Dependence between acute phase response, oxidative status and mastitis of cows.

There are many studies exploring the topic of acute phase response and oxidative status in inflammation of the mammary gland of cows. However, many phenomena are relatively not well known. Mastitis is associated with significantly higher concentrations of inflammatory and oxidative mediators in the cells and blood. Results of experiments have shown that there are evident changes in serum interleukins (IL), acidglycoprotein (alpha1AG), tumor necrosis factor (TNF), and haptoglobin (Hp). Thus, local as well as systemic inflammation might play important roles in increased mammary oxidative stress. Reactive oxygen species (ROS) have been implicated in the pathogenesis of a variety of diseases, including mastitis and in transgenic technology leading to production of new bacterial proteins, very important in prevention of mastitis. We can also observe an interaction between inflammatory and oxidative mediators. These results suggest an important role played by acute phase response and oxidative status in inflammation of the mammary gland.

Occurrence of Lawsonia Intracellularis and Brachyspira spp. infection in swine suffering from diarrhoea.

Principal aim of this study was to examine fecal samples from pigs suffering from diarrhea for the presence of Lawsonia intracellularis, Brachyspira hyodysenteriae and Brachyspira pilosicoli. The molecular techniques such as PCR and nested PCR were employed to detect the presence of p78 fragment of genomic DNA specific for Lawsonia intracellularis as well as fragment of tlyA gene specific for Brachyspira hyodysenteriae and 16S rDNA gene of Brachyspira pilosicoli. We assumed that about 25% of pigs were infected with Lawsonia intracellularis, about 10% with Brachyspira hyodysenteriae and only 0,8% with Brachyspira pilosicoli. In about 3% mixed infection with L. intracellularis and B. hyodysenteriae was observed. Results were comparable in herds that differed in quantity, breeding technology, hygienic standards and preventive treatment with different chemotherapeutics.

Shielded gradient coils and radio frequency probes for high-resolution imaging of rat brains.

A shielded gradient system and radio frequency probes for a 4.7-T/30-cm horizontal bore magnet are described. The systems were designed principally to obtain images and localized spectra from rat brains. The gradients can operate in either a shielded or non-shielded mode. The rf probe, which combines both highest sensitivity and highest resolution, consists of a large modified saddle type transmitter and a small surface reception coil, actively decoupled using diodes. The system performance is demonstrated on phantoms and on a rat brain, where an image with in plane resolution of 80 microns and a slice thickness of 150 microns is obtained.

Toxigenic Pasteurella multocida in rabbits with naturally occurring atrophic rhinitis.

In a commercial rabbitry nasal swabs were taken from 36 animals with enzootic upper respiratory disease resembling porcine atrophic rhinitis. 35 Pasteurella multocida strains were isolated from 17 rabbits. Among 30 strains tested for dermonecrotic toxin production 3, derived from 3 animals, were positive in the guinea pig skin test. 15 Bordetella bronchiseptica strains were recovered from 14 rabbits. No toxigenic strains were found among 6 isolates tested using the same method.

Production of enterotoxins by strains of Escherichia coli isolated from pigs.

The production of enterotoxins by 237 hemolytic strains of Escherichia coli isolated from pigs was determined with the use of CTE in CHO. Vero and Hela cells and ILT. More frequent (p less than 0.01) production of enterotoxins, determined by ILT, was found for the serotypes being pathogenic for the animals (63.8% of the strains). No correlation between intensity of ILT and particular serotype was observed. Both the serotypes pathogenic for pigs and other serotypes produced LT enterotoxins and ST toxin. The frequency of LT enterotoxin production was statistically insignificant compared to the frequency of ST enterotoxin production by strains with serotypes pathogenic for the pigs. Strains of E. coli producing only enterotoxin ST belonged both to the pathogenic serotypes as well as to other hemolytic serotypes. The cytotoxic activity of supernatants of E. coli strains with different serotypes isolated from pigs in Vero and Hela cells and simultaneous CTE in CHO cells was observed. This suggests the production by the strains of enterotoxin LT and cytotoxin VT. Seven out of the 96 isolates showing CTE in CHO cells gave no reaction in the ILT in pigs. This suggests the production by these isolates of a toxin (toxins) differing from the E. coli enterotoxins.

Persistence of La Crosse virus (California encephalitis serogroup) in north-central Illinois.

La Crosse (LAC) virus was first isolated in Illinois from a pool of 50 female Aedes triseriatus mosquitoes collected in July 1976, in Peoria Heights. From 1978 through 1981, 27 strains (11 from males and 16 from females) of LAC virus were recovered from 888 pools containing 22,021 adult A. triseriatus mosquitoes from the same study area. These mosquitoes had developed from larvae and pupae collected from 50 individually identified treeholes. Of the 14 trees that yielded LAC virus-positive mosquitoes, one was positive in 3 of 4 years and another was positive in all 4 years. The latter tree had minimum mosquito field infection rates (MFIR) ranging from 3.4 to 12.7/1,000. Eight (57%) of the trees with positive mosquitoes were red oak (Quercus rubra) while 10 (71%) were in the oak genus (Quercus). The four most productive treeholes accounted for 30% of mosquitoes tested and 52% of the LAC isolations. In 1979, 6,729 A. triseriatus mosquitoes were collected in man-baits and tested for virus. From 1,282 tested in 259 pools (mean = 5), 13 LAC isolates were made, resulting in a field infection rate (FIR) of 11.4/1,000. The remaining 5,447 were tested in 218 pools (mean = 25) and 48 strains of LAC were isolated for a FIR of 9.9/1,000. The relationship of these findings to the occurrence of human LAC encephalitis cases in Peoria County, Illinois is discussed. Repeated recovery of virus from this study area reflects a stable, yet dynamic, focus of LAC virus transmission.