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1.
Plasma renin substrate concentration was measured in 18, four-day-old pony foals after the administration of the natriuretic agent frusemide. Thirteen foals had been delivered spontaneously; labour had been induced in the remaining five mares. Plasma aldosterone concentration was measured in 12 of the spontaneously delivered foals. Renin substrate concentration had risen sharply within 15 mins (P<0.005) and peaked at 1 h. The response was consistently greater in the induced foals. Serum sodium concentration fell rapidly in the induced foals (P<0.002 by 60 mins) but was better maintained in the spontaneous group. Individual serum potassium concentrations varied widely and were higher in both the induced group and smaller (30 kg or less) spontaneous foals. Plasma renin substrate concentration was positively correlated with plasma potassium in both groups (P<0.05, P<0.001 respectively). Plasma aldosterone rose significantly within 30 mins (P<0.025) and did not stabilise during the experiment. Plasma aldosterone was significantly correlated with renin substrate concentration in both lighter (P<0.005) and heavier (P<0.05) spontaneously delivered foals. It is suggested that maturation of renal sodium and potassium handling occurs late in gestation in the foal and is in part related to body mass. ‘Premature’ delivery following induced labour is associated with a more rapid loss of sodium when challenged with frusemide, even though the response of the renin-angiotensin system may be exaggerated.  相似文献   
2.
Respiratory measurements and blood-gas and acid-base values are reported in nine term induced foals. Measurements were performed at 2, 15, 30 and 60 mins, 4, 12, 24 and 48 h, and four and seven days after birth. Minute respiratory volume was significantly lower at birth than values from 12 h old. Tidal volume peaked at 60 mins old, while respiration rate decreased significantly at 15 mins after birth. Oxygen consumption was high at birth and decreased to its lowest values at 24 and 48 h. The respiratory exchange ratio and ventilatory equivalent showed few significant changes to seven days, as did the minute alveolar ventilation and physiological deadspace. The blood-gas and acid-base values indicated that the foals rapidly establish adequate pulmonary ventilation within minutes of birth, and that those values changed little from 12 h to seven days after birth. Body position had a significant effect on arterial oxygen tension with Pao2 values in lateral recumbency being, on average, 14 mmHg lower than when the foals were standing.  相似文献   
3.
The extensive debate over trade liberalization policies in the United States holds a general consensus that some industries will benefit while others will not. This paper explores the impact of the North American Free Trade Agreement on U.S. retailers in states located along the border with Mexico. Overall, the impact of trade on U.S. border retailers has been beneficial. However, the results demonstrate that retailers in the region are vulnerable to exchange rate fluctuations and other macroeconomic influences that change the relative price ratio between the United States and Mexico. Furthermore, retailers in metropolitan statistical areas that have a relatively high concentration of retail sector employment are more susceptible to these changes.  相似文献   
4.
The purpose of this study was to compare the prevalence of nasal septal deviation and variations of the paranasal sinuses in normal and diseased cats. Prevalence of nasal septal deviation was 86.7%, 68.4%, and 71.4% in cats with rhinitis, neoplasia, and normal cats, respectively, with no statistically significant difference (P = 0.244). There was a statistically significant difference (P = 0.01) in the magnitude of nasal septal deviation between cats with and cats without nasal disease, using a cutoff value of 1 mm for maximum distance of deviation from midline. There was a statistically significant difference (P = 0.019) between cats with rhinitis and neoplasia when comparing the presence of a mass (7.7% and 53.8%, respectively), but not when comparing for lysis of the septum. Deviation of the frontal sinus septum occurred in 27.7% of all cats, while the sphenoid septum was oblique and eccentric in 96.6% of all cats. The mean length of the frontal sinus was longer in male cats than female cats. The presence of nasal septal deviation alone cannot be used as a criterion to diagnose nasal disease, but cats with rhinitis or neoplasia have more marked deviation than normal cats. The presence of a mass and lysis of the septum were only seen in cats with nasal disease and a mass is more likely to be seen with neoplasia than rhinitis. Male cats have a longer frontal sinus than female cats. Almost all cats have an oblique, eccentric sphenoid septum.  相似文献   
5.
Objective— To determine the clinical value of a novel osteoarthritis (OA) biomarker in detecting canine cruciate disease.
Study Design— Cross sectional clinical study.
Animals— Dogs (n=22) with cranial cruciate ligament (CCL) rupture and 12 control dogs.
Methods— Concentrations of collagenase-generated cleavage epitope of type II collagen (Col2-3/4Clong mono, or C2C) in serum, urine, and joint fluid were compared between a group of dogs with CCL rupture and a control group. Correlation of C2C concentrations to the clinical stage of stifle OA was also evaluated.
Results— There were no significant differences in C2C concentrations in serum, urine, and joint fluid between groups ( P >.05). Subjective scores of lameness, joint effusion, osteophytosis were significantly more severe in the CCL rupture group compared with the control group ( P <.05). There was no significant correlation of C2C concentrations with clinical stage of stifle OA ( P >.05).
