1,601 research outputs found
Separating within and between effects in family studies: an application to the study of blood pressure in children.
In epidemiology the analyses of family or twin studies do not always fully exploit the data, as information on differences between siblings is often used while between-families effect are not considered. We show how cross-sectional time-series linear regression analysis can be easily implemented to estimate within- and between-families effects simultaneously and how these effects can then be compared using the Hausman test. We illustrate this approach with data from the Uppsala family study on blood pressure in children with age ranging from 5.5 to 12.3 years for the younger and from 7.5 to 13.8 years for the older siblings. Comparing the effect of differences in birth weight on blood pressure within-family (in full siblings) and between-families (in unrelated children) allows us to study the contributions of fixed and pregnancy-specific maternal effects on birth weight and consequently on blood pressure. Our data showed a 0.88 mmHg decrease (95 per cent confidence interval: -1.7 to -0.03 mmHg) in systolic blood pressure for one standard deviation increase in birth weight between siblings within a family and 0.88 mmHg (95 per cent confidence interval: -1.6 to -0.2 mmHg) decrease in systolic blood pressure for one standard deviation increase in birth weight between unrelated children. These estimates were controlled for sex, age, pubertal stage, body size and pulse rate of the children at examination and for maternal body size and systolic blood pressure. The within- and between-families effects were not significantly different, p = 0.19, suggesting that fixed and pregnancy-specific factors have similar effects on childhood systolic blood pressure
Radially Extended Kinematics in the S0 Galaxy NGC 2768 from Planetary Nebulae, Globular Clusters and Starlight
There are only a few tracers available to probe the kinematics of individual
early-type galaxies beyond one effective radius. Here we directly compare a
sample of planetary nebulae (PNe), globular clusters (GCs) and galaxy starlight
velocities out to ~4 effective radii, in the S0 galaxy NGC 2768. Using a
bulge-to-disk decomposition of a K-band image we assign PNe and starlight to
either the disk or the bulge. We show that the bulge PNe and bulge starlight
follow the same radial density distribution as the red subpopulation of GCs,
whereas the disk PNe and disk starlight are distinct components. We find good
kinematic agreement between the three tracers to several effective radii (and
with stellar data in the inner regions). Further support for the distinct
nature of the two galaxy components come from our kinematic analysis. After
separating the tracers into bulge and disk components we find the bulge to be a
slowly rotating pressure-supported system, whereas the disk reveals a rapidly
rising rotation curve with a declining velocity dispersion profile. The
resulting V/sigma ratio for the disk resembles that of a spiral galaxy and
hints at an origin for NGC 2768 as a transformed late-type galaxy. A
two-component kinematic analysis for a sample of S0s will help to elucidate the
nature of this class of galaxy.Comment: 10 pages, 5 figures, accepted for publication in MRA
Imaging of the Merging Galaxy NGC 3597 and its Population of Proto--Globular Clusters
We present wide field-of-view near-infrared imaging from the NTT and very
deep optical imaging from the HST of the young merging galaxy NGC 3597. The
morphology of the galaxy and the properties of the newly formed proto-globular
clusters (PGCs) are examined. Our K band data reveals the presence of a second
nucleus, which provides further evidence that NGC 3597 is the result of a
recent merger. Combining new K band photometry with optical photometry, we are
able for the first time to derive a unique age for the newly formed PGCs of a
few Myrs. This is consistent with the galaxy starburst age of < 10 Myrs. From
deep HST imaging, we are able to probe the luminosity function ~8 magnitudes
fainter than normal, old globular clusters, and confirm that the PGCs have a
power-law distribution with a slope of ~-2.Comment: 19 pages, Latex, 10 figures, 4 tables, accepted by MNRA
Welfare in horse breeding
Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how positive welfare effects associated with breeding might be maximised. Further studies are needed to establish an evidence base about how stressful or painful various breeding procedures are for the animals involved, and what the lifetime welfare implications of ARTs are for future animal generations
Models predicting the growth response to growth hormone treatment in short children independent of GH status, birth size and gestational age
