Low-pressure microwave-induced helium plasma emission spectrometry: Vaporization characteristics of metal chlorides,nitrates, and sulfates

A low-pressure microwave-induced helium plasma serves as an excitation source for metal chlorides, nitrates, and sulfates vaporized from a filament, resulting in fractional vaporization and differential sensitivities of detection of the elements depending on the vapor pressures of their salts. The shapes of the single emission peaks, which are simple in the presence of potassium chloride, become complex and may double in number.     

Effects of acorn masting on population dynamics of three forest-dwelling rodent species in Hokkaido,Japan

The effects of the abundance of acorns of the oak, Quercus crispula, on the population dynamics of three rodent species (Apodemus speciosus, A. argenteus, and Clethrionomys rufocanus) were analyzed using time series data (1992–2006). The data were obtained in a forest in northern Hokkaido, Japan, by live trapping rodents and directly counting acorns on the ground. Apodemus speciosus generally increased in abundance following acorn masting. However, the clear effect of acorn abundance was not detected for the other two rodent species. Acorns of Q. crispula contain tannins, which potentially have detrimental effects on herbivores. Apodemus speciosus may reduce the damage caused by acorn tannins with tannin-binding salivary proteins and tannase-producing bacteria, whereas such physiological tolerance to tannins is not known in the other two rodent species. The differences in the effects of acorns between the three species may be due to differences in their physiological tolerance to tannins.     

Nupr1 deficiency downregulates HtrA1, enhances SMAD1 signaling,and suppresses age-related bone loss in male mice

Nuclear protein 1 (NUPR1) is a stress-induced protein activated by various stresses, such as inflammation and oxidative stress. We previously reported that Nupr1 deficiency increased bone volume by enhancing bone formation in 11-week-old mice. Analysis of differentially expressed genes between wild-type (WT) and Nupr1-knockout (Nupr1-KO) osteocytes revealed that high temperature requirement A 1 (HTRA1), a serine protease implicated in osteogenesis and transforming growth factor-β signaling was markedly downregulated in Nupr1-KO osteocytes. Nupr1 deficiency also markedly reduced HtrA1 expression, but enhanced SMAD1 signaling in in vitro-cultured primary osteoblasts. In contrast, Nupr1 overexpression enhanced HtrA1 expression in osteoblasts, suggesting that Nupr1 regulates HtrA1 expression, thereby suppressing osteoblastogenesis. Since HtrA1 is also involved in cellular senescence and age-related diseases, we analyzed aging-related bone loss in Nupr1-KO mice. Significant spine trabecular bone loss was noted in WT male and female mice during 6−19 months of age, whereas aging-related trabecular bone loss was attenuated, especially in Nupr1-KO male mice. Moreover, cellular senescence-related markers were upregulated in the osteocytes of 6−19-month-old WT male mice but markedly downregulated in the osteocytes of 19-month-old Nupr1-KO male mice. Oxidative stress-induced cellular senescence stimulated Nupr1 and HtrA1 expression in in vitro-cultured primary osteoblasts, and Nupr1 overexpression enhanced p16^ink4a expression in osteoblasts. Finally, NUPR1 expression in osteocytes isolated from the bones of patients with osteoarthritis was correlated with age. Collectively, these results indicate that Nupr1 regulates HtrA1-mediated osteoblast differentiation and senescence. Our findings unveil a novel Nupr1/HtrA1 axis, which may play pivotal roles in bone formation and age-related bone loss.     

Immunohistochemical Localization of Manserin,a Novel Neuropeptide Derived from Secretogranin II,in Rat Adrenal Gland,and its Upregulation by Physical Stress

We recently identified a novel 40-amino acid neuropeptide designated manserin from the rat brain (Yajima in NeuroReport 15: 1755–1759, 2004). Manserin is highly expressed in pituitary and hypothalamic nuclei, which suggests that it plays a role in the endocrine system. In this study, we employed immunohistochemical methods to investigate the presence of manserin in rat adrenal glands, as well as its regulation by physical stress. Immunohistochemical analysis using anti-manserin antibody showed that manserin is present in the rat adrenal medulla but not in the cortex. When the colocalization of manserin and phenylethanolamine N-methyltransferase (PNMT), an epinephrine-synthesizing enzyme, was examined, virtually all PNMT-positive cells expressed manserin. Interestingly, the immunoreactivity of manserin was significantly increased when the rats were exposed to water-immersion restraint stress. These results demonstrate for the first time that adrenal manserin, a novel neuropeptide, may have a potential physiological role under stress-inducing conditions.     

