Non-linear interpolation learning for example-based inverse problem regularization

A large number of signal recovery problems are not well-posed-if not ill-posed-that require extra regularization to be tackled. In this context, the ability to inject physical knowledge is of utmost importance to design effective regularization schemes. However, most physically relevant models are generally nonlinear: signals generally lie on an unknown low-dimensional manifolds structure, which needs to be learnt. This is however quite challenging when available training samples are scarce. To that end, we investigate a novel approach that builds upon learning a non-linear interpolatory scheme from examples. We show how the proposed approach resonates with transportbased methods, but with a learnt metric. This eventually allows to build efficient non-linear regularizations for linear inverse problems. Extensive numerical experiments have been carried out to evaluate the performances of the proposed approach. We further illustrate its application to a blind regression problem in the field of γ-ray spectroscopy

Growth Hormone Receptor Gene Expression in Puberty.

The mechanisms regulating the synergic effect of growth hormone and other hormones during pubertal spurt are not completely clarified. We enrolled 64 females of Caucasian origin and normal height including 22 prepubertal girls, 26 pubertal girls, and 16 adults to evaluate the role of Growth Hormone/Insulin-like growth factor-I axis (GH/IGF-I) during the pubertal period. In these subjects both serum IGF-I and growth hormone binding protein levels, as well as quantitative growth hormone receptor (GHR) gene expression were evaluated in peripheral lymphocytes of all individuals by real-time PCR. Our results showed significantly lower IGF-I levels in women (148±10 ng/ml) and prepubertal girls (166.34±18.85 ng/ml) compared to pubertal girls (441.95±29.42 ng/ml; p<0.0001). Serum GHBP levels were significantly higher in prepubertal (127.02±20.76 ng/ml) compared to pubertal girls (16.63±2.97 ng/ml; p=0.0001) and adult women (19.95±6.65 ng/ml; p=0.0003). We also found higher GHR gene expression levels in pubertal girls [174.73±80.22 ag (growth hormone receptor)/5×105 ag (glyceraldehyde 3-phosphate dehydrogenase)] compared with other groups of subjects [women: 42.52±7.66 ag (growth hormone receptor)/5×105 ag (glyceraldehyde 3-phosphate dehydrogenase); prepubertal girls: 58.45±0.18.12 ag (growth hormone receptor)/5×105 ag (glyceraldehyde 3-phosphate dehydrogenase)], but the difference did not reach statistical significance. These results suggest that sexual hormones could positively influence GHR action, during the pubertal period, in a dual mode, that is, increasing GHR mRNA production and reducing GHR cleavage leading to GHBP variations

Breast feeding: gamut of benefits.

Maternal milk is recommended as the optimal and exclusive source of early nutrition for all infants from birth and until at least their sixth month of age. Their nutritional virtues are due to potent immune factors and a unique composition which evolves in tandem with the infant's growth and developmental needs. Breast milk promotes sensory and cognitive development, and protects the infant against infectious and chronic diseases. Exclusive breastfeeding reduces infant mortality due to common childhood illnesses such as diarrhea or pneumonia, and improves recovery time during illness. Breastfeeding provides numerous short- and long-term health benefits for both the baby and its mother. Beyond the immediate benefits for infants, breastfeeding also contributes to a lifetime of good health. In this review we describe the influence of breastfeeding on mental and psychomotor development, on the risk of endocrine disorders, pediatric cancers and allergic diseases for the breastfed child. More prospective studies with comparable methodologies and longer periods of follow-up are necessary to allow firm conclusions on the effects of breastfeeding in some of these aspects

