Definition and biological significance of the major histocompatibility system (MHS) in man and animals

Already for some time the major histocompatibility system (MHS) is no longer considered to be only of importance in transplantation surgery. The MHS might also partly control specific immune responsiveness. In fact, tissue antigens may serve as a marker system for individual immunocompetence. So, in veterinary relevant species, tissue typing could be an important tool in breeding and health programs. The purpose of this review is to summarize the current knowledge of the MHS in different species.     

Flurbiprofen and immunosuppression of Trypanosoma brucei infection in the goat

Goats infected with Trypanosoma brucei and treated with the non-steroidal anti-inflammatory agent flurbiprofen, showed a marked increase in parasitaemia, followed in one of the four goats by death. The in vitro response to mitogens of peripheral blood lymphocytes and separated T- and B-lymphocytes from healthy goats treated with flurbiprofen was normal when compared with non-treated animals. T. brucei-infected goats, not treated with flurbiprofen, showed a marked immunosuppression which was mainly localized in the B-enriched lymphocyte fraction. A combination of T. brucei infection and treatment with flurbiprofen led to even more suppression, because the T-lymphocyte function was also suppressed. It is concluded that flurbiprofen first causes a rise in the parasitaemia and that this high parasitaemia is responsible for the observed immunosuppression.     

Infrared skin temperature measurements for monitoring health in pigs: a review

Infrared temperature measurement equipment (IRTME) is gaining popularity as a diagnostic tool for evaluating human and animal health. It has the prospect of reducing subject stress and disease spread by being implemented as an automatic surveillance system and by a quick assessment of skin temperatures without need for restraint or contact. This review evaluates studies and applications where IRTME has been used on pigs. These include investigations of relationships between skin, ambient and body temperatures and applications for detecting fever, inflammation, lesions, ovulation, and stress as well as for meat quality assessment. The best skin locations for high correlation between skin temperature and rectal temperature are most likely thermal windows such as ear base, eye region and udder. However, this may change with age, stressors, and biological state changes, for example, farrowing. The studies performed on pigs using IRTME have presented somewhat discrepant results, which could be caused by inadequate equipment, varying knowledge about reliable equipment operation, and site-specific factors not included in the assessment. Future focus areas in the field of IRTME are suggested for further development of new application areas and increased diagnostic value in the porcine and animal setting in general.     

Bioluminescence: the potential of a molecular non-invasive biooptical imaging technique and improvement of animal research

Bioluminescence is an optical imaging technique that exploits the emission of photons at specific wavelengths based on energy-dependent reactions catalysed by luciferases. The technique makes it possible to monitor measure, and track biological processes in living animals. A short review is presented of the potential of in vivo bioluminescence imaging (BLI) as a new bio-optical imaging technique for use in research into cancer infectious diseases, pharmacology, and toxicology. Bioluminescence has greatly improved the quality of longitudinal data obtained from animal research and has led to a significant reduction in the number of animals needed.     

Comparison of fluorescent antibody tests for tuberculosis and paratuberculosis with antigens coupled to insoluble spheres or taken up by macrophages

Sera of 106 cattle from farms with histories of Mycobacterium johnei infection and sera from 15 human tuberculous patients as well as a number of control sera were examined by means of two different fluorescent antibody tests (FAT) for the occurrence of antibodies against M. johnei and M. tuberculosis respectively. The antigens used were PPD johnin and PPD tuberculin. In the macrophage uptake FAT (MU/FAT) mouse macrophages after phagocytosis of the tuberculins served as the matrix; in the tests performed using the defined antigen substrate spheres (DASS) system, Sepharose beads activated by CNBr were used for the matrix. A good correlation was found between the results of the DASS/FAT and those of the MU/FAT, which is known to be a sensitive and specific test in the diagnosis of Johne's disease in cattle. It is suggested that the FAT, with utilization of the DASS system, might have good prospects for routine examination for antibodies against species of Mycobacterium.     

A study of the sensitivity of erythrocytes to lysis by heterologous sera via the alternative complement pathway

In order to get insight in the distribution of alternative complement pathway activities as detected by lysis of xenogeneic erythrocytes in the presence of magnesium and ethyleneglycol-bis-(2-aminoethyl)-tetra-acetic acid (EGTA) over the species, the 156 heterologous combinations of erythrocytes and sera out of thirteen animal species were tested. An order could be noticed in the species with respect to serum complement activity tending to negative correlation with the sensitivity of the corresponding erythrocytes to lysis by heterologous sera. So far, the most sensitive erythrocyte for each individual serum must be considered to be the target cell of choice for developing assays for alternative complement pathway activity in the serum involved. In this series of animals only for rabbit serum no sensitive target cell was found. The order observed, in connection with the failing lysis of erythrocytes by homologous sera, suggests further that in restriction of heterologous hemolysis in general one erythrocyte-associated, species-nonspecific regulatory principle may be involved, whereas in homologous restriction, most probably, also species-specific factors play a role.     

