Discussing drinking with paediatric patients with neurodegenerative conditions raises a wide range of dilemmas

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Modeling of Immunosenescence and Risk of Death from Respiratory Infections: Evaluation of the Role of Antigenic Load and Population Heterogeneity

It is well known that efficacy of immune functions declines with age. It results in an increase of severity and duration of respiratory infections and also in dramatic growth of risk of death due to these diseases after age 65. The goal of this work is to describe and investigate the mechanism underlying the age pattern of the mortality rate caused by infectious diseases and to determine the cause-specific hazard rate as a function of immune system characteristics. For these purposes we develop a three-compartment model explaining observed risk-of-death. The model incorporates up-to-date knowledge about cellular mechanisms of aging, disease dynamics, population heterogeneity in resistance to infections, and intrinsic aging rate. The results of modeling show that the age-trajectory of mortality caused by respiratory infections may be explained by the value of antigenic load, frequency of infections and the rate of aging of the stem cell population (i.e. the population of T-lymphocyte progenitor cells). The deceleration of infection-induced mortality at advanced age can be explained by selection of individuals with a slower rate of stem cell aging. Parameter estimates derived from fitting mortality data indicate that infection burden was monotonically decreasing during the twentieth century, and changes in total antigenic load were gender-specific: it experienced periodic fluctuations in males and increased approximately two-fold in females

Twin girls with hypophosphataemic rickets and papilloedema

A 7 year-old twin girl with hypophosphataemic rickets was evaluated for a recent onset of mild strabismus.She was a homozygous twin sister with hypophosphataemic rickets diagnosed at the age of 2 years, with a mutation in intron 21 of the PHEX gene, which was also present in her sister.The girls' clinical histories were remarkable for an important lower limb varus that progressively improved after starting phosphate supplementation with a galenical solution (Joulies solution 1 mmol phosphate/ml) and vitamin D 1,25 OH.During the examinations, both girls were in good general condition. Physical examinations were unremarkable, except for tibial varus, bilateral fifth finger clinodactyly and bilateral syndactyly of the third and fourth foot fingers. No major head shape abnormalities were noticeable except for a high forehead.One patient presented with a slight strabismus, normal isochoric isocyclic and reactive pupils, no signs of cranial nerve deficit, and no alterations in the rest of the neurological examination. An ophthalmological evaluation showed bilateral papilloedema. A cerebral MRI scan was then performed, suspecting elevated intracranial pressure (figure 1). The same examination was performed on the asymptomatic sister which also demonstrated papilloedema with similar findings on cranial MRI too. edpract;archdischild-2020-319615v1/BLKF1F1BLK_F1Figure 1Sagittal MR T1-weighted imaging shows a 12 mm cerebellar tonsillar herniation (shown by the white arrow) and bulb-medullary junction herniation. The apex of the epistropheus tooth almost reaches the occipital clivus (shown by the white line) and imprints the bulb. QUESTIONS: Which is the most likely diagnosis?CraniosynostosisPseudotumor cerebriDrusenArnold-Chiari malformationHow should these patients be managed?Acetazolamide treatmentThird to fourth ventricle cystostomyWait and see with periodical visual evoked potential follow-upNeurosurgeryHow should patients with X linked hypophosphataemic rickets (XLH rickets) be managed for the risk of craniosynostosis?Monitor cephalic anthropometric measuresPerform a MRI scan if clinical signs of craiosynostosis or intracranial hypertension are presentPerform a skull X-ray every 2 yearsPerform an MRI scan every 2 years Answers can be found on page 02

How does the chromatin fiber deal with topological constraints?

In the nuclei of eukaryotic cells, DNA is packaged through several levels of compaction in an orderly retrievable way that enables the correct regulation of gene expression. The functional dynamics of this assembly involves the unwinding of the so-called 30 nm chromatin fiber and accordingly imposes strong topological constraints. We present a general method for computing both the twist and the writhe of any winding pattern. An explicit derivation is implemented for the chromatin fiber which provides the linking number of DNA in eukaryotic chromosomes. We show that there exists one and only one unwinding path which satisfies both topological and mechanical constraints that DNA has to deal with during condensation/decondensation processes.Comment: Presented in Nature "News and views in brief" Vol. 429 (13 May 2004). Movies available at http://www.lptl.jussieu.fr/recherche/operationE_fichiers/Page_figurePRL.htm

