Effect of Feline Immunodeficiency Virus Infection on Toxoplasma gondii-specific Humoral and Cell-mediated Immune Responses of Cats with Serologic Evidence of Toxoplasmosis

Serum samples from 89 cats with serologic evidence of toxoplasmosis were identified by using an enzyme-linked immunosorbent assay (ELISA) that detected Toxoplasma gondii -specific immunoglobulin M (IgM) or T. gondii -specific immunoglobulin G (IgG). Concurrent feline immunodeficiency virus (FIV) infection was detected in 36 cats using an ELISA for detection of FIV-specific IgG. The majority of the cats in both the FIV-seropositive and FIV-seronegative groups were male and >5 years of age. FIV-seropositive cats were more likely to have T. gondii IgM titers without IgG ( P > 0.05) or any T. gondii IgM titer ( P > 0.05) than were FIV-seronegative cats. FIV-seronegative cats (1328) had a higher T. gondii IgG geometric mean titer than did FIV-seropositive cats (724) and were more likely to have T. gondii IgG titers 1:2048 than were FIV-seropositive cats ( P > 0.05). Cats with serologic evidence of both T. gondii and FIV infections had persistent T. gondii IgM titers for >12 weeks. Lymphoblast transformation in response to concanavalin A, T. gondii -specific intracellular antigens, and T. gondii -specific secretory antigens was compared in T. gondii seropositive and FIV-seronegative cats, cats with serologic evidence of T. gondii infection alone, and cats with serologic evidence of concurrent FIV and T. gondii infections. Lymphocytes from all but one cat in the FIV-seropositive group responded to concanavalin A. Whereas lymphocytes from FIV-seronegative cats with serologic evidence of toxoplasmosis responded to T. gondii -specific antigens, four of five of the FIV-seropositive cats with concurrent serologic evidence of toxoplasmosis did not.     

The effects of allopurinol on the ultrastructure of ischaemic and reperfused large intestine of sheep

Objective To test the possible inhibitory effect of allopurinol on reperfusion injury, caused by oxygen-derived free radicals, of sheep large intestine.
Design An ultrastructural study on caecal tissues from control and treated groups.  

Animals

Fifty sheep in four ischaemic and reperfused (treatment) groups and one control group. Three of the treatment groups were subdivided for half to be injected with allopurinol and the other half with its solvent, potassium hydroxide (KOH).
Procedure Ischaemia of the caecum was induced in the four treatment groups for 60 minutes by clamping the apex. Allopurinol and its KOH solvent were injected intravenously in three treatment groups prior to ischaemia. Samples were collected before and 1 hour after induction of ischaemia and 1 min, 1 h and 8 h after reperfusion. Tissues were processed and examined with an electron microscope.
Results Untreated and solvent injected sheep showed minor ultrastructural changes following ischaemia. With reperfusion, there was severe mitochondrial, goblet cell and basement membrane damage. Tissues from allopurinoltreated sheep were preserved and appeared similar to tissues from the control group.  

Conclusion:

Pre-treatment with allopurinol prevented damage to tissues whereas untreated or allopurinol solventtreated showed severe damage following reperfusion. It is believed that allopurinol, an analogue of hypoxanthine and xanthine, prevents reperfusion injury by competitively binding with xanthine oxidase. This reduces or inhibits the xanthine oxidase mediated conversion of hypoxanthine to xanthine thereby preventing the formation of oxygen-derived free radicals.     

Haemodynamic, pathological, haematological and behavioural changes during endotoxin infusion in equine neonates

The purpose of this study was to evaluate the effects of experimentally induced sublethal endotoxaemia in equine neonates. Four foals, between two and five days of age, were infused intravenously with 0.5 microgram/kg bodyweight of Salmonella typhimurium endotoxin (LPS) over a 5 h period. A four-day-old and a five-day-old foal, similarly infused with sterile isotonic saline, served as controls. Clinical signs were monitored, blood samples obtained for evaluation of selected haematological and biochemical parameters; and haemodynamic parameters were recorded hourly during the infusion, as well as 6 and 24 h post infusion. Depression, anorexia, increased rectal temperature, leucopenia followed by leucocytosis, hypoglycaemia, increased prothrombin time, partial thromboplastin time (APTT), pulmonary artery pressure, pulmonary artery wedge pressure, right atrial pressure, pulmonary and systemic vascular resistance and mild hypoxaemia were consistent findings in the foals receiving endotoxin. There was marked variation over time in the above parameters, during the infusion. Shock was not induced, and the foals appeared to be healthy shortly after the infusion was discontinued. The return to baseline values of body temperature (3 of 4 foals), APTT (1 of 4 foals) and neutrophil count (2 of 4 foals), during endotoxin infusion, suggests induction of early tolerance. The control foals remained alert and the temperature, prothrombin time and fibrinogen remained stable during the study. Hyperglycaemia, transient increased APTT and variations in selected haemodynamic parameters were recorded in the control foals during the infusion.     