Conclusion— This OA biomarker did not detect pathology associated with CCL rupture. Our results suggest that collagenase-specific degradation of type II collagen in articular cartilage may not be involved in the early stage of naturally occurring canine cruciate disease, and that pathology associated with naturally occurring CCL rupture is different from that of experimental OA model.
Clinical Relevance— C2C is not clinically useful in detecting CCL rupture in dogs.  相似文献   
6.
Technetium-99m stannous colloid (99mTcSnC) has been used to radiolabel human leukocytes to investigate various inflammatory disorders. We investigated the in vitro behavior of feline leukocytes labeled in whole blood with 99mTcSnC. Heparinized blood samples were collected from healthy cats and divided into control and test aliquots. The latter were labeled with 99mTcSnC using a standard procedure. Leukocyte viability was determined for each sample using a trypan blue exclusion test. Labeling efficiency was determined for test aliquots. Test aliquots were layered onto Histopaque-1077® and centrifuged before measurement of radioactivity of the blood components. Leukocytes from radiolabeled and control samples were washed and incubated with opsonized zymosan particles to allow assessment of phagocytic function. Aliquots were taken from radiolabeled feline leukocyte samples at 1, 3, 4, and 7 h postlabelling. After centrifugation of each aliquot, radioactivity of the supernatant and pellet was measured and the labeling retention determined. Leukocyte viability in both radiolabeled and control samples was >98%. The labeling efficiency was 95.2±0.14%. The distribution of radioactivity in feline blood was found to be 3.4±0.18% in plasma, 39.0±0.37% in erythrocytes, and 57.6±0.38% in leukocytes. Labeled feline leukocytes had phagocytic activity of 90.9±0.18% (control 91.3±0.15%). The radiolabeled leukocytes retained 93.4±0.19% of the radioactivity up to 7 h postlabeling. 99mTcSnC efficiently labeled feline leukocytes with no effect on viability and minimal effect on phagocytic function. The percentage retention of radioactivity by the leukocytes was still high at 7 h postlabeling.  相似文献   
7.
Nursery areas for juvenile fishes are often important for determining recruitment in marine populations by providing habitats that can maximize growth and thereby minimize mortality. Pacific ocean perch (POP, Sebastes alutus) have an extended juvenile period where they inhabit rocky nursery habitats. We examined POP nursery areas to link growth potential to recruitment. Juvenile POP were captured from nursery areas in 2004 and 2008, and estimated growth rates ranged from ?0.19 to 0.60 g day?1 based on differences in size between June and August. Predicted growth rates from a bioenergetics model ranged from 0.05 to 0.49 g day?1 and were not significantly different than observed. Substrate preferences and the distribution of their preferred habitats were utilized to predict the extent of juvenile POP nursery habitat in the Gulf of Alaska. Based on densities of fish observed on underwater video transects and the spatial extent of nursery areas, we predicted 278 and 290 million juvenile POP were produced in 2004 and 2008. Growth potential for juvenile POP was reconstructed using the bioenergetics model, spring zooplankton bloom timing and duration and bottom water temperature for 1982–2008. When a single outlying recruitment year in 1986 was removed, growth potential experienced by juvenile POP in nursery areas was significantly correlated to the recruitment time‐series from the stock assessment, explaining ~30% of the variability. This research highlights the potential to predict recruitment using habitat‐based methods and provides a potential mechanism for explaining some of the POP recruitment variability observed for this population.  相似文献   
8.
Computed tomography (CT) is a valuable imaging procedure but one that requires significant technical support. Although scanners are available for veterinary use, their successful installation requires in-depth facility planning. Maintenance costs for these highly complex systems are high and may greatly exceed acquisition costs. Equipment to move anesthetized horses and support them during scanning is also expensive. Transport and scan table equipment suitable for equine CT studies are described. Clinical scan protocols used for CT of the equine skull and extremities are detailed. Precise positioning is essential for interpretable scans. Significant training in anatomy and CT physics is required for the veterinary computed tomographer.  相似文献   
9.
ABSTRACT This paper presents an empirical analysis of the effect of impact fees on the value of land used in residential development. A random effects model is estimated to examine the relationship between impact fees and land values using forty‐three Texas cities that impose impact fees. Prior research suggests that higher impact fees result in higher lot values, and the results of this research support this suggestion. Results indicate that for each $1,000 increase in impact fees, lot values increase by 1.3 percent. Additionally, these results suggest that developers are able to pass a small amount of the impact fee to the owners of developable land. However, for undeveloped land the results are mixed. For each $1,000 in assessed impact fees, undeveloped land values decrease by 0.042 percent. These results support prior evidence that suggests home buyers may ultimately bear the majority of the cost of impact fees.  相似文献   
10.
