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1.
FASEB J ; 33(6): 7387-7402, 2019 06.
Article de Anglais | MEDLINE | ID: mdl-30860871

RÉSUMÉ

Glucocorticoids (GCs) potently induce T-cell apoptosis in a GC receptor (GR)-dependent manner and are used to control lymphocyte function in clinical practice. However, its downstream pathways remain controversial. Here, we showed that GC-induced transcript 1 (GLCCI1) is a novel downstream molecule of the GC-GR cascade that acts as an antiapoptotic mediator in thymic T cells. GLCCI1 was highly phosphorylated and colocalized with microtubules in GLCCI1-transfected human embryonic kidney QBI293A cells. GR-dependent up-regulation of GLCCI1 was associated with GC-induced proapoptotic events in a cultured thymocyte cell line. However, GLCCI1 knockdown in a thymocyte cell line led to apoptosis. Consistently, transgenic mice overexpressing human GLCCI1 displayed enlarged thymi that consisted of larger numbers of thymocytes. Further molecular characterization showed that GLCCI1 bound to both dynein light chain LC8-type 1 (LC8) and its functional kinase, p21-protein activated kinase 1 (PAK1), thereby inhibiting the kinase activity of PAK1 toward LC8 phosphorylation, a crucial event in apoptotic signaling. GLCCI1 induction facilitated LC8 dimer formation and reduced Bim expression. Thus, GLCCI1 is a candidate factor involved in apoptosis regulation of thymic T cells.-Kiuchi, Z., Nishibori, Y., Kutsuna, S., Kotani, M., Hada, I., Kimura, T., Fukutomi, T., Fukuhara, D., Ito-Nitta, N., Kudo, A., Takata, T., Ishigaki, Y., Tomosugi, N., Tanaka, H., Matsushima, S., Ogasawara, S., Hirayama, Y., Takematsu, H., Yan, K. GLCCI1 is a novel protector against glucocorticoid-induced apoptosis in T cells.


Sujet(s)
Apoptose/physiologie , Glucocorticoïdes/physiologie , Récepteurs aux glucocorticoïdes/physiologie , Lymphocytes T/cytologie , Séquence d'acides aminés , Animaux , Apoptose/effets des médicaments et des substances chimiques , Protéine-11 analogue à Bcl-2/biosynthèse , Protéine-11 analogue à Bcl-2/génétique , Lignée cellulaire , Dynéines cytoplasmiques/métabolisme , Dimérisation , Régulation négative , Techniques de knock-down de gènes , Glucocorticoïdes/pharmacologie , Humains , Hypertrophie , Mâle , Souris , Souris de lignée C57BL , Souris transgéniques , Microtubules/métabolisme , Phosphorylation , Cartographie d'interactions entre protéines , Maturation post-traductionnelle des protéines , Interférence par ARN , Petit ARN interférent/génétique , Petit ARN interférent/pharmacologie , Récepteurs aux glucocorticoïdes/génétique , Protéines recombinantes/métabolisme , Alignement de séquences , Similitude de séquences d'acides aminés , Transduction du signal/physiologie , Thymus (glande)/anatomopathologie , p21-Activated Kinases/métabolisme
2.
Kansenshogaku Zasshi ; 89(2): 237-43, 2015 Mar.
Article de Japonais | MEDLINE | ID: mdl-26552120

RÉSUMÉ

We analyzed non-serotype b encapsulated Haemophilus influenzae (non-b Hi) isolated from pediatric patients at Chiba Children's Hospital during 2000-2012. Among 3,532 clinical isolates of H. influenzae, there were 57 (1.6%) strains of non-b Hi, 152 (4.3%) of serotype b H. influenzae (Hib), and 3,323 (94.1%) of non-typeable H. influenzae (NTHi). Fifty-seven strains of non-b Hi were serotyped useing the slide agglutination test and PCR. Twenty-nine strains were identified as type e (Hie) and 28 as type f (Hif), and the results according to the slide agglutination test and PCR were completely identical. Whereas 52 of 57 strains (91.2%) were isolated from respiratory specimen, only one Hif strain (1.8%) was isolated from a sterile site. There were 47 (82.4%) ß-lactamase-non-producing ampicillin (ABPC)-sensitive strains (BLNAS), 5 (8.8%) ß-lactamase-producing strains (BLP), and only 1 (1.8%) ß-lactamase-non-producing ABPC-resistant strain (BLNAR). Thus the frequency of non-b Hi was lower than that of Hib. The source of non-b Hi was similar to that of NTHi, which was mainly isolated from respiratory specimen. Antimicrobial resistant pattern of non-b Hi was different from that of Hib in which the frequency of BLP was relatively high, and NTHi in which that of BLNAR was high. An increase of invasive H. influenzae infections caused by NTHi, Hie, and Hif was reported in the countries where Hib vaccine had been widely used. Because it is assumed that invasive non-Hib infection will be predominant in the near future in Japan, serotyping of invasive strains is crucial. Continuous monitoring of distribution of non-b Hi in the clinical isolates of H. influenzae is also important.


