Corelike structures in a stable L-form ofStreptococcus pyogenes

Corelike structures, which were interpreted as straight, large cylinders containing ribosome-like particles surrounded by an amorphous substance of low electron density, were found in a stable L-form ofStreptococcus pyogenes grown in the absence of antibiotics.     

Effects of Parenteral Lipid Infusion on DNA Damage in Very Low Birth Weight Infants

Very low birth weight (VLBW) infants are known to have poorly developed antioxidant system and may be at increased risk for radical damage. Previous studies have reported higher levels of lipid peroxide products in lipid emulsion used for parenteral nutrition. To examine the direct effects of parenteral lipid infusion on DNA damage in VLBW infants, we measured urinary 8-hydroxydeoxyguanosine (8-OHdG) levels in VLBW infants before, during, and after the parenteral lipid infusion. In both the lipid-infused and lipid-free groups, urinary 8-OHdG excretion levels at 14 days old were significantly ( p <0.01) lower than those at 2 and 7 days old. However, there were no significant differences in urinary 8-OHdG excretion levels between the lipid-infused and lipid-free groups at 2, 7, and 14 days old. Our results suggest that parenteral lipid infusion does not cause oxidative DNA damage, but irrespective of the infusion DNA damage during the first week of life is enhanced when compared with 14 days after birth in VLBW infants.     

Population genetics of Haminoea (Haloa) japonica Pilsbry, 1895, a widespread non-indigenous sea slug (Mollusca: Opisthobranchia) in North America and Europe

Haminoea japonica is an opisthobranch mollusk with a large non-indigenous range. This species is a vector for a parasite that causes the human skin disease cercarial dermatitis, and may have negative effects on populations of native species. Molecular evidence from the mitochondrial cytochrome c oxidase I gene and the histone 3 nuclear gene indicates that previously published morphology-based hypotheses on the spread of H. japonica out of Japan are correct. The most likely explanation for the current range of the species, which includes Japan, Korea, France, Spain, Italy, Canada and the USA is a recent, human-mediated dispersal from Japanese populations. The highest levels of nucleotide and haplotype diversity are found in Japan. Non-indigenous populations have low levels of genetic diversity (indicating bottlenecking). Haplotypes that were detected in the non-indigenous range of H. japonica have only been found in two localities in the native range; these two localities are in north-eastern Japan. In addition, the haplotype network structure and Spatial Analysis of Molecular Variance results confirm the origins of non-indigenous populations most likely trace to north-eastern Japan, which is where most Pacific oyster exports to North America also originated. Because there are no major shipping ports in north-eastern Japan, ballast water is less likely to be the mechanism of dispersal. The results of this study provide important data for the development of policies and regulations aimed to prevent further spread of this species in non-indigenous ranges.     

Mother–calf interactions and social behavior development in Commerson’s dolphins (Cephalorhynchus commersonii)

Mother–calf interactions and the behaviors of mothers during separation from their calves were examined in four Commerson’s dolphin (Cephalorhynchus commersonii) mother–calf pairs. Four infants were observed: 56.8 h over 30 days from birth to 263 days of age, 36.9 h over 20 days from birth to 149 days of age, 10.4 h over 3 days from birth to 2 days of age, and 15.0 h over 3 days from birth to 2 days of age. All four pairs shared common characteristics in the rate and frequencies of mother–calf interactions and the behaviors of mothers during the first week of life. After the first week, individual differences in changes in the frequency of each behavior were observed. The three behaviors considered representative of maternal care (parallel swimming, synchronous breathing, and body-to-body contact) were frequently performed in the first week; thereafter, the frequencies declined. Separate behaviors of mothers were infrequent during the first week and increased with an increase in infants’ age. Bumping by infants increased with time, suggesting an increase in soliciting by calves and conflict between mothers and calves. The frequency of flipper-to-body rubbing also changed but in a complex manner, probably because the calves needed to learn how to perform this behavior from their mothers and because initiator and recipient of this behavior can be changed quickly.     

(2-Nitroethyl)benzene: a major flower scent from the Japanese loquat Eriobotrya japonica [Rosales: Rosaceae]

(2-Nitroethyl)benzene was identified as a major component of the flower scent of the Japanese loquat Eriobotrya japonica [Rosales: Rosaceae], together with p-methoxybenzaldehyde and methyl p-methoxybenzoate. The corresponding volatiles from chopped leaves did not contain these three compounds. This is the first time that 1-nitro-2-phenyl-ethane has been demonstrated to be a natural product among Japanese plants, although two Japanese millipedes are known to possess the same aromatics.     

