A Consistent Orally-Infected Hamster Model for Enterovirus A71 Encephalomyelitis Demonstrates Squamous Lesions in the Paws,Skin and Oral Cavity Reminiscent of Hand-Foot-and-Mouth Disease

Enterovirus A71 (EV-A71) causes self-limiting, hand-foot-and-mouth disease (HFMD) that may rarely be complicated by encephalomyelitis. Person-to-person transmission is usually by fecal-oral or oral-oral routes. To study viral replication sites in the oral cavity and other tissues, and to gain further insights into virus shedding and neuropathogenesis, we developed a consistent, orally-infected, 2-week-old hamster model of HFMD and EV-A71 encephalomyelitis. Tissues from orally-infected, 2-week-old hamsters were studied by light microscopy, immunohistochemistry and in situ hybridization to detect viral antigens and RNA, respectively, and by virus titration. Hamsters developed the disease and died after 4–8 days post infection; LD₅₀ was 25 CCID₅₀. Macroscopic cutaneous lesions around the oral cavity and paws were observed. Squamous epithelium in the lip, oral cavity, paw, skin, and esophagus, showed multiple small inflammatory foci around squamous cells that demonstrated viral antigens/RNA. Neurons (brainstem, spinal cord, sensory ganglia), acinar cells (salivary gland, lacrimal gland), lymphoid cells (lymph node, spleen), and muscle fibres (skeletal, cardiac and smooth muscles), liver and gastric epithelium also showed varying amounts of viral antigens/RNA. Intestinal epithelium, Peyer’s patches, thymus, pancreas, lung and kidney were negative. Virus was isolated from oral washes, feces, brain, spinal cord, skeletal muscle, serum, and other tissues. Our animal model should be useful to study squamous epitheliotropism, neuropathogenesis, oral/fecal shedding in EV-A71 infection, person-to-person transmission, and to test anti-viral drugs and vaccines.     

Investigation of the antigen recognition and presentation capacity of pecteneal hyalocytes in the chicken (gallus gallus domesticus)

We investigated at different developmental stages the antigen recognition and presentation capacity of pecteneal hyalocytes that adhere to the pecten oculi in the eye of domestic chickens. Forty-eight fertilized eggs were used to investigate embryonic stages and 12 6-week-old chickens were used to investigate adults. Tissue samples from both embryos and adults were stained with monoclonal antibodies against MHC-II, TLR2/CD282 and TLR4, and also with RCA-1, WGA and SNA lectins. The developmental stage of the pecteneal hyalocytes was determined using Masson's triple staining. Pecteneal hyalocytes first appeared at Hamburger-Hamilton stages 30 34 and remained unchanged from their first appearance to adulthood. Chicken pecteneal hyalocytes were stained by monoclonal antibodies against TLR2 and TLR4, and were unstained by monoclonal antibodies for MHC-II. Hyalocytes were positive for RCA-I, WGA and SNA lectins. We found that pecteneal hyalocytes that adhere to the pecten oculi in domestic chickens recognized antigens, but could not present them. These cells have been assumed to be of monocyte/macrophage lineage; their functions in the immune response are not fully understood.     

Inorganic mercury in human astrocytes,oligodendrocytes, corticomotoneurons and the locus ceruleus: implications for multiple sclerosis,neurodegenerative disorders and gliomas

Neurotoxic metals have been implicated in the pathogenesis of multiple sclerosis, neurodegenerative disorders and brain tumours but studies of the location of heavy metals in human brains are rare. In a man who injected himself with metallic mercury the cellular location of mercury in his brain was studied after 5 months of continuous exposure to inorganic mercury arising from metallic mercury deposits in his organs. Paraffin sections from the primary motor and sensory cortices and the locus ceruleus in the pons were stained with autometallography to detect inorganic mercury and combined with glial fibrillary acidic protein immunohistochemistry to identify astrocytes. Inorganic mercury was found in grey matter subpial, interlaminar, protoplasmic and varicose astrocytes, white matter fibrous astrocytes, grey but not white matter oligodendrocytes, corticomotoneurons and some locus ceruleus neurons. In summary, inorganic mercury is taken up by five types of human brain astrocytes, as well as by cortical oligodendrocytes, corticomotoneurons and locus ceruleus neurons. Mercury can induce oxidative stress, stimulate autoimmunity and damage DNA, mitochondria and lipid membranes, so its location in these CNS cells suggests it could play a role in the pathogenesis of multiple sclerosis, neurodegenerative conditions such as Alzheimer’s disease and amyotrophic lateral sclerosis, and glial tumours.     

