MITOGENIC RESPONSIBILITIES OF LYMPHOCYTES IN CANINE BABESIOSIS AND THE EFFECTS OF SPLENECTOMY ON IT

In order to clarify the mechanisms of immune-responses in canine babesiosis, mitogen-induced transformation of lymphocytes from peripheral blood and its relation to parasitemia were chiefly examined in both intact and splenectomized dogs suffering from Babesia gibsoni. The lymphocyte responses to PHA-P, Con A and PWM in dogs infected with B. gibsoni were all extremely depressed as the parasite increased in their peripheral blood. The lymphocyte responses to the mitogens greatly decreased after splenectomy in both groups infected and noninfected with B. gibsoni. Furthermore, severe relapse of parasitemia appeared in the infected dogs after splenectomy. Mild parasitemia and moderate anemia were prolonged for at least 3 months with a high serum IFA titer to the parasite in splenectomized dogs

PASTEURELLA MULTOCIDA SEROTYPE 1 : A ASSOCIATED WITH RESPIRATORY INFECTION OF DOMESTIC RABBITS IN A HOLDING COLONY

Pasteurella multocida strains were isolated from adult domestic rabbits suffering from respiratory disease in a holding colony. The strains had uniform biochemical characteristics and were of serotype 1 : A (NAMIOKA & MURATA, 1961). The isolate was pathogenic to mice and rabbits. The injection of streptomycin and penicillin reduced the number of Pasteurella isolations from diseased rabbits

ROLE OF ADHERENT MONONUCLEAR CELLS DERIVED FROM ADULT PIGS AND SUCKLING PIGLETS IN RESPONSE TO POKEWEED MITOGEN-INDUCED IMMUNOGLOBULIN PRODUCTION

The effect of monocytes as an activator of a function of lymphocytes in pigs was studied using an in vitro Ig production system with pokeweed mitogen (PWM). When mononuclear cells (lymphocytes) from adult pigs were stimulated by PWM, optimal number of adherent cells (monocytes) collected from serum coated plastic Petri dishes were required for the generation of Ig producing cells, whereas the production was suppressed by the addition of excessive adherent cells. In neonatal and suckling piglets up to 6 weeks of age, PWM induced B lymphocyte differentiation was enhanced by addition of adherent cells from peripheral blood of adult pigs. On the other hand, adherent cells derived from piglets did not have the effect of increasing Ig production in the in vitro Ig production system with lymphocytes (non-adherent) derived from adult pigs

LYMPHOCYTE TRANSFORMATION OF PERIPHERAL BLOOD LYMPHOCYTES AND PLAQUE FORMING CELLS OF THE SPLEEN AND THE MESENTERIC LYMPH NODE IN SUCKLING PIGLETS WITH AND WITHOUT IMMUNOPOTENTIATORS

Lymphocyte transformation with mitogen, phytohemagglitinin (PHA) and concanavalin A (conA) was tested in peripheral blood lymphocytes from suckling piglets aged 1,2,3,4 and 5 weeks old respectively. A study was also made to observe plaque forming cells with sheep red blood cells (SRBC) in the spleen and nucleated cells of the mesenteric lymph nodes (MLN) of piglets aged 2,3 and 4 weeks respectively. Reratively high levels of lymphocyte responses were seen in the 1 week-old piglets. Differences of stimulation indexes (SI) of lymphocyte responses of the piglets were not significant in the animals aged from 1 to 5 weeks. The effect of administration of peptidoglycan and chemical composites of cultural supernates derived from Streptomyces olivaceogriseus sp. nov (FR41565) on the lymphocyte responses was investigated. The value of SI among the piglets treated with and without peptidoglycan and FR41565 was not significant. On the other hand, the count of plaque forming cells (PFC) of the splenic and MLN's cells with SRBC in the piglets aged 2 to 4 weeks was low in spite of the SRBC injections, and the count of PFC of MLN was fewer than that of the spleen of any age. The count of PFC was the highest in the piglets treated with the rapid acting immunopotentiator (FR41565) at 2 weeks of age while the highest count was seen in the piglets administered the slow acting substance (peptidoglycan) at 4 weeks of age. These results indicated that differentiation of B lymphocyte in suckling age piglets seems to be restrained by a certain suppressive activity which leads to poor production of immunoglobulin

RESTRICTION FRAGMENT LENGTH POLYMORPHISM FOR THE YC SUBUNIT GENE OF RAT LIVER GLUTATHIONE S-TRANSFERASE

An altered expression of the Yc subunit gene of rat glutathione S-transferase (GST) in the liver of the LEC rat, which is a mutant strain with spontaneous hereditary hepatitis associated with severe jaundice, has been reported. To provide further information concerning the structure of the Yc subunit gene, we carried out the Southern blot hybridization analysis of DNA samples from rats of eight different inbred strains including LEC with cDNA complementary to mRNA specific for the Yc subunit of rat liver GST as a probe. The hybridization patterns of the DNA samples from rats belonging to the different inbred strains showed interstrain variation in the length of restriction fragments with four restriction endonucleases. Since the DNA samples prepared from several rats of one inbred strain gave an identical hybridization pattern, the restriction fragment patterns for the Yc gene could be used as markers for genetic monitoring of inbred rat strains. Although the altered expression of Yc-Yc activity of GST has been observed in the liver of the LEC rat, the characteristic changes in the gene structure of the Yc subunit of LEC rat were not detected in the present hybridization analysis

INCORPORATION OF ^<15>N ADMINISTERED TO GERMFREE AND SPF PIGLETS AS ^<15>N-UREA INTO AMINO ACIDS OF HYDROLYZED LIVER AND MUSCLE PROTEINS

^N-urea was administered three times with a diet containing urea to two germfree and one specific pathogen free (SPF) piglets. They were killed on the fifth day after the last administration of ^N-urea. The ^N concentration in the amino acids isolated from the hydrolyzed trichloroacetic acid precipitates of the liver and muscle was determined. In SPF piglet, the ^N was incorporated into all of the essential and nonessential amino acids, except threonine in both the liver and muscle and except histidine in the muscle. The ^N concentration of each of the nonessential amino acids was higher than that of most of the essential amino acids in the liver and muscle. On the other hand, an excess of ^N was not detected in the pooled essential and nonessential amino acids nor in the ammonia and glutamic acid in germfree piglets. It was concluded that the ammonia nitrogen converted from urea by the action of intestinal-bacterial urease in the gastrointestinal tract was utilized for the synthesis of all of the essential and nonessential amino acids, except threonine, in the pigs

NONSPECIFIC CELL-MEDIATED CYTOTOXICITY OF PERIPHERAL BLOOD LYMPHOCYTES DERIVED FROM SUCKLING PIGLETS

Peripheral blood lymphocytes (PBL) from both adult pigs and suckling piglets showed natural killer (NK) activity against porcine B cell tumor cell line Mitsukaido, and this activity increased after incubation of PBL in glass Petri dishes at 37℃ for 16 h. The NK activity against homogeneous Mitsukaido was higher than that against heterogenous human chronic myelogenous leukemia cell line K562. NK activity of suckling piglets against Mitsukaido was not observed during 1 to 3 weeks of age. However, the activity rose slightly at 4 weeks old, and it remarkably at 5 weeks old. On the other hand, NK activity against K562 was not seen during 1 to 4 weeks of age, but at 5 weeks old, it was clearly recognized. These results indicated that the NK activity of piglets at 1 to 3 weeks of age was very low compared with adult controls