116 research outputs found
Long-term effectiveness of growth hormone therapy in children born small for gestational age: An analysis of LG growth study data
PURPOSE: Growth hormone (GH) treatment has been used to improve growth in short children who were born small for gestational age (SGA). The aim of this study was to investigate the long-term efficacy of GH treatment in these children. METHODS: Data from a multicenter observational clinical trial (ClinicalTrials.gov NCT01604395, LG growth study) were analyzed for growth outcome and prediction model in response to GH treatment. One hundred fifty-two children born SGA were included. RESULTS: The mean age of patients born SGA was 7.13 +/- 2.59 years. Height standard deviation score (SDS) in patients born SGA increased from -2.55 +/- 0.49 before starting treatment to -1.13 +/- 0.76 after 3 years of GH treatment. Of the 152 patients with SGA, 48 who remained prepubertal during treatment used model development. The equation describing the predicted height velocity during 1st year of GH treatment is as follows: the predictive height velocity (cm) = 10.95 + [1.12 x Height SDS at initial treatment (score)] + [0.03 x GH dose (ug/kg/day)] + [0.30 x TH SDS at initial treatment (score)] + [0.05 x age (year)] + [0.15 x Weight SDS at initial treatment (score)] +/- 1.51 cm. CONCLUSIONS: GH treatment improved growth outcome in short children born SGA. We also developed a prediction model that is potentially useful in determining the optimal growth outcome for each child born SGA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01604395
Structural hierarchies define toughness and defect-tolerance despite simple and mechanically inferior brittle building blocks
Mineralized biological materials such as bone, sea sponges or diatoms provide load-bearing and armor functions and universally feature structural hierarchies from nano to macro. Here we report a systematic investigation of the effect of hierarchical structures on toughness and defect-tolerance based on a single and mechanically inferior brittle base material, silica, using a bottom-up approach rooted in atomistic modeling. Our analysis reveals drastic changes in the material crack-propagation resistance (R-curve) solely due to the introduction of hierarchical structures that also result in a vastly increased toughness and defect-tolerance, enabling stable crack propagation over an extensive range of crack sizes. Over a range of up to four hierarchy levels, we find an exponential increase in the defect-tolerance approaching hundred micrometers without introducing additional mechanisms or materials. This presents a significant departure from the defect-tolerance of the base material, silica, which is brittle and highly sensitive even to extremely small nanometer-scale defects
Factors influencing growth hormone therapy effect during the prepubertal period in small for gestational age children without catch-up growth
Purpose: Because small for gestational age (SGA) children who fail to experience catch-up growth have an increased risk of short stature in adulthood, growth hormone (GH) treatment is recommended for effective growth. In this study, we evaluated the effect of GH treatment during the prepubertal period and analyzed for correlation between GH treatment response and clinical factors in SGA children. Methods: A retrospective, single-center study was conducted from 2014 to 2020. A total of 34 prepubertal children of short stature up to 4 years of age and born as SGA were enrolled. We recorded clinical data including birth data, age, weight, height, bone age (BA), and insulin-like growth factor 1 (IGF-1) levels. Results: The mean gestational age and birth weight were 37.50±2.51 weeks and 2,200.00±546.79 g. At the start of GH treatment, the mean chronological age and BA were 5.54±1.73 years and 4.52±1.85 years, respectively. The height standard deviation score (SDS) (-2.47±0.45) and IGF-1 SDS (0.16±1.57) were calculated. Height velocity was 9.43±1.40 cm during the first GH treatment year and 7.63±1.16 cm during the second year (P<0.05). The treatment growth response was positively correlated with young age (P=0.047) and lower BA (P=0.049) at the start of treatment. In multiple regression analysis, IGF-1 SDS change had a significantly positive association with GH treatment response (P=0.045). Conclusion: GH treatment is effective for short stature SGA children who do not experience catch-up growth. Early initiation of GH treatment improved growth outcomes. As IGF-1 SDS is positively correlated with height SDS, IGF-1 monitoring is important during GH treatment of SGA prepubertal children
Cosmic rays and molecular clouds
This paper deals with the cosmic-ray penetration into molecular clouds and
with the related gamma--ray emission. High energy cosmic rays interact with the
dense gas and produce neutral pions which in turn decay into two gamma rays.
