Epidemiological, molecular, and clinical features of enterovirus respiratory infections in French children between 1999 and 2005

Enteroviruses (EVs) can induce nonspecific respiratory tract infections in children, but their epidemiological, virological, and clinical features remain to be assessed. In the present study, we analyzed 252 EV-related infection cases (median age of subjects, 5.1 years) diagnosed among 11,509 consecutive children visiting emergency departments within a 7-year period in the north of France. EV strains were isolated from nasopharyngeal samples by viral cell culture, identified by seroneutralization assay, and genetically compared by partial amplification and sequencing of the VP1 gene. The respiratory syndromes (79 [31%] of 252 EV infections) appeared as the second most common EV-induced pediatric pathology after meningitis (111 [44%] of 252 cases) (44 versus 31%, P < 10⁻³), contributing to lower respiratory tract infection (LRTI) in 43 (54%) of 79 EV respiratory infection cases. Bronchiolitis was the most common EV-induced LRTI (34 [43%] of 79 cases, P < 10⁻³) occurring more often in infants aged 1 to 12 months (P = 0.0002), with spring-fall seasonality. Viruses ECHO 11, 6, and 13 were the more frequently identified respiratory strains (24, 13, and 11%, respectively). The VP1 gene phylogenetic analysis showed the concomitant or successive circulation of genetically distinct EV respiratory strains (species A or B) during the same month or annual epidemic period. Our findings indicated that respiratory tract infections accounted for the 30% of EV-induced pediatric pathologies, contributing to LRTIs in 54% of these cases. Moreover, the concomitant or successive circulation of genetically distinct EV strains indicated the possibility of pediatric repeated respiratory infections within the same epidemic season.     

Hereditary hemorrhagic telangiectasia: evidence for regional founder effects of ACVRL1 mutations in French and Italian patients

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by widespread arteriovenous malformations and caused by mutations in two major genes: ENG and ACVRL1. Two decades ago, a French epidemiological study pointed out that its prevalence was higher than previously thought and that its distribution varied greatly from one area to another, one of the highest concentrations of patients being found in the Haut-Jura mountains. Although germline mutations are usually family specific, some of them have been reported in unrelated patients, especially for ACVRL1. We performed haplotype analysis of 116 French and Italian patients carrying 13 ACVRL1 different mutations. For five of these mutations, we estimated the age of the most recent common ancestors (MRCAs) using the ESTIAGE program. Most mutations were related to both recurrent mutational events and founder effects with age estimates ranging from 100 to 550 years. The c.1112dupG mutation, which is likely to be responsible for the very high concentration of HHT patients found in the former epidemiological study, probably occurred in one inhabitant of the Haut-Jura Mountains more than three centuries ago. The p.Arg374Gln mutation occurred independently in at least two distinct geographical areas, including the area with the second highest prevalence in the epidemiological study and where the MRCA is rather recent (about 100 years ago). Partially shared haplotypes between French and Italian patients were found for three mutations. This suggests a common origin and a possible diffusion of these mutations from Italy to France.     

The neuronal tyrosine kinase receptor ligand ALKAL2 mediates persistent pain

The anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase known for its oncogenic potential that is involved in the development of the peripheral and central nervous system. ALK receptor ligands ALKAL1 and ALKAL2 were recently found to promote neuronal differentiation and survival. Here, we show that inflammation or injury enhanced ALKAL2 expression in a subset of TRPV1⁺ sensory neurons. Notably, ALKAL2 was particularly enriched in both mouse and human peptidergic nociceptors, yet weakly expressed in nonpeptidergic, large-diameter myelinated neurons or in the brain. Using a coculture expression system, we found that nociceptors exposed to ALKAL2 exhibited heightened excitability and neurite outgrowth. Intraplantar CFA or intrathecal infusion of recombinant ALKAL2 led to ALK phosphorylation in the lumbar dorsal horn of the spinal cord. Finally, depletion of ALKAL2 in dorsal root ganglia or blocking ALK with clinically available compounds crizotinib or lorlatinib reversed thermal hyperalgesia and mechanical allodynia induced by inflammation or nerve injury, respectively. Overall, our work uncovers the ALKAL2/ALK signaling axis as a central regulator of nociceptor-induced sensitization. We propose that clinically approved ALK inhibitors used for non–small cell lung cancer and neuroblastomas could be repurposed to treat persistent pain conditions.     

Treatment of Gastrointestinal Stromal Tumors with Imatinib Mesylate:A Major Breakthrough in the Understanding of Tumor-specific Molecular Characteristics

A specific treatment for gastrointestinal stromal tumors (GIST) has been found through improved understanding of the molecular mechanism of carcinogenesis. GIST are radio and chemo-resistant (less than 10 objective responses). Stromal tumors originate from the multiplication of the cells of Cajal, which intervene in intestinal motility and express the c-Kit gene, also called CD117, on their surface. CD117 is a protein with tyrosine kinase activity, and can be demonstrated through immunohistochemical staining techniques.Treatment with Imatinib mesylate (Glivec), a recently discovered selective inhibitor of tyrosine kinases already used in chronic myeloid leukemia (in which an overexpression of tyrosine kinase is observed) was associated with tumor regression of more than 50% in the initial series of patients with GIST treated in 2001. Since then, approximately 2,000 patients have been included in therapeutic trials, with an objective response rate between 60% and 70% 12 to 18 months after inclusion. The clinical benefit has been estimated at 80% to 90% in patients whose chance of survival until now has been less than 30% at one year (median survival 18 months). Nonetheless, imatinib mesylate has not shown any activity in CD117-negative sarcoma (10% of sarcoma). The therapeutic importance of this drug in the treatment of solid GI tumors deemed inoperable is considerable.     

