Cytotoxic Effects of Loperamide Hydrochloride on Canine Cancer Cells     

Rebecca Cohen REGAN  Robert Michael GOGAL  Jr  James Perry BARBER  Richard Cary TUCKFIELD  Elizabeth Wynne HOWERTH  Jessica Ann LAWRENCE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(12):1563-1568

Loperamide is a peripheral opiate agonist that can cause apoptosis and G2/M arrest in human cancer cell lines and may sensitize cells to chemotherapy. The objectives of this study were to investigate the effects of loperamide on viability, apoptosis and cell cycle kinetics in canine cancer cells and to establish whether the drug sensitizes cells to doxorubicin. Cell viability was assessed using Alamar Blue. Cell death and cell cycle were studied using flow cytometry with 7-Aminoactinomycin-D (7-AAD) and propidium iodide (PI), respectively. Loperamide decreased cell viability in a dose-dependent fashion and was most effective against canine osteosarcoma cells. In all cell lines, it induced a dose and time dependent apoptosis and resulted in accumulation in G0/G1. When co-incubated with doxorubicin, loperamide induced a synergistic cell kill in canine carcinoma cells. Investigation is warranted into the role of loperamide in the treatment of canine cancer.  相似文献   

The Post‐Cervical Insemination does not Impair the Reproductive Performance of Primiparous Sows     

PE Sbardella  RR Ulguim  DL Fontana  CV Ferrari  ML Bernardi  I Wentz  FP Bortolozzo 《Reproduction in domestic animals》2014,49(1):59-64

The study evaluated the reproductive performance of primiparous sows submitted to post‐cervical insemination (PCAI) compared with cervical artificial insemination (CAI). Difficulty with catheter introduction, the occurrence of bleeding or semen backflow during insemination, and volume and sperm cell backflow up to 60 min after insemination were also evaluated. Sows were homogenously distributed, according to body weight loss in lactation, lactation length, weaned piglets, weaning‐to‐oestrus interval and total born in previous farrowing, in two treatments: PCAI (n = 165) with 1.5 × 10⁹ sperm cells in 45 ml (2.4 ± 0.04 doses per sow) and CAI (n = 165) with 3 × 10⁹ sperm cells in 90 ml (2.5 ± 0.04 doses per sow). During PCAI, sows were inseminated in the absence of boars. Transabdominal real‐time ultrasonography was performed at oestrus onset, immediately before the first insemination and at 24 h after last insemination. There was no difference (P > 0.05) between treatments in farrowing rate (91.5% × 89.1%) and litter size (12.5 × 11.9 piglets born, respectively for PCAI and CAI sows). Successful passage of the intrauterine catheter in all the inseminations was possible in 86.8% (165/190) of sows initially allocated to PCAI treatment. Difficulty of introducing the catheter in at least one insemination did not affect the reproductive performance of PCAI sows (P > 0.05). Bleeding during insemination did not affect (P > 0.05) the farrowing rate in both treatments, but litter size was reduced in CAI and PCAI sows (P ≤ 0.06). Percentage of spermatozoa present in backflow within 1 h after insemination was greater in CAI than PCAI sows (P < 0.01). More than 85% of primiparous sows can be successfully post‐cervical inseminated with doses containing 1.5 × 10⁹ sperm cells in the absence of the boar during insemination without impairing the reproductive performance.  相似文献   

The effects of hypoxia,in vivo,on red blood cell β-adrenoceptors in the rainbow trout,Oncorhynchus mykiss     

Steve G. Reid  Steve F. Perry 《Fish physiology and biochemistry》1995,14(6):519-524

Rainbow trout, Oncorhynchus mykiss, were exposed to 48h of environmental hypoxia (water partial pressure of oxygen = 8.0 kPa) at either 5 or 15°C. Blood was sampled during hypoxia via a dorsal aorta cannula to measure arterial blood partial pressure of oxygen and plasma catecholamine concentrations. After 48h, the number (B_max) and dissociation constant (K_d) of red blood cell surface -adrenoceptors were determined using a radioligand-displacement binding assay. At 5°C, plasma catecholamine levels were elevated at 24h whereas at 15°C, levels were elevated at 48h. At either temperature, following 48h of hypoxia, there was no change in B_max or K_d of red blood cell surface -adrenoceptors, compared to normoxic control fish. This study demonstrates that chronic exposure to moderate hypoxia does not affect the number or affinity of cell surface -adrenoceptors on trout red blood cells.  相似文献   

Acute Toxicity of Ammonia to Spotted Gar, Lepisosteus oculatus, Alligator Gar, Atractosteus spatula, and Paddlefish, Polyodon spathula     

Perry J.  Boudreaux  Allyse M.  Ferrara  Quenton C.  Fontenot 《Journal of the World Aquaculture Society》2007,38(2):322-325

  相似文献   

Stereological Analysis of Blood Space and Tissue Types in the Pseudobranch of the Rainbow Trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>)     

