Evaluation of the sedative and clinical effects of xylazine, detomidine, medetomidine and dexmedetomidine in miniature donkeys.

Aim: To evaluate the sedative and clinical effects of I/V xylazine, detomidine, medetomidine and dexmedetomidine in miniature donkeys.Methods: Seven clinically healthy, male adult miniature donkeys with a mean age of 6 years and weight of 105 kg, were assigned to five I/V treatments in a randomised, cross-over design. They received either 1.1 mg/kg xylazine, 20 µg/kg detomidine, 10 µg/kg medetomidine, 5 µg/kg dexmedetomidine or saline, with a washout period of ≥7 days. The degree of sedation was scored using a 4-point scale by three observers, and heart rate (HR), respiration rate (RR), rectal temperature and capillary refill time (CRT) were recorded immediately before and 5, 10, 15, 30, 60, 90 and 120 minutes after drug administration.Results: All saline-treated donkeys showed no sedation at any time, whereas the donkeys treated with xylazine, detomidine, medetomidine and dexmedetomidine had mild or moderate sedation between 5 and 60 minutes after treatment, and no sedation after 90 minutes. All animals recovered from sedation without complication within 2 hours. The mean HR and RR of saline-treated donkeys did not change between 0 and 120 minutes after administration, but the mean HR and RR of donkeys treated with xylazine, detomidine, medetomidine and dexmedetomidine declined between 5 and 60 minutes after drug administration. The mean rectal temperature of all treated donkeys did not change between 0 and 120 minutes after administration. The CRT for all donkeys was ≤2 seconds at all times following each treatment.Conclusions and clinical relevance: Administration of xylazine at 1.1 mg/kg, detomidine at 20 µg/kg, medetomidine at 10 µg/kg and dexmedetomidine at 5 µg/kg resulted in similar sedation in miniature donkeys. Therefore any of the studied drugs could be used for sedation in healthy miniature donkeys.

Changes of acute-phase proteins during different phases of the estrous cycle in Ovsynch-synchronized Holstein cows.

BACKGROUND: Acute-phase proteins (APPs) may be increased due to different stresses during estrus phase in farm animals. AIMS: Determining changes of APPs at different phases of non-synchronized estrous cycle group (NSEG), and Ovsynch-synchronized estrous cycle group (SEG) in Holstein cows. METHODS: Twelve non-pregnant clinically and paraclinicaly healthy Holstein cows with a body condition score (BCS) of 2.75 and 70 days in milk were chosen. Two groups including NSEG and SEG were performed. Blood sampling was carried out from NSEG at the time of diestrus, proestrus, and estrus. In SEG, blood sampling was performed on day 7 (at the time of prostaglandin injection, equivalent diestrus), day 9 (at the time of gonadotropin-releasing hormone (GnRH) injection, equivalent proestrus), and day 10 (at the time of insemination, equivalent estrus) of synchronization protocol. Concentrations of haptoglobin (Hp), serum amyloid A (SAA), ceruloplasmin (Cp), and fibrinogen (Fib) were measured. RESULTS: Concentration of Hp at estrus phase was significantly higher compared with diestrus (P=0.001) and proestrus (P=0.019) in NSEG. Moreover, Hp level in the NSEG was significantly higher than SEG at estrus phase (P=0.002). Concentrations of SAA, Cp, and Fib had no significant differences during various phases of estrous cycle in each group or between equivalent phases of both groups. CONCLUSION: It seems that unlike SAA, Fib, and Cp, concentrations of Hp may be affected by different phases of estrous cycle. Although APPs are not specific indicators, their changes besides other clinical and paraclinical indices may be helpful for more accurate heat detection in dairy cows.

Altered expression and functional role of ion channels in leukemia: bench to bedside.

