Bibliothek

Notizen: Background.  Helicobacter pylori is a causative agent of gastritis, and H. pylori infection is thought to be correlated with iron-deficiency anemia (IDA) at puberty. The H. pylori feoB gene product, a high-affinity ferrous iron transporter, plays a central role in iron acquisition and virulence. This study was undertaken to analyze H. pylori feoB status according to clinical data, including antral gastritis with or without IDA.Methods.  Fourteen H. pylori-positive patients aged from 10 to 18 years were categorized into subgroups based on the presence or absence of IDA. Eight patients were diagnosed as having IDA; the other six showed normal hematological findings. Genomic DNA was isolated from H. pylori cultured from each gastric biopsy specimen. Five sets of primers were used for the PCR amplification of the feoB gene. Linking and sequencing of PCR products generated the feoB region, which was 1.93 kb in size. The feoB gene sequences of H. pylori J99 and 26695 were compared with the clinical strains, and the sequences of feoB regions in the IDA (+) and (–) groups were compared.Results.  Sequence analysis of the complete coding region of the feoB gene revealed 16 sites of polymorphism or mutation. Among these, three polymorphisms (E/T254A, I263V, and K511Q) were indigenous to the Korean clinical strains. Although statistically significant differences were observed at four sites (K127T, A273S/P, I438V and I441T) between IDA (+) and (–), the number of specimens was too low to assess the significance of the differences.Conclusion.  The four polymorphisms of the feoB gene observed appear to be related to the clinical phenotype of IDA, but the relation is unclear because of the small number of strains studied. Further studies are required to confirm a correlation between IDA and H. pylori infection.

Notizen: R-curve behavior of Si3N4–BN composites and monolithic Si3N4 for comparison was investigated. Si3N4–BN composites showed a slowly rising R-curve behavior in contrast with a steep R-curve of monolithic Si3N4. BN platelets in the composites seem to decrease the crack bridging effects of rod-shaped Si3N4 grains for small cracks, but enhanced the toughness for long cracks as they increased the crack bridging scale. Therefore, fracture toughness of the composites was relatively low for the small cracks, but it increased significantly to ∼8 MPa·m1/2 when the crack grew longer than 700 μm, becoming even higher than that of the monolithic Si3N4.

Notizen: Mixed vegetable juice was acidified to a pH below 4 and subjected to pasteurization regimes between 80 and 100 °C. Hunter colour scale values (L, a and b) of the pasteurized samples were analysed to determine the kinetics of green and total colour degradation. The ‘a’ value was chosen as the physical parameter for green colour while ‘Lab’ represented the total colour. A concept, based on fractional conversion, was used for the determination of kinetic parameters. The results revealed that degradation of green and total colour of the acidified vegetable juice followed first-order kinetics. Temperature dependency of the rate constants for both the green and the total colour could be described by the Arrhenius relationship. The activation energies of green and total colour degradation were 49.19 and 29.00 kJ mol−1, respectively.

Notizen: This paper explores the development of a knowledge base within the European Public Health and Environment Network (EPHEN) research group at University College London, which had a pressing need to change the way its work activities were conducted. It is intended to provide some insight to managers, group members within EPHEN, as to how this development can bring about changes to service delivery and practice that empowers service users and involves them in the process. It seeks also to identify possible difficulties that might be anticipated. Also a public Web site will be integrated into the system to promote health awareness, especially as EPHEN's primary concern is to encourage public health in society.

Notizen: 1. Heavy alcohol consumption has been known as a risk factor for hypertension, although the mechanism by which alcohol intake causes hypertension remains elusive.2. We tested the hypothesis that brief exposure to ethanol augments vascular contractility through the stress response in human chorionic plate arteries.3. Human chorionic plate arteries were mounted in organ baths and exposed to 5% ethanol for 15, 30 or 45 min.4. Brief exposure for 45 min, but not 15 min, not only augmented contractility to KCl and 5-hydroxytryptamine 5 h after the end of exposure, but also increased the expression of heat shock protein (HSP) 70 in the tissues.5. Reverse transcription–polymerase chain reaction showed gradual increases of hsp70 mRNA expression, but not heat shock cognate 70 (hsc70), hsp90α or glucose regulatory protein 78 (grp78) mRNA expression, in an exposure time-dependent manner 3 h after the end of exposure.6. These results indicate that ethanol augments vascular contractility through the stress response.