W.?P.?WaserEmail author  A.?Schmitz  S.?F.?Perry  A.?Wobschall 《Fish physiology and biochemistry》2005,31(1):73-82

The teleost pseudobranch, a reduced mandibular gill arch, morphologically closely resembles a gill hemibranch. It consists of several filaments bearing numerous lamellae. The vascular system of the pseudobranch also matches that of a gill, with afferent and efferent filamental arteries and the lamellar blood space. Despite the pseudobranch’s gill-like appearance, however, a gas exchange function is excluded in many teleosts by overlying opercular epithelium, effectively eliminating diffusional exchange with the external medium. The physiological function of the pseudobranch is still unknown, though its conspicuously close association with the ocular choroid rete mirabile, a structure supporting elevated oxygen partial pressures in the eye, suggests a role related to the process of oxygen secretion into the eyes of teleosts. In this paper we present new stereological data on the pseudobranch of rainbow trout (average weight: 478 ± 114 g, x ± SD, n = 12). The total Cavalieri volume of the pseudobranch was 46.4 μl (97 μl kg⁻¹), consisting of lamellae 49%, connective tissue 43.8%, large blood vessels 4.5%, filamental cartilage 2.3%, and central venous sinus 1.3%. Lamellae were comprised of pillar and pseudobranchial cells 81%, blood space 12.3%, and lacunar tissue 6.4%. The inner surface of the blood space in the lamellae was 12.2 cm² (25.5 cm² kg⁻¹), and its volume was 2.81 μl (5.88 μl kg⁻¹). The results demonstrate the pseudobranch’s potential for physiological functions requiring a high surface area or surface-to-volume ratio, i.e. ion transfer, gas exchange and other regulatory processes. More detailed analysis of the function of the pseudobranch, however, has to remain subject of future morphological and physiological studies.  相似文献   

Effects of prolonged epinephrine infusion on blood respiratory and acid-base states in the rainbow trout: Alpha and beta effects   总被引：2，自引：0，他引：2  

M. G. Vermette  S. F. Perry 《Fish physiology and biochemistry》1988,4(4):189-202

Rainbow trout were infused continuously for 12h with epinephrine in the presence or absence of alpha-and/or beta-adrenergic blockade to characterize the specific adrenergic mechanisms involved in the control of blood acid-base status and oxygen transport capacity. Infusion of epinephrine, alone, produced a transient respiratory acidosis, as indicated by an increase in carbon dioxide tension and a decrease in whole blood pH, yet arterial oxygen tension was elevated. Red blood cell pH increased by approximately 0.2 pH units during epinephrine infusion and this increase as well as the increase in oxygen tension were prevented by pretreatment with propranolol (a beta-adrenergic antagonist). Epinephrine infusion during alpha-adrenergic blockade caused a prolonged elevation of blood carbon dioxide tension and abolished the increases in hematocrit and hemoglobin concentrations observed during epinephrine infusion alone. Infusion of the alpha-adrenergic agonists phenylephrine (an alpha₁ agonist) or clonidine (an alpha₂ agonist) caused respiratory acidosis (decreased pH, increased CO₂ tension) and a reduction in oxygen tension. Infusion of isoprenaline (a non-specific beta agonist) caused delayed increases in carbon dioxide and oxygen tensions. We speculate that the increased carbon dioxide tension observed during epinephrine infusion is a result of beta-adrenoceptor mediated inhibition of red blood cell bicarbonate dehydration and not branchial convective or diffusive adjustments. The effects of epinephrine on blood O₂ tension, content and carrying capacity are discussed with reference to the participation of alpha- and beta-adrenergic mechanisms at the gill, spleen and red blood cell.  相似文献   

Quantification of presumptive Na+/H+ antiporters of the erythrocytes of trout and eel     

Scott D. Reid  Steve F. Perry 《Fish physiology and biochemistry》1994,12(6):455-463

