Characterization of a novel interaction between Islr2 and Vasorin and its role in retinal axon routing at the vertebrate optic chiasm

A striking feature of embryonic axon tracts is their high level of guidance stereotypy. To isolate new candidate molecules with putative functions in retinal axon pathfinding we focused on the extracellular leucine-rich repeat (eLRR) protein family in zebrafish. eLRR proteins are known to convey specialized, dynamic functions at the axon and growth cone membranes. The compilation of an eLRR gene catalogue and the analysis of their expression patterns allowed the identification of islr2 as a candidate putatively involved in early guidance decisions undertaken by retinal axons. We used the zebrafish to model Islr2 behaviour in vivo, taking advantage of the rapid development of its retinotectal projection and amenability to imaging. islr2sa82 mutants display the presence of ectopic ipsilateral projections, although zebrafish normally have a completely crossed retinal axon projection. These data suggest that islr2 facilitates retinal axon crossing to the opposite side of the brain. Taking advantage of a novel protein-protein interaction screening method, dedicated to detecting low affinity binding events, we identified Vasorin A and B as specific Islr2 binding partners. We generated immunoreagents in order to describe these proteins’ localization in zebrafish embryos and found that their expression domains are closely associated to the retinal axon pathway. Vasnb, in particular, is expressed by a small population of cells at the anterior ventral diencephalic midline, a location reminiscent of the glial knot. The knot is a structure identified in mouse and chick which was anatomically thought to redirect retinal axon fibers at the midline. vasna/vasnb single and double knockout animals, however, do not show overt phenotypes in the optic nerves traversing the chiasm. In conclusion, we propose that other midline factors act through Islr2 allowing retinal axons to cross the midline. They compensate for the absence of Vasna and Vasnb function in vivo, a scenario that is not surprising when considering the high level of signalling redundancy characteristic of the optic chiasm. In a parallel project, we created transgenic zebrafish lines expressing chromobodies in an inducible fashion. Chromobodies are single-domain antibodies derived from heavy-chain IgG2 and IgG3 of camelids. Actin- and PCNA-directed chromobodies can be expressed intracellularly, allowing to trace endogenous targets without the need of protein tagging or overexpression. This technique can be applied in live zebrafish embryos, introducing intracellular immunoreagents as a complementary technique for protein localization studies. Using Actin-CB we were able to follow detailed cytoskeletal dynamics during rapid cellular behaviours in living animals. Additionally, PCNA-CB allows accurate tracing of DNA replication forks foci in the nucleus, making it possible to discern cell cycle progression in vivo. These tools surprisingly do not cause morphological or developmental defects throughout the duration of early development and can be expressed to adulthood. This is the first report of the applicability of the chromobody technology to living vertebrates

A novel DNA/histone H4 peptide complex detects autoantibodies in systemic lupus erythematosus sera

Background: The detection of anti-dsDNA antibodies is critical for the diagnosis and follow-up of systemic lupus erythematosus (SLE) patients. The presently available assays are characterized by a non-optimal specificity (solid phase assays) or sensitivity (Crithidia Luciliae immunofluorescence test (CLIFT)). To overcome the limits of CLIFT and solid phase chromatin assays, we explored the diagnostic potential of an assay based on plasmid DNA containing a highly bent fragment of 211 bp from Crithidia Luciliae minicircles, complexed with histone peptides. Methods: Electrically neutral complexes of PK201/CAT plasmid (PK) DNA and histone 4 (H4) peptides were evaluated by electromobility shift assay. Complexes of H4 peptides and PK were absorbed to the solid phase to detect specific immunoglobulin G (IgG) in sera. Sera from 109 SLE patients, 100 normal healthy subjects, and 169 disease controls were tested. Results: H4(14-34) containing the consensus sequence for DNA binding interacts with PK, retarding its migration. H4(14-34)/PK complexes were used to test sera by ELISA. Anti-H4-PK antibodies were detected in 56 % of SLE sera (more frequently in patients with skin or joint involvement) versus 5.9 % in disease controls; inhibition assays show that sera react with epitopes present on DNA or on the complex, not on the peptide. Antibody titer is correlated with European Consensus Lupus Activity Measurement (ECLAM) score and anti-complement component 1q (C1q) antibodies, negatively with C3 levels. Anti-H4-PK antibodies compared with CLIFT and solid phase dsDNA assays display moderate concordance. Conclusions: The H4/PK assay is a simple and reliable test which is useful for the differential diagnosis and evaluation of disease activity in SLE patients

Evaluation of an intervention aimed at supporting new parents: the Baby Newsletter project

