Antihypertensive effect of ACE inhibitory oligopeptides from chicken egg yolks

Oligopeptides of 1 KDa or less were obtained by hydrolysis of chicken egg yolks with a crude enzyme, and by dialysis with a semipermeable membrane filter. Since the extracted peptides had an inhibitory action on the activity of angiotensin I-converting enzyme (ACE) in vitro, they were orally administered at 20, 100 and 500 mg/kg body weight to spontaneously hypertensive rats (SHR) for 12 weeks to analyze the physiological role on cardiovascular functions. The administered oligopeptides suppressed the development of hypertension at all dosages. After 12 weeks at 500 mg/kg body weight, the values for systolic, mean, and diastolic blood pressure were approximately 10% less in SHRs administered than controls. Furthermore, serum ACE activity of the peptide-administered groups was significantly lower than that of the control group in a dose-related manner. Our results imply that oligopeptides extracted from hen's egg yolks could potentially suppress the development of hypertension in SHR, and this effect might be induced by the inhibition of ACE activity.     

Mutations in the 2C region of poliovirus responsible for altered sensitivity to benzimidazole derivatives

MRL-1237, [1-(4-fluorophenyl)-2-(4-imino-1,4-dihydropyridin-1-yl) methylbenzimidazole hydrochloride], is a potent and selective inhibitor of the replication of enteroviruses. To reveal the target molecule of MRL-1237 in viral replication, we selected spontaneous MRL-1237-resistant poliovirus mutants. Of 15 MRL-1237-resistant mutants obtained, 14 were cross-resistant to guanidine hydrochloride (mrgr), while 1 was susceptible (mrgs). Sequence analysis of the 2C region revealed that the 14 mrgr mutants contained a single nucleotide substitution that altered an amino acid residue from Phe-164 to Tyr. The mrgs mutant, on the other hand, contained a substitution of Ile-120 to Val. Through the construction of a cDNA-derived mutant, we confirmed that the single mutation at Phe-164 was really responsible for the reduced susceptibility to MRL-1237. MRL-1237 inhibited poliovirus-specific RNA synthesis in HeLa cells infected with a wild strain but not with an F164Y mutant. We furthermore examined the effect of mutations of the 2C region on the drug sensitivity of cDNA-derived guanidine-resistant and -dependent mutants. Two guanidine-resistant mutants were cross-resistant to MRL-1237 but remained susceptible to another benzimidazole, enviroxime. Either MRL-1237 or guanidine stimulated the viral replication of two guanidine-dependent mutants, but enviroxime did not. These results indicate that MRL-1237, like guanidine, targets the 2C protein of poliovirus for its antiviral effect.     

Diversity and evolution of photosynthetic antenna systems in green plants

Photosynthetic antenna systems are mainly involved in the absorption of light energy required for photosynthesis. The typical green plants arrange chlorophylls a and b and carotenoids, including lutein and 9′‐cis neoxanthin, in their antenna systems; such antenna systems have prospered on earth. Therefore, these antenna systems should be highly evolved and should adapt to the photoenvironments in which plants grow. However, little information is available on the diversity and evolution of antenna systems in green plants as a whole. To approach this, the present study focused on the antenna systems in the Prasinophyceae, an assemblage of early diverging lineages of green plants and analyzed their photosynthetic pigments in detail. In the present study, various novel blue–green light‐absorbing siphonaxanthin series were detected in the early diverging species of the Prasinophyceae and the distribution of these carotenoids was revealed. Additionally, to clarify the evolution of antenna systems in the Ulvophyceae, a highly developed green algal group that specializes in inhabiting various aquatic environments, members of the Cladophorales belonging to this class were selected and their carotenoid compositions were determined to compare them with the molecular phylogenetic tree constructed on the basis of the 18S rRNA gene sequences of the Cladophorales. In this review, these data will be summarized and the remarkable variation of photosynthetic pigments will be presented. A possible scenario detailing the evolution of antenna systems in green plants will be elucidated.     

