Megakaryocytes with intracytoplasmic blood cells

The phenomenon of megakaryocytes containing intracytoplasmic blood cells was frequently observed in the bone marrow of rats. The frequency appeared to increase in inflammatory or neoplastic conditions. The types of blood cells engulfed were mainly neutrophils. For the first time, megakaryocytes also were found to be engulfed.     

Variations in muscle fiber composition between successfully and unsuccessfully raced quarter horses

Muscle biopsy samples were removed from the m gluteus medius of 47 retired running Quarter Horse (QH) mares. Horses were separated based on bloodline, past racing history and percentage Thoroughbred (TB). The bred to run and raced (BRRA) and bred to run and not raced (BRNR) groups possessed a lower percentage (P<.01) of fast-twitch low oxidative (FT) fibers (BRRA 38.6 and BRNR 36.2±2.54 respectively). These horses also possessed a higher percentage (P<.01) of fast-twitch high oxidative (FTH) fibers (BRRA 52.5 and BRNR 48.5±2.54, respectively) than not bred to run and not raced (NBNR) horses. Horses that were bred to run had higher (P<.05) FTH to FT fiber ratios (1.44) than horses that were not bred to run (.94). Successful racehorses possessed a lower percentage (P<.05) of slow-twitch (ST) fibers and a higher percentage (P<.05) of FT fibers than unsuccessful racehorses. Success or failure was determined by Speed Index. No differences (P>.05) were found in the percentage FTH fibers between successful and unsuccessful horses.     

Results of Craniotomy for the Treatment of Cerebral Meningioma in 42 Cats

Forty-two cats underwent craniotomy for removal of a meningioma between 1985 and 1991. Median duration of clinical signs before examination was 1.25 months. All cats had inappropriate demeanor: 48% were dull and 38% were lethargic. Neurological deficits included impaired vision in 93%, paresis in 83%, and seizures in 19%. Computed tomography (CT) showed solitary masses in 86% and multiple masses in 14%. Intraoperative complications included hemorrhage and difficulty excising deep or adherent masses. Anemia in 13 of 42 cats was the most common immediate postoperative complication. Ten of 42 cats had no improvement or a more severe neurological status after surgery. Eight of 42 cats died immediately after surgery; 6 of these were anemic. Of the cats that survived the immediate postoperative period, evaluation 10 to 14 days after surgery showed that 97% (33 of 34) were alert and 79% (27 of 34) had returned to normal behavior. Neurological deficits, except for vision impairment, had resolved in most cats. The duration of follow-up varied from 1.3 months to 55.1 months. Ten cats developed neurological abnormalities from 1 month to 44.2 months after surgery; of these, 6 had tumor recurrence or new growth confirmed by CT scan or necropsy. Overall survival was 71% at 6 months, 66% at 1 year, and 50% at 2 years. Age of cat and location of tumor did not significantly affect survival ( P = . 1034 and .1851, respectively). There were too few precise measurements of tumor size to make a valid statistical comparison of the effect of size on survival. Location or presence of multiple tumors did not affect final outcome. Results of this study indicate that surgical excision is a beneficial method of treatment of cranial meningioma in cats.     

Development of the B- and T-cell compartments in porcine lymphoid organs from birth to adult life: an immunohistological approach.

Using immunohistological techniques, we studied the development over time of B- and T-cell compartments in the lymphoid organs of specific-pathogen-free pigs. Tissue samples were collected at various time-points, starting 2 days before the pigs were born until the pigs were 10 months old. The samples were collected from the spleen, thymus, peripheral lymph node, mesenteric lymph node, duodenum, jejunum, ileum, jejunal Peyer's patch and ileal Peyer's patch. Monoclonal antibodies specific to B- and T-cells were used to identify where the following cells were localized: IgM-B cells (cells positive to surface immunoglobulin), IgM-, IgG- and IgA-containing cells (cells positive to cytoplasmic immunoglobulin), and CD2-, CD4- and CD8-positive cells. The development of the B- and T-cell subpopulations in each organ was analysed. Two days before birth, most organs contained quantities of IgM-B cells. The spleen, lymph nodes, Peyer's patches and, notably, the thymus, contained some immunoglobulin-containing cells (Ig-CC); this finding indicates that pigs have cells that secrete immunoglobulins before birth. Just after birth, the incidence of Ig-CC increased in most organs; first IgM-CC increased, then either IgG- or IgA-CC increased, depending on the organ. T-cell development was observed clearly in spleen and in the lamina propria of the small intestine, in contrast to other organs, in which the T-cell compartments containing various T-cell subpopulations were well developed before birth. Comparison of the incidence of CD4+ and CD8+ cells showed that the CD4:CD8 ratio of these cells in the spleen, lymph nodes, Peyer's patches and small intestine is low, especially in adult pigs, compared with the CD4:CD8 ratio in other species. Weaning had little influence on the incidence of B- and T-cells in lymphoid organs. This study is the first immunohistological survey to describe the development of the major B- and T-cell subpopulations in various lymphoid organs of pigs, and it should be useful for future immunopathological and comparative immunological studies in pigs.     

Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method

Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method. J. vet. Pharmacol. Therap. 34, 142-152. The fluoroquinolones enrofloxacin (EF) and ciprofloxacin (CF) residues were investigated in the edible tissues of two important Asian aquacultured species such as Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry method. Fish and prawn were treated with medicated feed with multiple doses of EF, in field conditions. A validation study of the analytical method was realized in terms of linearity, specificity, precision (repeatability and within-laboratory reproducibility), recovery and decision limit (CCα). The time needed before the antibiotic disappears from animal tissues or reach the maximum residue limit (MRL, 100μg/kg) was assessed. The concentration values of EF detected in Tra catfish tissue were between the MRL and 2×MRL concentrations, according to the fish density, 7days following the end of the enrofloxacin treatment (20mg/kg body weight per day, for seven consecutive days). The concentration value of ER in prawn tissue was lower than the MRL and the limit of quantification (LOQ, 14μg/kg) 5 and 7days after the stop of the EF treatment (50mg/kg body weight per day, for five consecutive days), respectively. The mean detected levels of CF was much lower in comparison with that of EF, indicating that only a small part of EF is metabolized into CF (<5%) in both Tra catfish and prawn.     

Revealing genetic relationships between compounds affecting boar taint and reproduction in pigs

Boar taint is characterized by an unpleasant taste or odor in intact male pigs and is primarily attributed to increased concentrations of androstenone and skatole and to a lesser extent by increased indole. The boar taint compounds skatole and indole are produced by gut bacteria, metabolized in the liver, and stored in the fat tissue. Androstenone, on the other hand, is synthesized in the testis along with testosterone and estrogens, which are known to be important factors affecting fertility. The main goal of this study was to investigate the relationship between genetic factors involved in the primary boar taint compounds in an attempt to discover ways to reduce boar taint without decreasing fertility-related compounds. Heritabilities and genetic correlations between traits were estimated for compounds related to boar taint (androstenone, skatole, indole) and reproduction (testosterone, 17β-estradiol, and estrone sulfate). Heritabilities in the range of 0.47 to 0.67 were detected for androstenone concentrations in both fat and plasma, whereas those for skatole and indole were slightly less (0.27 to 0.41). The genetic correlations between androstenone in plasma and fat were extremely high (0.91 to 0.98) in Duroc and Landrace. In addition, genetic correlations between androstenone (both plasma and fat) and the other sex steroids (estrone sulfate, 17β-estradiol, and testosterone) were very high, in the range of 0.80 to 0.95. Furthermore, a genome-wide association study (GWA) and a combined linkage disequilibrium and linkage analysis (LDLA) were conducted on 1,533 purebred Landrace and 1,027 purebred Duroc to find genome regions involved in genetic control of the boar taint compounds androstenone, skatole, and indole, and sex hormones related to fertility traits. Up to 3,297 informative SNP markers were included for both breeds, including SNP from several boar taint candidate genes. From the GWA study, we found that altogether 27 regions were significant at a genome-wide level (P < 0.05) and an additional 7 regions were significant at a chromosomal level. From the LDLA study, 7 regions were significant on a genome-wide level and an additional 7 regions were significant at a chromosomal level. The most convincing associations were obtained in 6 regions affecting skatole and indole in fat on chromosomes 1, 2, 3, 7, 13, and 14, 1 region on chromosome 6 affecting androstenone in plasma only, and 5 regions on chromosomes 3, 4, 13, and 15 affecting androstenone, testosterone, and estrogens.     

