Biological activity of obiopeptide-1, a synthetic peptide derived from the native immune-regulator obioactin

Tachyzoites of Toxoplasma gondii were killed in mouse macrophage and human somatic cell monolayers by a novel synthetic peptide (Obiopeptide-1) which is a Glycil-penta-Glutaminate (GpG) derivative of native Obioactin. In view of the worldwide prevalence of this protozoan disease and the lack of effective treatments, Obiopeptide-1 may be a new and unique antimicrobial active substance of non-antibiotic chemotherapeutic agents for intracellular parasites, T. gondii and associated nonspecific hypoimmune responses that occur in infected hosts.     

Quantitative changes in serum concentration of bovine gut chitinase in Theileria infection

Bovine gut chitinase is exclusively produced in the liver and secreted into the blood. In the present study, we established a semi-quantitative method by Western blot analysis for measurement of the chitinase content in blood and examined its alteration during postnatal development and experimental infection with hemoprotozoan parasite in cattle. Its serum levels from 1 week to 1 year of age showed a significant increase only in 3-4-month-old group. The plasma concentration of the gut chitinase was not changed during acute inflammation caused by lipopolysaccharide but increased gradually after a Theileria injection and peaked at 52 days post-infection. It appears that the increase in the blood chitinase levels might be a defensive response in cattle against protozoan infection.     

Expression of nerve growth factor (NGF), and its receptors trkA and p75 in ovaries of the cyclic golden hamster (Mesocricetus auratus) and the regulation of their production by luteinizing hormone

In the present study, changes in localization of nerve growth factor (NGF) and its receptors, trkA and p75 in the ovary were investigated during the estrous cycle of the golden hamster. The effect of LH surge on changes in localization of NGF, trkA and p75 in the ovary was also investigated. NGF and its receptors trkA and p75 were localized in oocytes, granulosa cells and theca cells of various stages of follicles throughout the estrous cycle. NGF and its two receptors were also present in numerous interstitial cells and luteal cells. The number of interstitial cells staining positively for NGF and its two receptors was greater in ovaries of day 1 (day 1=day of ovulation) than the other days during the estrous cycle. Treatment with the antiserum against luteinizing hormone releasing hormone (LHRH-AS) at 1100 h on day 4 completely blocked ovulation. There were few positive reactions for NGF and its two receptors in interstitial cells 24 hr after LHRH-AS injection. The effect of LHRH-AS treatment was blocked by a single injection of 10 IU human chorionic gonadotropin. The distinct widespread distribution of NGF and its two receptors in the ovary of golden hamsters suggest that NGF may be an important growth factor for regulation of ovarian function. Furthermore, the LH surge may be an important factor for inducing production of NGF and its two receptors in interstitial cells of the cyclic golden hamster.     

Cytopathogenicity of classical swine fever viruses that do not show the exaltation of Newcastle disease virus is associated with accumulation of NS3 in serum-free cultured cell lines

Pestiviruses can be distinguished as two biotypes, cytopathogenic (cp) and noncytopathogenic (noncp), by the morphological changes that they induce during growth in cultured cells. In this study, the cp phenotype of several classical swine fever viruses (CSFV) was evaluated by the detections of the nonstructural proteins NS2-3 and NS3 using immunoprecipitation and Western blotting in different porcine cell lines. Most CSFVs that showed the exaltation of Newcastle disease virus (END) phenomenon (END(+) viruses) did not induce cytopathic effect (CPE) in any cell line, and detections of NS2-3 and NS3 showed a strong signal for NS2-3 in the END(+) virus-infected cells. However, clear CPE was observed in serum-free cultured cells (FS-L3 and CPK-NS) infected with viruses that induce intrinsic interference but did not show the END phenomenon (END(-) viruses), and signal of NS3 was strongly detected than that of NS2-3 in these cells at 72 hr after infection. As the results of the analysis of FS-L3 cells infected with ALD (END(+) virus) and ALD-END(-) virus (END(-) virus) at several incubations, the signal of NS3 detected was strengthened with CPE that become evident progressively. These results suggest that CPE is associated with the accumulation of NS3, which is promoted in serum-free cell lines infected with END(-) viruses. Thus, indicating there is a close relationship between CPE and the quantity of NS3 produced in END(-) CSFV infection.     

Effects of the neutrophil elastase inhibitor (ONO-6818) on acetic acid induced colitis in Syrian hamsters

Neutrophil elastase (NE) released from neutrophils during inflammation is related to tissue disturbance and organ failure. We investigated the effects of an orally active NE inhibitor, ONO-6818, on acetic acid induced colitis in Syrian hamsters. The ulcer area, hemoglobin level in the colonic lumen, NE activity, and tissue myeloperoxidase (MPO) activity in the colitis control animals were significantly increased compared to the normal control ones. Either oral or subcutaneous treatment with ONO-6818 had significant inhibitory effects on the ulcer area, hemoglobin level and NE activity in the colonic lumen, but ONO-6818 did not have a significant inhibitory effect on tissue MPO activity. We conclude that NE is closely related to the development of inflammation in acetic acid-induced colitis in Syrian hamsters and that the condition is improved by the inhibition of NE.     

Thiazole orange positive platelets in a dog with Evans' syndrome

We examined transition for the percentage of reticulated platelets (RP%) and platelet count in a canine case of Evans' syndrome. The result demonstrated that measurement of the RP% can be useful in evaluating platelet production in the bone marrow and response to treatment.     

Cloning of a specific DNA region of white top pathogen of pea and its detection by polymerase chain reaction

White top strain (WT strain) of Pseudomonas syringae pv. pisi (Ppi) is a variant strain causing white top disease of peas. The WT strain is distinguishable from common Ppi strains only by symptom expression chlorosis and whitening of apical shoots. To develop a specific detection method for the WT strain, we cloned a specific DNA region of the WT strain using transposon tagging. Five mutants defective in white top symptom expression were obtained. A part of the Tn5-flanking region was cloned and labeled as a hybridization probe. One clone, pAY3, gave two signal bands, one of which was detected from the genomic DNA of all the WT and the common Ppi strains; another was specific to WT strains. A restriction map of pAY3 showed that it contains two BamHI fragments; one is 5.0kb in length involving a part of Tn5, and the other is 1.5kb, did not carry Tn5, and may have been accidentally ligated into pAY3. The 1.5-kb band was subcloned as pAY13 and was used as a probe. It hybridized specifically to WT strains. These results suggested that the WT strains have a specific DNA region and that part of the region was successfully cloned. Sequence analysis of pAY13 showed that it is similar to part of nonribosomal peptide synthetases (NRPSs) genes. The deduced amino acid sequence of pAY13 suggested the existence of eight conserved motifs of NRPSs. WT strain-specific PCR primers, PS1 and PS2, were designed from the DNA sequence. These primers gave a specific amplification product of 981bp from both the genomic DNA and a direct cell preparation of WT strains. No specific amplicon was produced from Ppi strains that caused only water-soaked lesions or from strains of other P. syringae pathovars. A specific amplicon was not produced from four strains of the pea pathogen: P. marginalis pv. marginalis, P. viridiflava, Erwinia carotovora ssp. carotovora, Xanthomonas campestris pv. pisi. Using the primers, WT strain was detected from water-soaked lesions and green and white tissues without water soaking.The sequence reported in this paper has been deposited in the DDBJ database under accession no. AB117755