Sujet(s)
Haemophilus influenzae/isolement et purification , Capsules bactériennes , Enfant , Enfant d'âge préscolaire , Résistance bactérienne aux médicaments , Haemophilus influenzae/effets des médicaments et des substances chimiques , Humains , Nourrisson , Sérogroupe
3.
J Med Microbiol ; 64(Pt 4): 355-358, 2015 Apr.
Article de Anglais | MEDLINE | ID: mdl-25657301

RÉSUMÉ

In Japan, publicly subsidized Haemophilus influenzae serotype b vaccines became available in 2011; consequently, the incidence of invasive H. influenzae infection in paediatric patients of less than 5 years of age decreased dramatically. In 2013, the first case of H. influenzae serotype f (Hif) meningitis in a Japanese infant was reported, and another case of Hif meningitis in a Japanese infant was observed in 2013. We experienced a fatal paediatric case of Hif bacteraemia in 2004; therefore, we conducted an analysis of the three Hif strains isolated from these three Japanese children with invasive Hif infections. All three strains were ß-lactamase-non-producing, ampicillin-sensitive strains, with MICs of 1 µg ml(-1) or less. However, one of the three strains showed slightly elevated MICs for ampicillin (1 µg ml(-1)), cefotaxime (0.25 µg ml(-1)) and meropenem (0.13 µg ml(-1)). A molecular analysis by multilocus sequence typing identified all three strains as sequence type (ST) 124, which is a predominant invasive Hif strain in many countries. SmaI-digested PFGE showed variable DNA fragmentation patterns among the strains, suggesting that some highly virulent strains have originated from a single ST124 clone and caused invasive Hif infections in Japan. Additional studies are needed to determine the factors that have led to the clonal expansion of virulent ST124 strains.


Sujet(s)
Bactériémie/microbiologie , Haemophilus influenzae/classification , Haemophilus influenzae/isolement et purification , Méningite à hémophilus/microbiologie , Sérogroupe , Ampicilline/pharmacologie , Antibactériens/pharmacologie , Bactériémie/épidémiologie , Enfant d'âge préscolaire , Électrophorèse en champ pulsé , Femelle , Génotype , Haemophilus influenzae/effets des médicaments et des substances chimiques , Humains , Nourrisson , Japon/épidémiologie , Méningite à hémophilus/épidémiologie , Tests de sensibilité microbienne , Épidémiologie moléculaire , Typage par séquençage multilocus , bêta-Lactamases/analyse
4.
Kansenshogaku Zasshi ; 87(5): 581-9, 2013 Sep.
Article de Japonais | MEDLINE | ID: mdl-24195167

RÉSUMÉ

We examined the antimicrobial susceptibility of 1,208 Haemophilus influenzae isolates obtained at a pediatric facility between 2009 and 2012. The percentage distribution of beta-lactamase-non-producing ampicillin (ABPC)-sensitive (BLNAS) strains was 38.2%, that of beta-lactamase-non-producing ABPC-intermediately resistant (BLNAI) strains was 13.9%, that of beta-lactamase-non-producing ABPC-resistant (BLNAR) strains was 38.2%, that of beta-lactamase-producing ABPC-resistant (BLPAR) strains was 5.2%, and that of beta-lactamase-producing clavulanic acid/amoxicillin-resistant (BLPACR) strains was 4.5%. Although the percentage of BLNAR strains increased dramatically from 13.9% (2000-2003; period I) to 32.7% (2004-2008; period II), it increased more slowly from period II to the present period (2009-2012). However, the percentage of BLNAI strains, which had decreased from 10.6% (period I) to 8.9% (period II), began to increase during the present period. Tosufloxacin (< or = 0.06 microg/mL) and tazobactam/piperacillin (< or = 0.13 microg/mL) exhibited a low 90% minimum inhibitory concentration for H. influenzae, as well as for BLNAR strains. A decreased susceptibility to cephems was also observed throughout all 3 periods. Serotype b strains (Hib) were observed in 54 of the 1,208 isolates (4.5%); their distribution decreased since period II (6.3%). In Hib, the percentage distribution of strains from patients less than 2 years of age, who are recommended to be vaccinated against Hib, decreased from 56.8% to 29.6%, and this reduction seems to have been achieved by increasing the percentage of Hib vaccine inoculations in Japan. Non-serotype b-capsulated strains were identified in 21 isolates (1.7%), and 11 of them were serotyped as type e, whereas the other 10 were serotyped as type f.