Abstract— Fifty-two cattle on two ranches in St. Kitts were divided into initial treatment and control groups, matched as closely as possible by age, sex and extent of dermatophilosis. Nine unaffected animals were included. The initial treatment group was given long-acting oxytetracycline at the rate of 20 mg.kg-1. After 4 weeks the control group was similarly treated. The cattle were observed at weekly intervals for a total of 6 weeks. In each group there was a pronounced decrease in the extent of the disease after treatment. This was most apparent in lightly affected animals and on the trunk. Lesions tended to persist in the tick predilection sites and extremities. Complete recovery occurred in 8 (21 per cent) of cattle. The disease tended to recur in treated animals particularly on one of the ranches in which a low standard of husbandry prevailed. On the other ranch improvements in tick control and feeding were associated with a continuing low level of infection. The results show that long-acting oxytetracycline can be used to conveniently halt outbreaks of dermatophilosis and allow time for changes in management designed to reduce recurrence of the disease. Résumé— 52 bovins présents sur 2 ranchs à Saint-Kitts, ont été divisés en groupes d'animaux traités et en groupe d'animaux témoins, répartis aussi minutieusement que possible selon l'âge, le sexe et l'extension de la dermatophilose. Le groupe des animaux traités a reçu de l'oxytétracycline-retard à la dose de 20 mg.kg-1. Après 4 semaines, le groupe d'animaux témoins fut traité de la même manière. Les bovins furent observés une fois par semaine pendant une durée totale de 6 semaines. Dans chaque groupe, il y eut une baisse sensible de l'extension de la maladie après le traitement. Ce fut le plus manifeste sur des animaux légèrement atteints et sur le tronc. Les lésions ont tendu à persister sur les sites de prédilection des tiques et sur les extrémités. Une guérison complète fut notée sur 8 (21%) des bovins. Les maladies tendaient à récidiver sur les animaux traités, principalement dans l'un des ranchs, où les conditions d'entretien étaient d'un niveau médiocre. Dans l'autre ranch, des améliorations dans l'erradication des tiques et dans l'alimentation ont été associées avec la persistance d'un niveau faible d'infection. Les résultats montrent que l'oxytétracycline retard peut être utilisée pour árrêter commodément les poussées de dermatophilose et laisser du temps pour modifier les méthods afin de récluire la récidive de la maladie. Zusammenfassung— 52 Rinder in zwei Betrieben auf St. Kitts wurden in je eine Erstbehandlungs-und eine Kontrollgruppe aufgeteilt, die mÖglichst ähnlich in Alter, Geschlecht und Ausprägungsgrad der Dermatophilose waren. Neun dieser Tiere waren nicht erkrankt. Die Erstbehandlungsgruppe erhielt ein Langzeit-Oxytetracyclin in der Dosierung von 20mg.kg-1. Nach 4 Wochen wurde die Kontrollgruppe nach dem gleichen Schema behandelt. Die Tiere wurden über einen Zeitraum von sechs Wochen in wÖchentlichen Abständen untersucht. In beiden Gruppen besserte sich der Schweregrad der Erkrankung nach Therapie deutlich, besonders bei den nur leicht befallenen Tieren und bei Läsionen im Stammbereich. Dagegen neigten die Veränderungen an den Prädilektionsstellen für Zecken und an den Gliedmaßen zur Persistenz. Acht der Tiere (21%) wurden vÖllig wiederhergestellt. Die Erkrankung neigte aber bei den therapierten Tieren zu Rezidiven, vor allem in einem der Betriebe mit niedrigem Pflegeniveau. Nach den vorliegenden Untersuchungen ist die Verwendung von Langzeit-Oxytetracyclin ein brauchbares Mittel, um die Dermatophilose zum Stillstand zu bringen und neue Ausbrüche zu verhindern, bis weitere Änderungen im Management zur Verringerung der Rezidivrate getroffen worden sind. Resumen Cincuenta y dos vacas de 2 explotaciones en St. Kitts se dividieron en un grupo de tratamiento y un grupo de control. Ambos grupos contenian aproximadamente la misma distributión de sexos y la dermatofilosis estaba extendida en igual medida. Se incluyeron 9 animales no afectados. Los animates del grupo de tratamiento inicial recibieron oxitetraciclina de actión retardada a una dosis de 20mg.kg-1. Cuatro semanas más tarde los animales del grupo de control recibieron el mismo tratamiento. Las vacas fueron observadas semanalmente durante 6 semanas. En cada grupo se produjo una marcada reducción en la extensién de la enfermedad después del tratamiento. Esto fue más marcado en aquellos animales afectados sólo de forma leve en la región del tronco. Las lesiones tendian a persistir en las zonas de predilectión de las garrapatas y en las extremidades. En ocho animales se observó una curatión completa (21%). La enfermedad tendia a recidivar en los animales tratados expecialmente en una de las explotaciones en la cual se mantenían unas condiciones de cría bastante desfavorables. En la otra explotación el control de garrapatas y una mejoria en la alimentatión aparecieron asociadas a un bajo nivel de presentación de la enfermedad. Estos resultados indican que la oxitetraciclina de actión retardada puede utilizarse para controlar focos de dermatofilosis, produciendo remisiones que permiten mejorar el manejo de las explotaciones y evitar recidivas de la enfermedad.  相似文献   
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