Tall stature: A challenge for clinicians

Clinicians generally use the term "tall stature" to define a height more than two standard deviations above the mean for age and sex. In most cases, these subjects present with familial tall stature or a constitutional advance of growth which is diagnosed by excluding the other conditions associated with overgrowth. Nevertheless, it is necessary to be able to identify situations in which tall stature or an accelerated growth rate indicate an underlying disorder. A careful physical evaluation allows the classification of tall patients into two groups: those with a normal appearance and those with an abnormal appearance including disproportion or dysmorphism. In the first case, the growth rate has to be evaluated and, if it is normal for age and sex, the subjects may be considered as having familial tall stature or constitutional advance of growth or they may be obese, while if the growth rate is increased, pubertal status and thyroid function should be evaluated. In turn, tall subjects having an abnormal appearance can be divided into proportionate and disproportionate syndromic patients. Before initiating further investigations, the clinician needs to perform both a careful physical examination and growth evaluation. To exclude pathological conditions, the cause of tall stature needs to be considered, although most children are healthy and generally do not require treatment to inhibit growth progression. In particular cases, familial tall stature subject can be treated by inducing puberty early and leading to a complete fusion of the epiphyses, so final height is reached. This review aims to provide proposals about the management of tall children

Fertility Preservation in Pediatric Oncology Patients: New Perspectives

Over the past 30 years, advances in antineoplastic treatment led to a significant increase in the survival of patients with childhood cancer. In Europe and the United States, 82% of children, adolescents, and young adults survive 5 years from the cancer diagnosis and the majority achieves long-term survival into adulthood. The impact of cancer therapy on fertility is related to the age of the patient and to the duration, dose/intensity, and type of treatment. Exposure to chemotherapy or to radiation to gonads or pituitary brings long-term complications of cancer-directed therapies that include effects on reproductive capacity. Different methods to preserve fertility can be offered. In prepubertal women, ovarian tissue freezing, in vitro maturation, and surgical movement of ovaries outside the field of irradiation are still experimental. In pubertal and postpubertal women, oocyte-embryo freezing is an established option. In men, the options are sperm cryopreservation, gonadal transposition, and testicular tissue or spermatogonial cryopreservation and reimplantation. Fertility risks and provision of strategies to minimize cancer treatment impact fertility include discussion of the tail of the option before cancer treatment. Having to make a decision in a limited time, while still coming to terms with a potentially life-threatening diagnosis, can cause patients to feel overwhelmed. To date, there are no uniform guidelines on how to approach this problem, so it is important to be aware of it for proper clinical practice

Celiac disease and short stature in children.

Celiac disease (CD) is a genetically determined gluten-sensitive enteropathy resulting in nutrient malabsorption, with an increasing incidence worldwide. In CD children, short stature may be the only presenting clinical feature, even in the absence of gastrointestinal symptoms. Generally, a gluten-free diet (GFD) leads to rapid catch-up growth within 1-2 years. The pathogenesis of CD-associated short stature is still unclear. Besides the involvement of the growth hormone (GH)/IGF-I axis, other pathogenetic mechanisms may include autoimmune disorders of the pituitary gland and altered ghrelin secretion. Furthermore, some CD patients do not show catch-up growth during a GFD, despite reversion to seronegativity for CD markers. These subjects may have GH deficiency and could benefit from GH therapy. This review deals with the problem of linear growth in CD children and points to the importance of the evaluation of GH secretion in those children who show no catch-up growth after the introduction of a GF

A 5.8 Mb interstitial deletion on chromosome Xq21.1 in a boy with intellectual disability, cleft palate, hearing impairment and combined growth hormone deficiency

BACKGROUND: Deletions of the long arm of chromosome X in males are a rare cause of X-linked intellectual disability. Here we describe a patient with an interstitial deletion of the Xq21.1 chromosome. CASE PRESENTATION: In a 15 year boy, showing intellectual disability, short stature, hearing loss and dysmorphic facial features, a deletion at Xq21.1 was identified by array-CGH. This maternally inherited 5.8 Mb rearrangement encompasses 14 genes, including BRWD3 (involved in X-linked intellectual disability), TBX22 (a gene whose alterations have been related to the presence of cleft palate), POU3F4 (mutated in X-linked deafness) and ITM2A (a gene involved in cartilage development). CONCLUSION: Correlation between the clinical findings and the function of gene mapping within the deleted region confirms the causative role of this microrearrangement in our patient and provides new insight into a gene possibly involved in short stature