Sujet(s)
Antibactériens/usage thérapeutique , Infections à Haemophilus/traitement médicamenteux , Haemophilus influenzae/isolement et purification , Enfant , Enfant d'âge préscolaire , Prédisposition aux maladies , Femelle , Humains , Nourrisson , Japon , Mâle , Sérotypie/méthodes , Résultat thérapeutique
5.
Kansenshogaku Zasshi ; 87(5): 590-5, 2013 Sep.
Article de Japonais | MEDLINE | ID: mdl-24195168

RÉSUMÉ

While the incidence of Haemophilus influenzae type b (Hib) meningitis is expected to decrease with the widespread use of the Hib vaccine, the resistance of Hib has actually increased. Therefore, selection of the initial antibiotics used for treatment must be performed with resistant bacteria, including beta-lactamase negative ampicillin resistant H. influenzae (BLNAR), in mind. Tazobactam/piperacillin (TAZ/PIPC) has a satisfactory minimum inhibitory concentration (MIC) against BLNAR and is a beta-lactamase inhibitor. Although there is no insurance coverage for its use in patients with meningitis, the penetration of TAZ/PIPC into cerebrospinal fluid (CSF) in animal experiments promises a satisfactory result, and we have been using a combination of ceftriaxone (CTRX) and TAZ/PIPC as an initial treatment and a resistant bacteria countermeasure in patients with Hib meningitis at our hospital since 2008. We examined the concentration of TAZ/PIPC in CSF to further investigate the possibility of using TAZ/PIPC as an antibiotic treatment against bacterial meningitis. In cases treated with a 1: 8 drug formulation of TAZ/PIPC against Hib meningitis at our hospital, we used the remaining portion of a CSF sample collected after the initiation of TAZ/PIPC administration and then measured the concentrations of TAZ and PIPC in the CSF. Six specimens from 5 patients between the ages of 6 and 59 months were examined. The dosage of TAZ/PIPC was 95.7-113.6 mg/kg/dose x 3 times/day, and the CSF concentrations at 0-105 minutes after the completion of the administration were 0.319-1.32 microg/mL for TAZ and 2.54-7.74 microg/mL for PIPC. With the approved dosage, the peak concentration level during the acute period indicated a sufficient CSF concentration level for the antibacterial and beta-lactamase inhibition effects against Hib. As an antibiotic treatment for H. influenzae meningitis, the combined usage of TAZ/PIPC is likely to be effective as a resistant bacteria countermeasure, in addition to third-generation cephem drugs and meropenem.


Sujet(s)
Antibactériens/usage thérapeutique , Méningite à hémophilus/liquide cérébrospinal , Acide pénicillanique/analogues et dérivés , Antibactériens/administration et posologie , Enfant d'âge préscolaire , Association de médicaments/méthodes , Femelle , Humains , Mâle , Méningite à hémophilus/traitement médicamenteux , Tests de sensibilité microbienne , Acide pénicillanique/liquide cérébrospinal , Pipéracilline/liquide cérébrospinal , Association de pipéracilline et de tazobactam , Résultat thérapeutique
6.
Pediatr Int ; 54(4): 558-62, 2012 Aug.
Article de Anglais | MEDLINE | ID: mdl-22830548

RÉSUMÉ

We report a 6-year-old boy with no major disease history or allergic conditions initially presented with pneumonia, progressed to acute respiratory distress syndrome and acute myocarditis caused by pandemic 2009H1N1 influenza diagnosed with RT-PCR testing, successfully managed with mechanical ventilation and percutaneous cardiopulmonary support system. Marked transient elevation of IgE in acute phase of the disease and the subsequent diagnosis of atopic asthma in our patient suggested a possible role of an underlying allergic condition in the clinicopathological process. Critically ill 2009H1N1-infected patient with acute respiratory failure should carefully be physiologically monitored together with serial assessment of biomarkers aiming at a favorable cardiac outcome by giving the timely diagnosis and intervention.


Sujet(s)
Sous-type H1N1 du virus de la grippe A , Grippe humaine , Myocardite/virologie , Enfant , Humains , Grippe humaine/épidémiologie , Mâle , Pandémies
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