A Long-Term Cultivation of an Anaerobic Methane-Oxidizing Microbial Community from Deep-Sea Methane-Seep Sediment Using a Continuous-Flow Bioreactor

Anaerobic oxidation of methane (AOM) in marine sediments is an important global methane sink, but the physiological characteristics of AOM-associated microorganisms remain poorly understood. Here we report the cultivation of an AOM microbial community from deep-sea methane-seep sediment using a continuous-flow bioreactor with polyurethane sponges, called the down-flow hanging sponge (DHS) bioreactor. We anaerobically incubated deep-sea methane-seep sediment collected from the Nankai Trough, Japan, for 2,013 days in the bioreactor at 10°C. Following incubation, an active AOM activity was confirmed by a tracer experiment using ¹³C-labeled methane. Phylogenetic analyses demonstrated that phylogenetically diverse Archaea and Bacteria grew in the bioreactor. After 2,013 days of incubation, the predominant archaeal components were anaerobic methanotroph (ANME)-2a, Deep-Sea Archaeal Group, and Marine Benthic Group-D, and Gammaproteobacteria was the dominant bacterial lineage. Fluorescence in situ hybridization analysis showed that ANME-1 and -2a, and most ANME-2c cells occurred without close physical interaction with potential bacterial partners. Our data demonstrate that the DHS bioreactor system is a useful system for cultivating fastidious methane-seep-associated sedimentary microorganisms.     

A lipid peroxidation-derived inflammatory mediator: identification of 4-hydroxy-2-nonenal as a potential inducer of cyclooxygenase-2 in macrophages

Cyclooxygenases (COXs) catalyze the conversion of arachidonic acid to eicosanoids, which mediate a variety of biological actions involved in vascular pathophysiology. In the present study, we investigated the role of lipid peroxidation products in the up-regulation of COX-2, an inducible isoform responsible for high levels of prostaglandin production during inflammation and immune responses. COX-2 was found to colocalize with 4-hydroxy-2-nonenal (HNE), a major lipid peroxidation-derived aldehyde, in foamy macrophages within human atheromatous lesions, suggesting that COX-2 expression may be associated with the accumulation of lipid peroxidation products within macrophages. To test the hypothesis that lipid peroxidation products might be involved in the regulation of prostanoid biosynthesis, we conducted a screen of oxidized fatty acid metabolites and found that, among the compounds tested, only HNE showed inducibility of the COX-2 protein in RAW264.7 macrophages. In addition, intraperitoneal administration of HNE resulted in an increase in cell numbers in the peritoneal cavity that was associated with significant increases in the peritoneal and tissue levels of COX-2 in mice. To understand the possible signaling mechanism underlying the inducing effect of HNE on COX-2 up-regulation, we examined the phosphorylation events that may lead to COX-2 induction and found that HNE did not stimulate the induction of nitric oxide synthase and activation of NF-kappaB but significantly activated p38 mitogen-activated protein kinase and its upstream kinase in RAW264.7 macrophages. Tyrosine kinases, such as the epidermal growth factor-like and Src family tyrosine kinases, appeared to mediate the stabilization of COX-2 mRNA via the p38 mitogen-activated protein kinase pathway. These findings suggest that HNE accumulated in macrophages/foam cells may represent an inflammatory mediator that plays a role in stimulation of the inflammatory response and contributes to the progression of atherogenesis.     

Expression of cyclin E in postmitotic neurons during development and in the adult mouse brain

Cyclin E, a member of the G1 cyclins, is essential for the G1/S transition of the cell cycle in cultured cells, but its roles in vivo are not fully defined. The present study characterized the spatiotemporal expression profile of cyclin E in two representative brain regions in the mouse, the cerebral and cerebellar cortices. Western blotting showed that the levels of cyclin E increased towards adulthood. In situ hybridization and immunohistochemistry showed the distributions of cyclin E mRNA and protein were comparable in the cerebral cortex and the cerebellum. Immunohistochemistry for the proliferating cell marker, proliferating cell nuclear antigen (PCNA) revealed that cyclin E was expressed by both proliferating and non-proliferating cells in the cerebral cortex at embryonic day 12.5 (E12.5) and in the cerebellum at postnatal day 1 (P1). Subcellular localization in neurons was examined using immunofluorescence and western blotting. Cyclin E expression was nuclear in proliferating neuronal precursor cells but cytoplasmic in postmitotic neurons during embryonic development. Nuclear cyclin E expression in neurons remained faint in newborns, increased during postnatal development and was markedly decreased in adults. In various adult brain regions, cyclin E staining was more intense in the cytoplasm than in the nucleus in most neurons. These data suggest a role for cyclin E in the development and function of the mammalian central nervous system and that its subcellular localization in neurons is important. Our report presents the first detailed analysis of cyclin E expression in postmitotic neurons during development and in the adult mouse brain.