Changes in important apoptosis-related molecules in the endothelin-1-induced hypertrophied cardiomyocytes: effect of the pretreatment with eicosapentaenoic Acid

Human heart failure is preceded by a process called cardiac remodeling, in which heart chambers progressively enlarge and contractile function deteriorates. Programmed cell death (apoptosis) of cardiac muscle cells has been identified as an essential process in the progression to heart failure. The execution of the apoptotic program entails complex interactions between and execution of multiple molecular subprograms. Endothelin (ET)-1, a potent vasoconstrictor peptide, is synthesized and secreted by cardiomyocytes and induces hypertrophy of cardiomyocytes. The cardiovascular benefit of fish oil containing eicosapentaenoic acid (EPA) in humans and experimental animals was reported. Recently, we found that ET-1-induced cardiomyocytic remodeling could be prevented by pretreatment with EPA. The aim of the present study is to investigate whether there would be any alteration in the expression of important apoptosis-related molecules in ET-1-administered hypertrophied cardiomyocytes. We also sought to determine, if there are alterations in apoptotic molecules, what type of role for EPA would then exist. Ventricular cardiomyocytes were isolated from 2-day-old Sprague-Dawley rats and were cultured for 3 days. At Day 4 of culture, the cardiomyocytes were divided into three groups: control, the ET-1 (0.1 nM)-treated group, and the ET-1 group pretreated with EPA (10 microM). Twenty-four hours after the treatment, the gene expressions of three important molecules related to apoptosis (caspase-3, Bax, and Bcl-2) in three experimental groups were evaluated by real-time polymerase chain reaction. The present study could not demonstrate any significant or representative alteration in any of the above three apoptosis-related important markers in either ET-1-induced hypertrophied cardiomyocytes with or without EPA pretreatment. The present study would at least be able to exclude the involvement of some representative molecules related to apoptosis in ET-1-induced hypertrophied cardiomyocytes. In addition, the present study demonstrates that the antihypertrophic effect of EPA to ET-1-administered cardiomyocytes appears not to modulate the apoptosis signaling cascade.     

Selective production of two diastereomers of disaccharide sugar alcohol, mannosylerythritol by Pseudozyma yeasts

Mannosylerythritol (ME) is the hydrophilic backbone of mannosylerythritol lipids as the most promising biosurfactants produced by different Pseudozyma yeasts, and has been receiving attention as a new sugar alcohol. Different Pseudozyma yeasts were examined for the sugar alcohol production using glucose as the sole carbon source. P. hubeiensis KM-59 highly produced a conventional type of ME, i.e., 4-O-β-d-mannopyranosyl-d-erythritol (4-ME). Interestingly, P. tsukubaensis KM-160 produced a diastereomer of 4-ME, i.e., 1-O-β-d-mannopyranosyl-d-erythritol (1-ME). In shake flask culture with 200 g/l of glucose, strain KM-59 produced 4-ME at a yield of 33.2 g/l (2.2 g/l/day of the productivity), while strain KM-160 produced 1-ME at 30.0 g/l (2.0 g/l/day). Moreover, the two strains were found to produce ME from glycerol; the maximum yields of 4-ME and 1-ME from 200 g/l of glycerol were 16.1 g/l (1.1 g/l/day) and 15.8 g/l (1.1 g/l/day), respectively. The production of 1-ME as the new diastereomer was further investigated in fed batch culture using a 5-l jar-fermenter. Compared to the flask culture, strain KM-160 gave three times higher productivity of 1-ME at 38.0 g/l (6.3 g/l/day) from glucose and at 31.1 g/l (3.5 g/l/day) from glycerol, respectively. This is the first report on the selective production of two diastereomers of ME, and should thus facilitate the functional development and application of the disaccharide sugar alcohol in the food and relative industries.