This makes molecular clouds potential sources of gamma rays, especially if they
are located in the vicinity of a powerful accelerator that injects cosmic rays
in the interstellar medium. The amplitude and duration in time of the
cosmic--ray overdensity around a given source depend on how quickly cosmic rays
diffuse in the turbulent galactic magnetic field. For these reasons, gamma-ray
observations of molecular clouds can be used both to locate the sources of
cosmic rays and to constrain the properties of cosmic-ray diffusion in the
Galaxy.Comment: To appear in the proceedings of the San Cugat Forum on Astrophysics
2012, 27 pages, 10 figure
Comparison of the clinical characteristics and outcomes of pediatric patients with and without diabetic ketoacidosis at the time of type 1 diabetes diagnosis
PURPOSE: We investigated the possible effects of diabetic ketoacidosis (DKA) at the initial diagnosis of type 1 diabetes mellitus (T1DM) on the clinical outcomes of pediatric patients. METHODS: Medical records of children and adolescents with newly diagnosed T1DM seen in the Ajou University Hospital from January 2008 to August 2020 were reviewed and analyzed. RESULTS: Among 129 diagnosed T1DM patients, 40.3% presented with DKA. Although demographic and basic characteristics did not differ between DKA and non-DKA patients, DKA patients needed a significantly higher insulin dosage than non-DKA patients for 2 years after diagnosis. However, control of glycated hemoglobin was not different between the DKA and non-DKA groups during the observation period. In the biochemical analysis, C-peptide, insulin-like growth factor-1, and insulin-like growth factor binding protein 3, high-density lipoprotein cholesterol, free T4, and T3 values were lower, but thyroid-stimulating hormone, initial serum glucose, uric acid, total cholesterol, triglyceride, and low-density lipoprotein cholesterol values were higher in DKA patients than non-DKA patients at the diagnosis of T1DM; however, these differences were temporarily present and disappeared with insulin treatment. Other clinical outcomes, such as height, thyroid function, and urine microalbumin level, did not vary significantly between the DKA and non-DKA groups during 5 years of follow-up. CONCLUSION: DKA at initial presentation reflects the severity of disease progression, and the deleterious effects of DKA seem to impact insulin secretion. Although no difference in long-term prognosis was found, early detection of T1DM should help to reduce DKA-related islet damage and the socioeconomic burden of T1DM
Effectiveness of growth hormone therapy in children with Noonan syndrome
PURPOSE: Recombinant human growth hormone (rhGH) has been used to improve growth in children with Noonan syndrome (NS). This study aimed to investigate the efficacy of rhGH therapy in Korean children with NS. METHODS: Seventeen prepubertal children (10 boys, 7 girls) with NS who received rhGH therapy for at least 3 years between 2008 and 2017 were included. To compare the response, age- and sex-matched children with GH deficiency (GHD; n=31) were included. Height and growth velocity before and during treatment were analyzed. RESULTS: The mean age of NS patients was 6.34+/-2.32 years. After treatment, the height standard deviation score (SDS) increased from -2.93+/-0.81 to -1.51+/-1.00 in patients with NS and from -2.45+/-0.42 to -1.09+/-0.47 in patients with GHD. There were no significant differences in growth velocity or change in height SDS between patients with NS and GHD. Growth velocity in the first year of treatment was higher in patients with PTPN11 mutations than those without PTPN11 mutations, but the change in height SDS was not significantly different between those 2 groups. CONCLUSION: rhGH therapy can increase linear growth in prepubertal children with NS. The growth response between patients with NS and patients with GHD was not significantly different. Furthermore, we observed that lower doses of growth hormone have a similar effect on height compared to previous studies in patients with NS. Our study indicates that rhGH treatment is useful for growth promotion
Long-term outcomes of Graves’ disease in children and adolescents receiving antithyroid drugs
