9(9):BR331-5

Department of Toxicology, Pharmaceutical Sciences Research Center and Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.

Background: Satureja Khuzestanica is an endemic plant of Iran that is widely distributed in the southern part of the country. It is famous for its medical uses as an analgesic and antiseptic in folk medicine. The present study was designed to explore the toxicological and pharmacological effects of essential oil of Satureja Khuzestanica (SKEO) in vivo.

Material/methods: The intraperitoneal LD50 of SKEO was determined. Teratogenicity was determined by administration of SKEO at doses of 500, 1000 and 1500 ppm to pregnant rats during days 6 to 015 of gestation. FRAP and TBARS assays were used to determine total antioxidant power and lipid peroxidation respectively. Diabetes and hyperlipidemia were induced by administration of streptozocin and lipid regimen in rats. SKEO (1000 ppm) was administered in drinking water for 10 days.

Results: SKEO is not lethal up to a dose of 2 g kg-1 in rats. In the teratogenicity test, dams of the treated group were active and did not show any signs of toxicity. A significant increase in the number of implantation and live fetuses were observed with SKEO (500 and 1000 ppm) in comparison to the control group. SKEO treatment decreased the normal blood lipid peroxidation level and increased total antioxidant power. Significant decreases in fasting blood glucose and triglyceride levels were observed with SKEO in diabetic and antihyperlipidemic rats respectively.

Conclusions: This preliminary study indicates the safety and interesting stimulatory effect of SKEO on reproduction. The antioxidant properties of SKEO may explain its antidiabetic and triglyceride-lowering effects.
View Article and Find Full Text PDF

Download full-text PDF

September 2003