Leukemic cells' (LCs) survival, proliferation, activation, differentiation, and invasiveness/migration can be mediated through the function of cation and anion channels that are involved in volume regulation, polarization, cytoskeleton, and extracellular matrix reorganization. This study will review the expression of ion channels in LCs and their possible function in leukemia progression. We searched relevant literature by a PubMed (2002-2019) of English-language literature using the terms "ion channels", "leukemia", "proliferation", "differentiation", "apoptosis", and "migration". Altered expression and dysfunction of ion channels can have a strong impact on hematopoietic cell and LCs physiology and signaling, which contributes to the vital processes such as proliferation, differentiation, and apoptosis. Indeed, it can be stated that changing expression of ion channels can affect the onset and progression as well as clinical features and therapeutic responses of leukemia via inducing the maintenance of LCs. Since ion channels are membrane proteins, they can be easily accessible in LCs for understanding their influence on leukemia progression. On the other hand, ion channels can be new potential targets for chemotherapeutic agents, which may open a novel clinical and pharmaceutical field in leukemia therapy.

Macrophage/microglial-mediated primary demyelination and motor disease induced by the central nervous system production of interleukin-3 in transgenic mice.

Activated macrophage/microglia may mediate tissue injury in a variety of CNS disorders. To examine this, transgenic mice were developed in which the expression of a macrophage/microglia activation cytokine, interleukin-3 (IL-3), was targeted to astrocytes using a murine glial fibrillary acidic protein fusion gene. Transgenic mice with low levels of IL-3 expression developed from 5 mo of age, a progressive motor disorder characterized at onset by impaired rota-rod performance. In symptomatic transgenic mice, multi-focal, plaque-like white matter lesions were present in cerebellum and brain stem. Lesions showed extensive primary demyelination and remyelination in association with the accumulation of large numbers of proliferating and activated foamy macrophage/microglial cells. Many of these cells also contained intracisternal crystalline pole-like inclusions similar to those seen in human patients with multiple sclerosis. Mast cells were also identified while lymphocytes were rarely, if at all present. Thus, chronic CNS production of low levels of IL-3 promotes the recruitment, proliferation and activation of macrophage/microglial cells in white matter regions with consequent primary demyelination and motor disease. This transgenic model exhibits many of the features of human inflammatory demyelinating diseases including multiple sclerosis and HIV leukoencephalopathy.

Chemical composition and antifungal effect of hydroalcoholic extract of Allium tripedale (Tvautv.) against Candida species.

BACKGROUND AND PURPOSE: Treatment of life-threatening fungal infections caused by Candida species has become a major problem. Candida spp. are the most important causative agents of candidiasis. Allium tripedale is a medicinal plant that has been traditionally used to treat infections. In the present study, we aimed to determine the chemical compounds and antimicrobial activity of hydroalcoholic extract of A. tripedale against different species of Candida. MATERIALS AND METHODS: Phytochemical analysis was performed to identify the possible bioactive components of this extract by using gas chromatography and mass spectroscopy (GC-MS). The hydroalcoholic extract of A. tripedale were collected. Different concentrations of A. tripedale (50, 25, 12.5, and 6.25 mg/ml) were used to evaluate its antifungal activity against Candida species (C. albicans, C. parapsilosis, and C. krusei) using disk diffusion assay. RESULTS: The GC-MS analysis revealed the presence of 40 different phytoconstituents with peak area; the major compounds were tetracosane, hexadecanoic acid, 1-eicosanol, 1,2-dihydro-pyrido[3,2,1-kl]phenothiazin-3-one, 2-hexadecen-1-ol, and 3,7,11,15-tetramethyl. Hydroalcoholic extract showed strong antimicrobial activity (inhibition zone ⩾ 20 mm), moderate antimicrobial activity (inhibition zone < 12-20 mm), and no inhibition (zone < 12 mm). In addition, the hydroalcoholic extract exhibited the highest antimicrobial properties against C. albicans strains. CONCLUSION: A. tripedale extract had a considerable inhibitory effect against various Candida species, but its highest inhibitory effect was against Candid albicans. Further investigations are required to detect the performance of this plant in the treatment of Candida infection.

Mechanism of inhibition of lysyl hydroxylase activity by the organophosphates malathion and malaoxon.

