We previously set forth appropriate three assay systems using Chinese hamster ovary cells to detect the Campylobacter jejuni cytotoxin. Although we could not reach a conclusion because the cytotoxins shown in this study were not purified, at least three different cytotoxins were detected in these assay systems. The first cytotoxin detected in the presence of fetal calf serum (FCS) was heat-labile and the molecular weight (Mw) was estimated at 50-100 k by ultrafiltration. The second cytotoxin detected in the presence of newborn calf serum (NCS) was heat-stable and Mw was estimated at 0.5-3.0 k. The third cytotoxin detected in serum-free culture (SFC) assay was heat-labile and non dialyzable. However, Mw was not estimated since the low Mw and heat-stable cytotoxin was also detected in this assay. The cytotoxic activity detected in FCS and NCS assays, but not that detected in SFC assay, was completely abolished by treatment with a reducing agent. In contrast, the cytotoxicity detected in both FCS and NCS assays was not inactivated by such an enzyme as trypsin, lipase, neuraminidase, and β-galactosidase. When the filtrate was heated at 100°C to inactivate the heat-labile cytotoxin, the cytotoxic activity was detected in the NCS assay but not in FCS assay. However, when NCS was added to this heated filtrate, the cytotoxicity was restored in FCS assay. Furthermore, when normal rabbit serum (NRS) was added, no cytotoxicity was restored. The cytotoxic activity in SFC assay was completely inactivated with FCS or NRS. These findings suggest that the cytotoxic activity is dependent on serum added to tissue culture medium and that the substance amplifying and/or inhibiting the cytotoxic activity may be present in serum.

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Hotbred (Thoroughbred) horses were grouped into three classes according to the levels of constant physical exercise (foals, 6 months old; racing horses, 5 years old; horses for breeding, 6-10 years old), and lipid peroxide levels in their sera were measured as thioburbituric acid-reactive substances. No significant differences were observed among them. The superoxide-scavenging abilities of sera were measured next; to examine the antioxidative properties of hotbreds, and were found to be highest in the racing horses. The higher scavenging ability of the racing horses might contribute to keep their lipid peroxide levels as low as those of the other two groups. HPLC analysis of substances in sera suggested that the presence of albumin-bound bilirubin was one of the reasons for the high superoxide-scavenging ability of sera of the racing horses. When the hotbreds were compared with coldbred (crossbred) horses, the lipid peroxide level of hotbreds was higher (7.0±1.2 nmol/ml) than that of coldbreds (2.6±0.7 nmol/ml). Comparison of the superoxide-scavenging abilities of sera between hotbreds and coldbreds showed that the hotbreds possessed higher scavenging ability than the coldbreds. These results indicated that the lipid peroxide level in sera of hotbreds was higher than that of coldbreds regardless of the higher superoxide-scavenging abilities of sera.

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The composition of intestinal ciliates excreted in the feces of 20 Tokara native ponies kept in Iriki farm of Kagoshima University was surveyed. Eleven genera consisting of 18 species were identified based on the description of Strelkow. One new genus including a new species, Wolskana tokarensis n. gen., n. sp., of the family Buetschliidae was recognized and described. The average ciliate density of all horses was 13.8×10³/ml. Those of stallions (n=5), mares (n=11) and foals (n=4) were 3.9, 16.1 and 43.3×10³/ml respectively. The value of stallions was significantly lower and that of foals higher than that of mares. Brillouin's diversity index of all horses was 1.554 on average. The index of stallions, 1.470, was significantly lower than those of mares, 1.539, and foals, 1.698. The average number of species per host was 11.7.