Background: Anticipatory guidance for parents is commonly used to improve parenting skills. The objective of this pre/post-intervention controlled study was to evaluate the effectiveness of a periodic newsletter with advice on childcare and development in improving parenting self-efficacy. Methods: This was a non-randomized pre/post-intervention controlled study. All the parents of children born between September 2014 and December 2015 resident in the S. Ilario d’Enza municipality (Italy) received eight Baby Newsletters. Parents resident in other municipalities of the same Health District were the control. Parents with linguistic barriers or with preterm or hospitalized children were excluded. Improvement in parenting self-efficacy was measured through the TOPSE (Tool to Measure Parenting Self-Efficacy) questionnaire during the first week (t0) after delivery and at 5 (t1) and 12 months (t2) of life at two vaccination appointments. A score ranging from 0 to 60 was computed for each of the eight domains investigated by the TOPSE. Variations of each TOPSE score between delivery and 12 months in the two groups were compared, adjusting for parity, education, age of parents, and child’s sex, and stratifying by parity and education. Results /findings: One hundred thirty-six families accepted to participate in the study. Scores at 12 months were higher than 1 week after delivery in both groups for all TOPSE domains. The improvement was slightly stronger in the Newsletter group for almost all the skills except learning and knowledge [difference in the mean of variation: -0.48 (95% CI: − 3.17; 2.21)]; the difference was significant only for play and enjoyment [2.18 (95% CI: 0.12; 4.25)]. The increase in scores in almost all domains was more pronounced for parents with high education level at first child. Conclusions: The intervention was effective in improving parents’ ability to play. However, it risks worsening existing differences between parents with high and with low education levels

New infrastructure for studies of transmutation and fast systems concepts

In this work we report initial studies on a low power Accelerator-Driven System as a possible experimental facility for the measurement of relevant integral nuclear quantities. In particular, we performed Monte Carlo simulations of minor actinides and fission products irradiation and estimated the fission rate within fission chambers in the reactor core and the reflector, in order to evaluate the transmutation rates and the measurement sensitivity. We also performed a photo-peak analysis of available experimental data from a research reactor, in order to estimate the expected sensitivity of this analysis method on the irradiation of samples in the ADS considered

Complementary feeding in preterm infants: a position paper by Italian neonatal, paediatric and paediatric gastroenterology joint societies

Nutrition in the first 1000 days of life is essential to ensure appropriate growth rates, prevent adverse short- and long-term outcomes, and allow physiologic neurocognitive development. Appropriate management of early nutritional needs is particularly crucial for preterm infants. Although the impact of early nutrition on health outcomes in preterm infants is well established, evidence-based recommendations on complementary feeding for preterm neonates and especially extremely low birth weight and extremely low gestational age neonates are still lacking. In the present position paper we performed a narrative review to summarize current evidence regarding complementary feeding in preterm neonates and draw recommendation shared by joint societies (SIP, SIN and SIGENP) for paediatricians, healthcare providers and families with the final aim to reduce the variability of attitude and timing among professionals

Intramural aortic hematoma: no flap no warning?

We report a case of type A intramural aortic hematoma (IMH) occurred in a 78 years old female. The clinical scenario (medical history of hypertension, severe substernal chest pain, early diastolic decrescendo murmur as for aortic insufficiency), the laboratory results (no significant troponin level), ECG and transthoracic echocardiography findings (no signs of myocardial ischemia) shifted the initial diagnostic suspicion from acute coronary syndrome to the acute aortic syndrome (AAS) and triggered further imaging tests. Computed tomography revealed an aneurismatic dilatation with thickening of the wall of the ascending aorta without intimal flap. No particular “warning message” for evidence of AAS was sent to the clinician on call. Subsequently, due to the persisting high clinical suspicion transesophageal echocardiography (TEE) was performed. TEE confirmed the aneurysm of the ascending aorta and highlighted an extended and marked aortic wall thickness, consisting with the diagnosis of type A IMH. Patient underwent urgent cardiac surgery that confirmed the diagnosis

May-Hegglin Anomaly, Sebastian Syndrome, Fechtner Syndrome, and Epstein Syndrome Are not Distinct Entities but Represent a Variable Expression of a Single Illness

May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are autosomal dominant macrothrombocytopenias distinguished by different combinations of clinical and laboratory signs, such as sensorineural hearing loss, cataract, nephritis, and polymorphonuclear Döhle-like bodies. Mutations in the MYH9 gene encoding for the nonmuscle myosin heavy chain IIA (NMMHC-IIA) have been identified in all these syndromes. To understand the role of the MYH9 mutations, we report the molecular defects in 12 new cases, which together with our previous works represent a cohort of 19 families. Since no genotype-phenotype correlation was established, we performed an accurate clinical and biochemical re-evaluation of patients. In addition to macrothrombocytopenia, an abnormal distribution of NMMHC-IIA within leukocytes was observed in all individuals, including those without Döhle-like bodies. Selective, high-tone hearing deficiency and cataract was diagnosed in 83% and 23%, respectively, of patients initially referred as having May-Hegglin anomaly or Sebastian syndrome. Kidney abnormalities, such as hematuria and proteinuria, affected not only patients referred as Fechtner syndrome and Epstein syndrome but also those referred as May-Hegglin anomaly and Sebastian syndrome. These findings allowed us to conclude that May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are not distinct entities but rather a single disorder with a continuous clinical spectrum varying from mild macrothrombocytopenia with leukocyte inclusions to a severe form complicated by hearing loss, cataracts, and renal failure. For this new nosologic entity, we propose the term "MHY9-related disease," which better interprets the recent knowledge in this field and identifies all patients at risk of developing renal, hearing, or visual defects