Sudden cardiac death in calves with experimental heavy infection of Strongyloides papillosus.

For obtaining the preliminary data on the pathogenesis of sudden death in calves naturally heavily infected with Strongyloides papillosus, we monitored 8 Holstein calves experimentally infected with the larvae on electrocardiographic and pneumographic changes. Six calves died suddenly on days 11 to 17 after infection. Sinus tachycardia had been recorded continuously since 1 to 6 days before death. Heart rates increased gradually until death. Since 1 or 2 days before death, various patterns of tachyarrhythmia and bradyarrhythmia had been observed among patterns of sinus tachycardia. Arrhythmias included serious ventricular premature beat, paroxysmal ventricular tachycardia, complete atrioventricular block and so on. The terminal pattern observed suddenly in all of the cases was ventricular arrhythmias consisting of serial ventricular tachycardia, flutter and fibrillation, which were followed by respiratory arrest. Abnormal pneumograms were not obtained before the terminal ventricular fibrillation. Two of 8 calves recovered from the infection, only one of which showed sinus arrest and the second degree of atrioventricular block transiently. We concluded that calves heavily infected with the larvae died due to sudden cardiac arrest.     

Effect of interferon-alpha 1 from E. coli on some cell functions

Interferon-alpha 1 from Escherichia coli transformed with a hybrid plasmid containing a human leukocyte complementary DNA insert, induces resistance to virus in appropriate target cells. It also shares the following properties with natural leukocyte interferon (IFN). (i) It enhances natural killing activity of human lymphocytes, (ii) it enhances antibody-dependent cell-mediated cytotoxicity, (iii) it suppresses antigen- and mitogen-induced leukocyte migration inhibition, (iv) it inhibits growth of IFN-sensitive Burkitt lymphoma cells. Since these activities are exhibited by a cloned protein species, they are due to IFN itself and not to other human proteins.     

Expression of feline interferon-alpha subtypes in Esherichia coli, and their antiviral activity and animal species specificity

Two kinds of FeIFN-alpha consisting of 166 amino acids (aa) and 171 aa were expressed in Escherichia coli, and the purified proteins were tested for antiviral activity on homologous and heterologous animal cells. Crude FeIFN induced in feline cells revealed antiviral activity on both homologous and heterologous animal cells. In contrast, both types of recombinant FeIFN-alpha revealed antiviral activity only on the feline cells. All of the FeIFN-alpha subtypes showed high activity to vesicular stomatitis virus, and the three species of feline viruses belonging to different families.     

Relationship between milk cortisol concentration and the behavioral characteristics of postpartum cows introduced to a new group

The objective of this study was to examine the relationship between milk cortisol concentration (MC) and behavioral responses to stress. As a stress response, the behaviors of 37 postpartum cows were observed when they were introduced into a new group. Milk samples for MC measurement and milk trait data were collected on the test day every 2 months after calving. The best linear unbiased prediction (BLUP) was estimated from each behavioral and milk trait data. Behavioral BLUP data were subjected to principal component (PC) analysis and three PCs were extracted. The first PC, with large loadings for eating and allogrooming, was positively correlated with milk yield. Therefore, individual differences in behaviors closely related with PC1 would have been unconsciously paid a lot of attention in terms of productivity. However, the second PC, with large loadings for drinking and self‐grooming, uncorrelated with any milk traits, had a negative correlation with MC. The third PC, with large loadings for exploring, fighting and the frequency of agonistic behavior, was uncorrelated with all traits. Both PC2 and PC3 were independent of productivity, and individual differences in behaviors related with these PCs may be scarcely considered.     

Canine Lat1: molecular structure, distribution and its expression in cancer samples

A full-length cDNA sequence of canine L-type amino acid transporter 1 (Lat1) was determined from a canine brain. The sequence was 1828 bp long and was predicted to encode 485 amino acid polypeptides. The deduced amino acid sequence of canine Lat1 showed 93.2% and 91.1% similarities to those of humans and rats, respectively. Northern blot analysis detected Lat1 expression in the cerebellum at 4 kb, and Western blot analysis showed a single band at 40 kDa. RT-PCR analysis revealed a distinct expression of Lat1 in the pancreas and testis in addition to the cerebrum and cerebellum. Notably, Lat1 expression was observed in the tissues of thyroid cancer, melanoma and hemangiopericytoma. Although the cancer samples examined were not enough, Lat1 may serve as a useful biomarker of cancer cells in veterinary clinic.     