Investigation of the expression and localization of glucose transporter 4 and fatty acid translocase/CD36 in equine skeletal muscle

OBJECTIVE: To investigate the expression and localization of glucose transporter 4 (GLUT4) and fatty acid translocase (FAT/CD36) in equine skeletal muscle. SAMPLE POPULATION: Muscle biopsy specimens obtained from 5 healthy Dutch Warmblood horses. PROCEDURES: Percutaneous biopsy specimens were obtained from the vastus lateralis, pectoralis descendens, and triceps brachii muscles. Cryosections were stained with combinations of GLUT4 and myosin heavy chain (MHC) specific antibodies or FAT/CD36 and MHC antibodies to assess the fiber specific expression of GLUT4 and FAT/CD36 in equine skeletal muscle via indirect immunofluorescent microscopy. RESULTS: Immunofluorescent staining revealed that GLUT4 was predominantly expressed in the cytosol of fast type 2B fibers of equine skeletal muscle, although several type 1 fibers in the vastus lateralis muscle were positive for GLUT4. In all muscle fibers examined microscopically, FAT/CD36 was strongly expressed in the sarcolemma and capillaries. Type 1 muscle fibers also expressed small intracellular amounts of FAT/CD36, but no intracellular FAT/CD36 expression was detected in type 2 fibers. CONCLUSIONS AND CLINICAL RELEVANCE: In equine skeletal muscle, GLUT4 and FAT/CD36 are expressed in a fiber type selective manner.     

Immunohistochemical identification and fiber type specific localization of protein kinase C isoforms in equine skeletal muscle

OBJECTIVE: To investigate whether protein kinase C (PKC) isoforms are expressed in equine skeletal muscle and determine their distribution in various types of fibers by use of immunofluorescence microscopy. ANIMALS: 5 healthy adult Dutch Warmblood horses. PROCEDURE: In each horse, 2 biopsy specimens were obtained from the vastus lateralis muscle. Cryosections of equine muscle were stained with PKC isoform (alpha, beta1, beta2, delta, epsilon, or zeta)-specific polyclonal antibodies and examined by use of a fluorescence microscope. Homogenized muscle samples were evaluated via western blot analysis. RESULTS: The PKC alpha, beta1, beta2, delta, epsilon, and zeta isoforms were localized within the fibers of equine skeletal muscle. In addition, PKC alpha and beta2 were detected near or in the plasma membrane of muscle cells. For some PKC isoforms, distribution was specific for fiber type. Staining of cell membranes for PKC alpha was observed predominantly in fibers that reacted positively with myosin heavy chain (MHC)-IIa; PKC delta and epsilon staining were more pronounced in MHC-I-positive fibers. In contrast, MHC-I negative fibers contained more PKC zeta than MHC-I-positive fibers. Distribution of PKC beta1 was equal among the different fiber types. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that PKC isoforms are expressed in equine skeletal muscle in a fiber type-specific manner. Therefore, the involvement of PKC isoforms in signal transduction in equine skeletal muscle might be dependent on fiber type.     

Effects of temperature and photoperiod on early growth and final number of tubers in potato (Solanum tuberosum L.)

Summary A phytotron experiment with all combinations of two photoperiod (12 or 18 h) and four temperature (18/12, 22/16, 26/20 or 30/24 °C; 12h/12h) treatments was carried out to analyse quantitative effects on early tuber growth, dry-matter partitioning and number of tubers of two cultivars. Higher temperatures and longer photoperiod delayed the onset of expolinear tuber growth and the onset of linear tuber bulking. Higher temperatures also gave lower absolute tuber growth rates. Photoperiod did not affect absolute tuber growth rate at lower temperatures. Higher temperature and longer photoperiod gave lower relative rates of partitioning of dry matter to the tubers. Differences between treatments in numbers of tubers initiated were inconsistent. This quantitative analysis of the effects of temperature and photoperiod on characteristics of tuber growth should prove useful in potato modelling.