Staphylococcal alpha-toxin synergistically enhances inflammation caused by bacterial components

This study was performed to investigate the in vivo effects of staphylococcal alpha-toxin on phagocytosis and the secretion of proinflammatory cytokines at local sites of intraperitoneal toxin-challenged mice. A dosage of 45 hemolytic units (HU) of alpha-toxin induced a marked increase in the peritoneal neutrophil count. The toxin caused a 52% decrease in phagocytosis by peritoneal macrophages, compared with that of control mice receiving Staphylococcus aureus particles alone. However, no effect on phagocytosis in neutrophils was observed. A dosage of 45 HU toxin and the synergistic activity of S. aureus particles strongly induced interleukin (IL) 6 secretion but only mildly induced IL-1alpha secretion. The toxin did not induce the secretion of tumor necrosis factor-alpha (TNF-alpha). Interestingly, S. aureus culture supernatant induced the secretion of TNF-alpha in cultured macrophages. These results suggest that alpha-toxin damages the primary host defense system by inducing the oversecretion of IL-1alpha and IL-6, but not TNF-alpha, via a mechanism that requires the synergistic action of bacterial components.     

Regional comparison of nitrogen export to Japanese forest streams

Nitrogen (N) emissions in Asian countries are predicted to increase over the next several decades. An understanding of the mechanisms that control temporal and spatial fluctuation of N export to forest streams is important not only to quantify critical loads of N, N saturation status, and soil acidification N dynamics and budgets in Japanese forested watersheds is not clear due to the lack of regional comparative studies on stream N chemistry. To address the lack of comparative studies, we measured inorganic N (nitrate and ammonium) concentrations from June 2000 to May 2001 in streams in 18 experimental forests located throughout the Japanese archipelago and belonging to the Japanese Union of University Forests. N concentrations in stream water during base flow and high flow periods were monitored, and N mineralization potential in soil was measured using batch incubation experiments. Higher nitrate concentrations in stream water were present in central Japan, an area that receives high rates of atmospheric N deposition. In northern Japan, snowmelt resulted in increased nitrate concentrations in stream water. The potential net N mineralization rate was higher in surface soil than in subsurface soil, and the high potential for N mineralization in the surface soil partly contributed to the increase in nitrate concentration in stream water during a storm event. Regional differences in the atmospheric N deposition and seasonality of precipitation and high discharge are principal controls on the concentrations and variations of nitrates in stream water in forested watersheds of Japan.     

Transformation of azuki bean by Agrobacterium tumefaciens

Stable transformation and regeneration was developed for a grain legume, azuki bean (Vigna angularis Willd. Ohwi & Ohashi). Two constructs containing the neomycin phosphotransferase II gene (nptII) and either the -glucuronidase (GUS) gene or the modified green fluorescent protein [sGFP(S65T)] gene were introduced independently via Agrobacterium tumefaciens-mediated transformation. After 2 days of co-cultivation on MS medium supplemented with 100 M acetosyringone and 10 mg l^–1 6-benzyladenine, seedling epicotyl explants were placed on regeneration medium containing 100 mg l^–1 kanamycin. Adventitious shoots developing from explant calli were excised onto rooting medium containing 100 mg l^–1 kanamycin. Rooted shoots were excised and repeatedly selected on the same medium containing kanamycin. Surviving plants were transferred to soil and grown in a green house to produce viable seeds. This process took 5 to 7 months after co-cultivation. Molecular analysis confirmed the stable integration and expression of foreign genes.     

A new species,Gazza rhombea, from the Indo-West Pacific, with a redescription ofG. achlamys Jordan & Starks, 1917 (Perciformes: Leiognathidae)

Gazza rhombea sp.nov. is described from 61 type and 81 non-type specimens, 19–176 mm in standard length, collected from the Indo-West Pacific. The species is similar to other congeners in general body appearance, differing from them in having the dorsolateral surface of the body scaled anterior to the dorsal fin origin, but not reaching to a vertical through the tip of the posterior branch of the supratemporal canal (vs. dorsolateral surface of body naked anterior to base of sixth or seventh dorsal fin spine base inG. achlamys; dorsolateral surface of body with scales extending anteriorly beyond tip of posterior branch of supratemporal canal inG. minuta), and having a long narrow anterodorsal extension from the subocular silvery region, in contact with the orbit only proximally (vs. broad anterodorsal extension, with proximal and distal contact with orbit inG. dentex).Gazza rhombea is also distinguishable fromG. achlamys andG. minuta by the morphology of the first dorsal fin pterygiophore, and the neural and hemal spines of the fifth preural centrum. The new species has usually been misidentified asG. achlamys, which is redescribed here, owing to its similarly deep-bodied appearance.     

