Occurrence and abundance of bregmacerotid larvae in Kagoshima Bay,southern Japan,with descriptions of ontogenetic larval characters

Regular collections of ichthyoplankton were made with a larva net at 9–14 stations from Oct. 1983 to Dec. 1988 in Kagoshima Bay, totalling 817 collections from 66 cruises. A total of 2172 bregmacerotid larvae obtained from 195 collections of 33 cruises were identified asB. atlanticus (2001),B. neonectabanus (169),B. macclellandii (1) andB. nectabanus (1, tentative identification). The peaks of mean densities of larvae collected occurred in autumn forB. atlanticus andB. neonectabanus. The larvae ofB. atlanticus occurred throughout the bay, and their densities and frequency of occurrence were lower in the northern part of the bay. In the southern part of the bay, stations in its southwest quadrant showed higher densities than the others. The larvae ofB. neonectabanus occurred only in the southern part of the bay in which stations in the northwest quadrant showed higher densities than the others.     

Age-related effects of major and trace element concentrations in rat liver and their mutual relationships

The concentrations of 22 major and trace elements in livers from rats aging from 5 to 113 weeks old were determined. The rats investigated were the same rats previously reported with respect to 29 elements in bones (femur) and 26 elements in kidneys. The samples were decomposed with high-purity nitric acid and hydrogen peroxide. Seven elements (Na, Mg, P, K, Ca, Fe and Zn) were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and 15 elements (Mn, Co, Cu, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Cs, Ba, Pb and Bi) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Analysis of variance (ANOVA) for age variations indicated that the concentrations of many elements, such as Mg, P, K, Mn, Fe, Cu, Zn, Sr, Mo and Cd, were almost constant across the ages of the rats with the exception of 5 weeks old (p > 0.05). Arsenic, Pb and Bi showed significant increasing trends, while Na and Co showed decreasing trends (p < 0.01). Selenium showed a decreasing trend except at the initial stage of 5–9 weeks old. Calcium, Rb, Sn, Sb, Cs and Ba showed significant age-related variations, but their patterns were not monotonic. The liver clearly contrasts with the kidneys, in which many elements showed significant age-related variations with increasing trends. The concentration ranges of Mg, P, K, Mn, Cu, Zn, and Mo were controlled within 15% across all ages of rats. The homeostasis of the aforementioned elements may be well established in the liver. The toxic elements, such as Cd, Pb and Bi, showed a narrow concentration range among age-matched rats.     

Growth-Dependent Catalase Localization in Exiguobacterium oxidotolerans T-2-2T Reflected by Catalase Activity of Cells

A psychrotolerant and H₂O₂-resistant bacterium, Exiguobacterium oxidotolerans T-2-2^T, exhibits extraordinary H₂O₂ resistance and produces catalase not only intracellularly but also extracellularly. The intracellular and extracellular catalases exhibited the same enzymatic characteristics, that is, they exhibited the temperature-dependent activity characteristic of a cold-adapted enzyme, their heat stabilities were similar to those of mesophilic enzymes and very high catalytic intensity. In addition, catalase gene analysis indicated that the bacterium possessed the sole clade 1 catalase gene corresponding to intracellular catalase. Hence, intracellular catalase is secreted into the extracellular space. In addition to intracellular and extracellular catalases, the inner circumference of the cells showed the localization of catalase in the mid-stationary growth phase, which was observed by immunoelectron microscopy using an antibody against the intracellular catalase of the strain. The cells demonstrated higher catalase activity in the mid-stationary growth phase than in the exponential growth phase. The catalase localized in the inner circumference can be dissociated by treatment with Tween 60. Thus, the localized catalase is not tightly bound to the inner circumference of the cells and may play a role in the oxidative defense of the cells under low metabolic state.     

Psychological stress contributed to the development of low-grade fever in a patient with chronic fatigue syndrome: a case report

Background

Low-grade fever is a common symptom in patients with chronic fatigue syndrome (CFS), but the mechanisms responsible for its development are poorly understood. We submit this case report that suggests that psychological stress contributes to low-grade fever in CFS.