Pancreatitis associated with clomipramine administration in a dog

A three-year-old, male, entire, Yorkshire terrier was presented with peracute onset of abdominal pain and vomitus. Clinicopathological abnormalities included severely increased serum lipase activity, immeasurably high serum trypsin-like immunoreactivity and mild hypocalcaemia. Canine pancreatic lipase immunoreactivity (cPLI) was intended to be measured, however, the sample got lost. Ultrasonography revealed a hypoechoic pancreas with small amounts of peripancreatic fluid and hyperechogenic mesentery. Acute pancreatitis (AP) was diagnosed and the dog recovered with appropriate therapy within 48 hours. Clomipramine, a selective serotonin reuptake inhibitor (SSRI) for alleviating signs of separation anxiety had been given for seven weeks. Two similar, albeit less severe, episodes associated with previous courses of clomipramine had occurred eight months earlier that responded to discontinuing clomipramine and supportive care. As SSRIs are associated with AP in human beings and no other trigger could be identified, we conclude that clomipramine should be considered as a potential cause when investigating causes for AP in susceptible breeds or other dogs presenting with compatible clinical signs.     

Prediction of effective population size in open nucleus breeding systems

A prediction equation for the effective population size in open nucleus breeding systems was derived, in terms of the cumulative effect of selection on gene frequency. Monte Carlo simulation was carried out to check the equation. From the results, it was found that the derived equation is applicable to most practical situations.     

The effect of intravenous administration of variable-dose midazolam after fixed-dose ketamine in healthy awake cats

The effects of intravenous administration of variable-dose midazolam and ketamine (3 mg/kg) were studied in twelve healthy unmedicated cats from time of administration until full recovery. A range of midazolam doses (0.0, 0.05, 0.5, 1.0, 2.0 and 5.0 mg/kg) was chosen, so that beneficial and/or detrimental effects could be documented and the therapeutic window for further study determined. One minute after administration of ketamine, all cats had assumed a lateral position, mostly with head up. Muscle tone was increased (100%), apneustic breathing pattern evident in 92% of cats, chewing without stimulation of the oropharyngeal area was observed in most cats (97%), but most cats did not salivate (87%). At 2.5 min after completion of ketamine injection and 1 min after administration of saline, a similar picture was observed, except that salivation was evident. All cats chewed or swallowed in response to a finger or laryngoscope placed in the oropharyngeal area and, while most cats were not aware of a noxious stimulus to the tail, some cats were aware of a noxious stimulus to the paw. Recovery from ketamine alone was rapid and smooth with cats rolling into sternal recumbency and then cautiously walking with ataxia. Recovery to walking without incoordination was also rapid (< 2 h) and no abnormal behavioural patterns were observed during recovery. Administration of midazolam after ketamine, had beneficial effects and the therapeutic window for midazolam was found to lie between 0.05 mg/kg and 0.5 mg/kg. Administration of any dose of midazolam after ketamine caused a greater proportion of cats to assume a laterally recumbent position with head down compared with ketamine alone, however, the time period of recumbency was only significantly longer with a midazolam dose of 2.0 mg/kg or above. Doses of midazolam of 0.5 mg/kg or above decreased muscle rigidity but did not affect salivation or respiratory pattern observed in cats which received ketamine alone. A significantly greater proportion of cats which received ketamine and midazolam 0.5 mg/kg or above did not swallow in response to a finger or a laryngoscope placed in the mouth compared with that which received ketamine alone. The length of time in which cats did not swallow was only significantly longer at midazolam doses of 1.0 mg/kg and above. At midazolam doses of 0.5 mg/kg or above, the proportion of cats without a nociceptive response to a tail or paw clamp was significantly greater than cats which received ketamine alone. The time period without nociceptive response, however, was not influenced by midazolam administration. The time taken for cats which received ketamine and midazolam 0.05 mg/kg or 0.5 mg/kg to assume sternal position, walk with ataxia, walk without ataxia, behave normally when approached or restrained and recover normal arousal state was not significantly different from cats which received ketamine alone. Ketamine and midazolam 5.0 mg/kg significantly prolonged all recovery times compared with ketamine alone. Unfortunately, a greater proportion of cats which received ketamine and midazolam 0.5 or 5.0 mg/kg exhibited detrimental behavioural effects. These were more likely to be adverse and included restlessness, vocalization and difficulty approaching and restraining cats. In this study, an