Intravital imaging of neutrophil recruitment in intestinal ischemia-reperfusion injury

Background

Neutrophils are known to be key players in innate immunity. Activated neutrophils induce local inflammation, which results in pathophysiologic changes during intestinal ischemia-reperfusion injury (IRI). However, most studies have been based on static assessments, and few have examined real-time intravital neutrophil recruitment. We herein report a method for imaging and evaluating dynamic changes in the neutrophil recruitment in intestinal IRI using two-photon laser scanning microscopy (TPLSM).

Biochemical Effects of Fatty Acid and its Derivatives on l-Glutamic Acid Fermentation

Tween 60 (polyoxyethylene sorbitan monostearate) has been found to be the most effective derivative of fatty acid in accumulating l-glutamic acid in biotin-sufficient medium. The effect was exceedingly subject to the influence of the addition time of the ester, and this was observed also on the growth curve of Brev. lactofermentum. Changes of the growth curve caused by the varied addition time of the ester corresponded to those by the concentration of biotin in the medium that did not contain Tween 60. The patterns of fermentation course in the two corresponding conditions, such as biotin 3 μg/l and biotin 20 μg/l-Tween 60 mg/ml, agreed closely with each other. It seemed that identical cells were grown on the conditions. The only difference between the cells was observed as to the contents of intracellular biotin. Although l-glutamic acid was not accumulated by biotin-sufficient cells, cells with sufficient biotin and capable of accumulating l-glutamic acid were obtained in the presence of Tween 60, in which case the ester neither prevented the cells from taking up biotin nor controlled the level of intracellular biotin.     

Structural components of the synaptonemal complex, SYCP1 and SYCP3, in the medaka fish Oryzias latipes

The synaptonemal complex (SC) is a meiosis-specific structure essential for synapsis of homologous chromosomes. For the first time in any non-mammalian vertebrates, we have isolated cDNA clones encoding two structural components of the SC, SYCP1 and SYCP3, in the medaka, and investigated their protein expression during gametogenesis. As in the case of mammals, medaka SYCP1 and SYCP3 are expressed solely in meiotically dividing cells. In the diplotene stage, SYCP1 is diminished at desynaptic regions of chromosomes and completely lost on the chromosomes at later stages. SYCP3 is localized along the arm and centromeric regions of chromosomes at metaphase I, and its existence on the whole chromosomes persists up to anaphase I, a situation different from that reported in the mouse, in which SYCP3 is confined to the centromeric regions but lost on the arm regions at metaphase I. Thus, the expression patterns of SC components are different in mammals and fish despite the resemblance in morphological structure of the SC, suggesting divergence in the function of the SC in regulation of meiosis-specific chromosomal behavior. Since the antibody against medaka SYCP3 is cross-reactive to other fishes, it should be generally useful for a meiosis-specific marker in fish germ cells.     

Encapsulation of lemongrass oil with cyclodextrins by spray drying and its controlled release characteristics

Inclusion of the two isomers of citral (E-citral and Z-citral), components of lemongrass oil, was investigated within the confines of various cyclodextrin (α-CD, β-CD and γ-CD) host molecules. Aqueous complex formation constants for E-citral with α-CD, β-CD and γ-CD were determined to be 123, 185, and 204 L/mol, respectively, whereas Z-citral exhibited stronger affinities (157, 206, and 253 L/mol, respectively). The binding trend γ-CD > β-CD > α-CD is a reflection of the more favorable geometrical accommodation of the citral isomers with increasing cavity size. Encapsulation of lemongrass oil within CDs was undertaken through shaking citral:CD (1:1, 1.5:1, and 2:1 molar ratio) mixtures followed by spray drying. Maximum citral retention occurred at a 1:1 molar ratio with β-CD and α-CD demonstrating the highest levels of total E-citral and Z-citral retention, respectively. Furthermore, the β-CD complex demonstrated the slowest release rate of all inclusion complex powders.     

Pseudospirochaetes in peritoneal exudates of mice injected with Bacillus aneurinolyticus

Bodies initially thought to be spirochaetes were observed in the ascites of mice injected intraperitoneally with Bacillus aneurinolyticus (KA bacillus). Electron microscopy revealed that these bodies were in fact 'pseudospirochaetes' originating from the flagellar bundles of the bacilli.