Maternal exposure to UV filters:Associations with maternal thyroid hormones, IGF-I/IGFBP3 and birth outcomes

Background: Several chemical UV filters/absorbers ('UV filters' hereafter) have endocrine-disrupting properties in vitro and in vivo. Exposure to these chemicals, especially during prenatal development, is of concern. Objectives: To examine maternal exposure to UV filters, associations with maternal thyroid hormone, with growth factor concentrations as well as to birth outcomes. Methods: Prospective study of 183 pregnant women with 2nd trimester serum and urine samples available. Maternal concentrations of the chemical UV filters benzophenone-1 (BP-1) and benzophenone-3 (BP-3) in urine and 4-hydroxy-benzophenone (4-HBP) in serum were measured by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The relationships between 2nd trimester maternal concentrations of the three chemical UV filters and maternal serum concentrations of thyroid hormones and growth factors, as well as birth outcomes (weight, height, and head and abdominal circumferences) were examined. Results: Positive associations between maternal serum concentrations of 4-HBP and triiodothyronine (T3), thyroxine (T4), insulin-like growth factor I (IGF-I) and its binding protein IGFBP3 were observed in mothers carrying male fetuses. Male infants of mothers in the middle 4-HBP exposure group had statistically significantly lower weight and shorter head and abdominal circumferences at birth compared to the low exposure group. Conclusions: Widespread exposure of pregnant women to chemical UV filters and the possible impact on maternal thyroid hormones and growth factors, and on fetal growth, calls for further studies on possible long-term consequences of the exposure to UV filters on fetal development and children’s health

Real-time detection of TDP1 activity using a fluorophore-quencher coupled DNA-biosensor

Real-time detection of enzyme activities may present the easiest and most reliable way of obtaining quantitative analyses in biological samples. We present a new DNA-biosensor capable of detecting the activity of the potential anticancer drug target tyrosyl-DNA phosphodiesterase 1 (TDP1) in a very simple, high throughput, and real-time format. The biosensor is specific for Tdp1 even in complex biological samples, such as human cell extracts, and may consequently find future use in fundamental studies as well as a cancer predictive tool allowing fast analyses of diagnostic cell samples such as biopsies. TDP1 removes covalent 3'DNA adducts in DNA single-strand break repair. This enzymatic activity forms the basis of the design of the TDP1-biosensor, which consists of a short hairpin-forming oligonucleotide having a 5'fluorophore and a 3'quencher brought in close proximity by the secondary structure of the biosensor. The specific action of TDP1 removes the quencher, thereby enabling optical detection of the fluorophore. Since the enzymatic action of TDP1 is the only "signal amplification" the increase in fluorescence may easily be followed in real-time and allows quantitative analyses of TDP1 activity in pure enzyme fractions as well as in crude cell extracts. In the present study we demonstrate the specificity of the biosensor, its ability to quantitatively detect up- or down-regulated TDP1 activity, and that it may be used for measuring and for analyzing the mechanism of TDP1 inhibition

Feasibility of a standardized ultrasound examination in patients with rheumatoid arthritis: A quality improvement among rheumatologists cohort.

BACKGROUND: Quality improvement is important to facilitate valid patient outcomes. Standardized examination procedures may improve the validity of US. The aim of this study was to investigate the learning progress for rheumatologists during training of US examination of the hand in patients with rheumatoid arthritis (RA). METHODS: Rheumatologists with varying degrees of experience in US were instructed by skilled tutors. The program consisted of two days with hands-on training followed by personal US examinations performed in their individual clinics. Examinations were sent to the tutors for quality control. The US examinations were evaluated according to a scoring sheet containing 144 items. An acceptable examination was defined as > 80% correct scores. RESULTS: Thirteen rheumatologists participated in the study. They included a total of 104 patients with RA. Only few of the initial examinations were scored below 80%, and as experience increased, the scores improved (p = 0.0004). A few participants displayed decreasing scores. The mean time spent performing the standardized examination procedure decreased from 34 min to less than 10 minutes (p = 0.0001). CONCLUSION: With systematic hands-on training, a rheumatologist can achieve a high level of proficiency in the conduction of US examinations of the joints of the hand in patients with RA. With experience, examination time decreases, while the level of correctness is maintained. The results indicate that US may be applied as a valid measurement tool suitable for clinical practice and in both single- and multi-centre trials

High export of dissolved silica from the Greenland Ice Sheet

Silica is an essential element for marine life and plays a key role in the biogeochemistry of the ocean. Glacial activity stimulates rock weathering, generating dissolved silica that is exported to coastal areas along with meltwater. The magnitude of the dissolved silica export from large glacial areas such as the Greenland Ice Sheet is presently poorly quantified and not accounted for in global budgets. Here we present data from two fjord systems adjacent to the Greenland Ice Sheet which reveal a large export of dissolved silica by glacial meltwater relative to other macronutrients. Upscaled to the entire Greenland Ice Sheet, the export of dissolved silica equals 22 ± 10 Gmol Si yr−1. When the silicate-rich meltwater mixes with upwelled deep water, either inside or outside Greenland's fjords, primary production takes place at increased silicate to nitrate ratios. This likely stimulates the growth of diatoms relative to other phytoplankton groups