Direct inhibition of lysyl hydroxylase by malathion and malaoxon was observed in an in vitro enzyme assay with recombinant lysyl hydroxylase expressed via a baculoviral system. The IC50 values for malathion and malaoxon were estimated to be approximately 60 and 45 mM, respectively. Additional kinetic studies showed this inhibition to be competitive or partially competitive with respect to the synthetic (collagen) peptide, partially uncompetitive with respect to Fe(2+), and partially noncompetitive with respect to ascorbic acid. The calculated values for the K(i) were consistent with the IC50 values. Allosteric effects were not found for any of the cofactors tested, the peptide substrate, or the inhibitors. Interactions were found to be unimolecular for lysyl hydroxylase and its substrate and cofactors as well as for the inhibitors malathion and malaoxon. A computer search of a protein structure database showed an unexpected region of partial homology between the active site sequence of acetylcholinesterase and a segment of lysyl hydroxylase, suggesting a possible molecular basis for these observations. These results suggest the possibility of a novel and hitherto unexpected class of inhibitors of lysyl hydroxylase, based on the organophosphate structure, that might be of value for testing as antifibrotic drugs.

Inhibition of lysyl hydroxylase by malathion and malaoxon.

The inhibition of lysyl hydroxylation in newly synthesized collagen by malathion and its oxidation product malaoxon were studied with cultured rat fetal lung fibroblasts. Exposure of these cells to 125 microM malathion or malaoxon for 96 h resulted in a 25 and a 30% decrease in the ratio of hydroxylated lysine/lysine residues, respectively, in acid hydrolyzed cell lysates compared to control values. This relative decrease in hydroxylysine was not caused by cytotoxicity or changes in total collagen content, which were found to remain constant as measured by Alamar Blue metabolism and Sircol dye binding assays. Direct inhibition of lysyl hydroxylase by malathion and malaoxon was observed using an in vitro enzyme assay with recombinant lysyl hydroxylase with a baculoviral system. The IC50 values for malathion and malaoxon were estimated to be approximately 60 and 45 microM, respectively. These observed IC50 values are consistent with calculated values for the intracellular concentration of malathion in the cell culture experiments. These results support a significant role for inhibition of lysyl hydroxylase activity as causing, or contributing to, the teratogenic effects of malathion and malaoxon.

Expression of the inducible nitric oxide synthase. Correlation with neuropathology and clinical features in mice with lymphocytic choriomeningitis.

Nitric oxide (NO) synthesized by the cytokine-inducible enzyme, nitric oxide synthase (iNOS), is thought to be a key mediator in the host immune response to infection, in which it may have protective, as well as injurious, actions. We sought evidence for a role of NO in the pathogenesis of lymphocytic choriomeningitis by examining the cerebral expression of the iNOS gene in mice after intracranial inoculation of lymphocytic choriomeningitis virus. In euthymic, but not athymic, mice, elevated expression of iNOS mRNA was observed in the brain by day 5 and increased further to high levels by day 6 postinfection. Of the peripheral organs, only the spleen showed significant increases in iNOS mRNA at day 3 postinfection. In situ hybridization revealed that iNOS RNA expression was restricted to cells within the inflammatory infiltrates and in proximity to areas of lymphocytic choriomeningitis virus infection in the brain. Immunostaining for iNOS protein identified numerous positive cells within the inflammatory infiltrates present in the meninges and choroid plexus. Phenotypic analysis revealed the majority of the iNOS containing cells to be Mac-1 positive. T lymphocytes that belonged to the CD8+ and CD4+ subsets were negative for iNOS expression. The kinetics and distribution of cerebral iNOS expression in lymphocytic choriomeningitis are consistent with a major role for the iNOS/NO pathway in the pathogenesis of this immune-mediated neurologic disease.

Chronic complement C3 gene expression in the CNS of transgenic mice with astrocyte-targeted interleukin-6 expression.

