Pharmacokinetics of meloxicam in adult goats: a comparative study of subcutaneous,oral and intravenous administration

AIMS: To determine the plasma disposition of meloxicam in goats following S/C, oral or I/V administration at a single dose of 0.5?mg/kg bodyweight.

METHODS: Five healthy Saanen goats, aged 12–14 months and weighing 35–40?kg, were used for a three phase cross-over design with a 10-day washout period, with meloxicam administered I/V, then orally and S/C. Heparinised blood samples (5?mL) were collected from all animals prior to drug administration (0 hours) and subsequently up to 96 hours. Concentrations of meloxicam in plasma were measured using high performance liquid chromatography. Concentration-time curves were fitted and pharmacokinetic parameters were estimated for each administration group.

RESULTS: Subcutaneous administration of meloxicam exhibited unique plasma distribution characteristics that differed from oral and I/V administration. Mean peak plasma concentrations were greater (1.91 (SD 0.39) vs. 0.71 (SD 0.17) µg/mL) and the time to reach them shorter (3.20 (SD 1.64) vs. 14.33 (SD 2.19) hours) following S/C compared with oral administration (p<0.05). The terminal half-life was longer (15.16 (SD 4.74) vs. 10.69 (SD 1.49) hours) and the MRT was shorter (15.67 (SD 2.37) vs. 24.33 (SD 3.12) hours) following S/C than oral administration (p<0.05), but bioavailability was similar (98.24 (SD 9.62) vs. 96.49 (SD 10.71)%).

CONCLUSION AND CLINICAL RELEVANCE: Subcutaneous administration of meloxicam resulted in long-term presence of drug at high concentration in goat plasma. This unique plasma disposition characteristic may offer an advantage in some clinical cases towards potentially improving the treatment efficacy in goats.     

First Report on the Frequency and Molecular Detection of Neuropathogenic EHV-1 in Turkey

There has been an increase in outbreaks of neuropathogenic equine herpesvirus-1 (EHV-1) in the United States and Europe. However, the presence and frequency of neuropathogenic EHV-1 in Turkish horses are not known at present. This study aimed to investigate the frequency of EHV-1 and neuropathogenic strains of EHV-1 in the Marmara Region of Turkey. Samples were analyzed for the presence of EHV-1 and neuropathogenic EHV-1 by real-time PCR TaqMan probe assays. Overall detection rate of EHV-1 was 45.5% (51 of 112). The detection rates were 70.5% (24 of 34) in aborted fetuses, 53.3% (8 of 15) in neonatal deads, 66.6% (4 of 6) in foals, 40% (2 of 5) in dead mares, and 25% (13 of 52) in living mares. Overall detection rate of neuropathogenic EHV-1 was 7.8% (4 of 51), and the real-time PCR results were confirmed by sequencing. Neuropathogenic strains of EHV-1 were detected in the brain and lung of two mares with neurological disease but without a history of abortion, in the brain of a foal that died of respiratory disorder, and in the nasal swab from a mare with a history of abortion. On histopathology, nonpurulent meningoencephalitis, hemorrhages, and vasculitis were seen in the brain. In conclusion, results of this study indicated, for the first time, that the neuropathogenic EHV-1 is circulating in the Marmara Region of Turkey. The results of this study also show that the current risk for non-neuropathogenic strains is high, whereas risk for the neuropathogenic EHV-1-G₂₂₅₄ strain seems to be low. As outbreaks of EHV-1 continue in the Marmara region of Turkey, surveillance for neuropathogenic EHV-1 genotype should be maintained.     

Endometrial adenocarcinoma in two young queens

Endometrial adenocarcinoma is described in two young intact female Persian cats presented with haemorrhagic vaginal discharge. The discharge had been present for 3 and 15 days in each case, respectively. On the basis of signalment, history, clinical, laboratory and diagnostic imaging findings a tentative diagnosis of pyometra was made in each cat and ovariohysterectomy was subsequently performed. Histological examination revealed endometrial adenocarcinoma in both cats together with ovarian luteal cysts and pyometra in one case. Immunohistochemistry revealed a diffuse and strongly positive reaction for oestrogen receptors in the nuclei of glandular epithelium in well‐differentiated areas of the neoplastic tissue. Poorly differentiated areas of solid growth pattern had weak and focal expression of oestrogen receptors. Furthermore, the neoplastic cells within these areas displayed moderate to strong diffuse nuclear staining with Ki‐67 antibody suggestive of a high proliferative capacity. The owners reported that the cats were clinically healthy 23 and 21 months after the surgery. These cases highlight the importance of histological examination of surgically resected tissue even when clinical signs and laboratory findings suggest pyometra.     

