Customization of Advia 120 thresholds for canine erythrocyte volume and hemoglobin concentration,and effects on morphology flagging results

This study sought to develop customized morphology flagging thresholds for canine erythrocyte volume and hemoglobin concentration [Hgb] on the ADVIA 120 hematology analyzer; compare automated morphology flagging with results of microscopic blood smear evaluation; and examine effects of customized thresholds on morphology flagging results. Customized thresholds were determined using data from 52 clinically healthy dogs. Blood smear evaluation and automated morphology flagging results were correlated with mean cell volume (MCV) and cellular hemoglobin concentration mean (CHCM) in 26 dogs. Customized thresholds were applied retroactively to complete blood (cell) count (CBC) data from 5 groups of dogs, including a reference sample group, clinical cases, and animals with experimentally induced iron deficiency anemia. Automated morphology flagging correlated more highly with MCV or CHCM than did blood smear evaluation; correlation with MCV was highest using customized thresholds. Customized morphology flagging thresholds resulted in more sensitive detection of microcytosis, macrocytosis, and hypochromasia than default thresholds.     

Cerebroside antibody inhibits sulfatide synthesis and myelination and demyelinates in cord tissue cultures

Antiserum to cerebroside was prepared in rabbits by injection of cerebroside together with bovine serum albumin in complete Freund's adjuvant. When applied to cultures of embryo mouse spinal cord at explantation, this antiserum inhibited sulfatide synthesis and myelination; when applied to myelinated cultures it inhibited sulfatide synthesis and produced demyelination. Complement fixation assays also show antibody to cerebroside in serums from rabbits with experimental allergic encephalomyelitis induced by injection of whole white matter. Absorption of such serum with cerebroside abolishes the inhibiting and demyelinating activities.     

Stability of disease expression in the potato late blight pathosystem: A preliminary field study

The interactions of four potato cultivars, with three isolates ofPhytophthora infestans were assessed in different environments and in different years. Preliminary tests with these cultivars and isolates were conducted in Toluca, Mexico, and Freeville, New York, U.S.A. in 1986 and 1987. Although data were available from only one year for cultivar Alpha, this cultivar had a dramatically different resistance ranking in Toluca, than that in Freeville — a result consistent with previous observations. The difference in resistance between two other cultivars also changed with site, but less dramatically and did not cause a change in resistance ranking. The resistance of the fourth cultivar appeared to be relatively unaffected by change in site. In both sites, all isolates ranked all cultivars in the same order. Although aggressiveness was slightly different in different locations and on different cultivars, variations were small and there were no consistent trends (consistent over all trials) concerning isolate aggressiveness. Thus, changes in location appeared to have different effects on the different cultivars but little or no effect on the isolates used.     

Comparison of aspiration and nonaspiration techniques for obtaining cytologic samples from the canine and feline spleen

Background: Ultrasound‐guided fine needle aspiration of the spleen is commonly used in the diagnostic evaluation of veterinary patients. Techniques using suction delivered through a 6–20‐cm³ syringe are the most commonly described means of obtaining cytologic samples of the spleen. Comparison studies of various human lesions have shown nonaspiration techniques to produce equal or superior cytologic specimens with less blood than specimens obtained using aspiration techniques. Objective: The purpose of this study was to compare the quality of splenic cytology specimens obtained using aspiration and nonaspiration techniques. Methods: Client‐owned dogs (n=24) and cats (n=7) receiving an abdominal ultrasound at the University of Tennessee College of Veterinary Medicine were enrolled in the study between January and June 2005. Samples were obtained from patients with and without sonographic splenic abnormalities. Two clinical pathologists, working independently and blinded to the method of sample collection, graded the cytologic specimens using a subjective scoring system for cellularity, amount of blood, and preservation of cellular morphology. Results: Agreement between the 2 independent observers was good. Direct comparison of the 2 techniques showed that samples obtained by the nonaspiration method had higher cellularity (P=.0002), less blood (P=.0023), and similar cell morphology (P=1.0000) compared with samples obtained by the aspiration method. Conclusion: These results suggest the nonaspiration technique is a superior method for obtaining a high‐quality cytologic specimen from the canine and feline spleen.     

