Cellular-resolution in vivo imaging of the feline retina using adaptive optics: preliminary results

Purpose To perform cellular‐level in vivo imaging of the feline retina using an adaptive optics flood illumination fundus camera (AO FIFC) designed for the human eye. Materials and methods Cellular‐level images were obtained from three eyes of two normal sedated cats. Ocular aberrations were corrected using an AO system based on a 52‐acuator electromagnetic deformable mirror and a 1024 lenslet Hartmann–Shack sensor (both Imagine Eyes, Orsay, France). A square 3°×3° area of the ocular fundus was flood‐illuminated by a pulsed LED emitting at 850 nm and imaged onto a low‐noise, high‐resolution CCD camera. The animal’s pupils were dilated and the effective pupil size was set to 7.5 mm. Conjunctival atraumatic clips were used to avoid eyeball movements and eyelid closure. The cornea was artificially hydrated throughout the experiments. Each acquisition consisted of 20 consecutive images, out of which 10 were numerically averaged to produce an enhanced final image. Results The total amount of ocular aberrations was greatly reduced by the AO correction, from 2.4 to 0.21 microns root mean square on average. The resulting images presented white dots distributed at a density similar to that of cone photoreceptors and they allowed us to visualize small blood vessels and nerve fiber bundles at a higher resolution than classically obtained with conventional fundus photography. Conclusion Retinal imaging with cellular resolution was feasible in cats under sedation using an AO FIFC designed for human eyes without any optical modification. The AO FIFC technology could find new applications in clinical, pharmacological, and toxicological investigations.     

Corpus luteum function following spontaneous or prostaglandin-induced estrus in Brahman cows and heifers

Corpus luteum (CL) function following spontaneous or prostaglandin F2 alpha-induced estrus was studied in 27 Brahman cows and 16 Brahman heifers. Females received one injection of 0, .38, .75 or 2.25 mg alfaprostol (PGF)/100 kg body weight at 12 +/- .1 d post-estrus. Serum progesterone (P4) during CL formation, following the subsequent estrus, increased over time (P less than .001, 1 to 13 d post-estrus) and was influenced by PGF (P less than .06) and a PGF X time interaction (P less than .02). Low serum P4 concentrations were observed during CL formation (d 3, 4, 10, and 12) in cattle that received 2.25 mg PGF. On d 13 post-estrus, CL were removed. No differences in weight, P4 content or number of luteinizing hormone (LH) receptors was evident between CL derived 13 d following spontaneous vs PGF-induced estrus. The CL formed following PGF-induced estrus had fewer large (P less than .002) and small (P less than .09) luteal cells in heifers, a lower (P less than .008) percentage composition of histological type I and II luteal cells in cows and a lower (P less than .0001) in vitro P4 response to LH in both cows and heifers when compared with the CL formed following spontaneous estrus. Cows had heavier (P less than .002) CL with a higher (P less than .05) number of large cells, a higher (P less than .09) percentage composition of histological cell type I and II luteal cells, and a higher (P less than .03) in vitro basal and stimulated P4 secretion. It is concluded that 1) the events associated with artificially shortening the estrous cycle with PGF altered subsequent CL function in Brahman females; 2) cows had heavier CL, which were composed of more steroidogenically functional luteal cells, than heifers and 3) age of animal interacted with PGF to alter subsequent CL function in Brahman females.     

Performance of broiler breeder pullets as influenced by composition of grower and layer diets 1

An experiment was conducted to determine the influence of three grower systems upon the subsequent performance of broiler type breeder pullets. The grower systems were full feeding a 10 per cent protein diet, full feeding a 16 per cent protein diet, and a skip‐a‐day feeding of the 16 per cent diet. One‐third of the pullets fed according to each of the feeding programmes were fed on each of three different layer diets. The use of the low protein and the skip‐a‐day feeding resulted in delaying age at sexual maturity. Total rate of egg production was not affected by the grower diet; however, the number of “ settable “ eggs was increased when maturity was delayed.

Performance of the laying hens was not influenced by the composition of the layer diet. Fertility or hatchability was not influenced by composition of either the grower or layer diet. These data would indicate that the low protein diet or the skip‐a‐day feeding system can be effectively used with feeding replacement broiler type birds.     

Plasma biochemistry reference values of wild bonnethead sharks,Sphyrna tiburo

Background — Elasmobranchs (sharks, skates, and rays) are of commercial, sport, research, and exhibit importance, however, blood chemistry reference values have been determined for few of these species. Objectives — The purpose of this study was to establish plasma biochemistry and PCV reference values for wild bonnethead sharks (Sphyrna tiburo). Methods — Heparinized blood samples were collected from 24 bonnethead sharks at the time of capture in trawl nets off the coast of South Carolina and Georgia. Weight, length, PCV, total solids (TS, by refractometry), and plasma biochemical analyses were done using standard techniques. Wilcoxon rank‐sum and Kendall tau b tests were used to compare values by animal size, boat and sex; 1–way ANOVA was used to compare TS and total protein (TP) concentrations. Results — Median (quartiles; minimum‐maximum) values were as follows: PCV 22% (22%, 26%; 17–28%), TS 6.3 (6.0, 6.8; 5.8–7.5) g/dL, total protein 2.9 (2.7,3.4; 2.2–4.3) g/dL, albumin 0.4 (0.4,0.4; 0.3–0.5) g/dL, globulins 2.6 (2.3,3.0; 1.9–3.8) g/dL, sodium 282 (279, 285; 273–292) mmol/L, potassium 7.3 (6.4, 7.9; 5.7–9.2) mmol/L, chloride 290 (285, 296; 277–304) mmol/L, total CO₂ 3 (2, 4; 0–5) mmol/L, calcium 16.8 (16.2,17.4; 15.8–18.2) mg/dL, phosphorus 8.8 (7.5,10.0; 5.9–12.7) mg/dL, urea nitrogen 1004 (986, 1028; 944–1068) mg/dL, creatinine <0.1 mg/dL, glucose 184 (165, 191; 155–218) mg/dL, aspartate aminotransferase 42 (33, 66; 15–132) U/L, lactate dehydrogenase <5 U/L, creatine kinase 82 (47, 233; 18–725) U/L, and osmolality 1094 (1078,1111; 1056–1139) mOsm/kg. No differences based on sex were detected. TS and total TP values were related by the fitted line TS = (1.006 × TP) + 3.318. Conclusions — Values reported here will be useful for evaluating the health status of bonnetheads in wild and captive research conditions and in exhibits.     