Changes of HCO3-/Cl- exchanger activity during meiotic maturation in Balb/c strain mouse oocytes and zygotes

Intracellular pH-regulatory mechanisms are acquired by growing mouse oocytes with meiotic competence, and these mechanisms become fully active when the oocytes develop to the germinal vesicle (GV) stage as shown in CF1 and Balb/c strains mice. On the other hand, there is some evidence showing that intracellular pH-regulatory mechanisms are inhibited at the stages of Metaphase I (MI) and II (MII) oocytes in the CF1 strain mouse and hamster. Since it has been shown that the intracellular pH regulatory mechanism can be functionally different among mouse strains (e.g., CF1, Balb/c), the aim of this study was to investigate the activity of HCO3-/Cl- exchanger (anion exchanger, AE), which protects cells against alkalosis during the meiotic maturation process, in the GV oocyte up to the pronuclear (PN) zygote derived from the Balb/c strain mouse. Intracellular pH (pHi) was recorded using a microspectrofluorometric technique during meiotic maturation stages. KSOM-based solutions were used as culture and recording solutions. AE activity was determined using a Cl- removal assay and was reported as the change in pHi per minute. AE activity was high in GV stage oocytes but was significantly inhibited at the MI and MII stages. AE activity was higher in the PN zygote stage. This activity was significantly inhibited in all oocyte and zygote stages by 4,4'-Diisocyanatostilbene-2,2'-disulfonic acid disodium salt. After alkalosis induction, the pHi of MI and MII stage oocytes did not completely recover; however, almost complete recovery occurred in the GV stage oocytes and PN zygotes. These results suggest that AE is inhibited during the meiotic maturation process in the Balb/c strain mouse.     

Use of cardiac troponin kits for the qualitative determination of myocardial cell damage due to traumatic reticuloperitonitis in cattle

This study was designed to investigate whether kits to measure circulating cardiac troponin-I (cTn-I) and cardiac troponin-T (cTn-T) can be used to determine myocardial cell damage in cattle with traumatic reticuloperitonitis (trp). Twenty cattle with trp were compared with 10 clinically healthy cattle. cTn-I and cTn-T were determined qualitatively and cTn-I was determined quantitatively; biochemical analyses were also performed on both groups. The mean serum concentrations of total protein, globulin, glucose and calcium, and the mean activities of creatine kinase mb, aspartate aminotransferase, lactate dehydrogenase and gamma-glutamyl transferase were higher in the cattle with trp than in the control group. The cTn-I and cTn-T kits both gave positive results in three of the cattle with trp and the quantitative measurement of cTn-I was positive in 11 of the trp cases. Both tests were negative in the healthy cattle.     

Dose-Dependent Immunohistochemical Changes in Rat Cornea and Retina after Oral Methylphenidate Administration

Methylphenidate hydrochloride (MPH), more commonly known as Ritalin, is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder, one of the most common behavioural disorders of children and young adults. The aim of this study was to investigate dose-dependent immunohistochemical Dopamine 2 receptor (D2) expression and apoptosis in the rat cornea and cornea. In this study, 27 female pre-pubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) and their control groups, were used. They were treated orally with methylphenidate dissolved in saline solution for 5 days per week during 3 months. At the end of the third month, after perfusion fixation, eye tissue was removed. Paraffin sections were collected for immunohistochemical and terminal deoxynucleotidyl-transferase-mediated dUTP-biotin nick end labelling assay studies. In our study, we observed that the cornea D2 receptor reactivity showed a dose-related increase after MPH treatment, especially in basal cells of the epithelium and a dose-dependent decrease in the retinal ganglion cell which was statistically meaningful. Analysis of the cornea thickness results showed no meaningful difference between groups. Apoptotic cell number showed a meaningful increase in the high dose treated group compared to the other groups of the study. The data suggest that Ritalin has degenerative effect on the important functional part of the eye, such as cornea and retina and its activating dopaminergic mechanism via similar neuronal paths, functionally and structurally, to induce morphological changes. As a result, we believe that this morphological changes negatively effecting functional organization of the affected cornea and retina.     

