Effect of a novel solution for organ preservation on equine large colon in an isolated pulsatile perfusion system     

Polyak MM  Morton AJ  Grosche A  Matyjaszek S  Freeman DE 《Equine veterinary journal》2008,40(4):306-312

REASONS FOR PERFORMING STUDY: Several therapeutic agents have been tested in models of ischaemia and reperfusion injury (IRI) in equine jejunum, with mixed results. This study was based on the use of an organ perfusion solution (OPS) designed to protect human allografts from IRI. HYPOTHESIS: A modified OPS can preserve the integrity of equine large colon during 12 h of isolated pulsatile perfusion, in the absence of oxygen and blood. METHODS: Segments of large colon were removed from anaesthetised horses, the contents removed and the mucosa rinsed with 0.9% saline. Experimental segments were perfused for 12 h with one litre modified OPS (n = 7) delivered by pulsatile flow through an extracorporeal circuit. Control segments (n = 4) were perfused on the same circuit with one litre of autologous blood. Vascular resistance, flow and pressure were measured serially, and aliquots of OPS and blood drawn hourly for routine biochemical analyses. Mucosal biopsies of the experimental and control segments were taken at 0, 6 and 12 h and in vivo mucosal tissue at 0 h for baseline comparison. All biopsies underwent histomorphometric analysis and immunohistochemical assessment of calprotectin activity. RESULTS: All colon segments were machine perfused without technical complications. Vascular and biochemical indices remained constant over 12 h in the OPS group, and were constant over 6 h in the control group, but deteriorated later. Mucosal integrity, expression of cyclooxygenases-1 and -2, and expression of mucosal calprotectin were unchanged in the OPS group compared with the baseline tissues, and mucosal integrity was superior to the control tissues. CONCLUSIONS: A modified OPS designed to target specific pathways of damage from IRI can preserve colonic mucosal integrity for 12 h in the absence of blood and oxygen.  相似文献   

Detection of calprotectin and its correlation to the accumulation of neutrophils within equine large colon during ischaemia and reperfusion     

Grosche A  Morton AJ  Polyak MM  Matyjaszek S  Freeman DE 《Equine veterinary journal》2008,40(4):393-399

REASON FOR PERFORMING STUDY: The cytosolic protein complex, calprotectin, is abundant in neutrophils and could be used to improve the ability to localise and assess neutrophil infiltration in the equine intestine during ischaemia and reperfusion (I/R), but further study is required. OBJECTIVES: To assess the number of calprotectin-containing cells by immunohistochemistry in correlation with direct counting and scoring of neutrophils in the equine colon during I/R. METHODS: One and 2 h ischaemia of the left dorsal colon were induced, followed by 30 min reperfusion under general anaesthesia or by 18 h reperfusion after anaesthetic recovery. Biopsies were processed for light microscopy and stained with H/E for detection of neutrophils. To identify calprotectin-containing cells, immunohistochemistry was performed on formalin-fixed tissues with the murine MAC 387 antibody and a biotin-free peroxidase staining procedure. The number of neutrophils within submucosal venules and the colonic mucosa were calculated and compared with the number of calprotectin-positive cells. RESULTS: The number of calprotectin-positive cells within submucosal venules and within the colonic mucosa correlated significantly with the accumulation of neutrophils within the corresponding tissue segments. Within the submucosal venules, both calprotectin-positive cells and H/E-stained neutrophils increased with duration of ischaemia and peaked after 30 min of reperfusion. After 18 h reperfusion the number of these cells declined within the vessels. After 2 h ischaemia, neutrophils started to migrate into the mucosa towards the epithelium, with a significant increase over time during reperfusion, and peak infiltration after 18 h reperfusion. CONCLUSIONS: Neutrophil infiltration into the colon after I/R is a time-dependent process, involving migration through the submucosa towards the epithelium.  相似文献   

In Vitro Fertilization (IVF) in Straws and a Short Gamete Coincubation Time Improves the Efficiency of Porcine IVF     

C Almiñana  MA Gil  C Cuello  I Caballero  J Roca  JM Vazquez  EA Martinez 《Reproduction in domestic animals》2008,43(6):747-752

The present study was designed to evaluate three different in vitro fertilization (IVF) systems: a straw‐IVF system with 10 min of coincubation, a straw‐IVF system with 6‐h coincubation and the microdrop‐IVF system with 6‐h coincubation (the traditional IVF system used routinely in most of IVF laboratories) in an attempt to reduce polyspermic penetration ( Experiment 1 ). When the straw‐IVF system was tested in combination with two coincubation times, the use of 10 min of coincubation significantly increased (p < 0.001) the penetration rate and the efficiency of fertilization (67.7 ± 6.4% vs 31.9 ± 6.5% and 41.5 ± 2.5% vs 17.6 ± 2.5% for 10 min and 6 h, respectively), while there were no significant differences in the incidence of monospermy between both systems (64.3 ± 5.1% and 67.7 ± 3.4%, for 10 min and 6 h, respectively). The penetration rate in the 6‐h microdrop‐IVF system was higher (93.8 ± 3.6%; p < 0.001) compared with the 10‐min straw‐IVF system (67.7 ± 6.4%), however, monospermy was severely reduced (25.0 ± 4.3% vs 67.7 ± 3.4%, for the 6‐h microdrop‐IVF system and 10‐min straw‐IVF system, respectively). The efficiency of the IVF showed similar values between microdrop and 6‐h straw‐IVF systems, but efficiency was significantly improved (p < 0.05) when the 10‐min straw‐IVF system was used. Experiment 2 was designed to compare porcine in vitro embryo production in two IVF systems, the 6‐h microdrop‐IVF system (1000 sperm per oocyte) and 10‐min straw‐IVF system (30 000 sperm per oocyte). The blastocyst formation rates tended (p = 0.06) to be higher when the 10‐min straw‐IVF system was used compared with the 6‐h microdrop‐IVF system. In addition, the number of total cells per blastocyst increased significantly (p < 0.05) in the 10‐min straw‐IVF system. These results showed that the 10‐min straw‐IVF system is an effective way to decrease polyspermic penetration, and improve the efficiency of fertilization and the quality of blastocysts in terms of cell number per embryo.  相似文献   