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The infection levels of Mycoplasma hyorhinis, M.hyopneumoniae and M.hyosynoviae in the lung of piglets were examined in relation to porcine reproductive and respiratory syndrome (PRRS). These animals consisted of 43 PRRS piglets with PRRS, 2 piglets infected with PRRS virus but symptom-free, and 10 control piglets free of PRRS virus and its antibody. M.hyorhinis was isolated from 40 of the 43 PRRS piglets, from 1 of the 2 latent infected piglets and from 3 of the 10 control piglets. The number of M.hyorhinis isolated from the lungs of PRRS piglets was more than 10⁵ CFU/g, but those isolated from the latent infected piglets and the control piglets were less than 10³ CFU/g. In addition to this, Haemophilus parasuis and Pasteurella spp. were frequently isolated from the piglets with PRRS (51.2% and 25.6%, respectively). On the other hand, M.hyopneumoniae was isolated from only 4 of 55 piglets tested, and M.hyosynoviae was not isolated. M.hyorhinis was also detected directly in the lung emulsion samples from almost all the PRRS piglets using a polymerase chain reaction-based method.

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The characteristics of anticoccidial activities of 6-azauracil (AzU) were investigated in the battery trials utilizing the White Leghorn cockerels, which were infected with Elmeria tenella, E.necatrix, E.acervulina, E.maxima and/or E.brunetti. AzU was mixed into the basal starter feed and fed ad libitum to the birds from 1 day before the inoculation of oocysts to the time of necropsy. AzU showed remarkable anticoccidial activity against E.tenella and E.necatrix infections at doses of 1, 000 ppm in feed or more, and fairly good effect against E.acervulina infection at the dose of 4, 000 ppm in feed. Inadequate effect against E.maxima infection and null in effect against E.brunetti at the dose of 4, 000 ppm were resulted for this drug. The effect of 6-azauridine, ribonucleoside of AzU against E.tenella and E.necatrix infections at 1, 000 ppm was tested and revealed negative results. In the test with AzU-resistant line of E.tenella, cross resistance was confirmed between AzU and emimycin riboside, a uridine analogue. Activity of AzU was studied in vitro against E.tenella in chick kidney cells. AzU inhibited the development of the first- and second-generation schizonts at 100-200 ppm in the medium. Degenerated parasites were observed.

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The antagonistic phenomena to anticoccidial activities of 6-azauracil (AzU) induced by certain nucleic acid precursors were examined in battery experiments. Each nucleic acid precursor, orotate, orotidine, uracil, uridine, adenine and adenosine was mixed in feed in combination with effective levels of AzU. The test feed was provided through the test term to White Leghorn cockerels which were infected with Eimeria tenella, E.necatrix or E.acervulina. In vitro tests were also conducted for antagonistic phenomena similarly to in vivo test using E.tenella cultured in chick kidney (CK) cells. Orotate and uridine reduced dose-dependently the anticoccidial activity of AzU in E.tenella infection in chickens. Uracil and orotidine revealed similar effect. Adenine and adenosine did not show any antagonistic effect to AzU. In E.necatrix infection, orotate and uridine had a similar tendency to that of E.tenella, whereas uracil and orotidine was less pronounced. The activity of AzU against E.acervulina was also blocked by the treatment with uridine and orotate. AzU inhibited the schizont's development of E.tenella in the CK cells, and this effect was reduced by uridine, but not by orotate and orotidine. The antagonistic effect of the pyrimidine nucleic acid precursors on AzU activity suggested that the anticoccidial effect of AzU to E.tenella, E.necatrix and E.acervulina is derived from inhibition of the metabolism of pyrimidine nucleotide synthesis in these parasites.

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To clarify the character of the anticoccidial activity of diclazuril a series of battery trials was conducted. Diclazuril showed excellent anticoccidial activity in the infection of chickens with Eimeria tenella, E.necatrix or E.accrvulina at the feeding level of 0.1 ppm. When diclazuril was administered in combination with a nucleic acid precursor, uracil, uridine, orotate or orotidine, the reduction of the activity of diclazuril to the infections induced by above species was not observed. While, bloody droppings with severe cecal lesions were resulted, when diclazuril was administered in combination with uridine 5¹-diphosphoglucose (UDPG) or its N-acetyl amine (UDPGNAC) to chickens infected with E.tenella. While, body weight gain of the birds and oocyst output was not affected by these combination-treatment. Results demonstrated that the antagonistic effect of UDPG and UDPGNAC to diclazuril was partial. The possibility of the cross resistance between diclazuril and 6-azauracil (AzU) in E.tenella was investigated using two populations induced resistance to AzU or diclazuril. The results demonstrated that the cross resistance does not exist between AzU and diclazuril, indicating that the mode of action of each drug is different.

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In order to determine the pathogenesis of ulcerative lesions of the articular cartilages in Japanese Black cattle, tissue samples of the ulcerative lesion, marginal portion of the ulcer, macroscopically normal portions and synovial membranes were histopathologically examined by light microscopy, scanning electron microscopy and contact microradiography. The results are summarized as follows: (1) In the ulcerative lesions, degeneration and complete destruction of articular cartilage and its replacement with a proliferation of myelogenic connective tissue were observed. (2) In macroscopically normal portions, fissures of the articular surface and changes of the trabecular pattern in subchondral bone were present. (3) In the marginal portions of the ulcerative lesions, evidences of the repair process such as connective tissue growth from subchondral bones and articular cartilages were seen. (4) In synovial membranes, no pathological findings were observed. And (5) among the above mentioned changes, no inflammatory findings were seen. In conclusion, the ulcerative lesions of bovine articular cartilage may be regarded as the early stage of osteochondrosis to osteoarthrosis since the findings such as non-inflammatory destruction or degeneration and remodeling of the joints are characteristics of the latter.

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Bovine follicular cysts were induced by treatments with ACTH (3 mg, im) daily for 14 days beginning in the late luteal phase. Cortisol concentrations in plasma significantly increased after ACTH treatments. During the formation of follicular cysts induced by the injections of ACTH, mean plasma concentrations of progesterone were significantly higher than those in the untreated preovulatory period, while mean plasma concentrations of estradiol-17β were significantly lower. During the treatment period, mean plasma concentrations of LH and FSH remained low, and the preovulatory surges of LH and FSH did not occur. Suppressed concentrations of LH and FSH might be caused by the increases in secretions of cortisol and progesterone, and by the decrease in secretion of estradiol-17β.

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Radiographical examination of the canine uterus intralumenally injected with barium solution revealed that barium was gradually condensed, segmented and distributed equally along the lumen like embryos in early pregnant uterus. Histological examination of the uterus intralumenally injected with bouillon solution alone showed a remarkable fish net- or tree branch-like growth of superficial glands towards the uterine lumen. The uterus injected with barium in bouillon solution induced two different histological changes: One consisted of cystic glandular hyperplasia in the whole endometrium, which was a so-called Swiss cheese endometrium, and the other was composed of a fish net- or tree branch-like growth in the superficial layer accompanied with cystic glandular hyperplasia in the basal layer. The latter represented endometrial differentiation into spongy layer, supraglandular layer and basal glandular layer, being similar to that during normal early placentation. These findings suggest that clotted barium in bouillon solution has stimulating effects on the uterus similar to those of embryos.

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This report deals with evaluation of histological characteristics of the canine deciduoma induced by insertion of the uterine grafts as a biological stimulus. Autografts induced severe uterine cystic endometrial hyperplasia, and the grafts were organized by maternal endometrium. On the other hand, allografts induced more severe hyperplasia of the uterine endometrium with stronger inflammation than autografts. Almost all allografts became necrotic and lytic in the uterine lumen. These results suggest that uterine grafts could induce deciduoma and that the maternal endometrium, though under the functional corpora lutea, recognized the uterine grafts to be a stimulant and showed severe cystic endometrial hyperplasia.

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A 5-year-old dog showed remarkable edematous swelling of the left hock with lameness and local cellulitis, and paecillomyces fungus was isolated from ulcerative lesion of the hock joint and mediastinum. At autopsy severe effusive pleuritis was shown and numerous necrotizing and granulomatous lesions with fungal elements were seen in the liver, pancreas, kidney and mediastinal lymph nodes.

