Prevalence of thermophilic campylobacters in crows (Corvus levaillantii, Corvus corone) and serogroups of the isolates

A total of 500 fecal droppings of crows collected from a seashore of an ocean bay and from a cemetery on a hill surrounded by a forest were examined for thermophilic campylobacters, and the Skirrow's biovars and Penner's serogroups of the isolates were determined. The organisms were isolated from 169 (62.6%) of 270 seashore crow samples and 106 (46.1%) of 230 cemetery crow samples. During the investigation period from May 1986 to April 1987, the monthly isolation rate of thermophilic campylobacters in the seashore crow varied from 32.0 to 85.0%. C. jejuni, C. coli, and C. laridis were isolated from 150, 21 and 14 samples, respectively. In case of the cemetery crow, the monthly isolation rate varied from 20.0 to 75.0%, and C. jejuni, C. coli, and C. laridis were detected from 80, 12 and 16 samples, respectively. Among 192 strains of C. jejuni selected from 98 seashore and 57 cemetery crow samples, 106 (93.0%) of 114 seashore crow strains and 69 (88.5%) of 78 cemetery crow strains were identified as Skirrow's biovar I. Of 192 strains of C. jejuni serogrouped, 169 strains were classified into 20 serogroups. The Penner's serogroup 2, one of common serogroups among poultry and human isolates in Japan, was the most predominant in crow strains.     

Parasitism of Toxocara canis larvae in Japanese quails by inoculation of the ascarid eggs.

The distribution of T. canis larvae and pathological changes caused by them were studied in Japanese quails orally inoculated with 1,500, 4,000 or 15,000 embryonated eggs. Larvae were distributed mainly in the liver and, to lesser extent, in the muscles, brain, eyes and other organs. The number of larvae varied from 7 to 3,346, and from 1 to 288 in the liver and muscles (breast and legs), respectively. A small number of larvae were also recovered from the heart, gizzard, brain and eyes. In the groups of quails inoculated with 4,000 or 15,000 eggs, small white foci were observed on the surface of the liver 6 or 12 hr after inoculation. Histopathological examinations revealed necrotic lesions, leukocytic infiltration, granuloma and nodular lesions. The pathological changes became more serious with the large size of inoculum and days after inoculation.     

Mange caused by Sarcoptes scabiei (Acari: Sarcoptidae) in wild raccoon dogs, Nyctereutes procyonoides, in Kanagawa Prefecture, Japan

Parasitological and histopathological examinations were performed in 25 raccoon dogs (Nyctereutes procyonoides) obtained in Kanagawa Prefecture, Japan, all of which were found to be heavily infected with Sarcoptes scabiei. The mites detected on these raccoon dogs were morphologically indistinguishable from the human species, and no Demodex mites were detected. Histopathological examinations showed prominent hyperkeratosis and acanthosis with eczema, and numerous burrows containing mites were observed in the epidermis. The enzootic dermatitis of wild raccoon dogs in recent years was clearly demonstrated to be caused by S. scabiei in the present study.     

The effect of small interfering RNA (siRNA) against the Bcl-2 gene on apoptosis and chemosensitivity in a canine mammary gland tumor cell line

The aim of this study was to investigate whether downregulation of Bcl-2 expression by small interfering RNA (siRNA) against the canine Bcl-2 gene would enhance the apoptosis and sensitivity of a canine mammary gland tumor cell line (CF33) to doxorubicin. Transfections of CF33 with siRNA were performed using cationic liposomes. Sequence-specific downregulation of Bcl-2 expression was measured by semiquantitative RT-PCR and Western blot analysis. Total viable cells were determined by MTS assay and apoptotic cell rates were determined by the immunohistochemical analysis on ssDNA. Our data showed the siRNA downregulated Bcl-2 expression which increased apotosis and also increased the sensitivity of CF33 to doxorubicin. This study indicated that downregulation of Bcl-2 expression by siRNA would be useful as a new protocol to increase the effect of doxorubicin on treatment of canine mammary gland tumors, requiring a detailed evaluation of siRNA in vivo.     

Diluted isoflurane as a suitable alternative for diethyl ether for rat anaesthesia in regular toxicology studies

Despite its explosive properties and toxicity to both animals and humans, diethyl ether is an agent long used in Japan in the anaesthesia jar method of rat anaesthetises. However, in response to a recent report from the Science Council of Japan condemning diethyl ether as acceptable practice, we searched for an alternative rat anaesthesia method that provided data continuous with pre-existing regular toxicology studies already conducted under diethyl ether anaesthesia. For this, we examined two candidates; 30% isoflurane diluted with propylene glycol and pentobarbitone. Whereas isoflurane is considered to be one of the representatives of modern volatile anaesthetics, the method of propylene glycol-diluted 30% isoflurane used in this study was our modification of a recently reported method revealed to have several advantages as an inhalation anaesthesia. Intraperitoneal pentobarbitone has long been accepted as a humane method in laboratory animal anaesthesiology. These 2 modalities were scrutinized in terms of consistency of haematology and blood chemistry with previous results using ether. We found that pentobarbitone required a much longer induction time than diethyl ether, which is suspected to be the cause of fluctuations in several haematological and blood chemical results. Conversely, only calcium ion concentration showed a slight difference from traditional results in the case of 30% isoflurane. Additionally, serum prolactin and corticosterone levels indicated that 30% isoflurane induced less stress than ether, confirming that 30% isoflurane can both provide results consistent with diethyl ether, while at the same time remove its disadvantages. As such 30% isoflurane appears to be a strong alternative anaesthetic agent for future regular toxicology studies in Japan.     

