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101.
Yong-Hoon L Lee DVM PhD KW Clarke VetMB DvetMed DVA Diplomate ECVA Hatim IK Alibhai BVSc PhD Diplomate ECVA & Dae Y Song DVM 《Veterinary anaesthesia and analgesia》2002,29(4):171-181
Objective To evaluate the effect of ephedrine on intramuscular blood flow and hemodynamic parameters during equine anesthesia. Study design Prospective experimental study. Animals Six healthy adult Welsh Mountain ponies (five males, one female, mean weight: 267 kg, range: 213–347 kg). Methods Halothane‐anesthetized ponies received an IV bolus of ephedrine (0.1 mg kg?1), followed 30 minutes later by a second IV ephedrine injection (0.2 mg kg?1). Changes in intramuscular blood flows (IMBF) in upper and lower triceps brachii were measured by laser Doppler flowmetry. Cardiopulmonary measurements were made at intervals for 30 minutes following each injection. Results were compared with values from a control group, similarly anesthetized but given saline in an earlier study. Results Ephedrine at either dose increased heart rate, arterial blood pressure (AP), cardiac index (CI) and intramuscular blood flow (IMBF), the effects on these parameters being significant and long‐lasting following the higher dose. Systemic vascular resistance remained unchanged, and was significantly lower than in the control saline group. PaO2 decreased significantly immediately following the first injection of ephedrine, then remained unchanged for the remainder of the experiment. PaCO2 increased slowly throughout the anesthetic period. One pony developed supraventricular premature complexes following the second injection. No other side effects were seen. Conclusion Ephedrine at dose rates of 0.2 mg kg?1 IV consistently increased in CI, AP, and IMBF in both forelimbs. Clinical relevance Ephedrine may be of use to improve AP, CI and IMBF during halothane anesthesia, although the occurrence of an arrhythmia in one pony is of concern. 相似文献
102.
The influence of temperature and water table position on carbon dioxide and methane emissions from laboratory columns of peatland soils 总被引:17,自引:0,他引:17
Laboratory columns (80 cm long, 10 cm diameter) of peat were constructed from samples collected from a subarctic fen, a temperate bog and a temperate swamp. Temperature and water table position were manipulated to establish their influence on emissions of CO2 and CH4 from the columns. A factorial design experiment revealed significant (P < 0.05) differences in emission of these gases related to peat type, temperature and water table position, as well as an interaction between temperature and water table. Emissions of CO2 and CH4 at 23°C were an average of 2.4 and 6.6 times larger, respectively, than those at 10°C. Compared to emissions when the columns were saturated, water table at a depth of 40 cm increased CO2 fluxes by an average of 4.3 times and decreased CH4 emissions by an average of 5.0 times. There were significant temporal variations in gas emissions during the 6-week experiment, presumably related to variations in microbial populations and substrate availability. Using columns with static water table depths of 0, 10, 20, 40 and 60 cm, CO2 emissions showed a positive, linear relation with depth, whereas CH4 emissions revealed a negative, logarithmic relation with depth. Lowering and then raising the water table from the peat surface to a depth of 50 cm revealed weak evidence of hysteresis in CO2 emissions between the falling and rising water table limbs. Hysteresis (falling > rising limb) was very pronounced for CH4 emissions, attributed to a release of CH4 stored in porewater and a lag in the development of anaerobic conditions and methanogenesis on the rising limb. Decreases in atmospheric pressure were correlated with abnormally large emissions of CO2 and CH4 on the falling limb. Peat slurries incubated in flasks revealed few differences between the three peat types in the rates of CO2 production under aerobic and anaerobic conditions. There were, however, major differences between peat types in the rates of CH4 consumption under aerobic incubation conditions and CH4 production under anaerobic conditions (bog > fen > swamp), which explain the differences in response of the peat types in the column experiment. 相似文献
103.
