Numerous viruses, including influenza virus, measles virus, Hantavirus, adenovirus, herpesviruses, varicella-zoster virus, cytomegalovirus, and Epstein-Barr virus, can cause lower respiratory tract infection in adults. Viral pneumonia in adults can be classified into two clinical groups: so-called atypical pneumonia in otherwise healthy hosts and viral pneumonia in immunocompromised hosts. Influenza virus types A and B cause most cases of viral pneumonia in immunocompetent adults. Immunocompromised hosts are susceptible to pneumonias caused by cytomegalovirus, herpesviruses, measles virus, and adenovirus. The radiographic findings, which consist mainly of patchy or diffuse ground-glass opacity with or without consolidation and reticular areas of increased opacity, are variable and overlapping. Computed tomographic findings, which are also overlapping, consist of poorly defined centrilobular nodules, ground-glass attenuation with a lobular distribution, segmental consolidation, or diffuse ground-glass attenuation with thickened interlobular septa. The radiologic findings reflect the variable extents of the histopathologic features: diffuse alveolar damage (intraalveolar edema, fibrin, and variable cellular infiltrates with a hyaline membrane), intraalveolar hemorrhage, and interstitial (intrapulmonary or airway) inflammatory cell infiltration. Clinical information such as patient age, immune status, community outbreaks, symptom onset and duration, and presence of a rash remain important aids in diagnosis of viral causes.

Dynamic enhancement with multi-detector row CT shows high sensitivity and negative predictive values for diagnosis of malignant nodules but low specificity because of highly enhancing benign nodules. Extent of enhancement reflects underlying nodule angiogenesis.

Collagen vascular diseases that demonstrate features of interstitial lung disease include systemic lupus erythematosus, rheumatoid arthritis, progressive systemic sclerosis, dermatomyositis and polymyositis, ankylosing spondylitis, Sjögren syndrome, and mixed connective tissue disease. At histopathologic analysis, interstitial lung diseases associated with collagen vascular diseases are diverse and include nonspecific interstitial pneumonia, usual interstitial pneumonia, bronchiolitis obliterans organizing pneumonia (BOOP), apical fibrosis, diffuse alveolar damage, and lymphocytic interstitial pneumonia. Although proportions of interstitial pneumonias vary, nonspecific interstitial pneumonia accounts for a large proportion, especially in progressive systemic sclerosis, dermatomyositis and polymyositis, and mixed connective tissue disease. The more favorable prognosis in interstitial pneumonia associated with collagen vascular diseases than in idiopathic interstitial pneumonias may be explained by the larger proportion of nonspecific interstitial pneumonia than of usual interstitial pneumonia. High-resolution computed tomography seems to help characterize and determine the extent of interstitial lung disease in collagen vascular diseases.

A variety of pulmonary resection techniques are currently available, including pneumonectomy (intrapleural, extrapleural, intrapericardial, and sleeve pneumonectomy), lobectomy, and limited resection (sleeve lobectomy, segmentectomy, nonanatomic parenchyma-sparing resection). However, pulmonary resection is often followed by postoperative complications that differ according to the type of surgery and the time elapsed since surgery was performed. The most common complications are bleeding, pulmonary edema, atelectasis, pneumonia, persistent air leak, bronchopleural fistula, and empyema. Other, less frequent complications include cardiac herniation, lung torsion, chylothorax, anastomotic dehiscence, wound infection, esophagopleural fistula, and recurrent tumor. The radiologist plays a major role in the diagnosis of various complications following pulmonary resection. Unfortunately, chest radiography has a relatively low diagnostic accuracy in the detection of these complications. When radiographic findings are subtle or equivocal, computed tomography frequently allows more accurate identification of the disease process. Several complications that follow pulmonary resection are life-threatening and require prompt management. Therefore, knowledge of the diverse radiologic appearances of these complications as well as familiarity with the clinical settings in which specific complications are likely to occur are vital for prompt, effective treatment.