Characterization of Th1 activation by Bartonella henselae stimulation in BALB/c mice: Inhibitory activities of interleukin-10 for the production of interferon-gamma in spleen cells

This study was conducted to analyze cytokine production mechanisms in mice after Bartonella henselae stimulation. BALB/c mice were inoculated intraperitoneally with 3 x 10(6) colony forming units of B. henselae (Houston-1 strain) twice at 10-day interval. Spleen cells were harvested from the mice and stimulated with the organisms. Following the stimulation, interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), IL-10, IL-12 and tumor necrosis factor-alpha (TNF-alpha) were measured in the culture supernatants of the spleen cells by ELISA. The spleen cells specifically secreted IFN-gamma, but not IL-4, indicating that T helper 1 (Th1) cells were activated following B. henselae stimulation. In addition, IL-10 and TNF-alpha productions were also detected in the culture supernatants of spleen cells. Neutralization of IL-10 in the culture supernatants significantly enhanced the production of IFN-gamma from the spleen cells stimulated with B. henselae. These results indicate that B. henselae predominantly stimulated Th1 cells and resulted in secreting IFN-gamma, however the production was partially inhibited by IL-10, which was produced simultaneously.     

Structure-physicochemical function relationships of soybean beta-conglycinin constituent subunits

Beta-conglycinin, one of the dominant storage proteins of soybean, has a trimeric structure, being composed of three subunits alpha, alpha', and beta. The alpha and alpha' subunits contain the extension regions in addition to the core regions common to all subunits, which are N-glycosylated. Physicochemical functions of recombinant nonglycosylated individual subunits and deletion mutants (alpha(c) and alpha'(c)) lacking the extension regions of the alpha and alpha' subunits were examined at pH 7.6 and 3.7 at low (mu = 0.08) and high (mu = 0.5) ionic strengths. Although individual recombinant subunits exhibited different properties at all conditions, there were some consistencies. Surface hydrophobicities and thermal stabilities of the individual subunits were likely to be conferred by their core regions, and the carbohydrate moieties did not contribute to these properties at any conditions examined here. Solubility at mu = 0.08, heat-induced association, and emulsifying ability remarkably depended on the extension regions and the carbohydrate moieties in addition to the structural features of the core regions. These findings indicate that various end products could be produced by the selection of soybean varieties containing beta-conglycinin with different subunit compositions and suggest a direction for a principle of soybean breeding.     

The effect of magmatic activity on hydrothermal venting along the superfast-spreading East pacific rise

A survey of hydrothermal activity along the superfast-spreading (approximately 150 millimeters per year) East Pacific Rise shows that hydrothermal plumes overlay approximately 60 percent of the ridge crest between 13 degrees 50' and 18 degrees 40'S, a plume abundance nearly twice that known from any other rige portion of comparable length. Plumes were most abundant where the axial cross section is inflated and an axial magma chamber is present. Plumes with high ratios of volatile ((3)He, CH(4), and H(2)S) to nonvolatile (Mn and Fe) species marked where hydrothermal circulation has been perturbed by recent magmatic activity. The high proportion of volatile-rich plumes observed implies that such episodes are more frequent here than on slower spreading ridges.     

Tradeoff between shade adaptation and mitigation of photoinhibition in leaves of Quercus mongolica and Acer mono acclimated to deep shade

We investigated susceptibility to photoinhibition in leaves acclimated to different light regimes in intermediately shade-tolerant Japanese oak (Quercus mongolica Fisch. ex Turcz. var. crispula (Blume) Ohashi) and shade-tolerant Japanese maple (Acer mono Maxim. var. glabrum (Lév. et Van't.) Hara), to elucidate adaptability to gap formation in leaves differing in shade acclimation. We hypothesized that there is a tradeoff between shade adaptation and capacity to mitigate photoinhibition associated with leaf morphology. We simultaneously measured chlorophyll fluorescence and gas exchange in seedlings that had been grown in full sunlight (open), 10% of full sun (moderate shade) and 5% of full sun (deep shade). Shade-tolerant A. mono adapted to deep shade through changes in leaf morphology, lowering its leaf mass per area (LMA), but Q. mongolica showed little change in LMA between moderate and deep shade. Photochemical quenching (qP) did not differ between species in full sunlight and moderate shade; however, in deep shade, qP of Q. mongolica was higher than that of A. mono, suggesting that Q. mongolica grown in deep shade is less susceptible to photoinhibition at gap formation. This is consistent with the finding that chronic photoinhibition 3 days after the transfer to full sunlight, indicated by the decrease in maximum photochemical efficiency, Fv/Fm, at predawn, was less in deep-shade-grown Q. mongolica than in deep shade-grown A. mono. In deep shade, the electron transport rate (ETR) of Q. mongolica was higher than that of A. mono, whereas thermal energy dissipation through photosystem II antennae, indicated by non-photochemical quenching, was lower in Q. mongolica than in A. mono. In deep shade, the greater ETR capacity in Q. mongolica in association with higher LMA and higher leaf N content could contribute to maintaining high qP and mitigating photoinhibition. These results indicate that, by maintaining a high electron transport capacity even in deep shade, the gap-dependent and intermediate-shade-tolerant Q. mongolica trades improved shade adaptation for higher growth potential when a gap event occurs.