Both CD4+ and CD8+ Lymphocytes Participate in the IFN-γ Response to Filamentous Hemagglutinin from Bordetella pertussis in Infants, Children, and Adults

Infant CD4+ T-cell responses to bacterial infections or vaccines have been extensively studied, whereas studies on CD8+ T-cell responses focused mainly on viral and intracellular parasite infections. Here we investigated CD8+ T-cell responses upon Bordetella pertussis infection in infants, children, and adults and pertussis vaccination in infants. Filamentous hemagglutinin-specific IFN-γ secretion by circulating lymphocytes was blocked by anti-MHC-I or -MHC-II antibodies, suggesting that CD4+ and CD8+ T lymphocytes are involved in IFN-γ production. Flow cytometry analyses confirmed that both cell types synthesized antigen-specific IFN-γ, although CD4+ lymphocytes were the major source of this cytokine. IFN-γ synthesis by CD8+ cells was CD4+ T cell dependent, as evidenced by selective depletion experiments. Furthermore, IFN-γ synthesis by CD4+ cells was sometimes inhibited by CD8+ lymphocytes, suggesting the presence of CD8+ regulatory T cells. The role of this dual IFN-γ secretion by CD4+ and CD8+ T lymphocytes in pertussis remains to be investigated

Semiautomated isolation and molecular characterisation of single or highly purified tumour cells from CellSearch enriched blood samples using dielectrophoretic cell sorting

Background: Molecular characterisation of single circulating tumour cells (CTCs) holds considerable promise for predictive biomarker assessment and to explore CTC heterogeneity. We evaluate a new method, the DEPArray system, that allows the dielectrophoretic manipulation and isolation of single and 100% purified groups of CTCs from pre-enriched blood samples and explore the feasibility of their molecular characterisation.Methods:Samples containing known numbers of two cell populations were used to assess cell loss during sample loading. Cultured breast cancer cells were isolated from spiked blood samples using CellSearch CTC and Profile kits. Single tumour cells and groups of up to 10 tumour cells were recovered with the DEPArray system and subjected to transcriptional and mutation analysis.Results:On average, 40% cell loss was observed when loading samples to the DEPArray system. Expected mutations in clinically relevant markers could be obtained for 60% of single recovered tumour cells and all groups of tumour cells. Reliable gene expression profiles were obtained from single cells and groups of up to 10 cells for 2 out of 3 spiked breast cancer cell lines.Conclusion:We describe a semiautomated workflow for the isolation of small groups of 1 to 10 tumour cells from whole blood samples and provide proof of principle for the feasibility of their comprehensive molecular characterisation

Simultaneous Determination of Various Isothiocyanates by RP-LC Following Precolumn Derivatization with Mercaptoethanol

Numerous isothiocyanates (ITCs) are poorly soluble in water which causes their precipitation in aqueous mobile phases used in reversed phase liquid chromatography (RP-LC), thus impacting the accuracy of the quantification. By comparing the amounts of ITCs injected and released from the column, losses could be estimated at 5–32% depending on polarities and concentrations. Results could be dramatically improved in terms of separation and quantification using RP-LC with a mercaptoethanol precolumn derivatization aimed at avoiding ITCs precipitation. The cancer chemoprotective allyl-ITC and sulforaphane were found in cabbage extracts at 1.2 and 2.7 μg g−1 fresh weight, respectively

Réponses immunitaires du grand prématuré à la vaccination contre la coqueluche

Les enfants nés prématurément, et plus particulièrement les grands prématurés nés avant31 semaines d’âge gestationnel, sont à haut risque de contracter des infections. Lavaccination peut prévenir certaines infections, dont la coqueluche qui est causée par labactérie Bordetella pertussis (Bp). Cependant, cette maladie infectieuse hautementcontagieuse est en recrudescence depuis plusieurs années malgré une bonne couverturevaccinale. La morbidité et surtout la mortalité de la coqueluche affectent plusparticulièrement les jeunes enfants, incomplètement ou non encore vaccinés.Il existe deux types de vaccins contre B. pertussis :les vaccins de première génération àcellules entières et les vaccins acellulaires, plus récents. Suite à l’apparition d’effetssecondaires causés par le vaccin à cellules entières, les vaccins acellulaires, comprenantseulement un certain nombre d’antigènes purifiés de B. pertussis, sont utilisés en Belgiquecomme dans de nombreux autres pays industrialisés.L’immunité protectrice contre B. pertussis fait appel tant à l’immunité cellulaire qu‘àl’immunité humorale. De nombreuses études ont démontré une production d’anticorpsspécifiques aux antigènes de B. pertussis suite à l’administration des différents types devaccins. Par contre, peu d’entre elles ont analysé la réponse d’immunité cellulaire spécifiquecaractérisée, entre autres, par une sécrétion d’Interféron-gamma (IFN-&Doctorat en Sciences médicalesinfo:eu-repo/semantics/nonPublishe