Effect of polypropylene fiber cross sectional shapes on some structural/mechanical fiber properties and compressibility behaviour of plain knitted fabrics

Synthetic fibers are generally produced with circular cross sectional shapes. Other cross sectional shaped fibers such as trilobal, triangular, hollow and pentagonal fibers are also produced to improve some properties of fibers and fabrics such as lustre, handle, wicking rate, strength, stiffness and bulkiness. In this research we aimed to investigate compressional behaviours of fabrics knitted from polypropylene fibers having three different cross sectional shapes; namely circular, trilobal and triangular. Morphological, structural and mechanical properties of produced fibers were evaluated by using scanning electron microscopy, X-ray diffractometry, differential scanning calorimetry and tensile tester, respectively. In terms of structural and mechanical properties, no significant differences were found related to fiber cross sectional shapes. Then, plain knitted farbrics were produced and compressional properties of these fabrics were investigated. Fabrics knitted from trilobal fibers showed the highest compressibility properties and it is followed by fabrics which are produced from triangular and circular fibers.     

The influence of thermal stabilization stage on the molecular structure of polyacrylonitrile fibers prior to the carbonization stage

Structural transformation from a linear chain structure to crosslinked chain structure, occuring during the thermal stabilization stage of carbon fiber manufacture, was followed through the use of infrared spectroscopy, differential scanning calorimetry (DSC), elemental analysis and gel-fraction measurements. The results obtained from the analysis of IR spectroscopy showed the gradual and continuous loss of intensity of the nitrile (C≡N) vibration at 2242 cm⁻¹ closely associated with the cyclization reactions whereas the intensity loss of the methylene (CH₂) groups vibration around 2920–2939 cm⁻¹ has been attributed to the loss of hydrogen atoms as part of the dehydrogenation reactions. The dehydrogenation index, evaluated using the absorbance ratio of A₁₄₅₂/A₁₃₆₈, also indicated the gradual loss of hydrogens in agreement with decreasing hydrogen content with progressing stabilization process. IR spectroscopy also showed the emergence of new absorption bands attributed to the formation of crosslinked ladder-like structure in the 1590–1600 cm⁻¹ region. The amount of newly formed crosslinked structure was characterized using DSC conversion index, IR conversion index and gel-fraction measurements. The results are compared and discussed in detail.     

Effects of Root Plant Growth Promoting Rhizobacteria Inoculations on the Growth and Nutrient Content of Grapevine

The objective of this study was to evaluate the effects of seven nitrogen (N₂)-fixing and/or phosphorus (P)-solubilizing and siderophore-producing microorganism based bio-fertilizers in single and triple strain combinations isolated from the acidic rhizospheric soil of native tea, grapevine, and wild red raspberries. As a result of this study, bacterial efficiency was found to be variable and depended on the bacterial strains and evaluated growth parameters. Plant growth-promoting rhizobacteria (PGPR) has improved macro- and micro-nutrient concentrations in grapevine leaves, and stimulated plant growth. Triple inoculation and single inoculation based bio fertilizers were found to stimulate overall plant growth, including shoot and leaf weight, main shoot length, leaf ground index, chlorophyll, nitrogen, zinc and iron content of grapevine cv ‘Italy’. Bio-fertilizers increased the nutrients such as nitrogen, zinc and iron concentrations and consequently increased the chlorophyll content of the leaves.     

Simultaneous Determination of Phorate and Oxyfluorfen in Well Water Samples with High Accuracy by GC-MS After Binary Dispersive Liquid-Liquid Microextraction

The potential risk of pesticides to cause harm to humans and other organisms even at trace levels calls for sensitive and accurate analytical techniques for their simultaneous qualitative and quantitative determinations. In this study, a sensitive binary dispersive liquid-liquid microextraction (B-DLLME) strategy was developed for the simultaneous determination of phorate and oxyfluorfen by gas chromatography mass spectrometry after extraction/preconcentration from aqueous solution. An experimental design was used to optimize parameters of the B-DLLME method to obtain maximum outcome. Under the optimum conditions of B-DLLME, the limit of detection (LOD) for phorate and oxyfluorfen were found to be 0.41 μg L^?1 and 0.54 μg L^?1, respectively. The detection limits correlate to about 37 and 73 folds enhancement in detection powers when compared to direct GC-MS determination of phorate and oxyfluorfen, respectively. In order to find out the applicability of developed method to real samples, recovery tests were performed for 20 μg L^?1 of phorate and oxyfluorfen spiked in well water samples. Percent recovery values were found to be 94.5% for phorate and 101.9% for oxyfluorfen.