Long-term Administration of Probiotics to Asymptomatic Pre-school Children for Either the Eradication or the Prevention of Helicobacter pylori Infection

Background:  The role of probiotics in the armamentarium remains to be defined. The aims of this study were to investigate whether the long-time administration of Lactobacillus gasseri OLL2716 (LG21) strain can eradicate H. pylori in asymptomatic pre-school children and/or prevent H. pylori infection.
Methods: A total of 440 children, from 5–7 years of age, attending a kindergarten in Thailand were screened by the Helicobacter pylori stool antigen (HpSA) test. Thereafter 132 H. pylori positive and 308 H. pylori negative children were recruited to eradication and randomized prevention arms, respectively. Children in the active and placebo treatment groups received Lactobacillus gasseri OLL2716 (LG21) containing cheese and ordinary cheese, respectively, for 12 months. Eradication was defined as reversion by HpSA at 12 months. Prevention was defined as persistently HpSA negative at 12 months.
Results:  Eighty-two of 132 H. pylori positive (62%) completed the eradication arm, of which 24 (29.3%) were negative at 12 months according to the HpSA test. In the randomized prevention arm, 123 of 156 (79%) and 99 of 122 (81%) completed active and placebo arms, respectively, of which 4.1% and 8.1%, respectively, were HpSA positive at 12 months based on a per-protocol analysis ( p  = .21).
Conclusion: Further trials are needed.     

The potential to induce glial differentiation is conserved between Drosophila and mammalian glial cells missing genes

Drosophila glial cells missing (gcm) is a key gene that determines the fate of stem cells within the nervous system. Two mouse gcm homologs have been identified, but their function in the nervous system remains to be elucidated. To investigate their function, we constructed retroviral vectors harboring Drosophila gcm and two mouse Gcm genes. Expression of these genes appeared to influence fibroblast features. In particular, mouse Gcm1 induced the expression of astrocyte-specific Ca(2+)-binding protein, S100beta, in those cells. Introduction of the mouse Gcm1 gene in cultured cells from embryonic brains resulted in the induction of an astrocyte lineage. This effect was also observed by in utero injection of retrovirus harboring mouse Gcm1 into the embryonic brain. However, cultures from mouse Gcm1-deficient mouse brains did not exhibit significant reductions in the number of astrocytes. Furthermore, in situ hybridization analysis of mouse Gcm1 mRNA revealed distinct patterns of expression in comparison with other well-known glial markers. The mammalian homolog of Drosophila gcm, mouse Gcm1, exhibits the potential to induce gliogenesis, but may function in the generation of a minor subpopulation of glial cells.     

Creutzfeldt-Jakob Disease with a prion protein gene codon 180 mutation presenting asymmetric cortical high-intensity on magnetic resonance imaging

ABSTRACT. Here we report a genetically confirmed case of Creutzfeldt-Jakob disease with a prion protein gene codon 180 mutation presenting atypical magnetic resonance imaging findings. The present case exhibited an acute onset and lateralized neurologic signs, and progressive cognitive impairment. No myoclonus or periodic synchronous discharges on electroencephalography were observed. Diffusion-weighted images revealed areas of high signal intensity in the right frontal and temporal cortices at onset that extended to the whole cortex and basal ganglia of the right cerebral hemisphere at 3 months. Although the cerebrospinal fluid (CSF) was initially negative for neuron specific enolase, tau protein, 14–3–3 protein, and abnormal prion protein, the CSF was positive for these brain-derived proteins at 3 months after onset.     

The Rothmund-Thomson gene product RECQL4 localizes to the nucleolus in response to oxidative stress

Mutations in the RECQL4 helicase gene have been linked to Rothmund-Thomson syndrome (RTS), which is characterized by poikiloderma, growth deficiency, and a predisposition to cancer. Examination of RECQL4 subcellular localization in live cells demonstrated a nucleoplasmic pattern and, to a lesser degree, staining in nucleoli. Analysis of RECQL4-GFP deletion mutants revealed two nuclear localization regions in the N-terminal region of RECQL4 and a nucleolar localization signal at amino acids 376-386. RECQL4 localization did not change after treatment with the DNA-damaging agents bleomycin, etoposide, UV irradiation and gamma irradiation, in contrast to the Bloom and Werner syndrome helicases that relocate to distinct nuclear foci after damage. However, in a significant number of cells exposed to hydrogen peroxide or streptonigrin, RECQL4 accumulated in nucleoli. Using a T7 phage display screen, we determined that RECQL4 interacts with poly(ADP-ribose) polymerase-1 (PARP-1), a nuclear enzyme that promotes genomic integrity through its involvement in DNA repair and signaling pathways. The RECQL4 nucleolar localization was inhibited by pretreatment with a PARP-1 inhibitor. The C-terminal portion of RECQL4 was found to be an in vitro substrate for PARP-1. These results demonstrate changes in the intracellular localization of RECQL4 in response to oxidative stress and identify an interaction between RECQL4 and PARP-1.     

