Assessment of Physical Performance in Adolescents of Varying Body Weight

Fifty-one healthy adolescents of both gender without any neuromuscular, musculoskeletal or cardiopulmonary disorders and between the ages of 12 and 17 with a mean age of 14.09 years (SD: 1.45 years) were recruited to participate in the 6-minute walk test. Several measurements such as height, weight and leg length were taken before testing, along with heart rate, blood pressure and oxygen saturation (SPO2) before, after and 10 minutes post 6-minute walk test. Walk distance was also quantified and used as an outcome measure. The adolescents were divided into two groups prior to statistical testing. The first group was classified as the “normal” weight group (n=41) and were characterized as normal if their body mass index (BMI) percentile was less than 85%. The second group was classified as the “overweight” weight group (n=10) and were characterized as overweight if their body mass index percentile was over 85%. Results from a multivariate regression analysis (OLS) suggest there is a significant, negative relationship between body mass index (BMI) and walk distance when controlling for leg length and age in the sample. The same statistical analysis indicates a significant, positive relationship between leg length and walk distance, controlling for BMI and age. An analysis of variance was performed for this study in order to investigate if there was any significance in change of blood pressure, SPO2 and heart rate over the three trials between the overweight and normal BMI groups. These tests revealed no significance in performance or change in vital sign between the two groups. Based on our results, we conclude that the 6-minute walk test can be used as a reliable assessment of physical fitness in the adolescent population

Replication fork regression in repetitive DNAs

Among several different types of repetitive sequences found in the human genome, this study has examined the telomeric repeat, necessary for the protection of chromosome termini, and the disease-associated triplet repeat (CTG)·(CAG)(n). Evidence suggests that replication of both types of repeats is problematic and that a contributing factor is the repetitive nature of the DNA itself. Here we have used electron microscopy to investigate DNA structures formed at replication forks on large model DNAs containing these repeat sequences, in an attempt to elucidate the contributory effect that these repetitive DNAs may have on their replication. Visualization of the DNA revealed that there is a high propensity for a paused replication fork to spontaneously regress when moving through repetitive DNAs, and that this results in a four-way chickenfoot intermediate that could present a significant block to replication in vivo, possibly leading to unwanted recombination events, amplifications or deletions

A balance between activating and repressive histone modifications regulates cystic fibrosis transmembrane conductance regulator (CFTR ) expression in vivo

International audienceThe genetic mechanisms that regulate CFTR, the gene responsible for cystic fibrosis, have been widely investigated in cultured cells. However, mechanisms responsible for tissue-specific and time-specific expression are not completely elucidated in vivo. Through the survey of public databases, we found that the promoter of CFTR was associated with bivalent chromatin in human embryonic stem (ES) cells. In this work, we analyzed fetal (at different stages of pregnancy) and adult tissues and showed that, in digestive and lung tissues, which expressed CFTR, H3K4me3 was maintained in the promoter. Histone acetylation was high in the promoter and in two intronic enhancers, especially in fetal tissues. In contrast, in blood cells, which did not express CFTR, the bivalent chromatin was resolved (the promoter was labeled by the silencing mark H3K27me3). Cis-regulatory sequences were associated with lowly acetylated histones. We also provide evidence that the tissue-specific expression of CFTR is not regulated by dynamic changes of DNA methylation in the promoter. Overall, this work shows that a balance between activating and repressive histone modifications in the promoter and intronic enhancers results in the fine regulation of CFTR expression during development, thereby ensuring tissue specificity

Misregulation of miR-1 processing is associated with heart defects in myotonic dystrophy

International audienc

Macular dystrophies mimicking age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly population in the Western world. AMD is a clinically heterogeneous disease presenting with drusen, pigmentary changes, geographic atrophy and/or choroidal neovascularization. Due to its heterogeneous presentation, it can be challenging to distinguish AMD from several macular diseases that can mimic the features of AMD. This clinical overlap may potentially lead to misdiagnosis. In this review, we discuss the characteristics of AMD and the macular dystrophies that can mimic AMD. The appropriate use of clinical and genetic analysis can aid the clinician to establish the correct diagnosis, and to provide the patient with the appropriate prognostic information. An overview is presented of overlapping and distinguishing clinical features

Comprehensive genomic characterization of squamous cell lung cancers

Lung squamous cell carcinoma is a common type of lung cancer, causing approximately 400,000 deaths per year worldwide. Genomic alterations in squamous cell lung cancers have not been comprehensively characterized, and no molecularly targeted agents have been specifically developed for its treatment. As part of The Cancer Genome Atlas, here we profile 178 lung squamous cell carcinomas to provide a comprehensive landscape of genomic and epigenomic alterations. We show that the tumour type is characterized by complex genomic alterations, with a mean of 360 exonic mutations, 165 genomic rearrangements, and 323 segments of copy number alteration per tumour. We find statistically recurrent mutations in 11 genes, including mutation of TP53 in nearly all specimens. Previously unreported loss-of-function mutations are seen in the HLA-A class I major histocompatibility gene. Significantly altered pathways included NFE2L2 and KEAP1 in 34%, squamous differentiation genes in 44%, phosphatidylinositol-3-OH kinase pathway genes in 47%, and CDKN2A and RB1 in 72% of tumours. We identified a potential therapeutic target in most tumours, offering new avenues of investigation for the treatment of squamous cell lung cancers.National Institutes of Health (U.S.) (Grant U24 CA126561)National Institutes of Health (U.S.) (Grant U24 CA126551)National Institutes of Health (U.S.) (Grant U24 CA126554)National Institutes of Health (U.S.) (Grant U24 CA126543)National Institutes of Health (U.S.) (Grant U24 CA126546)National Institutes of Health (U.S.) (Grant U24 CA126563)National Institutes of Health (U.S.) (Grant U24 CA126544)National Institutes of Health (U.S.) (Grant U24 CA143845)National Institutes of Health (U.S.) (Grant U24 CA143858)National Institutes of Health (U.S.) (Grant U24 CA144025)National Institutes of Health (U.S.) (Grant U24 CA143882)National Institutes of Health (U.S.) (Grant U24 CA143866)National Institutes of Health (U.S.) (Grant U24 CA143867)National Institutes of Health (U.S.) (Grant U24 CA143848)National Institutes of Health (U.S.) (Grant U24 CA143840)National Institutes of Health (U.S.) (Grant U24 CA143835)National Institutes of Health (U.S.) (Grant U24 CA143799)National Institutes of Health (U.S.) (Grant U24 CA143883)National Institutes of Health (U.S.) (Grant U24 CA143843)National Institutes of Health (U.S.) (Grant U54 HG003067)National Institutes of Health (U.S.) (Grant U54 HG003079)National Institutes of Health (U.S.) (Grant U54 HG003273