Monitoring serum insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and leptin during growth hormone treatment for disordered growth

OBJECTIVE: Serum IGF-I levels are monitored during GH replacement treatment in adults with GH defi- ciency (GHD) to guide GH dose adjustment and to minimize occurrence of GH-related side-effects. This is not routine practice in children treated with GH. The aim of this study was to evaluate changes in (1) serum IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio, and (2) serum leptin, an indirect marker of GH response, during the first year of GH treatment in children with disordered growth. DESIGN: An observational prospective longitudinal study with serial measurements at five time points during the first year of GH treatment was carried out. Each patient served as his/her own control. PATIENTS The study included 31 patients, grouped as (1) GHD (n=20) and (2) non-GHD (Turner syndrome n=7; Noonan syndrome n=4), who had not previously received GH treatment. MEASUREMENTS: Serum IGF-I, IGFBP-3 and leptin levels were measured before treatment and after 6 weeks, 3 months, 6 months and 12 months of GH treatment, with a mean dose of 0.5 IU/kg/wk in GHD and 0.7 IU/kg/wk in non-GHD groups. IGF-I, IGFBP-3 and the calculated IGF-I/IGFBP-3 molar ratio were expressed as SD scores using reference values from the local population. RESULTS: In the GHD group, IGF-I SDS before treatment was lower compared with the non-GHD (-5.4 ± 2.5 vs. -1.8 ± 1.0; P < 0.001). IGF-I (-1.8 SDS ± 2.2) and IGFBP-3 (-1.1 SDS ± 0.6) levels and their molar ratios were highest at 6 weeks and remained relatively constant thereafter. In the non-GHD group, IGF-I levels increased throughout the year and were maximum at 12 months (0.3 SDS ± 1.4) while IGFBP-3 (1.1 SDS ± 0.9) and IGF-I/IGFBP-3 molar ratio peaked at 6 months. In both groups, IGF-I SDS and IGF-I/IGFBP-3 during treatment correlated with the dose of GH expressed as IU/m2/week (r-values 0.77 to 0.89; P = 0.005) but not as IU/kg/week. Serum leptin levels decreased significantly during GH treatment in the GHD (median before treatment 4.0 g/l; median after 12 months treatment 2.4 g/l; P = 0.02) but not the non-GHD (median before treatment 3.0 g/l; median after 12 months treatment 2.6 g/l). In the GHD group, serum leptin before treatment correlated with 12 month change in height SDS (r = 0.70, P = 0.02). CONCLUSIONS: The pattern of IGF-I, IGFBP-3 and their molar ratio during the first year of GH treatment differed between the GHD and non-GHD groups. Calculation of GH dose by surface area may be preferable to calculating by body weight. As a GH dose-dependent increase in serum IGF-I and IGF-I/IGFBP-3 may be associated with adverse effects, serum IGF-I and IGFBP-3 should be monitored routinely during longterm GH treatment. Serum leptin was the only variable that correlated with first year growth response in GHD

The role of histone arginine methylation in gene expression of airway smooth muscle cells in asthma

Introduction and objectives: Asthma is estimated to affect at least 300 million people globally. About 25% of the patients do not respond to therapy; therefore we need to develop novel treatments. ASM cells have a crucial role in asthma, contributing to airway remodelling, inflammation and airflow obstruction. We have previously shown that epigenetic histone modifications, particularly histone lysine acetylation and methylation regulate the secretion of inflammatory mediators from ASM cells. Here we tested the hypothesis that histone arginine changes are also involved. Protein arginine N-methyltransferases (PRMTs) are the enzymes which catalyse histone arginine methylation (HRme, the addition of a methyl group to arginine residues on the N-terminal tails of histones), and inhibiting them represents a strategy to reduce the secretion of inflammatory mediators from ASM cells. Methods: Studies were performed in cultured human ASM cells from asthmatic and non-asthmatic donors at passage 6. PRMT expression in human ASM cells was investigated by qPCR. Protein levels of four PRMTs in human ASM cells were investigated by western blotting. The effect of inhibiting PRMTs on the secretion of eotaxin, IL-6, CXCL8 and IP-10 from healthy ASM cells, under basal conditions and following stimulation with TNF-α (1ng/ml), was investigated by ELISA. Results: We found that ASM cells express the PRMT1, PRMT2, PRMT3, CARM1, PRMT5, PRMT6, PRMT7 and FBX011 mRNA and PRMT1, CARM1, PRMT5, and PRMT6 protein. The analysis showed no difference in the levels of expression between cells isolated from asthmatic and non-asthmatic donors. Two PRMT inhibitors, namely TCE5003 – a PRMT1 inhibitor, and 217531 - a CARM1 inhibitor, significantly reduced the secretion of inflammatory mediators from ASM cells. Conclusions: ASM cells express a number of PRMTs at mRNA and protein levels. The inhibition of PRMTs results in the reduced secretion of inflammatory mediators from ASM cells. PRMTs may have an important role in regulating chemokine production from ASM cells in asthma, and are a promising target for future investigations in asthma