TIM TREVAIL DANIELLE GUNN‐MOORE INÉS CARRERA EMILY COURCIER MARTIN SULLIVAN 《Veterinary radiology & ultrasound》2011,52(5):516-520
Radiographs of 50 cats with no history of gastrointestinal disease were evaluated to establish a normal reference range for radiographic diameter of the feline colon. Thirteen cats with constipation and 26 with megacolon were also evaluated and compared with the normal cats to characterize the accuracy of the reference range and to identify a cutoff to distinguish constipation from megacolon. A ratio of maximal diameter of the colon to L5 length was the most repeatable and accurate measurement. A ratio <1.28 is a strong indicator of a normal colon (sensitivity 96%, specificity 87%). A value >1.48 is a good indicator of megacolon (sensitivity 77%, specificity 85%). 相似文献
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THIERRY OLIVRY † PETER F. MOORE DIANE K. NAYDAN BARRY J. PUGET VERENA K. AFFOLTER ARCHIE E. KLINE‡ 《Veterinary dermatology》1996,7(2):67-79
Abstract A combination of cellular and humoral immunological assaults directed against follicular matrical cells is suspected to cause alopecia areata (AA) in humans. The specific aims of this study were to determine whether cytotoxic T lymphocytes (CTL) were increased in the blood and skin lesions of canine AA. Additionally, we wished to determine if circulating antifollicular antibodies were present in the dog. Finally, we aimed to investigate whether bulbar inflammation was associated with decreased matrical cell proliferation and keratinocyte apoptosis. Canine AA lesions were infiltrated by intrabulbar CTL, perifollicular helper T cells and dendritic cells. A higher percentage of CTL was present in canine AA peripheral blood compared with that of normal dogs. Tissue-fixed and circulating antifollicular IgG antibodies were detected. Reduced matrical proliferation and increased keratinocyte apoptosis was observed in inflamed hair bulbs. This study demonstrates the existence of antifollicular cell-mediated and humoral immunological responses in canine AA. Résumé— L'association d'agressions immunologiques cellulaires et humorales dirigées contre les cellules matricielles folliculaires est suspectée d'être à l'origine de l'Alopécie Areata chez l'homme. Le but de cette étude était de montrer si le nombre de lymphocytes T cytotoxiques est augmenté dans le sang et dans les lésions cutanées lors d'Alopécie Areata chez le chien. En plus, nous souhaitions montrer la présence d'anticorps circulants antifolliculaire chez le chien. Enfin, nous voulions voir si l'inflammation du bulbe pileux était associée à une diminution de la prolifération des cellules matricielles et une apoptose des kératinocytes. Lors d'Alopécie Areata chez le chien, existe une infiltration lésionnelle par des lymphocytes T cytotoxiques intrabulbaires, des lymphocytes T auxiliaires périfolliculaires et des cellules dentritiques. Le pourcentage de lymphocytes T cytotoxiques était plus important dans le sang périphérique provenant de sujets à Alopécie Areata que dans le sang d'animaux sains. Par ailleurs, des anticorps antifolliculaire (IgG) circulants et fixés dans les tissus sont détectés. Une réduction de la prolifération des cellules matricielles et une augmentation de l'apoptose des kératinocytes sont observées dans les bulbes pileux atteints. Cette étude démontre l'existence de réponses immunologiques cellulaires et humorales contre le follicule pileux dans l'Alopécie Areata du chien. [Olivry, T., Moore, P.F., Naydan, D.K., Puget, B.J., Affolter, V.K., Kline, A.E. Antifollicular cell-mediated and humoral immunity in canine alopecia areata (Immunité contre le follicule pileux dans l'Alopécie Areata du chien). Veterinary Dermatology 1996; 7 : 67–79.] Resumen Se cree que la alopecia areata (AA) en la especie humana resulta de la combinación de la acción inmunológica celular y humoral contra células de la matriz folicular. Los objetivos especificos de este estudio fueron determinar si los linfocitos T citotóxicos (CTL) se encontraban aumentados en sangre y en las lesiones cutáneas de animales con AA. Además, descamos investigar la posible presencia de anticuerpos antifoliculares circulantes en el perro. Finalmente, nos propusimos investigar si la inflamación bulbar se encontraba asociada a una disminución en la proliferación de células de la matriz y a la apoptosis de queratinocitos. Las lesiones de la AA canina mostraban infiltración por CTL intrabulbares, células T colaboradoras y células dendríticas. Se encontró un porcentaje mayor de CTL en la sangre periférica de perros con AA respecto a perros normales. Se detectaron anticuerpos IgG antifoliculares circulantes y en tejido fijado. Se observó una disminución en la proliferación matrical y un aumento en queratinocitos apoptóticos en los bulbos foliculares inflamados. Este estudio demuestra la existencia de respuestas inmunitarias antifoliculares de tipo celular y humoral en la AA canina. [Olivry, T., Moore, P.F., Naydan, D.K., Puget, B.J., Affolter, V.K., Kline, A.E. Antifollicular cell-mediated and humoral immunity in canine alopecia areata (Immunidad antifolicular en la alopecia areata canina). Veterinary Dermatology 1996; 7 : 67–79.] Zusammenfassung— Eine Kombinaton von zellulären und humoralen immunologischen Angriffen, die gegen die follikulären Matrixzellen gerichtet sind, wird als Ursache bei der Alopecia areata (AA) des Menschen vermutet. Die besondere Absicht dieser Studie war, festzustellen, ob die zytotoxischen T-Lymphozyten (CTL) im Blut und in den Hautveränderungen bei kaniner AA erhöht sind. Zusätzlich wollten wir feststellen, ob beim Hund zirkulierende antifollikuläre Antikörper vorkommen. Schließlich beabsichtigten wir, zu untersuchen, ob die bulbäre Entzündung mit verminderter Matrixzellproliferation und Keratinozytenapoptose einhergeht. Die Veränderungen bei kaniner AA wurden von intrabulbären CTL, perifollikulären T-Helferzellen und dendritischen Zellen infiltriert. Verglichen mit dem peripheren Blut gesunder Hunde kam bei kaniner AA eine höherer Prozentsatz an CTL vor. Es wurden gewebsfixierte und zirkulierende antifollikuläre IgG-Antikörper festgestellt. In entzündeten Haarbulbi wurde eine reduzierte Matrixproliferation und eine erhöhte Keratinozytenapoptose beobachtet. Diese Studie zeigt die Existenz von antifollikulären zellvermittelten und humoralen immunologischen Reaktionen bei kaniner AA. [Olivry, T., Moore, P. F., Naydan, D. K., Puget, B. J., Affolter, V. K., Kline, A. E. Antifollicular immunity in canine alopecia areata (Antifollikuläre Immunität bei der Alopecia areata des Hundes). Veterinary Dermatology 1996; 7 : 67–79.] 相似文献
108.
RUSTIN M. MOORE DVM PhD Diplomate ACVS WILLIAM W. MUIR DVM PhD Diplomate ACVA Diplomate ACVECC ALICIA L. BERTONE DVM PhD Diplomate ACVS JULIAN L. OLIVER DVM PhD Diplomate ACVP 《Veterinary surgery : VS》1998,27(1):37-48
Objective—To determine the effect of platelet-activating factor (PAF) antagonist L-691,880 on low-flow ischemia and reperfusion (I-R) of the large colon in horses. Animals —12 adult horses. Experimental Design—Horses were anesthetized, and the large colon was exteriorized through a ventral median celiotomy and instrumented. Colonic arterial blood flow was reduced to 20% of baseline (BL) and maintained for 3 hours; flow was then restored, and the colon was reperfused for 3 hours. One of two solutions was administered intravenously 30 minutes before reperfusion: group 1, 10 mL/kg 0.9% NaCl; and group 2, 5 mg/kg PAF antagonist L-691,880 in 0.9% NaCl. Hemodynamic variables were monitored and recorded at 30-minute intervals. Systemic arterial and colonic venous blood were collected for measurement of blood gas tensions, oximetry analyses, packed cell volume, and total plasma protein concentrations. Colonic venous blood was collected for determination of lactate, 6-keto prostaglandin F1α (6-kPG), prostaglandin E2 (PGE2), and thromboxane B2 (TXB2) concentrations. Full-thickness biopsy specimens were harvested from the left ventral colon for histological evaluation. Results—There were no significant differences between the two groups for any hemodynamic or metabolic variables. Colonic venous pH decreased, and carbon dioxide tension and lactate concentration increased during ischemia but returned to BL values during reperfusion. Colonic venous 6-kPG concentration was significantly increased above BL value at 2 hours and remained increased through 6 hours in horses of both groups. Colonic venous PGE2 concentration was significantly greater in group 2 compared with group 1 throughout the study. Colonic venous PGE2 concentration was increased above BL value from 3 to 6 hours in horses of both groups. Colonic venous TXB2 concentration was not different between groups but was significantly increased above the BL value for the first hour of reperfusion. Low-flow I-R of the large colon caused significant mucosal necrosis, hemorrhage, edema, and neutrophil infiltration; however, there were no differences in histological variables between vehicle-control and PAF antagonist-treated horses. Conclusion—No protective effects of PAF antagonist L-691,880 were observed on colonic mucosa associated with low-flow I-R. Additionally, deleterious drug-induced effects on hemodynamic and metabolic variables and colonic mucosal injury were not observed. 相似文献
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110.
JIYOUNG PARK PETER GORDON JAMES E. MOORE II HARRY W. RICHARDSON 《Growth and change》2008,39(4):548-572
In previous research, the economic impacts of temporary shutdowns of the Los Angeles–Long Beach harbors were simulated after a hypothetical terrorist attack, applying the National Interstate Economic Model to estimate state‐by‐state as well as interindustry impacts. However, the unpredictable characteristic of terrorist attacks might not be applicable to the case of a ports shutdown such as the one caused by the lockout of September–October 2002. Market participants can be expected to have contingency plans based on anticipations of a strike or shutdown. Can we identify any of these in terms of the use of alternate ports, in terms of alternate modes or even alternate time periods? The purpose of this study is to examine these questions. The approach is elaborated by testing for the possible effects of trade diversion to other West Coast ports, transportation modes, and intertemporal substitutions. We use data from WISERTrade describing commodity‐specific trade for the major West Coast ports before, during, and after the 11‐day shutdown of the fall of 2002. Shippers’ ability to divert trade is a key ingredient in the economy's ability to withstand attacks and disruptions. The work estimates the impacts on 47 industrial sectors across 50 states (and the District of Columbia). 相似文献