Alterations in sarcolemmal Na+-Ca2+ exchange and ATP-dependent Ca2+-binding in hypertrophied heart

In order to examine changes in Ca2+ transport in heart sarcolemma, cardiac hypertrophy was induced in rabbits by stenosis of the abdominal aorta and hearts were removed 18-20 weeks later; sham-operated normal rabbits were used as controls. Sarcolemmal vesicles were isolated from the left ventricular tissue by a sucrose density gradient method and the membrane composition as well as activities of certain marker enzymes were monitored to determine the purity of control and experimental fractions; Na+-Ca2+ exchange and Ca2+-pump activities were assessed by the Millipore filtration technique. No changes in Ca2+-influx were observed in Na+-loaded vesicles from the hypertrophied hearts when studied in the presence of different concentrations of calcium as well as at different times of incubation. In contrast, Na+-induced Ca2+-efflux from Ca2+-loaded vesicles was enhanced in the hypertrophied heart at different times of incubation and at different concentrations of sodium. ATP-dependent Ca2+-binding activity of sarcolemma from hypertrophied heart, when measured at different times of incubation and at several concentrations of calcium, was more than the control. Minimal but an equal amount of cross contamination was seen in both control and experimental preparations; however, phosphatidylcholine, phosphatidylethanolamine and phosphatidic acid contents were increased in sarcolemma from hypertrophied hearts. These results suggest that the sarcolemmal Ca2+-transport systems may become adapted during the development of hypertrophy for augmenting Ca2+-efflux from the hypertrophied myocardial cell and this may prevent the occurrence of intracellular Ca2+ overload in a stable form of cardiac hypertrophy.     

Long-term effects of nigro-striatal denervation on striatal [3H]haloperidol binding

[³H]Haloperidol binding measured on pooled microdiscs punched from the rostral and dorsal corpus striatum of rats with unilateral, complete 6-hydroxydopamine-induced nigro-striatal destruction allowed sensitive measurement of the time-dependent fluctuations of the binding patterns related to denervation supersensitivity. Both number of binding sites (B_max) and apparent dissociation constant (K_D) increased 30 days after lesioning. On the other hand, B_max and K_D returned to control levels at 45 days while at later periods only B_max increased.     

The mammary ducts create a favourable microenvironment for xenografting of luminal and molecular apocrine breast tumours

There is a paucity of models for hormone receptor‐positive (HR+) breast cancer because of the difficulty of establishing xenografts from these tumours. We show that this obstacle can be overcome by injecting human tumour cells directly into the mammary ducts of immunodeficient mice. Tumours from 31 patients were infected overnight with a lentiviral vector expressing tdTomato and injected through the nipple into the mammary ducts of NOD‐SCID‐IL2RG?/? mice. Tumours formed in the mice in 77% of cases after the first injection (6/8 luminal A, 15/20 luminal B, and 3/3 molecular apocrine). Four luminal A and one molecular apocrine graft were tested in secondary and tertiary grafts: all were successfully passaged in secondary and 4/5 in tertiary grafts. None of the samples engrafted when injected subcutaneously. The morphology, oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), and Ki‐67 profiles of the clinical samples were maintained in the tertiary grafts. We also show that the intraductal approach can be used to test the response to targeted therapy with fulvestrant and palbociclib, using a genetically defined ER+ model. We conclude that the mammary ducts create a microenvironment that is uniquely favourable to the survival and growth of tumours derived from mammary hormone‐sensing cells. This approach opens the door to testing genomically targeted treatment of HR+ tumours in precision medicine programmes. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

High inter-observer agreement in immunohistochemical evaluation of HER-2/neu expression in breast cancer: a multicentre GEFPICS study

The accurate determination of HER-2 in invasive breast cancer has become a critical issue, particularly in the context of the results of recent trastuzumab (Herceptin((R))) adjuvant trials. This multicentre study evaluated inter-observer reproducibility in interpretation of HER-2 immunostains performed in different laboratories according to their in-house technique. A total of 74 HER-2 immunostains were evaluated by 16 pathologists and by a central review committee. As determined by central review, the HER-2 score was 0 in 33 cases (44%), 1+ in 10 cases (13%), 2+ in 9 cases (12%) and 3+ in 23 cases (31%). The overall kappa value was good (kappa=0.75). Agreement was excellent for the 0/1+ group (kappa=0.85) and for the 3+ group (kappa=0.82). As expected, the score 2+ group showed poor agreement (kappa=0.38). A quality assurance process showed that ring studies and adherence to national guidelines greatly improve inter-observer reproducibility.