Shell formation in the giant clam,Tridacna squamosa,may involve an apical Na+/Ca2+ exchanger 3 homolog in the shell-facing epithelium of the whitish inner mantle,which displays light-enhanced gene and protein expression

Coral Reefs - Na+/Ca2+ exchangers (NCXs) transport one Ca2+ in exchange for three Na+ and may participate in the calcification processes of mammalian osteoblasts and invertebrate calcifying cells....     

Analysis of expressed sequence tags from the red alga Griffithsia okiensis

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <10(-4)) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were C-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.     

Dasania marina gen. nov., sp. nov., of the order Pseudomonadales, isolated from Arctic marine sediment

An obligately aerobic bacterium, strain KOPRI 20902T, was isolated from a marine sediment in Ny-Arlesund, Spitsbergen Islands, Norway. Cells were irregular rods and motile with polar monotrichous flagellum. The optimum growth temperature was 17-22 degrees . Cells grew best in pH 7.0-10.0 and 3-4% sea salts (corresponding to 2.3-3.1% NaCl). The novel strain required Ca2+ or Mg2+ in addition to NaCl for growth. Sequence analysis of 16S rRNA gene revealed that the Arctic isolate is distantly related with established species (<92.4% sequence similarity) and formed a monophyletic group with Cellvibrio, which formed a distinct phylogenetic lineage in the order Pseudomonadales. Predominant cellular fatty acids [C16:1 omega7c/15:0 iso 2OH (45.3%), C16:0 (18.4%), ECL 11.799 (11.2%), C10:0 3OH (10.4%)]; DNA G+C content (37.0 mol%); nitrate reduction to nitrogen; absence of aesculin hydrolysis, N-acetyl-beta-glucosaminidase and esterase; no assimilation of arabinose, galactose, glucose, lactose, maltose, and trehalose differentiated the strain from the genus Cellvibrio. Based on the phylogenetic and phenotypic characteristics, Dasania marina gen. nov., sp. nov. is proposed in the order Pseudomonadales. Strain KOPRI 20902T (=KCTC 12566T=JCM 13441T) is the type strain of Dasania marina.     

Staphylococcus aureus isogenic mutant, deficient in toxic shock syndrome toxin-1 but not staphylococcal enterotoxin A production, exhibits attenuated virulence in a tampon-associated vaginal infection model of toxic shock syndrome.

Since menstrual toxic shock syndrome (MTSS) is associated with a predominant clone of Staphylococcus aureus which produces both toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin A (SEA), we sought to clarify the role of TSST-1 in a tampon-associated vaginal infection model in New Zealand White (NZW) rabbits, using isogenic tst+/sea+ S. aureus mutants in which tst was inactivated by allelic replacement. Rabbits infected with the tst-/sea+ strain became ill within 3 days, with fever, weight loss, conjunctival hyperemia, and lethargy. Mortality was significantly higher with the tst+/sea+ strain compared to its tst-/sea+ isogenic derivative (4/13 vs. 0/14; p < 0.05, Fisher's exact test, 2-tailed). Mean fever index was higher (p < 0.005; t test, 2-tailed) and weight loss more sustained among survivors in the tst+/sea+ group. Furthermore, culture filtrates from the tst+/sea+ strain induced a significantly greater response in mitogenesis and TNF alpha secretion from rabbit splenocytes in vitro compared to the tst-/sea+ isogenic derivative. Thus, regardless of the role of SEA, TSST-1 significantly contributed to both morbidity and mortality in this tampon-associated vaginal infection model in NZW rabbits. This is the first demonstration of the potential role of TSST-1 and SEA in the pathogenesis of MTSS with a MTSS-associated clinical S. aureus strain in a relevant animal model.     

Increased risk of cerebral white matter lesions in obstructive sleep apnea syndrome

Sleep and Biological Rhythms - The aim of this study was to investigate the relation between obstructive sleep apnea syndrome (OSAS) and cerebral white matter lesions (CWML) on brain magnetic...     

Demulsification of oil-in-water emulsions by aerial spores of a Streptomyces sp.

Of a number of actinomycetes isolated from Antarctica and coastal regions of Korea, one isolate, identified as a Streptomycessp., demulsified an emulsion of kerosene/0.2% Triton X-100 (2:1, v/v) within 1 min. The aerial spores broke emulsions of low viscosity hydrocarbons such as kerosene and gasoline within 1 min, but after 3 min of contact they could demulsify less than 50% of emulsions of high viscosity hydrocarbons diluted with kerosene.