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11.
12.
Transient requirement of the PrrA-PrrB two-component system for early intracellular multiplication of Mycobacterium tuberculosis 总被引:1,自引:0,他引:1 下载免费PDF全文
Ewann F Jackson M Pethe K Cooper A Mielcarek N Ensergueix D Gicquel B Locht C Supply P 《Infection and immunity》2002,70(5):2256-2263
Adaptive regulation of gene expression in response to environmental changes is a general property of bacterial pathogens. By screening an ordered transposon mutagenesis library of Mycobacterium tuberculosis, we have identified three mutants containing a transposon in the coding sequence or in the 5' regions of genes coding for two-component signal transduction systems (trcS, regX3, prrA). The intracellular multiplication capacity of the three mutants was investigated in mouse bone marrow-derived macrophages. Only the prrA mutant showed a defect in intracellular growth during the early phase of infection, and this defect was fully reverted when the mutant was complemented with prrA-prrB wild-type copies. The mutant phenotype was transient, as after 1 week this strain recovered full growth capacity to reach levels similar to that of the wild type at day 9. Moreover, a transient induction of prrA promoter activity was observed during the initial phase of macrophage infection, as shown by a prrA promoter-gfp fusion in M. bovis BCG infecting the mouse macrophages. The concordant transience of the prrA mutant phenotype and prrA promoter activity indicates that the PrrA-PrrB two-component system is involved in the environmental adaptation of M. tuberculosis, specifically in an early phase of the intracellular growth, and that, similar to other facultative intracellular parasites, M. tuberculosis can use genes temporarily required at different stages in the course of macrophage infection. 相似文献
13.
Camille Granger Paul Guedeney Camille Arnaud Soulef Guendouz Claire Cimadevilla Mathieu Kerneis Caroline Kerneis Michel Zeitouni Constance Verdonk Camille Legeai Guillaume Lebreton Pascal Leprince Eva Désiré Sabato Sorrentino Johanne Silvain Gilles Montalescot Fanny Hazan Shaida Varnous Richard Dorent 《Transplant international》2021,34(4):721-731
Available data on clinical presentation and mortality of coronavirus disease-2019 (COVID-19) in heart transplant (HT) recipients remain limited. We report a case series of laboratory-confirmed COVID-19 in 39 HT recipients from 3 French heart transplant centres (mean age 54.4 ± 14.8 years; 66.7% males). Hospital admission was required for 35 (89.7%) cases including 14/39 (35.9%) cases being admitted in intensive care unit. Immunosuppressive medications were reduced or discontinued in 74.4% of the patients. After a median follow-up of 54 (19–80) days, death and death or need for mechanical ventilation occurred in 25.6% and 33.3% of patients, respectively. Elevated C-reactive protein and lung involvement ≥50% on chest computed tomography (CT) at admission were associated with an increased risk of death or need for mechanical ventilation. Mortality rate from March to June in the entire 3-centre HT recipient cohort was 56% higher in 2020 compared to the time-matched 2019 cohort (2% vs. 1.28%, P = 0.15). In a meta-analysis including 4 studies, pre-existing diabetes mellitus (OR 3.60, 95% CI 1.43–9.06, I2 = 0%, P = 0.006) and chronic kidney disease stage III or higher (OR 3.79, 95% CI 1.39–10.31, I2 = 0%, P = 0.009) were associated with increased mortality. These findings highlight the aggressive clinical course of COVID-19 in HT recipients. 相似文献
14.
The authors have studied the files of 50 consecutive patients (1987-89) operated for abdominal aortic aneurysm (AAA) and examined with CT. The criteria for inclusion were surgical features. CT can be made more accurate for the study of AAA: Thus the location of the neck of the aneurysm relative to the renal arteries was defined in 94% of all cases. In addition, CT yields information about the wall of the aneurysm, whether it be thickened (3 inflammatory aneurysms were properly diagnosed) or, mor importantly, weakened (solution of continuity in the wall in the "prior-to-rupture" appearance). Owing to the quality of its performances and to its noninvasive character, the authors regard CT with contrast injection as an essential technique for the preoperative assessment of abdominal aortic aneurysm in most cases. The examination must be carried out strictly, especially for the contiguous sections of the renal arteries and their extension to the crural arch. As it demonstrates weakened areas more easily, a more accurate study of the aneurysmal wall with CT might increase the surgical indications for some smaller aneurysms, the potential evolution of which does not seem to be associated with their diameter only. 相似文献
15.
Soto-Hernández JL Morales VA Lara Giron JC Balderrama Bañares J 《Clinical imaging》1999,23(4):209-214
Actinomycosis is an uncommon cause of intracranial infection. Epidural empyema represents about 6% of CNS actinomycotic lesions. A case of an epidural empyema with parietal bone osteomyelitis caused by Actinomyces israelii is presented. Relevant neuroimaging features were bone erosions and a multiloculated collection with annular contrast enhancing on CT. Postoperative MRI revealed extensive involvement of the neighbor dura, falx, and subdural space. MRI was crucial to follow-up the response to antibiotic treatment. 相似文献
16.
