Tuning optical discs for plasmonic applications

We present simple physical and chemical procedures that allow tuning and modification of the topography of gratings present in optical storage discs into geometries optimal for grating coupled plasmon resonance excitation. After proper metal coating, the tuned surfaces exhibit sharp plasmon resonances that can be excited at wavelengths ranging from 260 nm to over 2.7 μm with relatively high quality factors. As an immediate exemplary application, use of such optimized gratings in aqueous medium for refractive index measurement is demonstrated. © Springer Science + Business Media, LLC 2009

Response to doxycycline and oxytetracycline treatments in cats infected with Mycoplasma spp. and analysis of haemato-clinical findings and risk factors

This study was planned to determine the efficacy of doxycycline and oxytetracycline in the treatment of feline Mycoplasma spp. infections and to analyze risk factors as well as clinical and haematological findings. Cats accepted to the clinic with complaints such as weakness, loss of appetite and fever were routinely examined. Clinical history of animal was demanded from the owner. An interview and a short questionnaire were conducted to owner to evaluate the risk factors associated with possible Mycoplasma status of animal. During the interview, the age, sex, breed, housing, flea infestation, worm control, external parasite control, other accompanying infections and vaccination status of cats were asked and the data recorded. Peripheral blood smears were stained with the DIFF-QUICK. Fifty positive cats were included in the study, 16 of which were treated with doxycycline (orally, 5 mg/kg twice a day) while other 34 with oxytetracycline (intramuscular injection, 10 mg/kg once a day). It was determined that all (100%) cats with Mycoplasma spp. infection had a flea infestation. Majority of cats (94%) did not receive the regular antiparasitic application and only 6 (12%) of them had complete vaccinations. Mycoplasma spp. infection was associated with younger age and outdoor access. Among the feline breed, striped cat (74%) was more prone to infection. The most common clinical signs encountered in cats were weakness (94%) and anorexia (84%). Haematological parameters revealed thrombocytopenia (86%), and anaemia (40%) in infected cats. At the end of the treatment, recovery rates for doxycycline and oxytetracycline groups were 87.5% and 67.6%, respectively. General status of these cats indicated significant improvement on the 4th day of treatment, and clinical symptoms are restored on the 7th day. Mycoplasmosis is an important infection for cats having anaemia, thrombocytopenia and leukocytosis. Flea infestations are risk factor for contamination of the disease. Based on our results, we recommend doxycycline treatment (5 mg/kg) for up to 21 days for elimination of Mycoplasma spp. in the blood of infected cats

Pharmacological assessment of netobimin as a potential anthelmintic for use in horses : Plasma disposition, faecal excretion and efficacy

This study aimed to determine the plasma disposition and faecal excretion of netobimin (NTB) and its respective metabolites as well as the efficacy against strongyles in horses following oral administration. Netobimin (10 mg/kg) was administered orally to 8 horses. Blood and faecal samples were collected from 1 to 120 h post-treatment and analysed by high performance liquid chromatography (HPLC). Using a chiral phase-based HPLC, plasma disposition of ABZSO enantiomers produced was also determined. Faecal strongyle egg counts (EPG) were performed by a modified McMaster’s technique before and after the treatment. Neither NTB nor ABZ were present and only albendazole sulphoxide (ABZSO) and sulphone metabolites (ABZSO2) were detected in the plasma samples. Maximum plasma concentration of ABZSO (0.53 ± 0.14 μg/ml) and ABZSO2 (0.36 ± 0.09 μg/ml) were observed at (tmax) 10.50 and 19.50 h, respectively following administration of NTB. The area under the curve (AUC) of the two metabolites was similar to each other. Netobimin was not detected, and ABZ was predominant in faecal samples. The maximum plasma concentration (Cmax) of (−)ABZSO was significantly higher than (+)ABZSO, but the area under the curves (AUCs) of the enantiomer were not significantly different each other in plasma samples. The enantiomers of ABZSO were close to racemate in the faecal samples analyzed. Netobimin reduced the EPG by 100%, 100%, 77%, 80% and 75% 2, 4, 6, 8 and 10 weeks post-treatment, respectively. The specific behaviour of the two enantiomers probably reflects different enantioselectivity of the enzymatic systems of the liver which are responsible for sulphoxidation and sulphonation of ABZ. Considering the pharmacokinetic and efficacy parameters NTB could be used as an anthelmintic in horses.Peer reviewe

Comparative plasma disposition, bioavailability and efficacy of ivermectin following oral and pour-on administrations in horses

Pour-on formulations of endectocides decrease the risk of injury for both user and animal, and are particularly convenient for animal owners who can apply the product. This study was designed to investigate the plasma disposition and efficacy of ivermectin (IVM) following pour-on, per os and intravenous administrations. Eighteen female horses weighing 510–610 kg were used in this study. The animals were allocated into three groups (per os, pour-on and intravenous groups). The equine paste, bovine pour-on and bovine injectable formulations of IVM were administered orally, topically and intravenously at the dose rates of 0.2, 0.5 and 0.2 mg/kg bodyweight, respectively. Heparinized blood samples and hair samples were collected at various times between 1 h and 40 days. The samples were analysed by high performance liquid chromatography with fluorescence detector. Faecal strongyle egg counts (EPG) were performed by a modified McMaster's technique before and at weekly intervals during 10 weeks after treatment. The results indicated that the plasma concentration and systemic availability of IVM was lower but the plasma persistence was prolonged after pour-on administration compared with per os route. IVM (paste) reduced the EPG by >95% for 10 weeks, whereas the reduction in pour-on group varied from 82 to 97%. EPG reduction in pour-on group was lower than that of per os group. Degradation on the application site, cutaneous biotransformation, binding of IVM to the haircoat and/or sebum are probably responsible for the relatively lower bioavailability of IVM in horses after pour-on administration. In conclusion, the poor plasma availability observed after pour-on administration could result in subtherapeutic plasma concentrations, which may promote the development of drug resistance in parasites.Peer reviewe