<p>Abstract</p> <p>Background</p> <p>Mathematical models can be used to predict individual growth responses to growth hormone (GH) therapy. The aim of this study was to construct and validate high-precision models to predict the growth response to GH treatment of short children, independent of their GH status, birth size and gestational age. As the GH doses are included, these models can be used to individualize treatment.</p> <p>Methods</p> <p>Growth data from 415 short prepubertal children were used to construct models for predicting the growth response during the first years of GH therapy. The performance of the models was validated with data from a separate cohort of 112 children using the same inclusion criteria.</p> <p>Results</p> <p>Using only auxological data, the model had a standard error of the residuals (SD<sub>res</sub>), of 0.23 SDS. The model was improved when endocrine data (GH<sub>max </sub>profile, IGF-I and leptin) collected before starting GH treatment were included. Inclusion of these data resulted in a decrease of the SD<sub>res </sub>to 0.15 SDS (corresponding to 1.1 cm in a 3-year-old child and 1.6 cm in a 7-year old). Validation of these models with a separate cohort, showed similar SD<sub>res </sub>for both types of models. Preterm children were not included in the Model group, but predictions for this group were within the expected range.</p> <p>Conclusion</p> <p>These prediction models can with high accuracy be used to identify short children who will benefit from GH treatment. They are clinically useful as they are constructed using data from short children with a broad range of GH secretory status, birth size and gestational age.</p
Insufficient weight at birth and preschool-age growth in children attending charitably funded crèches in the municipality of Santo André , in the State of São Paulo , Brazil
OBJETIVOS: comparar o crescimento alcançado e a prevalência de baixa estatura na idade pré-escolar entre recém-nascidos de peso insuficiente (PNI) e de peso adequado (PNA). MÉTODOS: foram estudadas 323 crianças com PNI e 886 com PNA de famílias de baixa renda de quinze creches filantrópicas de Santo André, São Paulo, Brasil, em 2001 e 2002. As variáveis foram o escore Z de peso e de estatura para a idade, pelo referencial Center for Disease Control (CDC) and National Center for Health Statistics (NCHS) 2000, comparando-se as médias dos dois grupos. Calculou-se a razão de prevalência (RP) de baixa estatura na idade pré-escolar em decorrência do peso insuficiente ao nascer. RESULTADOS: o escore z médio de peso foi -0,09 e 0,39 e o escore z médio de estatura foi de -0,06 e de 0,24 para as crianças de PNI e de PNA, respectivamente. A prevalência de baixa estatura foi de 2,78% para as crianças com PNI e de 0,79% para aquelas com PNA. A RP de baixa estatura na idade pré-escolar para as crianças de PNI foi de 3,5 (IC95% 1,3-9,4). CONCLUSÕES: as crianças com PNI apresentaram crescimento inferior e maior risco de falhas de crescimento até a idade pré-escolar, sugerindo um efeito negativo do peso insuficiente ao nascer sobre o crescimento infantil.OBJECTIVES: to compare rate of growth and prevalence of low stature at preschool age in children who were underweight at birth and in children born with a normal weight. METHODS: the study covered 323 children born underweight and 886 born with a normal weight from low-income families in fifteen charitably funded crèches in the municipality of Santo André, in the State of São Paulo, Brazil, in 2001 and 2002. The variables used were the z score for weight and height for age, using the Center for Disease Control (CDC) and National Center for Health Statistics (NCHS) 2000 benchmark, comparing the means for the two groups. The prevalence ratio was calculated for low stature in preschool age children resulting from insufficient weight at birth. RESULTS: the z score for weight was -0.09 and 0.39 and the average z score for height was -0.06 and 0.24 for underweight and normal weight at birth, respectively. The prevalence of low stature was 2.78% for children born underweight and 0.79% for normal weight. The PR for low stature at preschool age for children born underweight was 3.5 (CI95% 1.3-9.4). CONCLUSIONS: children born underweight had a lower rate of growth and greater risk of developing a growth disorder up to preschool age, suggesting a negative effect of insufficient birth weight on child growth
Proteins related to lipoprotein profile were identified using a pharmaco-proteomic approach as markers for growth response to growth hormone (GH) treatment in short prepubertal children