Apoptosis in antibody-dependent monocyte-mediated cytotoxicity with monoclonal antibody 17-1A against human colorectal carcinoma cells: enhancement with interferon γ

 Antibody-dependent cell-mediated cytotoxicity (ADCC) has been considered to be one of the main effector mechanisms by which unconjugated monoclonal antibody (mAb) 17-1A can exert an antitumor effect in vivo. Since the apoptotic pathway as well as the necrotic pathway have been shown to be utilized in various cytotoxic effector mechanisms, we investigated the role of apoptosis in ADCC mediated by monocytes (ADMC) using mAb 17-1A as an antibody and the human colorectal carcinoma cell line, COLO205, as target cells in vitro. The implications of the apoptosis during ADMC was demonstrated by means of both a DNA fragmentation assay and a TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay. Furthermore, interferon γ (IFNγ) was also found to enhance the induction of apoptosis significantly. The addition of superoxide dismutase did not reduce the level of the apoptosis, although superoxide anion (O₂ ^–) was observed to be produced. However, the release of tumor necrosis factor α (TNFα) was significantly enhanced during ADMC, while, in addition, apoptosis was significantly inhibited by the addition of anti-TNFα antibody. These findings indicated that apoptosis might be implicated in ADMC with mAb 17-1A, which was augmented by IFNγ, while, in addition, TNFα may also be one of the major mediators of apoptosis. Received: 1 August 1996 / Accepted: 27 August 1996     

Dark Induction of the Non-Photochemical Quenching of Chlorophyll Fluorescence by Acetate in Chlamydomonas reinhardtii

Addition of acetate to a suspension of Chlamydomonas reinhardtiicells in darkness induced transient and biphasic non-photochemicalquenching of Chl fluorescence (qN) due to ApH-dependent down-regulationof PSII and the transition from state 1 to state 2. We proposethat acetate-induced stimulation of the chlororespiratory electronflow triggers the regulation of PSII. (Received December 26, 1995; Accepted March 25, 1996)     

Multi-stage biofilm reactor for acetic acid production at high concentration

Summary Continuous production of acetic acid by liquid surface culture ofAcetobacter aceti M7 was investigated using a Multi-Stage Biofilm Reactor (MSBFR) composed of ten shallow flow horizontal reactors of laboratory scale. With varying dilution rate in the range from 0.049 to 0.2 h^–1, the maximum exit acetic acid concentration reached was as high as 98.0 g/l at the lowest dilution rate with step feed of ethanol-rich medium to stages 3, 5, and 7. The production rate (4.3 g/l/h) was rather high considering the inhibitory effect of high acetic acid concentration. This may be ascribed to non-homogeneous distribution of acetic acid concentration in the bioreactor and step feed of ethanol-rich medium.     

Mandible/basihyal relationships in red howler monkeys (Alouatta seniculus): A craniometrical approach

The morphological relationships between the cranium and basihyal of red howler monkeys (Alouatta seniculus) were analyzed based on measurements of 36 cranial and 3 basihyal dimensions and observations of the female specimen in spirits. In this study, 115 crania from 111 red howler monkeys and 4 mantled howler monkeys (Alouatta palliata) were used. The analyses from the standpoints of the correlation coefficients, principal component analysis, discriminant function analysis, age changes and sex differences were performed and the following results were obtained: (1) The cranial measurements closely related to the basihyal measurements were mandibular length, occipital breadth, facial length, ramus height, cranial base length, bigonial breadth and pr-i length. (2) Age changes for the mandibular measurements in males of red howler monkeys were remarkable, and, in particular, the development of the gonion toward posterior and lateral directions were characteristic. (3) The largest sex differences were found in the mandibular measurements of red howler monkeys among the Anthropoidea of seven genera compared. (4) The existence of a “cline” in the cranial measurements of the red howler monkey was recognized. (5) The inter-species differences in the crania between the red howler monkey and mantled howler monkey are obvious, metrically and non-metrically. Based on the results mentioned above, the morphological relationships between the mandible and basihyal in the red howler monkey are discussed.