Animal movement varies with resource availability,landscape configuration and body size: a conceptual model and empirical example

Landscape Ecology - Animals must move to find food, shelter and mates, and escape predation and competition. Changes in landscape configuration and resource availability can disrupt natural...     

外源水杨酸对盐胁迫下非洲菊抗氧化酶活性和生理特性的影响(英文)

以非洲菊(Gerbera jamesonii L.)品种Amaretto'为试材,研究外源水杨酸(SA)对缓解非洲菊生殖生长期因盐胁迫引起的过氧化伤害作用.在开花前分别用0、0.5和1.0mmol L-1SA对非洲菊植株进行预处理,3d后用100mmol L-1NaCl灌溉,持续2周;对照植株未经NaCl和SA处理.结果表明:盐胁迫处理后,叶片的超氧化物歧化酶(SOD)和过氧化物酶(POD)活性增加,丙二醛(MDA)含量、电解质外渗率和脯氨酸含量提高;外源SA预处理显著降低了盐胁迫植株叶片的MDA含量和电解质外渗率;在外源0.5mmol L-1SA预处理后,植株SOD和POD活性分别是对照的1.4倍和2.4倍;SA预处理后与植株耐盐性相关的生理生化指标呈显著相关,以0.5mmol L-1SA处理增强植株盐胁迫耐性的效果更好.说明外源SA处理能够诱导盐胁迫下非洲菊植株的抗氧化反应,水杨酸将是一种提高园艺作物耐盐性的有效物质.     

Effect of fenoldopam on renal function after nephrotomy in normal dogs

OBJECTIVE: To evaluate effects of fenoldopam on renal function in normal dogs subjected to bisection nephrotomy. In addition, effects of bisection nephrotomy on renal function in normal dogs were evaluated. STUDY DESIGN: Controlled, randomized, blinded experiment. SAMPLE POPULATION: Sixteen mixed-breed adult dogs. METHODS: Dogs were paired for sex, body weight, and approximate age and assigned to 1 of 2 groups: fenoldopam (F) or placebo (P). Baseline glomerular filtration rate (GFR) based on quantitative renal scintigraphy using (99m)Tc-DTPA, blood urea nitrogen (BUN), serum creatinine (SCr), urinalysis, and urine culture were performed before surgery. Left nephrotomy was performed via median celiotomy. Group F dogs were administered intravenous (IV) fenoldopam (0.1 microg/kg/min) for 90 minutes, whereas group P dogs were administered an equivalent volume of saline (0.9 % NaCl) solution for 90 minutes. Temperature, heart rate, respiration, direct arterial blood pressure, and urine volume were recorded during anesthesia. Renal function was assessed by measuring SCr, BUN, and GFR at 1, 21, and 42 days after surgery. RESULTS: There was no significant difference between groups in measured physiologic variables. No significant difference in GFR, BUN, or SCr between groups or between operated or control kidneys was detected. CONCLUSIONS: Bisection nephrotomy in normal dogs with renal arterial occlusion of 15 minutes and using a simple continuous capsular closure does not adversely affect renal function. CLINICAL RELEVANCE: Bisection nephrotomy, as described in this study, does not decrease renal function; perioperative administration of renoprotective agents is not necessary in normal dogs.     

Vecuronium bromide,phenylephrine and atropine combinations as mydriatics in juvenile double-crested cormorants (Phalacrocorax auritus)

Topical vecuronium bromide (Norcuron) and combinations with atropine and phenylephrine, were evaluated as mydriatics in juvenile double-crested cormorants (Phalacrocorax auritus). Nine cormorants were treated with each of four protocols: 1% atropine; 4 mg/mL vecuronium bromide (total 0.16 mg/eye); atropine with vecuronium; and atropine, 2.5% phenylephrine, followed by vecuronium. Drugs were applied topically at 15-min intervals (0.01 mL/drop). Pupil diameter was measured manually every 15 min with a pupil gauge calibrated to the nearest 0.5 mm. No effect was observed with atropine alone. Average +/- SD peak pupil diameter for vecuronium, atropine/vecuronium, and atropine/phenylephrine/vecuronium were 5.4 +/- 1.1 mm, 5.7 +/- 0.8 mm and 6.2 +/- 0.4 mm, respectively; and duration of peak diameters were 38 +/- 28 min, 79 +/- 71 min and 103 +/- 58 min, respectively. The combined atropine, phenylephrine and vecuronium provided the most consistent dilation with larger average pupil size and longer average duration. No side-effects from vecuronium were observed in these birds.     

