Seroprevalence of bovine leptospiral antibodies by microscopic agglutination test in Southeast of Iran

Objective:To evaluate serological findings of bovine leptospirosis which is a zoonotic disease with worldwide distribution caused by Leptospira interrogans. Methods: One hundred and sixty seven sera were collected from 9 commercial dairy herds in jiroft suburbs, from July to October 2011. Microscopic agglutination test (MAT) was used to evaluates serological findings of bovine leptospirosis in Jiroft suburb dairy farms, Kerman province, Iran. Results:Antibodies were found by MAT at least against one serovar of Leptospira interrogans in 29 samples (17.36%) among 167 sera at a dilution 1:100 or higher, and Leptospira pomona was the most prevalent serovar. Positive titers against more than one serovar were detected in 6 sera of the positive samples. Conclusion:This study is the first report of leptospirosis in Southeast Iran and showed that Leptospira pomona was the most and Leptospira icterohaemorrhagiae the least prevalent serovars in Southeast Iran.

Despite increased plasma concentration, inflammation reduces potency of calcium channel antagonists due to lower binding to the rat heart.

1. Rheumatoid arthritis reduces verapamil oral clearance thereby increases plasma concentration of the drug. This coincides with reduced drug effects through an unknown mechanism. 2. The effect of interferon-induced acute inflammation on the pharmacokinetics and electrocardiogram of verapamil (20 mg kg(-1), p.o.) and nifedipine (0.1 mg kg(-1), i.v.) was studied in Sprague-Dawley rats. 3. The effect of both acute and chronic inflammation on radioligand binding to cardiac L-type calcium channels was also investigated. 4. Acute inflammation resulted in increased plasma concentration of verapamil but had no effect on that of nifedipine. Verapamil binding to plasma proteins was unaffected. 5. As has been reported for humans, the increased verapamil concentration coincided with a reduction in the degree to which PR interval is prolonged by the drug. The effect of nifedipine on PR interval was also reduced by inflammation. 6. Maximum binding of (3)H-nitrendipine to cardiac cell membrane was significantly reduced from 63.2+/-2.5 fmol mg(-1) protein in controls to 46.4+/-2.0 in acute inflammation and from 66.8+/-2.2 fmol mg(-1) protein in controls to 42.2+/-2.0 in chronic inflammation. 7. Incubation of the normal cardiac cell membranes with 100 and 1000 pg ml(-1) of rat tissue necrosis factor-alpha did not influence the binding indices to the calcium channels. 8. Our data suggest that the reduced calcium channel responsiveness is because of altered binding to channels.

High performance liquid chromatographic determination of glucosamine in rat plasma.

PURPOSE: A high performance liquid chromatographic method was developed for the determination of glucosamine (GlcN) in rat plasma. METHOD: Internal standard, galactosamine, was added to 100 micro L of plasma containing GlcN followed by precipitation of plasma proteins with acetonitrile. Evaporation of the decanted supernatant solution was accelerated by the addition of methanol. GlcN was derivatized by addition of a solution containing 1-naphthyl isothiocyanate. Sample cleanup included passage through an anion exchange cartridge. Analysis was accomplished by injection of 0.1 mL of the sample solution into an isocratic HPLC system consisting of a C18 column, a mobile phase of acetonitrile: water: acetic acid: triethylamine (4.5: 95.5:0.1:0.05), a flow rate of 0.9 mL/min, and a UV detector set at 254 nm. RESULTS: Galactosamine and GlcN appeared 26 and 29 min post-injection, respectively. The assay was linear over the range of 1.25-400 micro g/mL (CV<10%) with a detection limit of 0.63 microg/mL and a limit of quantification of 1.25 microg/mL. The method was applied to the determination of GlcN in rat plasma after oral administration of 350 mg/kg of GlcN hydrochloride. CONCLUSION: The present assay is specific, sensitive, precise, and accurate and is suitable for pharmacokinetic studies.

Single dose pharmacokinetics and bioavailability of glucosamine in the rat.

PURPOSE: To study pharmacokinetics of glucosamine following various routes of administration of the hydrochloride salt to rats and locate the site of its first-pass metabolism. METHODS: Rat were cannulated in the jugular vein and single intravenous, oral and intra peritoneal doses of 350 mg/kg were administered. Serial blood samples were collected and plasma glucosamine concentrations were determined using HPLC. RESULTS: After intravenous administration, the apparent terminal half-life (1.09 +/- 0.98 h), apparent steady state volume of distribution (2.1 +/- 1.1 L.kg(-1)) and total body clearance (2.61 +/- 0.81 L.kg(-1.h-1)) were calculated. The peak plasma concentration, after oral administration, occurred approximately 30 min post-dose and the absolute bioavailability was 0.19. Glucosamine was completely bioavailable after intraperitoneal administration. CONCLUSION: Orally administered glucosamine is rapidly absorbed, highly distributed and efficiently cleared. The gut rather than liver is mainly responsible for the first pass metabolism since reduced bioavailability is observed after oral but not intraperitoneal doses.

Block copolymer micelles for the encapsulation and delivery of amphotericin B.

PURPOSE: To assess the effect of fatty acid substitution of a micelle-forming poly(ethylene oxide)-block-poly(N-hexyl stearate-L-aspartamide) (PEO-b-PHSA) on the encapsulation, hemolytic properties and antifungal activity of amphotericin B (AmB). METHODS: PEO-b-PHSA with three levels of stearic acid substitution were synthesized and used to encapsulate AmB by a solvent evaporation method. Size exclusion chromatography and UV spectroscopy were used to confirm and measure levels of encapsulated AmB. The hemolytic activity of encapsulated AmB toward human red blood cells and its minimum inhibitory concentration against Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans were obtained and compared to AmB alone. RESULTS: An increase in the level of stearic acid substitution on PEO-b-PHSA improved the encapsulation of AmB while reducing its hemolytic activity. PEO-b-PHSA micelles having 50% and 70% stearic acid substitution (mol fatty acid: mol reacted and unreacted hydroxyls) were completely non-hemolytic at 22 microg/ml. At 11% stearic acid substitution, AmB caused 50% hemolysis at 1 microg/ml. AmB in PEO-b-PHSA micelles was as effective as AmB alone against pathogenic fungi. CONCLUSIONS: PEO-b-PHSA micelles with a high level of stearic acid side chain substitution can effectively solubilize AmB, reduce its hemolytic activity yet retain its potent antifungal effects.