High-resolution computed tomography abnormalities in ex-insulators annually exposed to asbestos dust
Soulat JM Lauque D Esquirol Y Déprés M Giron J Claudel R Carles P 《American journal of industrial medicine》1999,36(6):593-601
BACKGROUND: characterize To the effects of high asbestos exposure during annual periods of insulation. METHOD: 170 ex-workers underwent clinical examination, spirometry, standard chest X-rays and high-resolution computed tomography (HRCT). Asbestos exposure was retrospectively assessed for latency, duration, and intensity. RESULTS: Sixty-six percent of these workers were annually exposed to high concentrations of asbestos dust. Respiratory symptoms were mild. One hundred and nineteen subjects had pleural or pulmonary changes on HRCT, compatible with asbestos exposure. Localized pleural thickening was found in 113 subjects (66.5%); pulmonary nodules or lines in 35 (20.6%). The presence of pleural plaques was linked to intensity of asbestos exposure (P <.01), and length of employment (P <.05). Parenchymal lesions were related to intensity (P <.05) and duration of exposure (P <.05). Lung function of subjects with X-ray changes was not significantly altered. CONCLUSIONS: Annual asbestos exposure led to a high prevalence of pleural plaques and to mild parenchymal anomalies. 相似文献
17.
Kazue Mizumura Takeshi Sugiur Hisashi Koda Kimiaki Katanosaka Banik Ratan Kumar Rocio Giron Makoto Tominaga 《Nihon shinkei seishin yakurigaku zasshi》2005,25(1):33-38
Bradykinin (BK), an endogenous algesic and sensitizing substance, excited nociceptors and sensitized their heat responses. These effects were mediated by B2 receptors (B2Rs) in normal condition, and B1 receptors were additionally recruited in inflammation. B2Rs were coupled with Gq/11 and their activation resulted in diacylglycerol and inositol triphosphate release. Diacylglycerol activated protein kinase (PK) Cepsilon in sensory neurons. To clarify what channel was modulated by PKC to depolarize nociceptor terminals, we examined the heat activation threshold (Tt) of heat-sensitive capsaicin receptor (TRPV1). Tt was lowered down to 31 degrees C by BK in concentration dependent manner through activation of PKCepsilon in cells heterologously expressing TRPV1 and B2Rs. Thus both excitation and sensitization to heat could be explained by one mechanism, lowering Tt of TRPV1. The same was observed in capsaicin-sensitive primary sensory neurons. However, TRPV1 knockout mice showed almost no change in BK-induced nociceptive behavior and nociceptor excitation, although BK-induced heat hyperalgesia completely disappeared, suggesting that TRPV1 was not the sole channel that was modulated by BK to depolarize nociceptor terminals. In addition nociceptor sensitivity to BK was augmented in inflamed animals, with B2R mRNA and protein upregulated. The mechanism for prostaglandin-induced augmentation of BK response is left open for future study. 相似文献
18.
Akshay Shetty Fanny Giron Mukul K. Divatia Muhammad I. Ahmad Sudha Kodali David Victor 《临床与转化肝病杂志(英文版)》2021,9(3):428-435
Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in the world. The rising prevalence of nonalcoholic steatohepatitis (NASH) has led to a 170% increase in NASH cirrhosis as the listing indication for liver transplantation from 2004 to 2013. As of 2018, NASH has overtaken hepatitis C as an indication for liver transplantation in the USA. After liver transplantation, the allograft often develops recurrent NAFLD among patients with known NASH cirrhosis. In addition to recurrent disease, de novo NAFLD has been reported in patients with other indications for liver transplantation. In this review, we will discuss the risk factors associated with recurrent and de novo NAFLD, natural course of the disease, and management strategies after liver transplantation. 相似文献
19.
目的:对一叶萩枝叶的化学成分进行研究。方法:应用各种色谱技术从一叶萩总碱部位中分离化合物,根据理化常数和波谱(NMR及MS等)分析方法对化合物的结构进行鉴定。结果:自一叶萩枝叶的总碱部位中分离得到11个化合物。分别鉴定为:(-)-15β-ethoxy-14,15-dihvdroviroallosecurinine(1),一叶萩碱(securinine,2),二氢一叶萩碱(14,15-dihydrosecurinine,3),4-epiph),llanthine(4),securitinine(5),右旋别一叶萩碱(viroallosecurinine,6),一叶萩醇A(securinol A,7),secu’amamineA(8),ent-phyllanthidine(9),(+)-aquilegiohde(10)和(+)-menisdaurilide(11)。结论:1为新化合物,4,8,10和11为首次从一叶萩中分离得到。 相似文献
20.
Fanny Varenne Ali Makky Mireille Gaucher-Delmas Frédéric Violleau Christine Vauthier 《Pharmaceutical research》2016,33(5):1220-1234