Purpose: Antithyroid drugs (ATDs) are primarily used as an initial treatment in pediatric patients with Graves’ disease (GD). We aimed to investigate the long-term outcomes in pediatric GD patients receiving ATDs. Methods: Retrospective data from a single center were collected from April 2003 to July 2020. A total of 98 children and adolescents aged 2–16 years diagnosed with GD and receiving ATDs was enrolled. We investigated the factors correlated with remission by comparing children who achieved remission after 5 years and those with persistent disease. Results: The study included 76 girls (77.6%) and 22 boys (22.4%). During the 5-year follow-up period, 18 children (18.3%) maintained remission, ATDs could not be discontinued in 74 patients (75.5%), and relapse occurred in 6 patients (6.2%). The remission group had significantly lower thyroid-stimulating hormone-binding inhibitory immunoglobulin (TBII) level at diagnosis (P=0.002) and 3 months (P=0.002), 1 year (P=0.002), 2 years (P≤0.001), 3 years (P≤0.001), 4 years (P≤0.001), and 5 years (P≤0.001) after ATD treatment than did the nonremission group. The remission group also had a shorter time for TBII normalization after ATD treatment (P≤0.001). Multiple logistic regression analysis showed that the time to TBII normalization (cutoff time=2.35 years) was related to GD remission (odds ratio, 0.596; 95% confidence interval, 0.374–0.951). Conclusion: TBII level and time to TBII normalization after ATD treatment can be used to predict remission in pediatric GD patients
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Eukaryote DIRS1-like retrotransposons: an overview
<p>Abstract</p> <p>Background</p> <p>DIRS1-like elements compose one superfamily of tyrosine recombinase-encoding retrotransposons. They have been previously reported in only a few diverse eukaryote species, describing a patchy distribution, and little is known about their origin and dynamics. Recently, we have shown that these retrotransposons are common among decapods, which calls into question the distribution of DIRS1-like retrotransposons among eukaryotes.</p> <p>Results</p> <p>To determine the distribution of DIRS1-like retrotransposons, we developed a new computational tool, ReDoSt, which allows us to identify well-conserved DIRS1-like elements. By screening 274 completely sequenced genomes, we identified more than 4000 DIRS1-like copies distributed among 30 diverse species which can be clustered into roughly 300 families. While the diversity in most species appears restricted to a low copy number, a few bursts of transposition are strongly suggested in certain species, such as <it>Danio rerio </it>and <it>Saccoglossus kowalevskii</it>.</p> <p>Conclusion</p> <p>In this study, we report 14 new species and 8 new higher taxa that were not previously known to harbor DIRS1-like retrotransposons. Now reported in 61 species, these elements appear widely distributed among eukaryotes, even if they remain undetected in streptophytes and mammals. Especially in unikonts, a broad range of taxa from Cnidaria to Sauropsida harbors such elements. Both the distribution and the similarities between the DIRS1-like element phylogeny and conventional phylogenies of the host species suggest that DIRS1-like retrotransposons emerged early during the radiation of eukaryotes.</p
Targeting the epigenome: effects of epigenetic treatment strategies on genomic stability in healthy human cells
Epigenetic treatment concepts have long been ascribed as being tumour-selective. Over the last decade, it has become evident that epigenetic mechanisms are essential for a wide range of intracellular functions in healthy cells as well. Evaluation of possible side-effects and their underlying mechanisms in healthy human cells is necessary in order to improve not only patient safety, but also to support future drug development. Since epigenetic regulation directly interacts with genomic and chromosomal packaging density, increasing genomic instability may be a result subsequent to drug-induced epigenetic modifications. This review highlights past and current research efforts on the influence of epigenetic modification on genomic stability in healthy human cells
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