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An occurrence of peripheral neuropathy in nine 14- to 55-day-old racing pigeons was documented. The predominant clinical signs were diarrhea, and leg and wing paralysis. Grossly, there was discoloration and swelling of all the peripheral nerve trunks. Microscopic lesions comprising swelling, fragmentation and demyelination of myelin sheaths, and proliferation of Schwann cells, were seen in the peripheral nerves of all birds examined. These changes were associated with moderate to severe swelling, fragmentation, atrophy and loss of axons. The peripheral nerve lesions in these cases were similar to those of dietary riboflavin deficiency in chickens. An analysis of the diet given to the pigeons indicated that the riboflavin concentration was only 0.9 mg/kg feed.

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Neutral glycosphingolipids (GSLs) were isolated from a lipid extract of Theileria sergenti piroplasms and analyzed by thin-layer chromatography (TLC) and liposome immune lysis assay (LILA); two predominant GSLs, designated as N-1 and N-2 were separated on TLC. N-1 GSL showed the same mobility as lactosylceramide (LacCer) on the TLC plate. On the other hand, the mobility of N-2 GSL on the TLC plate was identical to that of galactosylparagloboside. In order to characterize the molecular species of neutral GSLs from T.sergenti, N-1 and N-2 GSLs were tested by LILA with antibodies against LacCer and galactosylparagloboside, respectively. N-1 GSL had reactivity to anti-LacCer antibody and N-2 reacted with the antibody to galactosylparagloboside. These results suggest that N-1 and N-2 GSLs are LacCer (Galβ1-4Glcβ1-1Cer) and galactosylparagloboside (Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1Cer), respectively.

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Feedlot calves naturally infected with Eimeria spp. were medicated by a combination of sulfamonomethoxine and ormetoprim (Ektecin). Calves, less than one year old and positive for coccidiosis, were administered with Ektecin (5, 10 and 20 ml/100 kg of body weight/day) and Daimeton (100% sulfamonomethoxine: 5 g/100 kg of body weight/day) for five days. No diarrhea were found on and after 3 days of medication in all the groups, and no oocysts were detected on and after day 5, 2, 1 or 3 from calves of the respective medicated groups. In samples from a group of calves administered with lowest dose of Ektecin, eimerian oocysts of 4 species were detected on day 0, and additionally 3 species (totally 7 species) were found on day 3 of medication.

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Eight calves born in November-December of 1992 were necropsied at the ages of 29-230 days in an attempt to estimate the life span of Setaria marshalli in Japan. Worm ages were estimated on the base of active season for mosquitoes. Thirty worms estimated 4-9 months old recovered from 4 calves were all alive in the peritoneal cavity. Thirty-five out of 50 worms estimated 7-13 months old were dead with being entrapped by fibrin on the peritoneum. It is speculated that this is a normal fate of this parasite at the end of its life, and therefore, the life span of S.marshalli would be approximately one year after prenatal infection.

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Stem cell factor is a pleiotropic cytokine that plays an essential role in the development of hematopoietic cells, germ cells, and melanocytes. To obtain recombinant soluble chicken stem cell factor (chSCF), a baculovirus containing the cDNA encoding chSCF polypeptide from amino acids -25 to 170 was constructed. The chSCF produced in insect cells infected with the virus was purified by ion exchange column chromatography. The ability of the purified protein to induce the outgrowth of neurites from chicken dorsal root ganglia cultured in vitro was demonstrated.

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An 8-year-old intact female Maltese was presented with anorexia and weight loss. Severe anemia, leukocytosis, and marked thrombocytosis were noticed. Blast cells resembled to megakaryoblasts were observed in peripheral blood smear. Based on bone marrow biopsy and histopathological examination, it was diagnosed as megakaryoblastic leukemia. Canine megakaryoblastic leukemia is very rare, however this is the first case report in Japan.

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