Antioxidant and cytotoxic activities of naphthalene derivatives from <Emphasis Type="Italic">Diospyros kaki</Emphasis>

4,8-Dihydroxy-5-methoxy-2-naphthaldehyde (Compound I) was isolated from blackened heartwood of Diospyros kaki and was methylated with diazomethane. Antioxidant and cytotoxic activities of Compound I and two methylated derivatives [4-hydroxy-5,8-dimethoxy-2-(2-oxopropyl)-naphthalene (D-1) and 2-glycidyl-4-hydroxy-5,8-dimethoxy naphthalene (D-2)] were evaluated. Compound I showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and reducing power than D-1 and D-2. However, D-1 and D-2 exhibited slightly stronger 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)⁺ (ABTS⁺) radical scavenging activity than Compound I. Compound I also exhibited stronger cytotoxic activity than D-1 and D-2 against the growth of HT-29 colon cancer cells. The results supported the hypothesis that methylation of naphthalene derivatives slightly increased ABTS⁺ radical scavenging activity, but significantly decreased DPPH radical scavenging activity, reducing power, and cytotoxic activity.     

Lactococcus garvieae outbreaks in Brazilian farms Lactococcosis in Pseudoplatystoma sp. – development of an autogenous vaccine as a control strategy

This study evaluated the control of streptococcosis outbreaks in Brazil, isolated from diseased sorubim and identified as Lactococcus garvieae by genetic sequencing. This report determined the potential for lactococcosis control in sorubim Pseudoplatystoma sp. with two vaccines: an aqueous‐based, whole‐cell inactivated vaccine (bacterin) and an oil‐adjuvanted bacterin. Their efficacy was evaluated at 30 days post‐vaccination (d.p.v.) by challenge with L. garvieae, and the antibody production response at 15, 30 and 60 d.p.v. and the non‐specific immune response were compared amongst treatments. High protection levels (P < 0.05) were achieved with the oil‐adjuvanted vaccine with a relative percentage survival value of 81.7% at 30 d.p.v. Additionally, the oil‐adjuvanted vaccine increased the immunogenicity of the bacterin as indicated by greater agglutination antibody titres from 15 until 60 d.p.v. This is the first report of a positive effect of vaccine administration on the specific immunity of sorubim, and the study showed that a specific antibody plays an important role in sorubim defence against lactococcosis because the innate immune responses were similar in all of the studied animals. These results demonstrated that oil‐adjuvanted vaccine can be an effective alternative for the protection of sorubim from L. garvieae disease.     

Diatoms and the ecological conditions of their growth in sea ice in the arctic ocean

A summer field survey off Point Barrow, Alaska, revealed that Arctic sea ice develops a growth of phytoplanktonic diatoms. The diatoms are found in a brine solution in microfissures between ice crystals on the underside of the ice. The chlorophyll content of this layer is 100 times more than that of the surrounding sea waters; this has led to a hypothesis that a considerable fraction of the primary production of the Arctic Sea may be carried out in sea ice, especially during the spring and early summer months.     

Chilling-injury in cucumber fruits. IV. The analogy between osmotic-stress injury and chilling-injury

At warm temperatures, young cucumber fruit with rigid cell walls was found to suffer osmotic-stress injury when hydrated or dehydrated. The osmotic-stress injury of hydrated fruit was similar to chilling-injury of cucumber fruit stored at 5°C, whereas the stress injury of dehydrated young fruit appeared similar to injury of fruit chilled to 0°C. In contrast, adult fruit, with soft cell walls, did not develop osmotic-stress injury.On the basis of these results, together with previous reports, it is proposed that cell wall rigidity and water stress in the fruit are the direct causes of chilling-injury.     

Ecological studies of Yersinia enterocolitica I. Dissemination of Y. enterocolitica in pigs

Pigs were examined on five farms for carrier status of Yersinia enterocolitica. Yersinia enterocolitica biovar 4, serovar 3, phagovar VIII was isolated consistently from the feces of fattening pigs on one farm and sporadically from those of similar pigs on the other farms and of sows on all five farms, during a one-year period of weekly surveys. Seasonal variation was not a feature of fattening pigs on a highly contaminated farm. In other pigs, however, the organisms were not isolated during the summer months. On a highly contaminated farm, the organisms were excreted in the feces of 8 to 15-week-old pigs within 1–3 weeks of entering pens which were thought to be contaminated with the organisms. On a detailed observation of natural infection of Y. enterocolitica in eight pigs, the organism appeared in the pigs' feces within 2–7 weeks of them being moved to a pen which had been washed thoroughly after becoming contaminated, by a previous group of pigs, with feces containing 10⁵ viable organisms per g. Thus, Y. enterocolitica is apparently transmitted from infected feces or picked up from the floor of a contaminated pen, and the regular schedule of pig movement among the pens is an important factor in the spread of Y. enterocolitica within a piggery. Intestinal colonization continues for a long time and does not occur by re-infection. The organisms were not isolated from eight pigs at the time of slaughter, and their serum O-agglutinin titers were $\text{1}\text{40}$ or less. Thus, circulating antibody may not inhibit intestinal colonization by Y. enterocolitica.     