The effect of plant density and day-length on growth and development in the carnation

Carnation plants cultivar ‘White Sim’ were grown in containers arranged to simulate the aerial environment of bed-grown crops. The effects of 2 plant densities (9 plants and 100 plants m^?2) and 2 day-lengths (natural days and continuous light) were recorded on the growth of individual plants. The reduction in yield of flowers per plant at high density was greater than could be accounted for simply by a reduction in light intensity. An interaction between light intensity and intra-plant competition is proposed as an explanation of this effect. Continuous light had little effect on the growth and flowering of 2nd and 3rd generation shoots grown at high density.     

Effects of shoot size,number of continuous-light cycles and solar radiation on flower initiation in the carnation

Carnation plants (Dianthus cary ophyllus L.) cultivar ‘White Sim’, were grown in containers in a glasshouse under short (8 h) days. When the primary shoots had 4, 8 or 12 pairs of visible leaves, the plants were moved to a continuous-light area, lit by tungsten lamps for 5, 10, 15 or 30 days, and then returned to short days. This was repeated with several sets of plants at different times of year to obtain a range of radiation flux densities.The number of continuous-light cycles required to initiate a given proportion of shoots was dependent upon the radiation integral, a generalised linear model gave quantitative relationships between the proportion of responding shoots, the number of cycles of continuous light (CL) and the radiation integral. For shoots with 4 visible leaf pairs the model

$\text{keta;=μ+∝X}{}_1\text{+βX}{}_2$

accounted for 83% of the deviance, where η is the linear predictor, μ, α and β are parameters, X₁ = log_e (number of CLs + 1) and X₂ = log_e mean radiation (calories cm^?2 day^?1). For shoots with 8 visible leaf-pairs, 76% of the deviance was removed.Under low radiation integrals, intra-plant competition resulted in only a small proportion of shoots on a plant initiating flowers; increasing the number of CL cycles only partially mitigated this effect. At low radiation integrals, shoots that failed to initiate flowers in CL were often delayed by this treatment and initiated flowers later than shoots in short days. Both the CL-requirement and the limiting effect of the radiation integral on the proportion of shoots that initiated flowers decreased as shoot size increased.It is concluded that competition for photosynthetic assimilates under low radiation conditions can severely limit flower initiation in the carnation.     

Nemaline Rods in Canine Myopathies: 4 Case Reports and Literature Review

The diagnosis of nemaline rod myopathy (NM) is based on the presence of numerous pathognomonic rods within a fresh frozen muscle biopsy specimen. Three forms of congenital NM have been described in humans, and rods have been found to occur in various other conditions. A similar myopathy was described in 1986 in a family of cats. In this report, we describe a case of congenital NM in a 10-month-old Border Collie, an adult-onset NM in an 11-year-old Schipperke, and 2 acquired myopathies with nemaline rods in adult dogs associated with hypothyroidism and Cushing's syndrome. Common clinical features included exercise intolerance, abnormal electromyography, and the presence of nemaline rods in fresh, frozen, and glutaraldehyde-fixed biopsies from proximal appendicular limb muscles. Staining of cryostat sections of muscle biopsy specimens by the modified Gomori trichrome technique disclosed numerous rod bodies that were localized to type 1 fibers by the histochemical adenosine triphosphatase reaction. Accumulation of rods also was demonstrated by electron microscopy in 2 of the cases with localized enlargement and streaming of Z lines. Documentation of NM in a young Border Collie and the adult-onset form in the Schipperke alerts clinicians to the existence of this disorder in these breeds.     

Social and Breed Effects on the Expression of a PGF2α Induced Oestrus in Beef Cows