Both cytokines and complement are thought to play significant, but poorly understood roles, in the pathogenesis of a variety of neurodegenerative diseases. In this study, we examined the expression of C3, the central component of complement, in the brains of transgenic mice with constitutive astrocyte expression of the proinflammatory cytokine, interleukin-6 (IL-6). Immunohistochemistry studies demonstrated elevated deposition of C3 in the brains of transgenic animals compared with normal animals. Northern blot analysis of mRNA from brain and other tissues demonstrated an age-related increase in C3 gene expression only in the brains of transgenic animals, indicative of local synthesis. In situ hybridization studies revealed coincidence between C3 and IL-6 transgene expression, as well as areas of neuronal and white matter damage observed in cerebellum and hind brain. Furthermore, C3 mRNA expression was observed in ependymal cells, perivascular mononuclear cells, endothelial cells, and scattered cells throughout the white matter and the brain stem. The overlap in C3 mRNA expression with areas of pathology suggests that complement may contribute to the inflammation and cellular injury observed in this model. The transgenic mice used in these studies provide a novel and valuable tool for examining the role of complement in central nervous system pathobiology.

Reactive gliosis as a consequence of interleukin-6 expression in the brain: studies in transgenic mice.

Gliosis is a characteristic pathologic state in many CNS disorders. Cytokines are considered to be effectors of gliosis. In order to explore the role of IL-6 in gliosis, the temporal and spatial expression of the IL-6 gene and its consequent effects on the brain were studied in a GFAP-IL6 transgenic mouse model. In GFAP-IL6 mice, IL-6 transgene expression was detectable in the brain at 1 week postnatally and increased to maximal levels by 3 months of age before declining at 8 and 12 months. Enhanced glial fibrillary acidic protein (GFAP) (marker for astrocytes) and Mac-I (marker for microglia) mRNA expression were first prominent at 1 month, increased to maximum levels by 3 months and remained significantly elevated through 12 months of age. Western blot analysis revealed that the enhanced GFAP mRNA expression in these transgenic mice was accompanied by increased GFAP protein levels. Immunostaining for Mac-I demonstrated that in addition to an increased staining intensity, the number of cells expressing the microglial/macrophage marker was also apparently increased, particularly in the cerebellum and brain stem. Concurrent with IL-6 transgene mRNA expression and reactive gliosis, upregulation of IL-1 alpha/beta, TNF alpha, ICAM-1 and EB22/5.3 (acute-phase reactant) but not inducible nitric oxide synthase gene expression was also observed. EB22/5.3 mRNA expression was most prominent and increased progressively with age. Expression of the IL-6, GFAP and EB22/5.3 RNAs was found to have similar distribution in the brain being found predominantly in the cerebellum, brain stem and sub-cortical regions. In conclusion, the constitutive expression of IL-6 in the brain induced the development of a pronounced and lifelong reactive gliosis affecting both astrocytes and microglia. The altered state of these cells may contribute to the functional and structural CNS impairment exhibited by the GFAP-IL6 mice. Finally, in these mice, expression of the EB22/5.3 gene correlated closely with the progression of neuropathy indicating that this acute-phase response gene was a good marker for and may be involved in the pathogenesis of CNS injury mediated by the expression of IL-6.

Progressive decline in avoidance learning paralleled by inflammatory neurodegeneration in transgenic mice expressing interleukin 6 in the brain.

Inflammation with expression of interleukin 6 (IL-6) in the brain occurs in many neurodegenerative disorders. To better understand the role of IL-6 in such disorders, we examined performance in a learning task in conjunction with molecular and cellular neuropathology in transgenic mice that express IL-6 chronically from astrocytes in the brain. Transgenic mice exhibited dose- and age-related deficits in avoidance learning that closely corresponded with specific progressive neuropathological changes. These results establish a link between the central nervous system expression of IL-6, inflammatory neurodegeneration, and a learning impairment in transgenic mice. They suggest a critical role for a proinflammatory cytokine in the cognitive deficits and associated neuroinflammatory changes that have been documented in neurodegenerative diseases such as Alzheimer disease and AIDS.