Ecological studies of Yersinia enterocolitica. III. Cross-protection against fecal excretion between Y. enterocolotica serovars 3 and 5.27 in pigs

Yersinia enterocolitica biovar 4 serovar 3 and biovar 2 serovar 5.27 failed to establish in the intestines of pigs when challenged with the homologous or heterologous strains. After inoculation, the serum O-agglutinin titers were 1/10 or less and were not boosted by challenge with either serovar. Y. enterocolitica were not recovered in any specimens at the time of slaughter.     

Pathogenesis of pemphigus vulgaris in dog and man - a review

Pemphigus vulgaris is a vesiculobullous disorder that predominantly involves the oral mucous membrane of the canine and human patients. The oral lesions are usually painful erosions and ulcers. This predilection for mucous membrane may reflect the smaller number of desmosomes in the oral epithelium as compared with the epidermis. The discovery of autoantibodies against the intercellular substance of stratified epithelium in patients with pemphigus vulgaris suggests that this disease represents an autoimmune disease. The exact role of these autoantibodies in the pathogenesis of pemphigus vulgaris is not clearly understood. The diagnosis is usually based on the presence of the characteristic flaccid bullae and erosions. Biopsy specimen taken from the edge of a fresh blister and adjacent epithelial layers is suitable for routine microscopic examination and direct immunofluorescence study. Combination of corticosteroids and immunosuppresive agents are used for treatment of this disease.     

Borna disease virus infection in domestic cats: evaluation by RNA and antibody detection

Borna disease virus (BDV) infection has been suggested to cause spontaneous neurological disease in cats referred to as staggering disease. However the evaluation of BDV infection in neurologically asymptomatic cats remained unclear. In the present study, BDV infected, asymptomatic cats in Tokyo were surveyed both by the presence of plasma antibodies against BDV-p24 and -p40 and by RNA detection in peripheral blood mononuclear cells. Seven of 32 domestic cats (21.9%) were serologically or genetically judged to be BDV-infected. Six cats were positive for anti-BDV antibody and two cats were positive for BDV RNA. Within the 2 RNA-positive cats, only one was positive for anti-BDV antibodies. Furthermore, the findings of anti-BDV-p40 and anti-BDV-p24 antibody-positive cats did not completely overlap. These results suggest that there are neurologically asymptomatic domestic cats infected with BDV present in the Tokyo area.     

The comparison between the cerebral blood flow directly measures and cerebral blood flow velocity in the middle and basilar cerebral arteries measured by transcranial Doppler ultrasonography

Transcranial Doppler ultrasonography (TCD) may be useful for determining alterations in cerebral blood flow (CBF) during excessive hemodynamic changes by non-invasive measurement of the CBF velocity. The purpose of this study was to measure the correlation between CBF and the middle cerebral artery (MCA) and basilar artery (BA) flow velocities, as measured by TCD during excessive hemodynamic changes produced by hypertension and hypotension in adult dogs. The peak, diastolic, and mean flow velocities were measured by TCD. Arterial hypertension was induced by administration of dopamine at 5 and 15 microg/kg/min, and hypotension was induced by hemorrhage. During the hemodynamic changes, the BA velocity correlated more closely with the alteration in the CBF than the MCA velocity. In terms of percentages of the values during anesthesia, there was good correlation between CBF and the MCA and BA velocities. In conclusion, our findings indicate that MCA and BA velocity measurements, as a percentage of the values during anesthesia, both give an equally accurate indication of alterations in CBF during excessive hemodynamic changes.     

Combined administration of ghrelin and GHRH synergistically stimulates GH release in Holstein preweaning calves

Ghrelin is a gut peptide which participates in growth regulation through its somatotropic, lipogenic and orexigenic effects. Synergism of ghrelin and growth hormone-releasing hormone (GHRH) on growth hormone (GH) secretion has been reported in humans and rats, but not in domestic animals in vivo. In this study, effects of a combination of ghrelin and GHRH on plasma GH and other metabolic parameters, and changes in plasma active and total ghrelin levels were studied in Holstein bull calves before and after weaning. Six calves were intravenously injected with vehicle (0.1% BSA-saline), ghrelin (1 microg/kg BW), GHRH (0.25 microg/kg BW) or a combination of ghrelin plus GHRH at the age of 5 weeks and 10 weeks (weaning at 6 weeks of age). Ghrelin stimulated GH release with similar potency as GHRH and their combined administration synergistically stimulated GH release in preweaning calves. After weaning, GH responses to ghrelin and GHRH became greater compared with the values of preweaning calves, but a synergistic effect of ghrelin and GHRH was not observed. The GH areas under the concentration curves for 2h post-injection were greater in weaned than in preweaning calves (P<0.05) if ghrelin or GHRH were injected alone, but were similar if ghrelin and GHRH were injected together. Basal plasma active and total ghrelin levels did not change around weaning, but transiently increased after ghrelin injection. Basal plasma insulin, glucose and non-esterified fatty acid levels were reduced after weaning, but no changes by treatments were observed. In conclusion, ghrelin and GHRH synergistically stimulated GH release in preweaning calves, but this effect was lost after weaning.