The return ofPhytophthora infestans, a potato pathogen that just won't quit

Summary Since the early 1980s and continuing through the end of the 20^th century, potato late blight caused byPhytophthora infestans has become noticeably more problematic throughout the world. Exotic strains of the pathogen are largely responsible for the increased problems. The new strains were initially detected in Europe, but subsequently they have been detected in Asia, the Middle East, South America and North America. Populations in the Middle East and South America may represent secondary migrations from Europe. Several independent migrations have occurred such that migrant populations in North America are very different from those in Europe. Also, population structures ofP. infestans are different in different worldwide locations. In some locations the migrant strains are resistant to metalaxyl, but in other locations either migrant or indigenous strains may be resistant. In most locations, the migrant strains are more aggressive than the previous indigenous strains.     

Reproductive biology of the commercially and recreationally important cobia Rachycentron canadum in northeastern Australia

The reproductive biology of 315 cobia, Rachycentron canadum, from northeastern Australia was studied for an 18-month period. Cobia ranged from 181 to 1,470 mm FL (0.06–55 kg). Length–frequency distributions of males and females did not differ significantly. The sex ratio of females to males was 2.18:1. Histological data showed that cobia developed hydrated oocytes during a protracted spawning season between September and June. Gonadosomatic index peaked from October to December, coinciding with the monsoon or “wet” season. Estimated length at first maturity for female cobia was 671 mm FL. Length at 50% maturity (L ₅₀) for females was estimated at 784 mm FL (1–2 years of age). Batch fecundity ranged from 577,468 to 7,372,283 eggs with a mean of 2,877,669 (± SD 1,603,760) eggs. Relative batch fecundity was 249 eggs per g, and no relationship between relative fecundity and fork length was found. There was a significant positive relationship between the total number of eggs produced and fork length. Spawning frequency, estimated by the post-ovulatory follicle method, was 7.6 days. Based on the detection of hydrated oocytes in fish caught at night, cobia most likely spawn at night. Cobia also feed throughout the spawning period. This is the first report on the reproductive biology of cobia in Australian waters, and provides valuable data for future population assessments of cobia throughout the Indo-Pacific.     

Reproductive dynamics and nursery habitat preferences of two commercially important Indo-Pacific red snappers <Emphasis Type="Italic">Lutjanus erythropterus</Emphasis> and <Emphasis Type="Italic">L. malabaricus</Emphasis>

Red snappers were examined for reproductive biology and age-0 habitat preferences. Spawning in red snappers occurred throughout the year in northern Australia and eastern Indonesia; at least 10–30% of females and 40–80% of males were in ripe or spawning condition in most months. Northern Australian populations showed a spawning peak from July to December (L. erythropterus) and September to March (L. malabaricus). Eastern Indonesian L. malabaricus had a less defined pattern with two peaks: January–March and October. Size at first maturity was 240 mm for males and 250–300 mm for females. L ₅₀ estimates were similar between species in northern Australia: 270–280 mm (males) and 350–370 mm (females). Maximum batch fecundity was 676,100 oocytes for L. erythropterus and 997,000 oocytes for L. malabaricus. Higher mean abundances of age-0 L. erythropterus were found in silty and coarse sand/rubble estuarine habitats of northern Australia (456 ± 119 fish/km²) compared with sandy coastal habitats (5 ± 3 fish/km²). Most age-0 snapper caught at Sape (eastern Indonesia) were L. malabaricus (91%) with mean abundances of 312 ± 14 fish/km². The similarities in the reproductive characteristics of red snappers suggest that successful management approaches adopted in northern Australia should be considered in eastern Indonesia.     

Springs in time: fish fauna and habitat changes in springs over a 20‐year interval

• 1. Despite the range of threats to springs and the number of spring‐endemic species, studies of temporal changes in the fauna of springs have rarely been reported. Changes in the fish of 22 Oklahoma (USA) springs were compared among surveys in 1981, 1982, and 2001.
• 2. Twenty‐year assemblage differences were correlated with physical alteration of specific springs and stocking of native fish, which was made possible by past habitat changes that produced pools. Physical alteration of springs is a major ongoing threat to Oklahoma springs.
• 3. Variation in spring fish assemblages among the three surveys was apparently affected by fish movement in and out of springs, and the greater rain‐induced connectivity between springs and streams during one year.
• 4. Although flow reduction is a commonly cited threat to springs, there was little evidence of flow reduction impacts in this study because Oklahoma springs may have been affected prior to 1981 and high‐flow springs, which most often contain fish, were in areas with low groundwater water use.

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