Genomic Affinity Relationships in the Genus Avena

Many interspecific hybrids between diploid, tetraploid and hexaploid Avena species were obtained without artificial embryo cultures. Most of the hybrids showed variable chromosome pairing with univalents, bivalents and multiple associations, even in PMC in the same hybrid, at first metaphase; making ii very difficult to understand the degree of genome affinity between parent species, and especially between different species. The basic or theoretical chromosome pairing consisting of bivalents and univalents is presented, in which the chromosome ratios (%) statistically agree with observations. In addition, the per cent frequency of chromosomes forming multivalents is calculated. On the bases of these numerical data, the genomic affinity relationships are discussed for present and previously reported interspecific hybrids or Avena.     

Hrp Pilus – Reaching Through the Plant Cell Wall

A number of Gram negative pathogenic bacteria are equipped with a macromolecule translocation machinery that enables them to inject virulence determinants directly into the cells of their eukaryotic hosts. For plant pathogens, the plant cell wall represents an extra challenge for such injection. The ability to overcome this barrier has turned out to be so beneficial that two non-homologous injection systems, type III and type IV secretion machineries, have evolved. A morphologically similar pilus structure is associated with both of these systems. In this review, the direct protein translocation by type III (Hrp) secretion machinery is discussed with focus on the function of Hrp pilus. Comparisons between the Hrp system and the analogous translocation of T-DNA by Agrobacterium type IV secretion machinery are made and the differences between type III systems of plant and animal pathogens are discussed. Alternative hypothetical models for the mechanistic mode of action of the pilus are presented.     

Reproductive characteristics of Japanese monkeys on Shimokita Peninsula,Japan, the northernmost habitat of wild primates in the world

The Shimokita Peninsula in Aomori Prefecture, Japan, which is inhabited by Japanese monkeys (Macaca fuscata), is the northernmost habitat for wild primates in the world. This study was the first to determine the conception dates of specific individuals and estimate the pregnancy rate of wild populations in this region. The pregnancy rate of animals aged 5 years or more at delivery was estimated to be 40.9% (27/66). Conception dates of each fetus were also estimated using a regression line of Pig-tail monkeys (Macaca nemestrina), which are taxonomically related to Japanese monkeys and have a similar physique. The conception dates were distributed across 90 days between September 24th and December 23rd, with a mean conception date of November 4th (SD=22.3 days, n=53). Using these findings, the mean birth date was estimated as April 25th, more than two weeks earlier than the mean birth date in previous research determined using direct observations carried out over the past 20 years ago. Global warming due to climate change is thought to be one of the main causes of this difference.     

Tolerance to low temperatures of Toxocara cati larvae in chicken muscle tissue

Infectivity of Toxocara cati larvae in muscle tissue of chickens after storage at 4°C and -25°C was assessed in a mouse bioassay to provide information on the risk of meat-borne toxocarosis. Muscle tissue samples of 30-day old T. cati infections were stored at 4°C for 14 and 28 days and at -25°C for 12, 24 and 48h, whereafter, larvae were released by digestion. For each experimental group, the released larvae were inoculated in six mice. After 15 days, mice were euthanized and larval burden was assessed by digestion. In the control group (no storage of the infected chicken meat), 47.9% of the inoculated larvae established in mice, whereas storage of meat at 4°C for 14 days or 28 days reduced the recovery to 24.1% or 3.3%, respectively. Muscle larvae exposed to -25°C for 12, 24 or 48h did not establish in the mice. The observation that larvae retain infective after refrigeration at exposure in 4°C for 28 days, emphasize the zoonotic potential of poultry meat as a causative agent of human toxocarosis.