فهرست مطالب soltan ahmed ebrahimi

The aim of this study was to evaluate the effects of conjugated lino­leic acid (CLA) on apoptosis of tachyzoites of T. gondii, RH strain (type I) and the cyst-forming Tehran strain (type II) in vitro. Toxoplasma strains were injected into the peritoneal cavity of BALB/c mice. The Tehran strain forms cysts in the brain of mice. Bradyzoites within the cysts are reactivated to proliferative tachyzoites, by dexamethasone. Tachyzoites were aspirated from the peritoneum of infected mice, and the percentage of viable parasites was estimated with trypan blue staining. Tachyzoites were inoculated into HeLa cells cultivated in DMEM medium. Different concentrations of CLA were evaluated on T. gondii in HeLa cells by the tetrazolium (MTT) colorimetric assay. Differentiation between apoptosis and cell death was determined by flow cytome­try using Annexin V and propidium iodide (PI) double staining. The statistical analy­sis performed by GraphPad Prism version 6.00. CLA induces apoptosis in virulent (RH) and avirulent (Tehran) strains of T. gondii. The results of MTT indicated that CLA could decrease the proliferation of tachyzoites of both strains in HeLa cells. Conjugated linoleic acid has anti-toxoplasmacidal activity on tachyzo­ites of T. gondii. Therefore, we recommended further studies on this component in order to achieve a new drug against the parasite.

Wide distribution and low half-life of acyclovir has led to a high dose consumption of the drug. Recent studies have shown that encapsulation of acyclovir in nano-carriers can increase effectiveness and decrease its side effects. We investigated the inhibitory effect of acyclovir loaded nano-niosomes against herpes simplex virus type-1 (HSV-1) in cell culture. In-vitro cytotoxicity study of empty niosomes (E-N), acyclovir loaded niosomes (ACV-N) and ACV as a free drug against HeLa cell line was performed by MTT assay and the viral titers was tested by TCID50 assay. The results indicated that a significant higher antiviral activity for acyclovir loaded nano-niosomes of about 3 times in comparison with free drug. The results of this study revealed ACV-N have a higher antiviral activity compared with free drug; it could be a suitable carrier for delivery of acyclovir in the treatment of HSV-1 infections.

This study aimed to investigate and to compare the effects of nifedipine and amlodipine, dihydropyridine (DHP) calcium channel blockers (CCBs) on perfusion pressure of isolated perfused rat kidney. Following the establishment of renal perfusion with a constant baseline pressure of 85-95 mmHg, the renal vasculature was constricted by phenylephrine (PE) injection. Changes in the baseline perfusion pressure were recorded. Then nifedipine and amlodipine prepared in perfusion medium was fed to the kidney for 30 min. Finally alterations in the baseline pressure arising from PE administrations in the presence of CCBs were recorded and data analyses were done. PE-induced increases in perfusion pressure attenuated significantly in the presence of 5 and 10 μM of nifedipine and 1, 5, and 10 μM of amlodipine. Increases in perfusion pressure arising from PE (100 and 200 μM) in the presence of amlodipine (1, 5, and 10 μM) was significantly less than that in the presence of nifedipine (1, 5, and 10 μM). Calculated EC50 value of amlodipine for inhibition was significantly lower than that of nifedipine. Based on the EC50 values, the potency of amlodipine in inhibiting PE-induced responses is significantly higher compared to nifedipine. The potency of amlodipine in inhibiting PE-induced increments in renal perfusion pressure is significantly higher compared to nifedipine.

A checkerboard broth microdilution method was performed to investigate the in vitro antifungal activities of three diazeniumdiolates derivatives (DETA/NO, DPTA/NO, DEA/NO) alone and in combination with ketoconazole, amphotricin B or terbinafine against five Candida species, Cryptococcus neoformance and four dermatophyte strains. MICs and MLCs were recorded, and synergy was calculated by using fractional inhibitory and fractional lethal concentration index. DETA/NO with a half-life of 57h at 25°C showed antifungal activity against all tested dermatophyte species (MIC 0.150 to 2.5mg/ml), DPTA/NO with a half life of 3h at 37°C showed antifungal activity against five species of Candida and Cryptococcus neoformans, and DEA/NO with a half life of 2 min at 37°C and 16 min at 25°C did not show antifungal activity against tested strains. Combinations of DPTA-NO with either ketoconazole or amphotericin B were either synergistic or indifferent for all tested strain of Candida and Cryptococcus neoformance. DETA/NO was unable to enhance the antifungal activity of terbinafine against dermatophyte strains. Even where no synergistic activity was achieved, there was still a decrease in the MIC of one or both drugs which were used in combination. Antagonism was observed between terbinafine and DETA-NO against Trichophyton rubrum. Our result suggests that DETA/NO and DPTA/NO may be useful for development of new therapeutic strategies for treatment of dermatophyte and Candida infections. Clinical studies are warranted to elucidate the potential utility of these combination therapies.

The isolated perfused rat kidney experiment was introduced in 1959 for studying the regulation of renal blood flow and is recognized as a valuable preparation for studying physiological and biochemical aspects of renal function such as hemodynamics, glomerular filtration rate (GFR) and overall handling of fluids. Dose-response curves are obtained by injection of bolus doses of drugs into the perfusion line. However current injection methods can cause several problems such as low reproducibility and altered baseline pressure. The aim of the present work is to develop a simple method of introducing the drug into the perfusion circuit which is free from these aberrations. This was achieved using a six-way injection valve placed in the perfusion circuit, just before the kidney. To assess the reproducibility of this method, 400 L epinephrine (10-7 M) was injected seven times into an isolated perfused rat kidney. The mean peak pressure rise (mmHg) was 30.30.6, 28.50.8 and 27.10.6 at 100, 120 and 140 mmHg base perfusion pressures respectively. Base pressure returned to pre-injection levels under all conditions tested. Low standard deviation of pressure maxima indicates the high reproducibility of this method while multiple injections can be made in a relatively shorter time. This method can be applied to all organ perfusion setups such as isolated hind limb, tail, arteries and arterioles.