Insulin glargine has a long duration of effect following administration either once daily or twice daily in divided doses in healthy cats     

Marshall RD  Rand JS  Morton JM 《Journal of Feline Medicine and Surgery》2008,10(5):488-494

The pharmacological effects of glargine administered once or twice daily were compared in six healthy cats. A two-way crossover study was performed with insulin and glucose concentrations measured following subcutaneous administration of glargine once daily (0.5U/kg) or twice daily (0.25U/kg, repeated after 12h). Nadir glucose concentration and mean daily glucose concentration did not differ significantly following insulin administration once daily or twice daily in divided doses. Time to reach last glucose nadir differed, with longer intervals occurring following twice daily dosing. Blood glucose failed to return to baseline concentration by 24h in three of six cats in each treatment group. Insulin variables were not significantly different following once or twice daily dosing. This study in healthy cats demonstrates that glargine has a long duration of action with carry-over effects to the next day likely, regardless of dosing regimen. A study in diabetic cats is required to determine the best dosing regimen.  相似文献   

The effect of organophosphate insecticides on adrenal corticosterone formation     

Morton Civen  Charlesta B. Brown 《Pesticide biochemistry and physiology》1974,4(3):254-259

In vitro and in vivo experiments with Sprague-Dawley rats showed that the three organophosphate insecticides tested (see below) depressed endogenous corticosterone synthesis and blocked corticosteroidogenesis in response to ACTH and cAMP stimulation of a suspension of adrenal cells. Pregnenolone stimulation of adrenal cells was not inhibited at the insecticide concentrations which blocked the ACTH and cAMP stimulation of corticosteroidogenesis. It was concluded that the insecticides act beyond the site of action of ACTH and at or beyond the level of cAMP metabolism and prior to the metabolism of pregnenolone.Insecticides tested were: dichlorvos (O,O-dimethyl-O,2,2-dichlorovinyl phosphate), Dursban (phosphorothioic acid: O,O-diethyl O-3,5,6-trichloro-2-pyridyl ester), and Diazinon (phosphorothioic acid: O,O-diethyl O-(2-isopropyl-6-methyl-4-pyrimidinyl ester).  相似文献   

A vesicular (blistering) skin condition in a dog following putative contact exposure to Plumbago auriculata          下载免费PDF全文

A Seavers  D Robson  JM Weingarth 《Australian veterinary journal》2016,94(8):290-292

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Temporal and spatial variation of a winter soundscape in south-central Alaska     

Timothy C. Mullet  Stuart H. Gage  John M. Morton  Falk Huettmann 《Landscape Ecology》2016,31(5):1117-1137

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Ordering of ruthenium cluster carbonyls in mesoporous silica     

W Zhou  JM Thomas  DS Shephard  BFG Johnson  D Ozkaya  T Maschmeyer  RG Bell  Q Ge 《Science (New York, N.Y.)》1998,280(5364):705-708

The anionic ruthenium cluster carbonylates [Ru6C(CO)16]2- or [H2Ru10(CO)25]2- interspersed with bis(triphenylphosphino)iminium counterions (PPN+) are incorporated from solution into the pores of MCM-41 mesoporous silica (3 nanometers in diameter), where they form tightly packed arrays. These arrays were shown by high-resolution transmission electron microscopy, Fourier transform optical diffraction, and computer simulations to be well ordered both along and perpendicular to the axis of the cylindrical pores. In their denuded state produced by gentle thermolysis, the cluster carbonylates yield nanoparticles of ruthenium that are less well ordered than their assimilated precursors but show good activity as hydrogenation catalysts for hexene and cyclooctene. In both their as-prepared and denuded states, these encapsulated clusters are likely to exhibit interesting electronic and other properties.  相似文献   

Near extinction of a large, widely distributed fish     

JM Casey  RA Myers 《Science (New York, N.Y.)》1998,281(5377):690-692

Are extinctions of marine vertebrates as rare and unlikely as current data indicate? Long-term research surveys on the continental shelf between the Grand Banks of Newfoundland and southern New England reveal that one of the largest skates in the northwest Atlantic, the barndoor skate (Raja laevis), is close to extinction. Forty-five years ago, research surveys on St. Pierre Bank (off southern Newfoundland) recorded barndoor skates in 10% of their tows; in the last 20 years, none has been caught, and this pattern of decline is similar throughout the range of the species.  相似文献   

Low-voltage organic transistors on plastic comprising high-dielectric constant gate insulators   总被引：1，自引：0，他引：1  

CD Dimitrakopoulos  S Purushothaman  J Kymissis  A Callegari  JM Shaw 《Science (New York, N.Y.)》1999,283(5403):822-824

The gate bias dependence of the field-effect mobility in pentacene-based insulated gate field-effect transistors (IGFETs) was interpreted on the basis of the interaction of charge carriers with localized trap levels in the band gap. This understanding was used to design and fabricate IGFETs with mobility of more than 0.3 square centimeter per volt per second and current modulation of 10(5), with the use of amorphous metal oxide gate insulators. These values were obtained at operating voltage ranges as low as 5 volts, which are much smaller than previously reported results. An all-room-temperature fabrication process sequence was used, which enabled the demonstration of high-performance organic IGFETs on transparent plastic substrates, at low operating voltages for organic devices.  相似文献