Human thymic stromal lymphopoietin: a novel epithelial cell-derived cytokine and a potential key player in the induction of allergic inflammation

Allergy is the result of a complex immune cascade leading to the dysregulated production of Th2 cytokines, the generation of allergen-specific IgE-producing B cells and the subsequent activation and degranulation of mast cells upon allergen challenge. Dendritic cells (DCs) play an important role in several models of allergy, but factors instructing DCs to induce a dysregulated Th2 response are currently unknown. In this review, we present recent evidence that human thymic stromal lymphopoietin (TSLP), a novel IL-7-like cytokine, might represent an early trigger of the allergic immune cascade. TSLP-activated human DCs produce Th2-attracting chemokines but no IL-12, and induce naive CD4⁺ and CD8⁺ T cell differentiation into effector cells with a typical pro-allergic phenotype. TSLP is produced by human epithelial, stromal, and mast cells. It is highly expressed by the keratinocytes of atopic dermatitis but not in other types of skin inflammation. Thus, epithelial- and stromal-cell-derived TSLP might represent one of the factors initiating the allergic responses, and could be a target for a curative therapeutic approach to allergy.     

Incidence and natural history of mucopolysaccharidosis type III in France and comparison with United Kingdom and Greece

Sanfilippo syndrome, or mucopolysaccharidosis type III (MPSIII) is a lysosomal storage disease with predominant neurological manifestations in affected children. It is considered heterogeneous with respect to prevalence, clinical presentation, biochemistry (four biochemical forms of the disease referred to as MPSIIIA, B, C, and D are known), and causative mutations. The perspective of therapeutic options emphasizes the need for better knowledge of MPSIII incidence and natural history. We performed parallel retrospective epidemiological studies of patients diagnosed with MSPIII in France (n = 128), UK (n = 126), and Greece (n = 20) from 1990 to 2006. Incidences ranged from 0.68 per 100,000 live‐births in France to 1.21 per 100,000 live‐births in UK. MPSIIIA, which predominates in France and UK, was absent in Greece, where most patients have MPSIIIB. The study confirmed the large allelic heterogeneity of MPSIIIA and MPSIIIB and detected several yet undescribed mutations. Analysis of clinical manifestations at diagnosis and over a 6–7 years follow‐up indicated that almost all patients, whatever the disease subtype, expressed neurological manifestations before the age of 5 years, including language acquisition delay, cognitive delay, and/or abnormal behavior. In contrast to relatively homogeneous early onset manifestations, disease progression showed significant variation depending on subtype and age at diagnosis. Different severities of disease progressions and different allele distribution between France and UK suggested that mutations are not equally deleterious, although genotype–phenotype correlation could not be established. Notwithstanding the rapidity of further clinical deterioration, all MPSIII patients suffer early onset devastating neurological manifestations that deserve early treatment when available. © 2010 Wiley‐Liss, Inc.     

Liver glycogen storage diseases due to phosphorylase system deficiencies: diagnosis thanks to non invasive blood enzymatic and molecular studies

Glycogen storage disease (GSD) due to a deficient hepatic phosphorylase system defines a genetically heterogeneous group of disorders that mainly manifests in children. We investigated 45 unrelated children in whom a liver GSD VI or IX was suspected on the basis of clinical symptoms including hepatomegaly, increased serum transaminases, postprandial lactatemia and/or mild fasting hypoglycemia. Liver phosphorylase and phosphorylase b kinase activities studied in peripheral blood cells allowed to suspect diagnosis in 37 cases but was uninformative in 5. Sequencing of liver phosphorylase genes was useful to establish an accurate diagnosis. Causative mutations were found either in the PYGL (11 patients), PHKA2 (26 patients), PHKG2 (three patients) or in the PHKB (three patients) genes. Eleven novel disease causative mutations, five missense (p.N188K, p.D228Y, p.P382L, p.R491H, p.L500R) and six truncating mutations (c.501_502ins361pb, c.528+2T>C, c.856-29_c.1518+614del, c.1620+1G>C, p.E703del and c.2313-1G>T) were identified in the PYGL gene. Seventeen novel disease causative mutations, ten missense (p.A42P, p.Q95R, p.G131D, p.G131V, p.Q134R, p.G187R, p.G300V, p.G300A, p.C326Y, p.W820G) and seven truncating (c.537+5G>A, p.G396DfsX28, p.Q404X, p.N653X, p.L855PfsX87, and two large deletions) were identified in the PHKA2 gene. Four novel truncating mutations (p.R168X, p.Q287X, p.I268PfsX12 and c.272-1G>C) were identified in the PHKG2 gene and three (c.573_577del, p.R364X, c.2427+3A>G) in the PHKB gene. Patients with PHKG2 mutations evolved towards cirrhosis. Molecular analysis of GSD VI or IX genes allows to confirm diagnosis suspected on the basis of enzymatic analysis and to establish diagnosis and avoid liver biopsy when enzymatic studies are not informative in blood cells.     

Allogeneic bone marrow transplantation in mevalonic aciduria

Mevalonic aciduria is a rare, inborn error of isoprene biosynthesis characterized by severe, periodic attacks of fever and inflammation, developmental delay, ataxia, and dysmorphic features. This autosomal recessive disease is caused by a mutation in the mevalonate kinase gene that severely reduces mevalonate kinase activity. A 3-year-old boy with mevalonic aciduria whose condition had failed to improve with antiinflammatory treatment underwent allogeneic bone marrow transplantation from an HLA-identical sister who was a heterozygous carrier of the mutant gene. We observed sustained remission of febrile attacks and inflammation during a 15-month follow-up period.     

