Total and Differential Leucocyte Counts and Lymphocyte Subpopulations in Lymph, Afferent and Efferent to the Supramammary Lymph Node, During Endotoxin-Induced Bovine Mastitis

Leucocyte trafficking in afferent and efferent mammary lymph and the supramammary lymph node in cows was examined during 4 h after intramammary infusion of endotoxin from Escherichia coli. Total and differential leucocyte counts were measured in milk, blood and lymph. The proportions of CD4(+), CD8(+), major histocompatibility complex (MHC) class II(+) and IgM(+) lymphocytes were examined in the lymph and lymph node. At post-infusion hour (PIH) 4, the flow rates of both lymph fluids had increased approximately eightfold. Total leucocyte concentration increased in afferent lymph, but decreased in efferent lymph. Neutrophils increased in afferent lymph at PIH 2 and in efferent lymph and milk at PIH 4. The predominant cell type in afferent lymph shifted from lymphocyte to neutrophil while lymphocyte was still at PIH 4 the predominant type in efferent lymph. Among the lymphocytes, B cells were predominant in afferent lymph and lymph node at PIH 4 while T cells, mainly CD4(+) cells, were predominant in efferent lymph both at PIH 0 and PIH 4. The CD4 : CD8 ratio was higher in efferent lymph and the challenged lymph node than in afferent lymph and the control node, respectively. There was a significant difference in proportions of each lymphocyte subpopulation except for IgM(+) cells, between afferent and efferent lymph after infusion. According to the results, there was already during the first hours of the immune response, a non-random trafficking of neutrophils and lymphocyte subpopulations resulting in a changed distribution of cells in afferent and efferent lymph and a difference in lymphocyte reactivity between the two lymph fluids.     

Electrophysiologic differentiation of homozygous and heterozygous Abyssinian-crossbred cats with late-onset hereditary retinal degeneration

OBJECTIVE: To develop a method to electrophysiologically differentiate heterozygous-carrier Abyssinian-crossbred cats from homozygous-affected Abyssinian-crossbred cats before clinical onset of inherited rod-cone retinal degeneration. ANIMALS: 14 back-crossed Abyssinian-crossbred cats of unknown genotype (homozygous or heterozygous) for inherited rod-cone retinal degeneration, 24 age-matched mixed-breed control cats, 6 age-matched heterozygous Abyssinian-crossbred cats, and 6 homozygous Abyssinian cats. PROCEDURE: Electroretinography (ERG) of heterozygous and homozygous cats revealed differences, especially for scotopic recordings. Frequent ophthalmoscopy and ERG (2 to 5 times; at intervals of 3 to 6 months) of back-crossed cats were performed. Amplitudes and implicit times were analyzed by use of a graphic representation of results. Ratios for amplitudes of the b-waves to amplitudes of the a-waves (b-wave:a-wave) were compared. RESULTS: 8 back-crossed cats had decreased a-wave amplitudes, increased b-wave implicit times, and abnormal ERG waveforms. Values for the b-wave:a-wave for the highest scotopic light intensity were significantly higher for those same 8 cats. CONCLUSIONS AND CLINICAL RELEVANCE: The 8 back-crossed Abyssinian-crossbred cats with abnormal results developed fundus changes over time consistent with disease. A graphic representation of ERG results can be used to differentiate between genotypes prior to funduscopic changes. Values for the b-wave:a-wave ratio provide confirmation. These ERG analyses may be applied clinically in the diagnosis of retinal degenerations in various species. IMPACT FOR HUMAN MEDICINE: Cats with hereditary rod-cone degeneration may be a useful model for comparative studies in relation to retinitis pigmentosa in humans. Similar evaluations of ERG results could possibly be used for humans with suspected generalized retinal degeneration.     

