Host-pathogen biotic interactions shaped vitamin K metabolism in Archaeplastida.

Menaquinone (vitamin K2) shuttles electrons between membrane-bound respiratory complexes under microaerophilic conditions. In photosynthetic eukaryotes and cyanobacteria, phylloquinone (vitamin K1) participates in photosystem I function. Here we elucidate the evolutionary history of vitamin K metabolism in algae and plants. We show that Chlamydiales intracellular pathogens made major genetic contributions to the synthesis of the naphthoyl ring core and the isoprenoid side-chain of these quinones. Production of the core in extremophilic red algae is under control of a menaquinone (Men) gene cluster consisting of 7 genes that putatively originated via lateral gene transfer (LGT) from a chlamydial donor to the plastid genome. In other green and red algae, functionally related nuclear genes also originated via LGT from a non-cyanobacterial, albeit unidentified source. In addition, we show that 3-4 of the 9 required steps for synthesis of the isoprenoid side chains are under control of genes of chlamydial origin. These results are discussed in the light of the hypoxic response experienced by the cyanobacterial endosymbiont when it gained access to the eukaryotic cytosol.

Solitary fibrous tumor of the pleura: Can computed tomography features help predict malignancy? A series of 56 patients with histopathological correlates.

OBJECTIVE: To identify computed tomography (CT) predictors of malignancy, from a retrospective study of preoperative CT scans of patients with solitary fibrous tumors (SFT) of the pleura. PATIENTS AND METHODS: The CT scans of 56 patients with histopathologically confirmed SFT (33 women and 23 men; mean age, 60years) who underwent surgery between December 2004 and November 2012 were retrospectively analyzed by three radiologists working in consensus, blinded to the final histological diagnosis. RESULTS: SFT was asymptomatic and incidentally discovered in 22 patients (45.8%). Resection specimen analysis (R0 resection in all cases) revealed that 23 tumors (41%) were malignant. The CT features, which significantly differed between malignant and benign SFTs were tumor size (P=0.002) with a discriminative threshold value of 10cm, tumor heterogeneity before (P=0.02) and after (P=0.03) intravenous administration of iodinated contrast material, presence of intratumoral hydric attenuation areas (P=0.01), pleural effusion (P=0.01), measurable intratumoral vessels (P=0.02), hypervascularization with visible intratumoral vessels and/or marked enhancement (P=0.001). Presence of intratumoral calcifications (P=0.2) and maximum post-contrast enhancement value (P=0.6) were not significantly different between the two groups. CONCLUSION: A size greater than or equal to 10cm, hypervascularization, attenuation heterogeneity and association with pleural effusion are individual variables that suggest malignant SFT on CT.

THORACIC INVOLVEMENT IN CONNECTIVE TISSUE DISEASES: RADIOLOGICAL PATTERNS AND FOLLOW-UP.

Connective tissue diseases (CTDs) are a heterogeneous group of idiopathic inflammatory diseases involving various organs. A thoracic involvement is frequent, and chest-CT represents the imaging technique of reference in its assessment. Pulmonary abnormalities related to CTDs are various; although several disease-specific aspects have been described, the two most clinically relevant complications are represented by interstitial lung disease and pulmonary arterial hypertension. The early identification of a thoracic involvement, with the adoption of specific therapies, can significantly change patient's prognosis. The aim of this article is to review the most common typical and atypical CT features of thoracic involvement occurring in CT, especially focusing on interstitial lung disease.

Pulmonary aspergillosis.

Aspergillosis is a mycotic disease usually caused by Aspergillus fumigatus, a saprophytic and ubiquitous airborne fungus. Aspergillus-related lung diseases are traditionally classified into four different forms, whose occurrence depends on the immunologic status of the host and the existence of an underlying lung disease. Allergic broncho-pulmonary aspergillosis (ABPA) affects patients with asthma or cystic fibrosis. Saprophytic infection (aspergilloma) occurs in patients with abnormal airways (chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis) or chronic lung cavities. Chronic necrotizing aspergillosis (semi-invasive form) is described in patients with chronic lung pathology or mild immunodeficiency. Invasive aspergillosis (angio-invasive or broncho-invasive forms) occurs in severely immuno-compromised patients. Knowledge of the various radiological patterns for each form, as well as the corresponding associated immune disorders and/or underlying lung diseases, helps early recognition and accurate diagnosis.