Solitons in Yakushevich-like models of DNA dynamics with improved intrapair potential

The Yakushevich (Y) model provides a very simple pictures of DNA torsion dynamics, yet yields remarkably correct predictions on certain physical characteristics of the dynamics. In the standard Y model, the interaction between bases of a pair is modelled by a harmonic potential, which becomes anharmonic when described in terms of the rotation angles; here we substitute to this different types of improved potentials, providing a more physical description of the H-bond mediated interactions between the bases. We focus in particular on soliton solutions; the Y model predicts the correct size of the nonlinear excitations supposed to model the ``transcription bubbles'', and this is essentially unchanged with the improved potential. Other features of soliton dynamics, in particular curvature of soliton field configurations and the Peierls-Nabarro barrier, are instead significantly changed

Boy with crackling neck

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Comparison of two European paediatric emergency departments: does primary care organisation influence emergency attendance?

Backround: To compare paediatric Emergency Department (ED) attendances and admission outcomes in twoEuropean hospitals with different paediatric primary care set-up. Methods: This is a retrospective prevalence study comparing all paediatric ED attendances during calendar years 2013 in two EDs with similar catchment area: one in Italy (Trieste) where paediatric primary care is provided by office paediatricians, the other, in the UK (Cambridge), where paediatric primary care is provided by general practitioners. Data on reason for presentation, discharge diagnosis and admission rate were collected and sub-group analysis for specific age groups (<1 year, 1 \u2013 4 years, 5 \u2013 15 years) was performed. Results: Over 12 months, 20.331 children (0 \u2013 15 years old) were seen in Cambridge and 18.646 in Trieste, with a very similar age distribution in both centres, except for the youngest age group: the percentage of infants seen in comparison with the total number of children attending ED was 1/3 higher in England than in Italy (15.4% vs 11. 4%). The reasons for attendance were similar: under 1 year of age, the chief complaints were fever, breathing difficulties and gastrointestinal problems while in the older age groups trauma represented the commonest reason. Among discharge diagnoses, no differences were found between the two hospitals, except for faltering growth and \u201c well child \u201d , more frequently diagnosed in English children under 5 years. The proportion of admissions was three times higher in Cambridge (14.1% vs 4.8%) with most children being admitted for infectious diseases. Conclusions: ED attendances in infants are more common in a primary care setting provided by general practicioner and, moreover, admission rates in all age groups are 1/3 reduced by primary care based paediatricians. Due to the methodological limits of this study, it isn't possible to evaluate whether these results depend only on paediatric primary care set-up or be determined by other confounding factors. New studies are needed to confirm this preliminary evidence

Base sequence dependent sliding of proteins on DNA

The possibility that the sliding motion of proteins on DNA is influenced by the base sequence through a base pair reading interaction, is considered. Referring to the case of the T7 RNA-polymerase, we show that the protein should follow a noise-influenced sequence-dependent motion which deviate from the standard random walk usually assumed. The general validity and the implications of the results are discussed.Comment: 12 pages, 3 figure

Severe anaemia after gastric biopsy in an infant with eosinophilic gastritis

Background: Eosinophilic gastrointestinal disorders (EGID) are characterized by eosinophilic inflammation and are subclassified according to the affected site(s) as eosinophilic esophagitis, eosinophilic gastritis, eosinophilic enteritis and eosinophilic colitis. Clinical presentation includes dyspeptic symptoms, vomiting, abdominal pain, diarrhoea and gastrointestinal bleeding. Peripheral eosinophilia is usually found but is not required for the diagnosis. The treatment is based on dietary elimination therapy, consisting of removal of common food triggers, most frequently cow's milk in infants. Corticosteroids are used as first line drug therapy in EG if dietary therapy fails to achieve an adequate clinical response or is impractical. Case presentation: A four month old infant was admitted for an episode of melena and hematemesis. An esophagogastroduodenoscopy showed haemorrhagic gastritis with ulcerative lesions and fibrin. A significant gastric bleeding was noted after the procedure. The gastric mucosa biopsies showed an eosinophilic infiltration. Conclusions: A clinically relevant anaemia is a quite rare complication in infants with eosinophilic gastritis and a biopsy may worsen bleeding, to a potentially severe level of low haemoglobin. In infants with low haemoglobin levels and suspect eosinophilic gastritis a watchful follow up after the biopsy should be considered, as well as the possibility of postponing the biopsy to reduce the bleeding risk