Investigating genome wide dna methylation in airway smooth muscle cells from asthmatic and non-asthmatic donors

Rationale: Genetic mechanisms fail to fully explain asthma pathogenesis and environmental factors are considered to play an important role. Environmental factors may lead to permanent changes in epigenetic patterns and contribute to asthma. Epigenetics is the study of heritable changes in gene expression that are not due to changes in DNA sequence. DNA methylation is a reversible modification of DNA structure in which a methyl group is added to cytosine residues. Parental smoking affects the methylation of buccal cell DNA from children and children with early onset wheeze have an altered blood DNA methylation profile to healthy individuals. No studies have compared DNA methylation profiles in the disease relevant cell type of airway smooth muscle (ASM) cells. Methods: DNA was isolated from ASM cells at passage 5 and bisulphite treated to convert epigenetic information into sequence-based information. Site specific, quantitative genome wide methylation was determined using the Illumina 450K Infinium Methylation BeadChip array. Hits were validated by Pyrosequencing. RNA was extracted simultaneously for mRNA expression analysis by real time PCR. Results: There were no independent CpG sites associated with asthmatic status of ASM cells following multiple test correction. Without correction over 13000 CpG sites showed a significant difference in methylation (linear modelling, p value >0.05) between asthmatic and non-asthmatic cells, and a biologically relevant difference in methylation of greater that 10% (β value >0.1 ). 10 of these sites were selected as top hits. 7 sites positively validated by pyrosequencing. They were associated with 7 different genes; LGALS3BP, ATP11A, ZNF696, KLF6, TBX1, RUNX3, and SPINT2. Expression of these genes was measured in ASM cells isolated from asthmatic and non-asthmatic donors. LGALS3BP expression was undetectable while ATP11A and ZNF696 displayed no difference in expression between cells from asthmatic and non-asthmatic donors. KLF6 and SPINT2 showed a trend towards increased expression in cells from asthmatic donors while RUNX3 and TBX1 showed a trend towards decreased expression. Conclusions: Differences in CpG methylation exist between ASM isolated from asthmatic and non-asthmatic donors. Future work will focus on identifying differentially methylated regions of DNA and further defining the association to gene and protein expression

Internet Addiction and Its Correlates among College Students of Surat City: A Cross Sectional Study

Introduction: The number of internet users in 2018 was 4.021 billion, increased 7 percent year-on-year. More than nine-tenths of Indian teens use Internet. Due to social distancing norms put forward due to COVID-19 dependency and availability of Internet usage has increased.Objective: To assess the extent of Internet addiction and determine its predictors among college students of Surat city. Method: A cross sectional study was conducted from March-September 2021 among 400 first- and second-year students selected by systematic random sampling from four colleges selected purposively. Outcome variables were Young’s Internet addiction Test and Duke Health Profile Score which were assessed in terms of mean score. Univariate analysis was done, followed by t-test, ANOVA and Pearson Correlation to establish associations. Predictors were determined by Binary Logistic Regression.Results: Around one-tenth (12.8%) participants were seen with no Internet addiction, with majority being mildly (44.8%) and moderately (36.5%) addicted. Severe addiction was seen in around one out of twenty participants (6.1%). Social networking (32%) and education (34.5%) were the major reasons for use of Internet. Higher pocket money (aOR=4.3), greater monthly internet expenditure (aOR=2.8), ownership of internet enabled mobile phone (aOR=3.9), lying down posture while accessing internet (aOR=4.8) and evening (aOR=2.2) or night time (aOR=8.7) of internet access were significant predictors for Internet addicts. Conclusion: In this study more than four fifth of the college students had Internet Addiction even at young age. Physical, Mental, Social and General health were significantly negatively correlated with internet addiction

Charge dynamics through pi-stacked arrays of conjugated molecules: effect of dynamic disorder in different transport/transfer regimes

We provide further computational evidence that the electronic coupling between pi-stacked molecules is strongly modulated by the thermal motions at room temperature, not only in supramolecular flexible systems (like DNA) but also in molecular crystals. The effect of this modulation on the charge dynamics is different for different transfer/transport mechanisms and depends on the modulation timescale. In the case of charge transfer (CT) between a donor and an acceptor, the effect of electronic coupling fluctuations introduces a corrective term in the expression of the rate constant (different for adiabatic and non-adiabatic CT). For the transport in molecular crystals, this fluctuation can be the limiting factor for the charge mobility. Although the fluctuation of the electronic coupling is similar in magnitude for all systems containing molecular pi-stacking, its importance for the charge dynamics increases with the decrease of the reorganization energy

Resonant transmission through an open quantum dot

We have measured the low-temperature transport properties of a quantum dot formed in a one-dimensional channel. In zero magnetic field this device shows quantized ballistic conductance plateaus with resonant tunneling peaks in each transition region between plateaus. Studies of this structure as a function of applied perpendicular magnetic field and source-drain bias indicate that resonant structure deriving from tightly bound states is split by Coulomb charging at zero magnetic field.Comment: To be published in Phys. Rev. B (1997). 8 LaTex pages with 5 figure