Topical dimethyl sulfoxide inhibits corneal neovascularization and stimulates corneal repair in rabbits following acid burn.

Neovascularization of the cornea is characterized by the growth of blood vessels caused by imbalances between angiogenic and anti-angiogenic factors. We investigated whether the expression of Vascular endothelial growth factor (VEGF), Vascular endothelial growth factor receptor (VEGF), Vascular endothelial growth inhibitor (VEGI) receptors, as well as topical drug treatments, participate in regulating corneal neovascularization after corneal damage and remodeling. We used 72 mature male New Zealand rabbits. Corneal burns were induced by hydrofluoric acid under general anesthesia. The rabbits then were treated with indomethacin or dimethyl sulfoxide (DMSO). The animals were euthanized on days 2, 7 and 14 after injury. Each cornea was fixed with 10% neutral formalin. On days 2, 7 and 14, VEGF, flk1/KDR and flt1/fms were strongly expressed in the epithelial, stromal and inflammatory cells, but not in the corneal endothelial cells. On day 7, newly formed blood vessels were observed growing toward the center of the cornea. In the control, indomethacin treated, DMSO-treated, and indomethacin + DMSO-treated animals, VEGI, VEGF, and the receptors, flk1/KDR, flt1/fms and flt4, were expressed at different densities in the neovascular regions. This was particularly evident in the indomethacin- and indomethacin + DMSO-treated groups on days 7 and 14, compared to day 2. Treatment with VEGF and DMSO stimulated repair of corneal damage. We suggest that VEGI in the endothelial cells of neovascularized cornea may act as a signaling protein that promotes balance between cell proliferation and apoptosis. Topical administration of DMSO inhibited corneal neovascularization more effectively than indomethacin.

The use of fucosphere in the treatment of dermal burns in rabbits.

The aim of this study was to prepare a new microsphere (fucosphere) system based on polyion complexation of fucoidan with chitosan, and to evaluate its treatment efficiency on dermal burns. The physicochemical properties such as mean particle size and distribution, zeta potential and bioadhesive properties of the microspheres were investigated. The formulation which had the high surface charge, narrow size distribution and the highest bioadhesive property was selected and applied on seven male New Zealand white rabbits with dermal burns. Biopsy samples were taken on day 7, 14 and 21. Each burn site was evaluated macroscopically and histopathologically and the findings were compared with controls of fucoidan solution and chitosan microspheres. The microspheres between the size ranges of 367 and 1017 nm were obtained. The work of bioadhesion of microspheres, with the surface charges +6.1 to +26.3 mV, changed between 0.081 and 0.191 mJ cm(-2). Macroscopically and histopathological observations indicated that the fastest healing of the burns was obtained in group treated with fucosphere after 21 days of treatment (P<0.05). Rete peg formation values and nuclear organize regions (NORs) were higher with treated fucospheres than the other groups on day 14. In conclusion, in vitro and in vivo evaluation of fucospheres indicated that the new microsphere system shortened the treatment period of burns and provided fast and effective healing by improving regeneration and re-epithelization. Hence fucosphere may find application in the treatment of dermal burns.

Effects of hyperosmolar ionic and low osmolar non-ionic contrast media on acid base, blood gas and electrolyte status in dogs.

The dogs in groups I, II and III in equal numbers received diatrizoate, iohexol and ioxilan at a dose of 700 mgI/kg intravenously (i.v.) as a bolus, respectively. Blood samples were collected prior to contrast media (CM) administration and thereafter at 3, 15, 30, 60, 90 and 180 min to evaluate acid-base, venous blood gas status (pH, PCO2, PO2, HCO, BE, O2) and electrolytes (Na+, Ca++, K+). Values of pH, PCO2, BE, HCO, Na+ and K+ remained unchanged or within non-significant fluctuations compared with the baseline values. PO2 was significantly different from the baseline values in group 1 up to 90 min after administration, significant alterations were found for O2 saturation in group 1 up to 90 min, and in group II at 3, 60 and 180 min; and for Ca++ in group 1 at all time points except at 90 min, and groups II and II at 3 and 15 min post administration. It was concluded that none of the CM are considered to cause long-lasting and major effects on acid-base, blood gas and electrolyte status.

Effects of hyperosmolar ionic and low osmolar non-ionic contrast media on coagulation times and some blood parameters in dogs: an in vivo study.

The purpose of this study is to evaluate the effects of hyperosmolar ionic contrast media (CM) (diatrizoate) and low osmolar non-ionic CM (iohexol and ioxilan) on coagulation time and some blood parameters in dogs in vivo. The animals were divided into three groups in equal numbers. The dogs in groups I, II and III received diatrizoate, iohexol and ioxilan at the dose of 700 mgI/kg intravenously (IV) as a bolus, respectively. Administration of contrast media and blood samples were collected from vena cephalica antebrachii prior to CM administration and thereafter at 3, 15, 30, 60, 90 and 180 min and 24 h to measure the coagulation factors [activated partial thromboplastin time (APTT), prothorombin time (PT), fibrinogen and fibrinogen degradation products] and some other blood parameters [red blood cells, platelet, white blood cells, haematocrit (Ht) and haemoglobin (Hb)]. While a statistically significant decrease was observed on APTT at 15 min in group III, no significant differences were found in groups I and II. All the groups had insignificant alterations for PT, fibrinogen and fibrinogen degradation product, following CM administration. Significant decreases were observed for platelet at 3 min in all groups. This decrease was also significant at 15- and 30- min intervals in group I. There were significant decreases for erythrocytes, Ht and Hb measurements within 30 min, and no significant alterations were observed for leucocytes within 60 min in all groups compared with baseline values. No differences were observed with regard to coagulation times and some blood parameters as far as long-lasting and major effects of each CM are concerned.

The effect of Alkanna tinctoria Tausch on burn wound healing in rabbits.

Eighteen adult male New Zealand White rabbits were used in the treatment of partial thickness, severe and olive oil burns. Both right and left sides of the animals were burned to make partial thickness, severe and hot olive oil burn wounds. The solution of A. tinctoria TAUSCH in 16% prepared in medical olive oil in weight basis, were applied to the left, and right side served as control. It was topically applied twice a day by gently rubbing against the burn area. While complete healing of partial thickness and olive oil burn wounds occurred in 7 to 10, and 26 days, respectively, with well formed dermal-epidermal junctions in both groups, severely burned wounds appeared to be nonresponsive to A. tinctoria.

Effect of experimental therapeutic ultrasound on the distal antebrachial growth plates in one-month-old rabbits.

The effect of therapeutic ultrasound (US) on the growth plates of growing bone was determined through fluorescence labelling and histopathological evaluation in one-month-old rabbits. Mean growth rates and mean heights of the growth plates of the US exposed radius vs. control radius, and US exposed ulna vs. control ulna showed no statistically significant differences at all intensities and time intervals. Mean growth rates and heights of the growth plates of the US exposed radius for 0.2 W/cm(2) (SATA) US vs. 0.5 W/cm(2) US showed the same type of pattern compared to those of the control radius for 0.2 W/cm(2)vs. 0.5 W/cm(2) at days 10, 15 and 20. Similar results were also found for the ulna. Effects of 0.5 W/cm(2) US on the mean growth rates and mean heights of the growth plates were superior to those of 0.2 W/cm(2) US at day 10. The results at day 10 were reversed for the same comparisons at days 15 and 20. No cavitation effect of US was observed on growth plate cells. There was no evidence of partial or complete premature closure of the growth plates or of angular deformity of the carpal region.