Social organization and breed effects following PGF2αwere studied in mature Angus, Brahman and Senepol cows allocated into two groups (each A = 5, B = 5 and S = 5). Variables including interval to oestrus onset (IEO), oestrous duration (DE), total mounts received (TMR), and oestrous intensity (IE) were derived via HeatWatch®. Breed‐type influenced IEO (B = 42.6 ± 6.7 h; S = 54.6 ± 6.0 h; and A = 27.8 ± 5.8 h; p < 0.003). Within breeds, dominant B (69.4 ± 13.3 h) and S (65.5 ± 7.4 h) cows were slower (p < 0.05) to be detected in oestrus than subordinate (38.1 ± 4.4 h) and intermediate (40.6 ± 6.0 h). However, within A, dominant cows (16.4 ± 12.5 h) were detected in oestrus earlier (p < 0.05) than intermediate (44.3 ± 9.2 h) and subordinates (32.7 ± 5.1 h). Angus (21.5 ± 2.4 h) and B (22.1 ± 3.0 h) cows had longer (p < 0.01) DE than S (9.1 ± 2.8 h). Dominants (20.4 ± 3.0) and intermediates (20.2 ± 2.3 h) cows had longer DE (p < 0.04) than subordinates (12.1 ± 2.1 h) although the interaction breed × social order showed that dominant S had shorter DE than dominant A and B (10.1 ± 3.3; 34.8 ± 6.0 h; and 20.0 ± 6.4 h, respectively; p < 0.001). Angus cows had less TMR than B (p < 0.02) and tended to be less than S cows (p < 0.06). Overall, greatest (p < 0.008) IE occurred in the first 9 h after onset of oestrus with no breed effect (p > 0.05). Dominant cows tended (p < 0.10) to have less TMR (3.2 ± 0.7 mounts) than subordinate (4.1 ± 0.4 mounts) and intermediate (4.7 ± 0.6 mounts) throughout, especially 3–6 h after oestrus onset (p < 0.07). Breed and social order both influence PGF2α‐induced oestrus behaviour.     

Proteomic profiling using SELDI‐TOF mass spectrometry: a diagnostic tool for canine B‐cell lymphoma

Introduction: Surface enhanced laser desorption ionization time of flight (SELDI‐TOF) mass spectrometry is a powerful new tool for biomarker discovery and diagnostic test development. In this process, proteins in biological samples are selectively bound to chip surfaces that have various chemistries and then subjected to mass spectrometry. Selectively bound proteins are separated by mass and the relative quantities of each protein compared among samples. Unlike conventional diagnostic test formats that commonly use single biomarkers, SELDI‐TOF technology allows multiple biomarkers to be used in a single assay to improve sensitivity and specificity. This technology has been used to improve diagnostic tests for human prostate and ovarian cancers. The objective of this study is to investigate the utility of this technology for the proteomic profiling of canine B‐cell lymphoma. Developing a diagnostic serum screening test for B‐cell lymphoma in dogs would be valuable as early diagnosis and treatment may confer a more favorable outcome. Methods: Serum samples were collected from 26 dogs diagnosed with B‐cell lymphoma prior to treatment and from 26 apparently healthy dogs that were similar in age, breed, and sex to the test group. Serum proteins were selectively bound to weak cationic, strong anionic, and nickel chelating chip surface chemistries under optimized buffer conditions, and subjected to mass spectrometry. The protein profiles were then compared using Biomarker Wizard and classification trees developed using Biomarker Patterns software from Ciphergen Biosystems, Inc (Fremont, CA). Results: To date several putative biomarkers have been identified. These putative biomarkers have been used to build classification tree models that predict disease in test samples. Preliminary results using cross‐validation of the test and control sample sets indicate that trees built with two or more biomarkers have greater than 90% sensitivity and specificity. Conclusions: Proteomic profiling using SELDI‐TOF technology in canine serum is feasible. Further testing is planned to confirm these initial results.     

Evaluation of Indicators of Weight-Carrying Ability of Light Riding Horses

To answer the question of whether horse height, cannon bone circumference, and loin width can be used as indicators of weight-carrying ability in light horses, eight mature horses underwent a submaximal mounted standard exercise test under four conditions: carrying 15, 20, 25, or 30% of their body weight. Heart rate was monitored, plasma lactate concentration was determined in jugular blood samples pre-exercise, immediately post-exercise, and 10 minutes post-exercise, with serum creatine kinase activity determined at the same times as plasma lactate concentrations, with additional samples collected at 24 hours and 48 hours post-exercise. Muscle soreness and muscle tightness scores were determined using a subjective scoring system 24 hours before and 24 hours after exercise. Heart rates remained significantly higher when the horses carried 25 and 30% of their body weight. Plasma lactate concentrations immediately and 10 minutes after exercise differed when horses carried 30% of their body weight compared with 15, 20, and 25% weight carriage. Horses tended to have a greater change in muscle soreness and muscle tightness when carrying 25% of their body weight, and a significant change in soreness and tightness scores was found in horses carrying 30% of their body weight. Loin width and cannon bone circumference were found to be negatively correlated to the changes in muscle soreness and tightness scores. In conclusion, the data suggest that horses with wider loin and thicker cannon bone circumference became less sore when carrying heavier weight loads.