A target site for template-based design of measles virus entry inhibitors

Measles virus (MV) constitutes a principal cause of worldwide mortality, accounting for almost 1 million deaths annually. Although a live-attenuated vaccine protects against MV, vaccination efficiency of young infants is low because of interference by maternal antibodies. Parental concerns about vaccination safety further contribute to waning herd immunity in developed countries, resulting in recent MV outbreaks. The development of novel antivirals that close the vaccination gap in infants and silence viral outbreaks is thus highly desirable. We previously identified a microdomain in the MV fusion protein (F protein) that is structurally conserved in the paramyxovirus family and constitutes a promising target site for rationally designed antivirals. Here we report the template-based development of a small-molecule MV inhibitor, providing proof-of-concept for our approach. This lead compound specifically inhibits fusion and spread of live MV and MV glycoprotein-induced membrane fusion. The inhibitor induces negligible cytotoxicity and does not interfere with receptor binding or F protein biosynthesis or transport but prevents F protein-induced lipid mixing. Mutations in the postulated target site alter viral sensitivity to inhibition. In silico docking of the compound in this microdomain suggests a binding model that is experimentally corroborated by a structure-activity analysis of the compound and the inhibition profile of mutated F proteins. A second-generation compound designed on the basis of the interaction model shows a 200-fold increase in antiviral activity, creating the basis for novel MV therapeutics. This template-based design approach for MV may be applicable to other clinically relevant members of the paramyxovirus family.     

The effect of Halofuginone in the amelioration of radiation induced-lung fibrosis

The lung is one of the most sensitive organs to ionizing radiation, and damage to normal lung tissue remains a major dose limiting factor for patients receiving radiation to the thorax. Radiation induced lung injury (RILI) which is also named as “radiation pneumonpathy” is a continuous process and regarded as the result of an abnormal healing response. It has been shown that transforming growth factor β-1 (TGF-β1) plays an integral role in the radiation induced lung fibrosis formation by promoting the chemoattraction of fibroblasts and their conversion to myofibroblasts. Halofuginone is a, low molecular weight plant derived alkaloid, isolated from the Dichroa febrifuga plant that exhibits antifibrotic activity and inhibition of type I collagen synthesis. Halofuginone has been shown to protect against radiation induced soft tissue fibrosis by virtue of inhibiting various members of TFG-β signaling pathway. By the light of these findings, we hypothesize that Halofuginone may be able to ameliorate the radiation induced lung fibrosis.     

Risk of vasovagal syncope and cardiac arrhythmias in children with mitral valve prolapse

OBJECTIVE: Postural phenomena, cardiac arrhythmias and autonomic dysfunction are responsible for presyncope and syncope in patients with mitral valve prolapse (MVP). In this study, arrhythmia and vasovagal syncope incidence were investigated in children with MVP. METHODS: Between April 2005 and December 2006, 37 children with MVP and 26 healthy children were evaluated.Telecardiography, electrocardiography (ECG), echocardiography, Holter monitoring, exercise test and head-up tilt test were performed. RESULTS: The MVP group consisted of 19 boys and 18 girls with a mean age of 11.8 years. The control group was similar with respect to age and gender. Telecardiography, ECG, Holter monitoring, exercise test and QTc of all children were within normal limits.There was a statistically significant difference between the two groups in terms of QT dispersion. The tilt table test was positive in 11 of 37 (29.7%) children with MVP and in 1 of 26 (3.8%) normal healthy children. This difference was statistically significant (P < 0.01). CONCLUSION: Arrhythmia and syncope frequency was found to be higher in children with MVP than in the normal population. The risk of vasovagal syncope indicated by a positive tilt test was found to be increased in children with MVP. Therefore, patients and families must be informed about the conditions that may predispose to vasovagal syncope and caution should be recommended in these patients.     

Multiple sulfatase deficiency: A case series of four children

Multiple sulfatase deficiency is biochemically characterized by the accumulation of sulfated lipids and acid mucopolysaccharides. The gene sulfatase-modifying factor 1 (SUMF1), recently identified, encodes the enzyme responsible for post-translational modification of a cysteine residue, which is essential for the activity of sulfatases. We describe clinical findings and mutation analysis of four patients. The patients presented with hypotonia, developmental delay, coarse face, ichthyosis, and hepatosplenomegaly. The diagnosis was made through clinical findings, enzymatic assays, and mutation analysis. We were detected to be homozygous for a novel missense mutation c. 739G > C causing a p.G247R amino acid substitution in the SUMF1 protein.Key Words: Child, multiple sulfatase deficiency, sulfatase-modifying factor 1 gene     

Risperidone versus haloperidol in children and adolescents with AD

Objective The aim of the study was to compare safety, efficacy and tolerability of risperidone with haloperidol in the treatment of Autistic Disorder (AD). Method This study was designed as a double-blind, prospective, for a 12-week period. A total of 30 subjects, between the ages of 8 and 18 with AD based on DSM IV criteria, were included in the study. Behavioral Rating Scales were performed by the investigators and the parents. Safety assessment included vital signs, electrocardiogram, electroencephalogram, adverse events, laboratory tests, extrapyramidal symptoms and the side effects. Both treatments were applied in a once daily dosage regimen of 0.01–0.08 mg/kg/day. Results The reduction from baseline in Ritvo–Freeman Real Life Rating Scale (RF-RLRS), sensory motor (subscale I) and language (subscale V) scores were significant in risperidone group (P < 0.05). Compared to haloperidol, risperidone led to a significantly greater reduction in the Aberrant Behavior Checklist (ABC) and Turgay DSM-IV Pervasive Developmental Disorder (PDD) scale scores (P < 0.05 and P < 0.01). There was a greater increase of prolactin in the risperidone group, while alanine amino transferase (ALT) had further increased in the haloperidol group. Sensory motor behaviors (subscale I) and language at the end of the 12th week, RF-RLRS sensory motor and language subscale scores decreased in the risperidone group further than the other group (P < 0.05). Conclusions Risperidone was found to be more effective than haloperidol in the treatment of behavioral symptoms, impulsivity, language skills, and impaired social relations in children with AD. These results demonstrated that both drugs were safe and well tolerated in the treatment of AD.