The presumptive Na⁺/H⁺ exchange sites of trout and eel erythrocytes were quantified using amiloride-displaceable 5-(N-methyl-N-[³H]isobutyl)-amiloride (³H-MIA) equilibrium binding to further evaluate the mechanisms of i) hypoxia-mediated modifications in the trout erythrocyte -adrenergic signal transduction system and ii) the marked differences in the catecholamine responsiveness of this system between the trout and eel. MIA was a more potent inhibitor of both trout apparent erythrocyte proton extrusion (IC₅₀ = 20.1 ± 1.1 mol l^–1, N = 6) activity (as evaluated by measuring plasma pH changes after addition of catecholamine in vitro) and specific ³H-MIA binding (IC₅₀ = 257 ± 8.2 nmol l^–1, N = 3) than amiloride, which possessed a proton extrusion IC₅₀ of 26.1 ± 1.6 mol l^–1 (N = 6) and a binding IC₅₀ of 891 ± 113 nmol l^–1 (N = 3). The specific Na⁺ channel blocker phenamil was without effect on adrenergic proton extrusion activity or specific ³H-MIA binding. Trout erythrocytes suspended in Na⁺-free saline and maintained under normoxic conditions possessed 37,675 ± 6,678 (N = 6) amiloride-displaceable ³H-MIA binding sites per cell (B_max, presumptive Na⁺/H⁺ antiporters) with an apparent dissociation constant (K_D) of 244 ± 29 nmol l^–1 (N = 6). Acute hypoxia (PO₂ = 1.2 kPa; 30 min) did not affect the K_D, yet resulted in a 65% increase in the number of presumptive Na⁺/H⁺ antiporters. Normoxic eel erythrocytes, similarly suspended in Na⁺-free saline, possessed only 17,133 ± 3,716 presumptive Na⁺/H⁺ antiporters (N = 6), 45% of that of trout erythrocytes, with a similar K_D (246 ± 41 nmol l^–1, N = 6). These findings suggest that inter- and intra-specific differences in the responsiveness of the teleost erythrocyte -adrenergic signal transduction system can be explained, in part, by differences in the numbers of Na⁺/H⁺ exchange sites.  相似文献   

Cryptic genetic diversity in “widespread” Southeast Asian bird species suggests that Philippine avian endemism is gravely underestimated     

David J. Lohman  Krista K. Ingram  Kevin Winker  Robert G. Moyle  Perry S. Ong  Thomas M. Braile  Dwi Astuti 《Biological conservation》2010,143(8):1885-1890

Mistakenly classifying morphologically cryptic endemic species as populations of widespread species potentially interferes with the conservation of biodiversity because undetected endemics that are imperilled may lack appropriate protection. It also impedes the reconstruction of the evolutionary history of a taxon by obscuring the number and distributional limits of species. Here, we present genetic and phylogenetic evidence corroborated by morphology that Philippine populations of seven widespread, non-migratory passerine birds might represent unrecognized, distinct species. An extrapolation based on this finding suggests that the proportion of endemic bird species in the Philippines could be much higher than currently estimated. This high degree of cryptic diversity in a well-studied, volant taxon implies that large numbers of unrecognized species can be expected in less thoroughly studied groups. We predict that genetic investigations of insular populations of widespread species will frequently reveal unrecognized island endemics, and because of the vulnerability of island habitats and their biota, these taxa may be particularly susceptible to extinction.  相似文献   

The impact of Theileria parva infections and other factors on calf mean daily weight gains in smallholder dairy farms in Murang’a District, Kenya     

G. K. Gitau  J. J. McDermott  B. McDermott  B. D. Perry 《Preventive veterinary medicine》2001,51(3-4)

The association between mean daily weight gain, Theileria parva infections, clinical East Coast fever and other possible determinants of weight gain were examined in a longitudinal observational study that was conducted in cohorts of female calves from five agro-ecological zone (AEZ)-grazing strata. The strata were upper-midlands (UM) 1 zero-grazing, UM 1 open-grazing, UM 2 zero-grazing, UM 4 zero-grazing and UM 4 open-grazing. In total, 225 calves on 188 smallholder dairy farms were visited within the first 2 weeks of life and thereafter at biweekly intervals up to the age of 6 months between March 1995 and August 1996. During each visit, the calves were weighed and other calf-management practices in the farm during the visit such as housing, feeding and tick control also were recorded. Other events such as morbidity and mortality between or during the visits were also recorded.The overall mean daily weight gains were 0.24–0.29 kg (S.D.=0.17–0.22 kg) and were lower than the recommended targets for smallholder farms of 0.40–0.50 kg. The major tendency in variability of daily weight gains was due to visit-to-visit variation (especially in calves >3 months old).Differences in mean daily gains were associated with AEZ-grazing strata and calf-level factors that included breed of calf, calf sickness, incidence of ECF, feeding of milk, concentrate feeds and minerals and interaction between calf age and AEZ-grazing strata (P<0.05). ECF and other calf sicknesses exerted a temporal effect on calf-growth at the height of illness and immediately after; calves later recovered the lost growth except where other factors such as poor calf nutrition prevailed. Improvement in calf-growth in Murang’a District is achievable and extension services should continue to target individual-calf-level management practices.  相似文献   

Disorders of the avian integument.     

R A Perry  J Gill  G M Cross 《Veterinary Clinics of North America: Small Animal Practice》1991,21(6):1307-1327

The avian integument consists of highly specialized structures that show extreme variations between species. Feathers are the most obvious part of the integument, and their color and beauty forms an important basis for the attraction of birds to humans. Any disorder in the feathers can be distressing for a client and frustrating for the avian practitioner. The cause of some disorders may be apparent, but others have a complex pathogenesis involving management, human-bird interaction, malnutrition, psychologic factors, disease, or hormone imbalances.  相似文献