TET2 is a component of the estrogen receptor complex and controls 5mC to 5hmC conversion at estrogen receptor cis-regulatory regions

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Obesity and Television Watching in Preschoolers in Greece: The GENESIS Study

The aim of the current work was to evaluate the effect of preschoolers' television (TV) watching time on the prevalence of obesity even after controlling for their total energy intake and their physical activity status. A representative sample of 2,374 Greek children aged 1–5 years was examined (“Growth, Exercise and Nutrition Epidemiological Study in preSchoolers”, GENESIS study). Children's TV watching time on a usual weekday and at a usual weekend was recorded. The overall mean of children's TV viewing time was 1.32 h/day. The majority of participants (74.0%) spent <2 h/day watching TV whereas only 3.1% spent >4 h/day in front of a TV set. Overall, 65.2% of participants were normal weight, 17.2% were overweight, and the rest 17.6% were obese. The prevalence of obesity was significantly higher among those with TV viewing time ≥2 h/day (21.7%) compared to those watching TV <2 h/day (16.1%, P = 0.003). TV viewing time remained significantly associated with the likelihood of being obese even after controlling for potential confounders (i.e., socio demographic and other characteristics and physical activity status) only among children aged 3–5 years. However, further adjusting for children's total energy intake revealed that the association between the TV viewing time and the probability of being obese was no longer statistically significant. On the other hand, physical activity status continued to be an independent factor of being obese. The current findings support the hypothesis that the effect of TV viewing time on childhood obesity is independent of physical activity status and may be attributed to the increased total energy intake during TV watching.     

Taxonomic distinctness indices for discriminating patterns in freshwater rotifer assemblages

Taxonomic distinctness indices measure the taxonomic relatedness among species and have been used for environmental assessment to detect disturbed habitats. This is the first application of the Average Taxonomic Distinctness (Δ⁺) and Variance in Taxonomic Distinctness (Λ⁺) indices to the presence/absence data of rotifer communities to examine their sensitiveness in discriminating perturbed environments. The 26 Greek lakes studied spanned a wide range of morphological and physical–chemical characteristics. Δ⁺ was significantly correlated (P < 0.05) with maximum depth, salinity and trophic state, while Λ⁺ was correlated only with salinity. The index Δ⁺ identified lakes characterized by periods of increased salinity. Communities in these lakes were less diverse, consisting of more closely related species as seen by the reduced number of families than other lakes with similar species richness. Lakes identified by Λ⁺ had a higher community distinctness than expected due to the overrepresentation of the family Brachionidae; they were also characterized by periods of water-level fluctuations. Both indices were unaffected by sampling effort in terms of number of species and sampling visits; whereas Shannon diversity index (H′) was correlated to species number. Also, based on the randomization test, the taxonomic distinctness indices differentiated lakes anthropogenically disturbed based on the expected patterns of diversity of the area.

     

Metabolically active antigen presenting cells are required for human T cell proliferation in response to the superantigen streptococcal M protein

Abstract M protein from type 5 group A streptococci has been identified as a member of the family of polyclonal T cell activators termed superantigens because it preferentially stimulates T cells bearing specific Vβ elements of the T cell receptor (TCR). In this study the molecular and cellular requirements for presentation of this protein to T cells were investigated. Only accessory cells (AC) expressing class II major histocompatibility complex (MHC) molecules were capable of supporting T cell activation in response to a 22 kDa fragment of M protein (pep M). Despite the need for class II elements, processing of pep M5 by the antigen-presenting cells (APC) was not required for T cell proliferation induced by pep M5. Fixation of APC by paraformaldehyde (PF) treatment impaired their ability to induce optimal T cell proliferation in response to pep M5 withouth significantly affecting interleukin (IL-2) production. In contrast, PF-fixation of cells from the B cell lymphoma line, Raji, did not affect their ability to present pep M5 to human T cells. Addition of rIL-1 and IL-6 to PF-treated APC restored pep M5-induced blastogenesis. Our data suggest that pep M5 directly associates with HLA class II molecules forming a complex that can induce IL-2 production but not optimal proliferation by T cells. Additional signals provided by the AC are required to trigger optimal T cell proliferation in response to this superantigen.     

Immunocytological and Preliminary Immunohistochemical Studies of Prothymosin ��, a Human Cancer�Cassociated Polypeptide, With a Well-characterized Polyclonal Antibody

Prothymosin α (ProTα) is a nuclear polypeptide of great biological and, possibly clinical, importance, because its expression levels have been associated with early diagnosis/prognosis of human cancer. It is therefore interesting to raise easily available and cost-effective antibodies that would be applied to develop reliable ProTα immunodiagnostics. In this study, New Zealand white rabbits and laying hens were parallel immunized against intact ProTα or the synthetic fragments ProTα[1-28], ProTα[87-109], and ProTα[101-109], all conjugated to keyhole limpet hemocyanin (KLH). The corresponding antibodies G and Y were immunochemically evaluated in parallel with ELISA and Western blot systems and applied to fluorescence immunocytology experiments using various cancer cell lines and normal cells. The antibody G raised against ProTα[101-109]/KLH had excellent functional characteristics in the Western blot and immunocytology experiments, where the fluorescent signal was almost exclusively shown in the cell nucleus independently of the cells assayed. The above antibody has been applied to preliminary IHC staining of human cancer prostate tissues, leading to a high percentage of clearly and intensively stained nuclei in the adenocarcinoma tissue; this antibody can be further used in cancer tissue immunostaining and in research concerning the role of ProTα in tumorigenesis. (J Histochem Cytochem 56:1023–1031, 2008)     

Perspective on the Technical Challenges Involved in the Implementation of Array-CGH in Prenatal Diagnostic Testing

Our aim was to construct a streamlined technical workflow to facilitate a prospective, multi-centre evaluation of array comparative genomic hybridisation (array-CGH) in the prenatal diagnostic context. A collection of commercially available DNA extraction and quantification techniques were evaluated and compared using minimal quantities of amniotic fluid, chorionic villi and cultured cells. When prenatal DNA of suitable quality and quantity was obtained, array-CGH was performed using Oxford Gene Technology’s (OGT, Oxford, UK) CytoSure? ISCA 8 × 60 K oligo array platform. With starting quantities of 2–4 ml amniotic fluid, 2–5 mg chorionic villi or under 150,000 cultured cells the following optimised technical workflow was identified: DNA extraction using the iGENatal? kit (igenbiotech, Madrid, Spain) and quantification by the Qubit^® 2.0 Fluorometer with the Qubit^® dsDNA BR assay kit (Invitrogen?, Eugene, OR, USA). In addition, it was elucidated that array-CGH can be successfully performed with as little as 125 ng DNA in the experiment using the OGT CytoSure? ISCA 8 × 60 K oligo array platform. Amidst an on-going debate on whether array-CGH should be applied in the prenatal diagnostic setting, by following the technical recommendations described here genetics laboratories can now gain exposure to prenatal array-CGH testing without compromising the conventional karyotype result.