<p>Abstract</p> <p>Background</p> <p>The broad range in growth observed in response to growth hormone (GH) treatment is mainly caused by individual variations in both GH secretion and GH sensitivity. Individual GH responsiveness can be estimated using evidence-based models that predict the response to GH treatment; however, these models can be improved. High-throughput proteomics techniques can be used to identify proteins that may potentially be used as variables in such models in order to improve their predictive ability. Previously we have reported that proteomic analyses can identify biomarkers that discriminate between short prepubertal children with idiopathic short stature (ISS) who show good or poor growth in response to GH treatment. In this study we used a pharmaco-proteomic approach to identify novel factors that correlate with the growth response to GH treatment in prepubertal children who are short due to GH deficiency or ISS. The study included 128 short prepubertal children receiving GH treatment, of whom 39 were GH-deficient and 89 had ISS. Serum protein expression profiles at study start and after 1 year of GH treatment were analyzed using SELDI-TOF. Cross-validated regression and random permutation analyses were performed to identify significant correlations between protein expression patterns and the 2-year growth response to GH treatment.</p> <p>Results</p> <p>At start of treatment we identified a combination of seven protein peaks that correlated with the 2-year growth response in the GH-deficient group (R<sup>2 </sup>= 0.73). After 1 year of treatment, a combination of four peaks in the GH-deficient group (R<sup>2 </sup>= 0.64), eight peaks in the ISS group R<sup>2 </sup>= 0.47) and eight peaks in the total study group correlated with the 2-year growth response R<sup>2 </sup>= 0.38).</p> <p>The peaks identified corresponded to apolipoproteins A-I, A-II, C-I, C-III, transthyretin and serum amyloid A 4, which are all part of the high-density lipoprotein.</p> <p>Conclusion</p> <p>Using a proteomic approach we identified biomarkers related to the lipoprotein profile that could be used to predict growth response to GH treatment in prepubertal children who are short as a result of GH-deficiency or who have ISS.</p> <p>These results support our previous findings that apolipoproteins and transthyretin may have a role in GH sensitivity.</p
The City Initiative for Newborn Health
This article describes the critical first steps taken to revitalize the vast public health system of Mumbai City through the active participation of personnel from within the system. It focuses on one of two components of an ambitious action-research project aimed at improving the survival and health of newborn infants and mothers living in slum communities in Mumbai
A randomized controlled study comparing pain experience between a newly designed needle with a thin tip and a standard needle for oocyte aspiration
Background: Ultrasound-guided transvaginal oocyte retrieval is often performed under local anaesthesia on an outpatient basis. The objective of this study was to compare the overall pain experience of a newly designed reduced needle (RN) compared with a thicker standard needle (SN). Methods: A prospective, randomized, multi-centre study was performed at four different clinics from June to December 2009. The oocyte aspiration was performed under local anaesthesia, either with a needle with a reduced diameter (0.9 mm) for the last 50 mm ;from the tip (RN) or with a SN (1.4 mm). A total of 257 patients were randomized (RN: n = 129; SN: n = 128). The primary endpoint was the overall pain experience self-assessed and registered by the patient on a visual analogue scale (VAS 0 mm no pain to 100 mm unbearable pain) immediately after the oocyte retrieval. Secondary end-points such as vaginal bleeding and several embryological parameters were also registered. Results: The overall pain during the oocyte retrieval procedure was significantly lower in the RN group than in the SN group (mean 21.0 mm, SD 17.5 mm and median 19.0 mm versus mean 26.0 mm, SD 19.9 mm and median 24.0 mm; P = 0.040, difference between groups mean -5.0 mm, 95% Cl: 9.7 to -0.4). This was also true when adjusting for baseline characteristics such as number of follicles, number of previous oocyte pick-up, body mass index and age, by a multiple linear regression analysis. Significantly more patients (40 of 126) had less than expected vaginal bleeding in the RN group when compared with the SN group (24 of 124; 32 versus 19%; P = 0.03 and 95% Cl: 1.7-23.0%). No differences were found between the two needles with regard to additional i.v. analgesia, aspiration time, oocyte recovery, fertilization, cleavage rate, number of good quality embryos, number of embryos for freezing and pregnancy rate. Conclusions: Oocyte aspiration performed with the newly designed thinner-tipped needle resulted in significantly less overall pain and less vaginal bleeding, without prolonging the retrieval procedure or influence the oocyte recovery rate, when compared with a SN
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