Case presentation

A 26-year-old female nurse with CFS was admitted to our hospital. She had been recording her axillary temperature regularly and found that it was especially high when she felt stress at work. To assess how psychological stress affects temperature and to investigate the possible mechanisms for this hyperthermia, we conducted a 60-minute stress interview and observed the changes in the following parameters: axillary temperature, fingertip temperature, systolic blood pressure, diastolic blood pressure, heart rate, plasma catecholamine levels, and serum levels of interleukin (IL)-1β and IL-6 (pyretic cytokines), tumor necrosis factor-α and IL-10 (antipyretic cytokines). The stress interview consisted of recalling and talking about stressful events. Her axillary temperature at baseline was 37.2°C, increasing to 38.2°C by the end of the interview. In contrast, her fingertip temperature decreased during the interview. Her heart rate, systolic and diastolic blood pressures, and plasma levels of noradrenaline and adrenaline increased during the interview; there were no significant changes in either pyretic or antipyretic cytokines during or after the interview.

Conclusions

A stress interview induced a 1.0°C increase in axillary temperature in a CFS patient. Negative emotion-associated sympathetic activation, rather than pyretic cytokine production, contributed to the increase in temperature induced by the stress interview. This suggests that psychological stress may contribute to the development or the exacerbation of low-grade fever in some CFS patients.

     

Analysis of microbiota involved in the aged natural fermentation of indigo

Although the indigo reduction process is performed via natural fermentation and maintained under open-air condition, the indigo-reducing reactions continue for 6 months (on average) or longer. Identifying the mechanism underlying the maintenance of this process could lead to the development of a novel, long-lasting, unsterilized bioprocesses. To determine the mechanisms underlying the maintenance of the indigo fermentation system microbiota for more than 6 months in a reduced state in an anaerobic alkaline environment, we examined changes in the microbiota in one early-phase batch and two aged batches of indigo fermentation fluid. The microbiota in the aged fermentation fluid consisted mainly of the genera Alkalibacterium, Amphibacillus, Anaerobacillus and Polygonibacillus and the family Proteinivoraceae. The genera Alkalibacterium, Amphibacillus and Polygonibacillus are known to include indigo-reducing bacteria. Although the transition speed was slower in the aged fermentation fluid than in the early-stage fluid, the microbiota in the aged fermentation fluid maintained for more than 6 months was drastically changed within a period of 3 months. The results of this study indicate that the bacterial consortia consisted of various indigo-reducing species that replace the previous group of indigo-reducing bacteria. The notable transitional changes may be concomitant with changes in the environmental conditions, such as the nutritional conditions, observed over 3 months. This flexibility may lead to important changes in the microbiota that allow for the maintenance of a fermentation-reducing state over a long period.     

Responses of pre‐dispersal seed predators to sequential flowering of Dipterocarps in Malaysia

Many species of Dipterocarpaceae and other plant families reproduce synchronously at irregular, multi‐year intervals in Southeast Asian forests. These community‐wide general flowering events are thought to facilitate seed survival through satiation of generalist seed predators. During a general flowering event, closely related Shorea species (Dipterocarpaceae) stagger their flowering times by several weeks, which may minimize cross pollination and interspecific competition for pollinators. Generalist, pre‐dispersal seed predators might also track flowering hosts and influence predator satiation. We addressed the question of whether pre‐dispersal seed predation differed between early and late flowering Shorea species by monitoring flowering, fruiting and seed predation intensity over two general flowering events at the Pasoh Research Forest, Malaysia. Pre‐dispersal insect seed predators killed up to 63 percent of developing seeds, with Nanophyes shoreae, a weevil that feeds on immature seeds being the most important predator for all Shorea species. This weevil caused significantly greater pre‐dispersal seed predation in earlier flowering species. Long larval development time precluded oviposition by adults that emerged from the earliest flowering Shorea on the final flowering Shorea. In contrast, larvae of weevils that feed on mature seeds before seed dispersal (Alcidodes spp.), appeared in seeds of all Shorea species almost simultaneously. We conclude that general flowering events have the potential to satiate post‐dispersal seed predators and pre‐dispersal seed predators of mature fruit, but are less effective at satiating pre‐dispersal predators of immature fruit attacking early flowering species.