Surface antigens on equine sarcoid cells and normal dermal fibroblasts as assessed by xenogeneic antisera

To characterise the expression of surface antigens on equine sarcoid cells compared to normal equine fibroblasts, immune sera were produced in rabbits against transformed cells of a virus-containing sarcoid cell line (Mc-1) and normal dermal fibroblasts, respectively. The specificities of the sera were analysed by antibody-dependent cellular cytotoxicity against 51Cr-labelled target cells using human lymphocytes as effector cells. Anti-Mc-1 antiserum induced strong cytotoxicity against transformed cells of two sarcoid cell lines (Mc-1 and Bay Mc-1), whereas the cytotoxicity against transformed cells of equine testis, or against cells grown in short term or primary cultures derived either from sarcoids or normal dermis was low or absent. In contrast, anti-normal dermal fibroblasts antiserum did not induce antibody-dependent cellular cytotoxicity against Mc-1 or Bay Mc-1 but reacted strongly against both normal fibroblasts and primary cultured cells derived from sarcoids. The apparent specificity of the anti-Mc-1-induced cytotoxicity was confirmed by absorption of the anti-serum with either normal dermal fibroblasts and equine testis cells or Mc-1 cells. Immunoprecipitation of 125I-surface labelled Mc-1 cells by absorbed anti-serum and analysis by SDS-PAGE and autoradiography revealed that anti-Mc-1 antibodies reacted with at least four surface components with a wide range of molecular weights. Immunofluorescence with rabbit anti-human beta 2mu serum indicated that Mc-1 cells in contrast to equine lymphocytes and fibroblasts did not express class 1 major histocompatibility complex antigens.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunohistochemical studies of cone photoreceptors and cells of the inner retina in feline rod-cone degeneration

Previous studies using electroretinography and immunohistochemistry have shown normal cone function and structure in early stages of hereditary rod‐cone degeneration of Abyssinian cats. To further investigate the cone photoreceptors and the inner retina of dystrophic cats, antibodies against green‐ and blue‐sensitive cones and specific cell types of inner retina were used in seven cats with the recessively inherited rod‐cone degeneration, and three normal European short‐haired cats. There was a reduction in number of both types of cones early in the disease. Changes at early stages of disease also occurred among horizontal cells in which there was an extension and a thickening of their lateral processes. The regular configuration of bipolar cells was changed in the more advanced stages of disease and their apical dendrites were lost. Abnormalities were not observed in the amacrine cells and in the ganglion cell layer in any of the present cases. This study shows that the cone system is morphologically abnormal in young cats at an earlier stage of disease than previously shown. The present findings also support the assumption that the inner retina is largely preserved throughout the disease process.     

Dog as a model for studying conspecific and heterospecific social learning

In human communities social learning (i.e., learning by the observation of knowledgeable individuals) plays an important role; it shapes cultures, traditions, and cognition. Dogs seem to be an ideal system for modeling human cognition from the social learning aspect. The present review offers a short overview on the relevant general theories of social learning, discusses the adaptive value of social learning, introduces dog as a model system, presents evidence for different forms of social learning in dogs and argues for practical implications that social learning might have in this species.     

The Diurnal Variation of Urea in Cow’s Milk and how Milk Fat Content,Storage and Preservation Affects Analysis by a Flow Injection Technique

Six Swedish Red and White dairy cows, producing 20-39 kg of 4% fat-corrected milk were given a ration balanced in energy and protein. They had access to feed from 05.15 to 09.00 and from 13.00 to 16.30 and were milked at 06.15 and 15.30. The milk was analysed for urea with a FIA technique.There was a significant diurnal variation in milk urea. The highest values were found 3–5 h after the beginning of the morning feeding and the lowest values (down to 60% of the max. values) during late night. Within 1 h after the start of the morning feeding the urea values had increased significantly, but they had decreased within the same time after the start of the afternoon feeding. Since there was a pronounced diurnal variation in the milk fat content, the urea concentration was also recalculated to concentration in the water phase of the milk. It was higher in that phase, but the pattern of the diurnal variation was not changed significantly. However, analyses on milk with a very high fat content may give misleading results.There were no important differences in the milk urea concentration of different udder quarters. When calculated as concentration in the water phase of the milk, no differences in urea concentration were found between the beginning and the end of milking. The analytical method had a good precision (coefficient of variation max. 3%). The milk urea concentration was not changed significantly after storage during 10 days at 4°C when no preservative was added; but after 17 days the milk had turned sour and the urea value had increased. When a preservative (bronopole) was added the urea concentration remained unchanged during 17 days. Deepfreezing did not influence the urea concentration.     

