The Auxological and Biochemical Continuum of Short Children Born Small for Gestational Age (SGA) or with Normal Birth Size (Idiopathic Short Stature)

Objective. Retrospective single-centre analysis of growth characteristics in 182 healthy short children born small for gestational age (SGA) or appropriate for gestational age (idiopathic short stature, ISS). Methods. Birth size references from the USA and Sweden were compared, and for the classification as SGA or ISS the Swedish reference was chosen. Height, target height (TH), bone age (BA), predicted adult height (PAH), IGF-I and IGFBP-3 values were compared between SGA and ISS. Results. In the combined group, birth weight and length showed a symmetric Gaussian distribution. The American reference overestimates the percentage of short birth length and underestimates that of low birth weight. In childhood, SGA children were shorter than ISS (−3.1 versus −2.6 SDS, P < .001), also in comparison to TH (−2.6 versus −1.9 SDS, P < .001). TH, height SDS change over time, BA delay, and PAH were similar. IGF-I and IGFBP-3 were lower in ISS (P = .03 and .09). Conclusions. SGA children represent the left tail of the Gaussian distribution of birth size in short children. The distinction between SGA and ISS depends on birth size reference. Childhood height of SGA is lower than of ISS, but the other auxological features are similar

Prediction models for short children born small for gestational age (SGA) covering the total growth phase. Analyses based on data from KIGS (Pfizer International Growth Database)

<p>Abstract</p> <p>Background</p> <p>Mathematical models can be developed to predict growth in short children treated with growth hormone (GH). These models can serve to optimize and individualize treatment in terms of height outcomes and costs. The aims of this study were to compile existing prediction models for short children born SGA (SGA), to develop new models and to validate the algorithms.</p> <p>Methods</p> <p>Existing models to predict height velocity (HV) for the first two and the fourth prepubertal years and during total pubertal growth (TPG) on GH were applied to SGA children from the KIGS (Pfizer International Growth Database) - 1^styear: N = 2340; 2^ndyear: N = 1358; 4^thyear: N = 182; TPG: N = 59. A new prediction model was developed for the 3^rdprepubertal year based upon 317 children by means of the all-possible regression approach, using Mallow's C(p) criterion.</p> <p>Results</p> <p>The comparison between the observed and predicted height velocity showed no significant difference when the existing prediction models were applied to new cohorts. A model for predicting HV during the 3^rdyear explained 33% of the variability with an error SD of 1.0 cm/year. The predictors were (in order of importance): HV previous year; chronological age; weight SDS; mid-parent height SDS and GH dose.</p> <p>Conclusions</p> <p>Models to predict growth to GH from prepubertal years to adult height are available for short children born SGA. The models utilize easily accessible predictors and are accurate. The overall explained variability in SGA is relatively low, due to the heterogeneity of the disorder. The models can be used to provide patients with a realistic expectation of treatment, and may help to identify compliance problems or other underlying causes of treatment failure.</p

Anti-Müllerian hormone levels in girls and adolescents with Turner syndrome are related to karyotype, pubertal development and growth hormone treatment

STUDY QUESTION In girls and adolescents with Turner syndrome (TS), is there a correlation between serum AMH levels and karyotype, spontaneous puberty and other biochemical markers of ovarian function, or growth hormone (GH) therapy? SUMMARY ANSWER Serum anti-Müllerian hormone (AMH) correlates with karyotype, pubertal development, LH, FSH and are measurable in a higher percentage of TS patients under GH therapy. WHAT IS KNOWN ALREADY Most girls with TS suffer from incomplete sexual development, premature ovarian failure and infertility due to abnormal ovarian folliculogenesis. Serum AMH levels reflect the ovarian reserve in females, even in childhood. STUDY DESIGN, SIZE, DURATION Cross-sectional study investigating 270 karyotype proven TS patients aged 0-20 years between 2009 and 2010. PARTICIPANTS/MATERIALS, SETTINGS, METHODS Studies were conducted at three University Children's hospitals in Europe. Main outcome measures were clinical data concerning pubertal development as well as laboratory data including karyotype, serum AMH, LH, FSH, estradiol (E2), inhibin B and IGF. RESULTS AND THE ROLE OF CHANCE Serum AMH was detectable in 21.9% of all TS girls and correlated strongly with karyotypes. A measurable serum AMH was found in 77% of TS girls with karyotype 45,X/46,XX, in 25% with ‘other' karyotypes and in only 10% of 45,X TS girls. A strong relationship was also observed for measurable serum AMH and signs of spontaneous puberty such as breast development [adjusted odds ratio (OR) 19.3; 95% CI 2.1-175.6; P = 0.009] and menarche (crude OR 47.6; 95% CI 4.8-472.9; P = 0.001). Serum AMH correlated negatively with FSH and LH, but did not correlate with E2 and inhibin B. GH therapy increased the odds of having measurable AMH in TS (adjusted OR 4.1; 95% CI 1.9-8.8; P < 0.001). LIMITATIONS, REASONS FOR CAUTION The cross-sectional design of the study does not allow longitudinal interpretation of the data; for that further studies are needed. High percentage of non-measurable AMH levels in the cohort of TS require categorized analysis. WIDER IMPLICATIONS OF THE FINDINGS Serum AMH levels are a useful marker of the follicle pool and thus ovarian function in pediatric patients with TS. These findings are in line with the published literature. The finding that GH therapy may affect AMH levels is novel, but must be confirmed by future longitudinal studie

Влияние масштабного фактора на параметры механоэлектрических преобразований в железобетонных балках в условиях изгиба

В данной работе проведены исследования железобетонных изделий разного размера в процессе непрерывного испытания в условиях четырехточечного изгиба. Был проведен сравнительный анализ изменения максимального коэффициента взаимной корреляции спектра электрического сигнала от величины приложенной нагрузки и показано влияние размера изделия на параметры электрического отклика.In the thesis studies of reinforced concrete products of different sizes during the process of continuous testing under conditions of four-point bending were carried out. A comparative analysis of the change in the maximum cross-correlation coefficient of the electric signal spectrum versus the applied load was made, and the influence of the product size on the electric response parameters was shown

Электроимпульсный пробой и разрушение горных пород и твердых диэлектриков при воздействии разнополярных импульсов напряжения

Исследования электрической прочности внедрения канала разряда в горные породы при одновременном воздействии разнополярных импульсах высокого напряжения.In the dielectric displacement course in an electric field become two phenomena groups apparent. The first group is peculiar for dialectic only. The internal charged particles will always exist if the dielectric is placed in an electric field. Hence, the opposite electric charges will be shifted in relation to each other