199 research outputs found
Primary growth hormone insensitivity (Laron syndrome) and acquired hypothyroidism: a case report
<p>Abstract</p> <p>Introduction</p> <p>Primary growth hormone resistance or growth hormone insensitivity syndrome, also known as Laron syndrome, is a hereditary disease caused by deletions or different types of mutations in the growth hormone receptor gene or by post-receptor defects. This disorder is characterized by a clinical appearance of severe growth hormone deficiency with high levels of circulating growth hormone in contrast to low serum insulin-like growth factor 1 values.</p> <p>Case presentation</p> <p>We report the case of a 15-year-old Caucasian girl who was diagnosed with Silver-Russell syndrome at the age of four and a half years. Recombinant growth hormone was administered for 18 months without an appropriate increase in growth velocity. At the age of seven years, her serum growth hormone levels were high, and an insulin-like growth factor 1 generation test did not increase insulin-like growth factor 1 levels (baseline insulin-like growth factor 1 levels, 52 μg/L; reference range, 75 μg/L to 365 μg/L; and peak, 76 μg/L and 50 μg/L after 12 and 84 hours, respectively, from baseline). The genetic analysis showed that the patient was homozygous for the R217X mutation in the growth hormone receptor gene, which is characteristic of Laron syndrome. On the basis of these results, the diagnosis of primary growth hormone insensitivity syndrome was made, and recombinant insulin-like growth factor 1 therapy was initiated. The patient's treatment was well tolerated, but unexplained central hypothyroidism occurred at the age of 12.9 years. At the age of 15 years, when the patient's sexual development was almost completed and her menstrual cycle occurred irregularly, her height was 129.8 cm, which is 4.71 standard deviations below the median for normal girls her age.</p> <p>Conclusion</p> <p>The most important functional tests for the diagnosis of growth hormone insensitivity are the insulin-like growth factor 1 generation test and genetic analysis. Currently, the only effective treatment is daily administration of recombinant insulin-like growth factor 1 starting from early childhood. However, these patients show a dramatically impaired final height. In our case, unexplained central hypothyroidism occurred during treatment.</p
Digital identity of researchers and their personal learning network
Paper produzido no âmbito da Tese de Doutoramento em Educação, especialidade de Educação a Distância e eLearning (EDeL), Universidade Aberta.In a networked society, everyday experience is shared in networks at a personal, professional and academic level. Thus, there is a need to have digital literacy skills to obtain and produce contents in a collaborative way, sharing the knowledge acquired in the personal learning network. This paper is a reflection of literature revision in the PhD project of Online Distance Education and e-learning, concerning themes such as digital identity and personal learning networks. In this way we aim to make a literature analysis about the necessity of digital literacy so that we may obtain competencies for a personal learning network.info:eu-repo/semantics/publishedVersio
Machine-learning of atomic-scale properties based on physical principles
We briefly summarize the kernel regression approach, as used recently in
materials modelling, to fitting functions, particularly potential energy
surfaces, and highlight how the linear algebra framework can be used to both
predict and train from linear functionals of the potential energy, such as the
total energy and atomic forces. We then give a detailed account of the Smooth
Overlap of Atomic Positions (SOAP) representation and kernel, showing how it
arises from an abstract representation of smooth atomic densities, and how it
is related to several popular density-based representations of atomic
structure. We also discuss recent generalisations that allow fine control of
correlations between different atomic species, prediction and fitting of
tensorial properties, and also how to construct structural kernels---applicable
to comparing entire molecules or periodic systems---that go beyond an additive
combination of local environments
Association of early life factors and acute lymphoblastic leukaemia in childhood: historical cohort study
In a historical cohort study of all singleton live births in Northern Ireland from 1971–86 (n=434 933) associations between early life factors and childhood acute lymphoblastic leukaemia were investigated. Multivariable analyses showed a positive association between high paternal age (⩾35 years) and acute lymphoblastic leukaemia (relative risk=1.49; 95% confidence interval (CI)=0.96–2.31) but no association with maternal age. High birth weight (⩾3500 g) was positively associated with acute lymphoblastic leukaemia (relative risk=1.66; 95% CI=1.18–2.33). Children of mothers with a previous miscarriage or increased gestation (⩾40 weeks) had reduced risks of ALL (respective relative risks=0.49; 95% CI=0.29–0.80, and 0.67; 95% CI=0.48–0.94). Children born into more crowded households (⩾1 person per room) had substantially lower risks than children born into less crowded homes with also some evidence of a lower risk for children born into homes with three adults (relative risks=0.56; 95% CI=0.35–0.91 and 0.58; 95% CI=0.21–1.61 respectively). These findings indicate that several early life factors, including living conditions in childhood and maternal miscarriage history, influence risk of acute lymphoblastic leukaemia in childhood
DNA vaccination for prostate cancer: key concepts and considerations
While locally confined prostate cancer is associated with a low five year mortality rate, advanced or metastatic disease remains a major challenge for healthcare professionals to treat and is usually terminal. As such, there is a need for the development of new, efficacious therapies for prostate cancer. Immunotherapy represents a promising approach where the host’s immune system is harnessed to mount an anti-tumour effect, and the licensing of the first prostate cancer specific immunotherapy in 2010 has opened the door for other immunotherapies to gain regulatory approval. Among these strategies DNA vaccines are an attractive option in terms of their ability to elicit a highly specific, potent and wide-sweeping immune response. Several DNA vaccines have been tested for prostate cancer and while they have demonstrated a good safety profile they have faced problems with low efficacy and immunogenicity compared to other immunotherapeutic approaches. This review focuses on the positive aspects of DNA vaccines for prostate cancer that have been assessed in preclinical and clinical trials thus far and examines the key considerations that must be employed to improve the efficacy and immunogenicity of these vaccines
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