Functional analysis of a novel POLγA mutation associated with a severe perinatal mitochondrial encephalomyopathy

Mutations in the mitochondrial DNA polymerase gamma catalytic subunit (POLγA) compromise the stability of mitochondrial DNA (mtDNA) by leading to mutations, deletions and depletions in mtDNA. Patients with mutations in POLγA often differ remarkably in disease severity and age of onset. In this work we have studied the functional consequence of POLγA mutations in a patient with an uncommon and a very severe disease phenotype characterized by prenatal onset with intrauterine growth restriction, lactic acidosis from birth, encephalopathy, hepatopathy, myopathy, and early death. Muscle biopsy identified scattered COX-deficient muscle fibers, respiratory chain dysfunction and mtDNA depletion. We identified a novel POLγA mutation (p.His1134Tyr) in trans with the previously identified p.Thr251Ile/Pro587Leu double mutant. Biochemical characterization of the purified recombinant POLγA variants showed that the p.His1134Tyr mutation caused severe polymerase dysfunction. The p.Thr251Ile/Pro587Leu mutation caused reduced polymerase function in conditions of low dNTP concentration that mimic postmitotic tissues. Critically, when p.His1134Tyr and p.Thr251Ile/Pro587Leu were combined under these conditions, mtDNA replication was severely diminished and featured prominent stalling. Our data provide a molecular explanation for the patient´s mtDNA depletion and clinical features, particularly in tissues such as brain and muscle that have low dNTP concentration.     

A 3-week, randomized, placebo-controlled trial of asenapine in the treatment of acute mania in bipolar mania and mixed states

Objective:  Asenapine is approved for bipolar disorder and schizophrenia. This was a 3-week, randomized, double-blind, placebo-controlled trial of asenapine for treating acute bipolar mania.
Methods:  After a single-blind placebo run-in period, adults (n = 488) experiencing manic or mixed episodes were randomized to flexible-dose sublingual asenapine (10 mg BID on day 1; 5 or 10 mg BID thereafter; n = 194), placebo (n = 104), or oral olanzapine (15 mg BID on day 1; 5–20 mg QD thereafter; n = 191). Primary efficacy, change in Young Mania Rating Scale (YMRS) total score from baseline to day 21, was assessed using analysis of covariance with last observation carried forward [(LOCF); primary analysis]. A mixed model for repeated measures [(MMRM); prespecified secondary analysis] was also used to assess efficacy. Tolerability and safety assessments included adverse events, physical examinations, extrapyramidal symptom ratings, and laboratory values.
Results:  Mean daily dosages were asenapine 18.2 mg and olanzapine 15.8 mg. Significantly greater least squares (LS) mean ± SE changes in YMRS scores were observed on day 2 with asenapine (−3.0 ± 0.4) and olanzapine (−3.4 ± 0.4) versus placebo (−1.5 ± 0.5, both p < 0.01) and were maintained until day 21 (−10.8 ± 0.8 with asenapine, −12.6 ± 0.8 with olanzapine; both p ≤ 0.0001 versus placebo, −5.5 ± 1.1) with LOCF. The results of MMRM analyses were consistent with those of LOCF. Asenapine had a modest impact on weight and metabolic measures.
Conclusions:  These results indicate that asenapine is rapidly acting, efficacious, and well tolerated for patients with bipolar I disorder experiencing an acute manic episode.     

Near strongly resonant periodic orbits in a Hamiltonian system

We study an analytic Hamiltonian system near a strongly resonant periodic orbit. We introduce a modulus of local analytic classification. We provide asymptotic formulae for the exponentially small splitting of separatrices for bifurcating hyperbolic periodic orbits. These formulae confirm a conjecture formulated by V. I. Arnold in the early 1970s.     

Cycle dependency of intrauterine vascular endothelial growth factor levels is correlated with decidualization and corpus luteum function

OBJECTIVE: To determine intrauterine levels of vascular endothelial growth factor (VEGF)-A during the menstrual cycle in the human female and to investigate the impact of decidualization and corpus luteum function. DESIGN: Prospective clinical study. SETTING: Tertiary university center. PATIENT(S): Fifty-four women with infertility problems. INTERVENTION(S): Intrauterine concentrations of VEGF-A were determined at various time points during the secretory phase using a novel intrauterine microdialysis device. Concomitantly, intrauterine insulin-like growth factor binding protein (IGFBP)-1 levels served as a paracrine parameter for decidualization. Serum progesterone (P) and E(2) levels were determined as markers for corpus luteum function.Intrauterine VEGF levels. RESULT(S): The VEGF levels in utero were clearly cycle dependent with increasing levels during the late secretory and premenstrual phases. There was a significant correlation with the decidualization marker IGFBP-1. In contrast, intrauterine VEGF levels showed a significant negative correlation with serum E(2) and P. CONCLUSION(S): Intrauterine VEGF levels are regulated in a cycle-dependent way. Increasing levels in the late secretory phase are clearly correlated with decidualization. In contrast, decreasing serum levels of steroids produced by the regressing corpus luteum are less likely to be responsible for increasing VEGF levels in the premenstrual phase.