Evaluation of cystatin C as an endogenous marker of glomerular filtration rate in dogs

Cystatin C is a cysteine protease inhibitor produced by all nucleated cells. It is freely filtered by the glomerulus and is unaffected by nonrenal factors such as inflammation and gender. Because of greater sensitivity and specificity, cystatin C has been proposed to replace creatinine as a marker of glomerular filtration rate (GFR) in humans. The aims of this study were to validate an automated assay in canine plasma and to evaluate the usefulness of cystatin C as a marker of GFR in dogs. Western blotting was used to demonstrate cross-reactivity of an anti-human cystatin C antibody. An immunoturbidimetric assay was used to detect cystatin C in 25 clinically healthy dogs and 25 dogs with renal failure. Mean cystatin C concentration in the healthy dogs and the dogs with renal failure was 1.08 +/- 0.16 mg/L and 4.37 +/- 1.79 mg/L respectively. Intra- and interassay variability was <5%. The assay was linear (r = .974) between 0.14 and 7.53 mg/L. Both cystatin C and creatinine concentrations were measured in banked, frozen serum from 20 remnant kidney model dogs and 10 volume-depleted dogs for which GFR measurements by exogenous creatinine clearance had been determined previously. In the remnant kidney model, cystatin C was better correlated with GFR than creatinine (r = .79 versus .54) but was less well correlated with GFR in volume-depleted dogs (r = .54 versus .95). GFR measurements were repeated in the remnant kidney model dogs 60 days after initial GFR measurements. At this time, cystatin C and creatinine concentrations correlated equally well with GFR (r = .891 versus .894, respectively). Cystatin C concentration is a reasonable alternative to creatinine for screening dogs with decreased GFR due to chronic renal failure.     

Effects of a synthetic facial pheromone on behavior of cats

OBJECTIVE: TO evaluate the effects of a synthetic feline facial pheromone (FFP) on behavior and food intake of healthy versus clinically ill cats. DESIGN: Original study. ANIMALS: 20 cats were used in each of 2 studies. In each study, 7 cats were considered healthy, and 13 cats were determined to be clinically ill. PROCEDURE: In study 1, cats were assigned either to exposure to FFP (treated group; 4 healthy, 6 ill cats) or to exposure to the vehicle (70% ethanol solution; control group; 3 healthy, 7 ill cats). Cats were placed in a cage containing a small cotton towel that had been sprayed with FFP or vehicle 30 minutes previously. Cats were then videotaped for 125 minutes, and food intake was measured during this period. Videotapes were scored at 5-minute intervals for various behaviors. In study 2, cats were categorized in 1 of 2 groups; group 1 (2 healthy, 8 ill cats) had a cat carrier placed in their cages, and group 2 (5 healthy, 5 ill cats) did not. All cats were exposed to FFP, and 24-hour food intake was measured. RESULTS: Differences between behaviors of healthy versus clinically ill cats were not identified. In the first study, significant increases in grooming and interest in food were found in cats exposed to FFP compared with vehicle. For all cats, significant positive correlations were detected between grooming and facial rubbing, walking and facial rubbing, interest in food and facial rubbing, eating and facial rubbing, grooming and interest in food, and grooming and eating. In the second study, 24-hour food intake was significantly greater in cats exposed to FFP and the cat carrier, compared with cats exposed to FFP alone. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that exposure to FFP may be useful to increase food intake of hospitalized cats.     

A comparison of the cytologic and histologic features of meningiomas in four dogs

Abstract: The cytologic and histologic features of 2 intracranial and 2 spinal (extramedullary cervical) canine meningiomas were compared. Cerebrospinal fluid analysis in 2 cases revealed mild, mixed cell pleocytosis, primarily composed of small lymphocytes and monocytoid cells, with a moderate increase in total protein concentration. Cytologic features suggestive of meningioma included cells with both epithelial and mes-enchymal characteristics and a tendency towards cell clustering. Tumor location also was useful in making a diagnosis. The 4 meningiomas differed histologically from one another, and included angioblastic, psam-momatous, meningotheliomatous, and microcystic anaplastic types, which conformed to a classification scheme for human meningiomas. The classification scheme could not be applied to cytologic specimens.     

Iron and transferrin in acute experimental Salmonella cholerae-suis infection in pigs

The effects of experimental Salmonella cholerae-suis inoculation with a virulent and an avirulent strain on serum iron (SI), total iron-binding capacity (TIBC), and transferrin (TF) were evaluated. Inoculation of virulent strain 38 was followed by significant (P less than 0.05) decreases of SI, TIBC, and TF. Exposure to avirulent strain 33 was followed by moderate decreases of SI, TIBC, and TF. When exposure to avirulent strain 33 was followed by challenge exposure with virulent strain 38, the SI, TIBC, and TF values remained at initial values or were higher. Negative correlation was observed between rectal temperature and SI and TIBC values, but was significant (P less than 0.0001) only 7 days after inoculation of the virulent strain 38.