Réponses immunitaires du grand prématuré à la vaccination contre la coqueluche

Les enfants nés prématurément, et plus particulièrement les grands prématurés nés avant31 semaines d’âge gestationnel, sont à haut risque de contracter des infections. Lavaccination peut prévenir certaines infections, dont la coqueluche qui est causée par labactérie Bordetella pertussis (Bp). Cependant, cette maladie infectieuse hautementcontagieuse est en recrudescence depuis plusieurs années malgré une bonne couverturevaccinale. La morbidité et surtout la mortalité de la coqueluche affectent plusparticulièrement les jeunes enfants, incomplètement ou non encore vaccinés.Il existe deux types de vaccins contre B. pertussis :les vaccins de première génération àcellules entières et les vaccins acellulaires, plus récents. Suite à l’apparition d’effetssecondaires causés par le vaccin à cellules entières, les vaccins acellulaires, comprenantseulement un certain nombre d’antigènes purifiés de B. pertussis, sont utilisés en Belgiquecomme dans de nombreux autres pays industrialisés.L’immunité protectrice contre B. pertussis fait appel tant à l’immunité cellulaire qu‘àl’immunité humorale. De nombreuses études ont démontré une production d’anticorpsspécifiques aux antigènes de B. pertussis suite à l’administration des différents types devaccins. Par contre, peu d’entre elles ont analysé la réponse d’immunité cellulaire spécifiquecaractérisée, entre autres, par une sécrétion d’Interféron-gamma (IFN-&Doctorat en Sciences médicalesinfo:eu-repo/semantics/nonPublishe

Prévalence de la colonisation fongique à Candida sp en réanimation chirurgicale au C.H.U. de Bicêtre (AP-HP) (étude sur 173 patients en 9 mois)

PARIS6-Bibl. St Antoine CHU (751122104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Les infections broncho-pulmonaires à germes atypiques chez l'enfant :Mythe ou réalité ?

Mycoplasma pneumoniae and Chlamydia pneumoniae are the most common atypical pathogens seen in respiratory infections in children. Currently, the management of atypical pneumonia due to these pathogens is blurry. The clinical features are hardly specific ;it appears that M. pneumoniae respiratory infect ions are associated with chest pain and the absence of wheezing, however, further confirmations are needed. Hoarseness is frequently seen with C. pneumoniae infection. Co-infections with viruses, bacteria or even between M. pneumoniae and C. pneumoniae can be frequent. Infection with either of these bacteria seems to increase the incidence of asthma. PCR appears to be the most sensitive and specific for rapid diagnosis of M. pneumoniae and C. pneumoniae infections, however, it cannot dif ferentiate asymptomatic carriage from infection. Serodiagnosis can be helpful. This requires two serum samples taken with several weeks interval. Macrolides are the classical antibiotics used for treatment of these pathogens. In vivo efficacy of antibiotic treatment of M. pneumoniae remains unclear. Resistance to macrolides in M. pneumoniae treatment has been described. In conclusion, there is still a lack in scientific literature of high level evidences and clear consensus in the management of suspicious infection due to M. pneumoniae and C. pneumoniae.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cellular and humoral immune responses of preterm babies to the first administration of the pertussis vaccines.

info:eu-repo/semantics/nonPublishe

Le point en néonatologie

During the last years, neonatology has greatly improved. In the last decade, mortality and morbidity have decreased :mortality from respiratory failure of prematurity has decreased from 22% to 12%, mortality of the very low birthweight infants under 1000 g fell from 56% to 35% and mortalities related to asphyxia have diminished from 21% to 12% and to malformations from 33% to 28%. Prematurity is now the first cause of neonatal mortality. During this period, the number of babies under 1000 g has increased 4-fold and the number of multiple births increased more than 2-fold from 3% to 7% of the live births of our hospital. Attitudes towards the premature infant have changed, especially towards the extremely small (called the micropremies). The number of disabled children has increased in parallel with the better survival of the very immature newborns who till recently were not rescuscitated.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Hypoxic pulmonary vasoconstriction and gas exchange in acute canine pulmonary embolism.

Hypoxic pulmonary vasoconstriction (HPV) is inhibited in several models of acute lung injury. Whether HPV is preserved in pulmonary embolism is unknown. We investigated the effects of a reduction in the fraction of inspired O2 (FIO2) on pulmonary hemodynamics and gas exchange in anesthetized dogs before and after autologous blood clot pulmonary embolism. In a first group of 14 dogs, stimulus-response curves for HPV were constructed as pulmonary arterial pressure (Ppa) vs. FIO2 varied between 1.0 and 0.06 at a cardiac output (Q) kept constant at 3.5 l.min-1.m-2. Gas exchange was evaluated by using the multiple inert-gas elimination technique at FIO2 of 1.0, 0.4, and 0.1. Embolism decreased the relative magnitude of HPV, expressed as the gradient between Ppa and pulmonary arterial occluded pressure in hypoxia divided by (Ppa-pulmonary arterial occluded pressure) at FIO2 of 1.0, from 1.8 to 1.2 (P < 0.05). Retention minus excretion gradients for sulfur hexafluoride and ethane were increased by decreased FIO2 (P < 0.005 and P < 0.05, respectively) before but not after embolism. Hypoxia-induced deterioration in gas exchange before embolism was related to the amount of baseline very low ventilation-perfusion (VA/Q) ratios. Similar results were obtained in a second group of seven dogs with Q decreased to maintain Ppa at the same average value as before embolism. However, gas exchange was not affected by inspiratory hypoxia before as well as after embolism in this group, which presented with a lesser amount of baseline very low VA/Q. In both groups of dogs, increase in the FIO2 from 0.4 to 1.0 did not affect gas exchange. We conclude that 1) pulmonary embolism is associated with a partial inhibition of HPV, 2) HPV does not contribute to preserve gas exchange in pulmonary embolism, and 3) a strong HPV may deteriorate gas exchange in severe hypoxia in the presence of minor very low VA/Q inequality.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe