Effect of three anthelmentics on disposition kinetics of florfenicol in goats

The pharmacokinetic aspects of florfenicol (FLO) were investigated via intravenous (I.V.) and intramuscular (I.M.) injections in five goats at a dose of 20 mg kg⁻¹ b.wt. Animals were pre-treated with albendazole orally in a dose of 2.5 mg kg⁻¹ b.wt, ivermectin or rafoxanide subcutaneously in a dose 0.2 and 7.5 mg kg⁻¹ b.wt, respectively. Florfenicol was injected intramuscularly two hours following anthelmentic administration and blood samples were taken by jugular venapuncture at standardized intervals. The concentrations of florfenicol (FLO) in serum were determined by high performance liquid chromatography (HPLC) method. The obtained results revealed that ivermectin administration did not induce a significant difference in serum florfenicol concentration between anthelmentic-treated and non-treated goats. On the other hand, goats pre-treated with rafoxanide or albendazole showed a significant decrease in serum florfenicol level as compared to non-anthementic treated goats. The absorption half-life (t_½ab), C_max, AUMC, AUC and systemic bioavailability (F%) are significantly decreased, whereas elimination half-life (t_½el) and MRT are increased in goats pre-treated by the three tested anthementics.     

Effect of histamine and histamine antagonists on portal blood pressure in patients with hepatosplenic schistosomiasis.

1 Histamine injection via the cannulated portal vein significantly raised the portal pressure in normal volunteers. This elevation was reversed by an H1-receptor blocker but not an H2-receptor blocker. When an H1-receptor blocker was injected first followed by histamine, no significant change in portal pressure was obtained. On the other hand, an H2-receptor blocker failed to antagonize the effect of histamine. 2 Histamine injection induced a non-significant increase in the portal pressure in patients with schistosomal portal hypertension, but when an H1-receptor blocker was injected a significant drop in the portal pressure was obtained. No similar effect was found after an H2-receptor blocker injection. 3 Angiographic study showed that histamine induced intrahepatic portal vasoconstriction in the normal controls. A similar change was obtained in the schistosomal group, particularly on the periportal neovascular formation. 4 In the light of the present study, it is suggested that histamine may contribute in part to the physiopathologic changes that lead to portal hypertension in hepatosplenic schistosomiasis. H1-receptor antagonists may have a role in the treatment of portal hypertension, particularly in bleeding varices.     

SULFONAMIDES IN BUFFALOES: EFFECT ON CERTAIN BLOOD CONSTITUENTS AND SERUM ENZYMES

1. Three groups of four clinically healthy buffaloes were injected with sulphadiazine, or sulphadimidine, or sulphathiazole in a single dose of 100 mg/kg body weight. 2. Changes in the serum enzyme activities (SGOT, SGPT and alkaline phosphatase) observed with the tested sulphonamides were insignificant, except for increases in SGOT level 6 h after sulphathiazole injection, and in GOT/GPT ratio 30 min and 24 h after sulphadimidine injection. 3. The creatinine level was not affected in sulphonamide-injected animals. All blood samples collected 15 min to 24 h after sulphathiazole injection showed marked increase in glucose and urea levels. Concerning the other two sulphonamides, no significant change was observed in these parameters except for an increased glucose level 24 h after sulphadiazine injection.     

Bioassay chamber for angiogenesis with perfused explanted arteries and electrospun scaffolding

OBJECTIVE: The purpose of this study was to test the hypothesis that explanted perfused arteries can serve as the initial endothelial cell culture source to evaluate the onset of angiogenesis in a cellulose acetate electrospun scaffold. METHODS: Electrospun scaffolds with fiber diameters roughly controlled in three broad ranges: 0.01 to 0.2, 0.2 to 1, and 1 to 5 microm (Nanomed Nanotechnol Biol Med 2:37-41, 2006), were used in cell culture to determine which provides the best culture topology. This scaffold was then tested in a bioassay chamber whose cellular source was an explanted abdominal aorta from donated euthanized mice. Scaffolds were draped over a cannulated vessel perfused for 24 h. Cell viability, density, and morphology were quantified. RESULTS: The largest fiber diameter group provided the best culture topology for human umbilical vein endothelial cells, showing high cell viability and density, and enhanced elongated cell morphology. Addition of single-walled carbon nanotubes decreased cell density significantly but chitosan heightened cell density and promoted spontaneous capillary tube like structure. Viability of endothelial cells increased with higher flow in the bioassay chamber. CONCLUSIONS: Endothelial cells showed a growth preference towards larger diameter fibers. Addition of chitosan improved culture conditions. Thus, this study provides a proof of principle for the possibility of co-culturing tissue engineered vascular networks from a perfused explant.     

Anorectal pressure in patients with symptomatic hemorrhoids

This study was carried out on 30 patients with symptomatic internal hemorrhoids and 20 normal controls. The anal sphincter pressure was studied before and after surgery. A significantly high anal pressure was found in all patients with symptomatic internal hemorrhoids, when compared with normal controls, and there was no relation between this increase and the degree of hemorrhoids. One week following surgery, this high pressure was reduced significantly and was not affected by the type of operation. Thus, this increase in resting anal pressure is due to an overactivity of the internal hemorrhoids, which is secondary to the presence of the hemorrhoidal mass.