Plasma biochemistry reference values of wild-caught southern stingrays (Dasyatis americana).

Stingrays are prominent marine animals; however, there are few published reference values for their blood chemistry and hematology. Twenty-eight southern stingrays (Dasyatis americana) were caught using the bottom trawl nets of fishery-independent boats operated by the South Carolina Department of Natural Resources during June and July 2002 from Winyah Bay, South Carolina, to St. Augustine, Florida. Median values of blood and plasma obtained from live animals promptly after capture are as follows: packed cell volume = 0.22 L/L (22%), total solids (TS) = 56.5 g/L (5.65 g/dl), total protein (TP) = 26 g/L (2.6 g/dl), sodium = 315 mmol/L, potassium = 4.95 mmol/L, chloride = 342 mmol/L, calcium = 4.12 mmol/L (16.5 mg/dl), phosphorus = 1.5 mmol/L (4.7 mg/dl), urea nitrogen = 444 mmol/L (1,243 mg/dl), glucose = 1.69 mmol/L (30 mg/dl), aspartate aminotransferase = 14.5 U/L, creatine phosphokinase = 80.5 U/L, osmolality = 1065 mOsm/kg, and lactate = 3.1 mmol/L. Bicarbonate was less than the low end of the instrument range (5 mmol/L) in all but three samples. Anion gap was negative in all samples. Albumin was less than the low end of the instrument range (1 g/dl) in all except one sample. Osmolality was significantly higher in the rays caught in the southern region. TS and TP values were linearly related to each other, and the equation for the fitted line is TS = (11.61 x TP) + 25.4 (in g/L) [or TS = (1.161 x TP) + 2.54 (in g/dl)]. The reference ranges reported in this study can be used to aid in the management of aquarium stingrays and to create a baseline for health monitoring of the wild Dasyatis spp.     

按年龄计算肉鸡和火鸡的氨基酸需求量

在评估家禽营养需要量的研究中所用的日粮,是按百分比的方式进行配合的,这通常导致家禽的营养需要量以占日粮的百分比来表示。美国国家研究委员会(NRC)在1994年的报告中基于公布的评估数据提出了各种家禽所需养分占日粮的百分比。对产蛋母鸡的每日氨基酸需要量和采食量进行的估     

Effects of storage conditions and hemolysis on vitamin E concentrations in porcine serum and liver.

Vitamin E (alpha-tocopherol) is an antioxidant vitamin important in protecting unsaturated fatty acids in lipid membranes from peroxidation. Variation in collection, storage, and shipping conditions of samples can potentially lead to breakdown of vitamin E prior to analysis. Therefore, the purposes of this project were 1) to determine the stability of vitamin E in refrigerated and frozen porcine liver and serum and 2) to evaluate the effects of red blood cell (RBC) hemolysis on porcine serum vitamin E concentrations. Porcine liver and nonhemolyzed serum were collected and stored refrigerated or frozen. Samples were analyzed for vitamin E immediately or on days 2, 3, 7, or 14. In addition, porcine RBCs were added to normal serum at concentrations from 1 x 10(6) to 1 X 10(9) RBC/ml and hemolyzed by freeze-thaw prior to analysis for vitamin E or products of lipid peroxidation.     

Parturition in the multiparous mare fed to obesity

At 40 to 75 days of pregnancy, 20 multiparous mares of Quarter Horse breeding were blocked by expected foaling date and assigned to one of two treatment groups such that average age, body weight, body condition and percent body fat were similar between groups. Body condition was evaluated using a scoring system based on visual appraisal and palpable fat cover, with scores ranging from 1 to 9. Percent body fat was estimated by ultrasonographic scanning of rump fat thickness. The two treatment groups were: 1) control—fed to maintain and foal at a moderate condition (condition score 5.5 to 7.0) and 2) obese— fed to achieve and foal at an extremely high degree of body fatness (condition score 9). Condition score (p<0.001), body weight (p<0.01) and percent body fat (p<0.05) were greater for obese compared to control mares prior to and following parturition. Gestation was not affected by treatment. Parturition was observed and video taped from a raised platform located outside of a foaling stall. The duration of stages II and III of parturition, all intermediate times, the interval from birth of the foal to standing and nursing, and the degree of cervical and vaginal bruising incurred during parturition were not different between treatment groups. Foal birth weights and placenta weights did not differ between treatment groups, however, the nonfoal/non-placenta weight loss was greater in obese compared to control mares (33.2 vs 17.4 kg, SE = 3.6, p<0.05). Excessive body fat stored during gestation in the multiparous mare was not detrimental to parturition.