Notizen: [Auszug] The involvement of immune mechanisms in tumor angiogenesis is unclear. Here we describe a new mechanism of tumor vasculogenesis mediated by dendritic cell (DC) precursors through the cooperation of β-defensins and vascular endothelial growth factor-A (Vegf-A). Expression of mouse ...

Notizen: [Auszug] Characterizing fine-scale variation in human recombination rates is important, both to deepen understanding of the recombination process and to aid the design of disease association studies. Current genetic maps show that rates vary on a megabase scale, but studying finer-scale variation using ...

Notizen: Background  A keloid results from excessive collagen deposition, the cause of which remains elusive. A thorough understanding of the pathophysiology of keloid tissue can help determine the most appropriate treatment strategy.Objectives  To assess the differences in gene expression between keloids and adjacent normal skin in order to define the genes involved in keloid formation.Methods  Three Korean patients with keloids underwent excision of the keloid and adjacent normal skin, which was used as the control. We investigated expression patterns of genes in the keloids and the normal skin using cDNA microarray and in situ hybridization techniques.Results  Nine genes in the keloid tissue were consistently upregulated over the 2·0 ratio compared with the normal control from the cDNA microarray composed of 3063 clones: collagen type I α1 (〈accessionId ref="info:ddbj-embl-genbank/NM_000088"〉NM_000088), DNA segment on chromosome 21 (unique) 2056 expressed sequence (D21S2056E, NNP-1, 〈accessionId ref="info:ddbj-embl-genbank/NM_003683"〉NM_003683), suppressor of Ty 5 homologue (〈accessionId ref="info:ddbj-embl-genbank/NM_003169"〉NM_003169), phosphoglycerate dehydrogenase (〈accessionId ref="info:ddbj-embl-genbank/NM_032692"〉NM_032692), adenosine triphosphate synthase β (〈accessionId ref="info:ddbj-embl-genbank/NM_001686"〉NM_001686), serine (or cysteine) proteinase inhibitor, clade H (heat shock protein 47, 〈accessionId ref="info:ddbj-embl-genbank/NM_001235"〉NM_001235), LIV-1 protein, oestrogen regulated (LIV-1, 〈accessionId ref="info:ddbj-embl-genbank/NM_012319"〉NM_012319), interleukin-11 receptor α (IL11RA, 〈accessionId ref="info:ddbj-embl-genbank/NM_004512"〉NM_004512) and carbonyl reductase 3 (CBR3, 〈accessionId ref="info:ddbj-embl-genbank/NM_001236"〉NM_001236). From the in situ hybridization study, the staining signals in the keloid tissue hybridized with anti sense probes of NNP-1 mRNA were stronger than signals in normal controls. Further, endothelial epithelium, but not the epidermis, expressed the signal equally in both keloid and normal control tissue.Conclusions  We identified nine upregulated genes in keloid tissue using cDNA microarray. Of the nine, the NNP-1 gene was confirmed by topological information using the in situ hybridization technique. We conclude that these nine genes, especially NNP-1, probably contribute either directly or indirectly to keloid formation.

Notizen: Granulocyte-macrophage colony-stimulating factor (GM-CSF) is an important regulator in inducing differentiation and proliferation of immune cells. The functional roles of porcine GM-CSF (pGM-CSF) have not yet been revealed. Therefore, expression patterns of pGM-CSF were investigated in immune cells after cloning and sequencing of whole pGM-CSF cDNA. Whole cDNA of pGM-CSF was amplified from porcine alveolar macrophages stimulated by lipopolysaccharide (LPS), using 5′- and 3′-rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR) methods. The products of 5′- and 3′-RACE-PCR were cloned, and the nucleotide sequence of whole pGM-CSF cDNA was determined (GenBank accession number AY116504). The kinetics of pGM-CSF mRNA expression were studied in porcine immune cells such as alveolar macrophages and spleen cells, using a real-time quantitative PCR. The expression of pGM-CSF in LPS-, phytohemagglutinin (PHA)-, or concanavalin A (ConA)-stimulated cells was always higher as compared to the control cells. The expression levels of pGM-CSF in alveolar macrophages were highest at 5 h after LPS stimulation and then continuously decreased in the late phase. In spleen cells, the LPS-stimulated group showed the highest levels after 5 h, but the PHA- and the ConA-stimulated groups showed slightly increased expression levels at the early phase and peaked at 24 h. To our knowledge, this is the first published report describing the nucleotide sequence of whole cDNA and the expression pattern of pGM-CSF using real-time quantitative PCR. These results indicate that pGM-CSF has its own characteristic expression profile in different immune cells.