The effects of utilization of hazelnut oil,sunflower oil and their products on performance and fatty acid composition of yolk in layer hens

This research has been performed to determine the effects of hazelnut crude oil, sunflower crude oil and its refinery by-products over the laying hens performance and the fatty acid composition of the egg’s yolk. Four hundreds 36-week-old Nick Brown layer hens were allocated into five groups. Treatment groups were supplemented with 1.5% of sunflower crude oil, hazelnut crude oil, acidulated sunflower soapstock, acidulated hazelnut soapstock and acidulated hazelnut crude oil. The daily feed consumption for groups that were fed with crude oils were numerically improved as compared for those nourished with acidulated soapstocks. Although the percentages of cracked and broken eggs in acidulated hazelnut soapstock group was significantly higher than the other groups, daily feed consumption and egg production values were not different. The usage of acidulated hazelnut soapstock reduced the percentage of intact egg ratio. Egg’s specific gravity and yolk color index were the highest level throughout the experiment from start to end in hazelnut crude oil group (p < 0.05). In group that was nourished by hazelnut oil, Omega 3/Omega-6 fatty acid ratios in egg yolk were higher than the groups that were fed with sunflower oil. The oleic acid content of the egg yolk was increased in the groups which were supplemented with hazelnut crude oil and acidulated hazelnut crude oil. Consequently, hazelnut crude oil and acidulated hazelnut crude oil improved the egg shell quality, yolk color index and yolk oleic acid value which would increase egg’s shelf life. On the other hand acidulated hazelnut soapstock supplementation adversely affects the quality of egg shell.     

Recognition of the Nor98 variant of scrapie in the Swedish sheep population.

Within the framework of the active surveillance for transmissible spongiform encephalopathies in sheep in Sweden, 4 cases of the atypical form of scrapie, Nor98, were identified during 2003. Nor98 is a recently recognized and poorly understood variant of scrapie, first described in Norway. The cases were positive by the rapid test (enzyme-linked immunosorbent assay). Immunohistochemical staining showed diffuse thin-granular staining of the cerebellar cortex. Western immunoblotting analysis of specimens of brain stem and cerebellum showed a light band of approximately 12 kDa. Typical scrapie was ruled out based on the confirmatory testing. The affected ewes were from 4 different flocks. They were between 7 and 9 years old. Two were of the ARQ/ARQ genotype, 1 ARR/ARQ, and 1 ARR/AHQ. Two ewes had shown ataxia, and the other 2 had no clinical signs. Whole-flock slaughter was applied, and testing of the flock mates did not reveal additional cases. Nor98 differs from typical scrapie in its epidemiology, frequency of genotypes of sheep affected, clinical signs, microscopic lesions, distribution of scrapie prion protein in the brain, and characteristics of the immunostaining and immunoblotting profiles.     

Biological variation in random and leukotriene B4-directed migration of canine neutrophils

Seasonal, sexual, parental and age-related effects on peripheral blood neutrophil migration were studied in 25 dogs. Random and chemotactic movements were estimated by measuring migration towards buffer and leukotriene B4, respectively. Significant effects were seen only in the comparison between the two sexes. Neutrophils from bitches exhibited 19% greater random migration but 10% smaller chemotactic responsiveness than neutrophils from male dogs. A progesterone-mediated suppression of chemotaxis is hypothesized in metoestral bitches. It is concluded that the observed differences are probably too subtle to play any role in combatting bacterial infections, but may constitute a source of bias in the evaluation of isolated cases of disease-associated defective chemotaxis.