Advances in soil microbial ecology and the biodiversity

Recent studies on the colony formation of soil bacteria opened the way to categorize soil bacteria into colony forming curve (CFC) groups of different growth rates. A bacterial culture collection comprising organisms from every CFC group is called an ecocollection. Outlines of ECs of paddy soil 1992 and grassland soil 1987 and 1992 were described. Phylogenetic studies by 16S rDNA sequencing showed a great diversity of culture strains of the ecocollections (EC). A set of alternative concepts was proposed; the active and the quiescent forms of bacterial cells in soil. The former is able to be cultivated and thus counted by the plate method, while the latter is not unless it transforms into the former. Based on the results several points required for extensive cataloguing of soil bacteria were noted.     

Nicotine-induced vascular endothelial growth factor release via the EGFR-ERK pathway in rat vascular smooth muscle cells

Cigarette smoke has been firmly established as an independent risk factor for atherosclerosis and other vascular diseases. The proliferation and migration of vascular smooth muscle cells (VSMC) induced by growth factors have been proposed to play an important role in the progression of atherosclerosis. In the present study, we investigated the effects of nicotine, which is one of the important constituents of cigarette smoke, on vascular endothelial growth factor (VEGF) release, in rat VSMC. The stimulation of cells with nicotine resulted in a time- and concentration-dependent release of VEGF. Hexamethonium, an antagonist of nicotinic acetylcholine receptor (nAChR), inhibited nicotine-induced VEGF release. We next investigated the mechanisms by which nicotine induces VEGF release in the cells. The nicotine-induced VEGF release was inhibited by treatment with U0126, a selective inhibitor of MEK, which attenuated the nicotine-induced ERK phosphorylation. Nicotine induced a transient phosphorylation of ERK. Furthermore, AG1478, a selective inhibitor of epidermal growth factor receptor (EGFR) kinase, inhibited nicotine-induced ERK phosphorylation and VEGF release. These data suggest that nicotine releases VEGF through nAChR in VSMC. Moreover, VEGF release induced by nicotine is mediated by an EGFR-ERK pathway in VSMC. VEGF may contribute to the risk of cardiovascular diseases in cigarette smokers.     

Affinity pulldown of γ‐secretase and associated proteins from human and rat brain

γ‐Secretase is a transmembrane protease complex responsible for the processing of a multitude of type 1 transmembrane proteins, including amyloid precursor protein (APP) and Notch. A functional complex is dependent on the assembly of four proteins: presenilin (PS), nicastrin, Aph‐1 and Pen‐2. Little is known about how the substrates are selected by γ‐secretase, but it has been suggested that γ‐secretase associated proteins (GSAPs) could be of importance. For instance, it was recently reported from studies in cell lines that TMP21, a transmembrane protein involved in trafficking, binds to γ‐secretase and regulates the processing of APP‐derived substrates without affecting Notch cleavage. Here, we present an efficient and selective method for purification and analysis of γ‐secretase and GSAPs. Microsomal membranes were prepared from rat or human brain and incubated with a γ‐secretase inhibitor coupled to biotin via a long linker and a S‐S bridge. After pulldown using streptavidin beads, bound proteins were eluted under reducing conditions and digested by trypsin. The tryptic peptides were subjected to LC‐MS/MS analysis, and proteins were identified by sequence data from MS/MS spectra. All of the known γ‐secretase components were identified. Interestingly, TMP21 and the PS associated protein syntaxin1 were associated to γ‐secretase in rat brain. We suggest that the present method can be used for further studies on the composition of the γ‐secretase complex.     

Psb30 contributes to structurally stabilise the Photosystem II complex in the thermophilic cyanobacterium Thermosynechococcus elongatus

A deletion mutant that lacks the Psb30 protein, one of the small subunits of Photosystem II, was constructed in a Thermosynechococcus elongatus strain in which the D1 protein is expressed from the psbA₃ gene (WT*). The ΔPsb30 mutant appears more susceptible to photodamage, has a cytochrome b₅₅₉ that is converted into the low potential form, and probably also lacks the PsbY subunit. In the presence of an inhibitor of protein synthesis, the ?Psb30 lost more rapidly the water oxidation function than the WT* under the high light conditions. These results suggest that Psb30 contributes to structurally and functionally stabilise the Photosystem II complex in preventing the conversion of cytochrome b₅₅₉ into the low potential form. Structural reasons for such effects are discussed.