BACKGROUND/OBJECTIVESSargassum horneri is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of South Korea, China, and Japan. Recently, an extreme amount of S. horneri moved into the coasts of Jeju Island from the east coast of China, which made huge economic and environmental loss to the Jeju Island. Thus, utilization of this biomass becomes a big issue with the local authorities. Therefore, the present study was performed to evaluate the anti-inflammatory potential of crude polysaccharides (CPs) extracted from S. horneri China strain in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.MATERIALS/METHODSCPs were precipitated from S. horneri digests prepared by enzyme assistant extraction using four food-grade enzymes (AMG, Celluclast, Viscozyme, and Alcalase). The production levels of nitric oxide (NO) and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1β were measured by Griess assay and enzyme-linked immunosorbent assay, respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-κB, and mitogen-activated protein kinases (MAPKs) were measured by using western blot. The IR spectrums of the CPs were recorded using a fourier transform infrared spectroscopy (FT-IR) spectrometer.RESULTSThe polysaccharides from the Celluclast enzyme digest (CCP) showed the highest inhibition of NO production in LPS-stimulated RAW 264.7 cells (IC50 value: 95.7 µg/mL). Also, CCP dose-dependently down-regulated the protein expression levels of iNOS and COX-2 as well as the production of inflammatory cytokines, including TNF-α and IL-1β, compared to the only LPS-treated cells. In addition, CCP inhibited the activation of NF-κB p50 and p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase, in LPS-stimulated RAW 264.7 cells. Furthermore, FT-IR analysis showed that the FT-IR spectrum of CCP is similar to that of commercial fucoidan.CONCLUSIONSOur results suggest that CCP has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.

Summary The interface between the membrane (MS) and cytoplasmic (C) rings of the bacterial flagellar motor couples torque generation to rotation within the membrane. The structure of the C-terminal helices of the integral membrane protein FliF (FliFC) bound to the N-terminus of the switch complex protein FliG (FliGN) reveals that FliGN folds around FliFC to produce a topology that closely resembles both the middle and C-terminal domains of FliG. The interface is consistent with solution-state NMR, SAXS, in vivo interaction studies and cellular motility assays. Co-folding with FliFC induces substantial conformational changes in FliGN, and suggests that FliF and FliG have the same stoichiometry within the rotor. Modeling the FliFC:FliGN complex into cryoEM rotor density updates the architecture of the middle and upper switch complex and shows how domain shuffling of a conserved interaction module anchors the cytoplasmic rotor to the membrane.

MotA and MotB are membrane proteins that form the stator of the bacterial flagellar motor. Each motor contains several MotA 4 MotB 2 complexes, which function independently to conduct protons across the membrane and couple proton flow to rotation. The mechanism of rotation is not understood in detail but is thought to involve conformational changes in the stator complexes driven by proton association/dissociation at a critical Asp residue of MotB (Asp 32 in the protein of Escherichia coli). MotA has four membrane segments and MotB has one. Previous studies using targeted disulfide crosslinking showed that the membrane segments of the two MotB subunits are together at the center of the complex, surrounded by the TM3 and TM4 segments of the four MotA subunits. Here, the cross-linking studies are extended to TM1 and TM2 of MotA, using Cys residues introduced in several positions in the segments. The observed patterns of disulfide cross-linking indicate that the TM2 segment is positioned between segments TM3 and TM4 of the same subunit, where it could contribute to the proton-channel-forming part of the structure. TM1 is at the interface between TM4 of its own subunit and the TM3 segment of another subunit, where it could stabilize the complex. A structural model based on the cross-linking results shows unobstructed pathways reaching from the periplasm to the Asp 32 residues near the inner ends of the MotB segments. The model indicates a close proximity for certain conserved, functionally important residues. The results are used to develop an explicit model for the proton-induced conformational change in the stator.The bacterial flagellar motor is an ion-fueled machine capable of turning at hundreds of revolutions per second (1-3). In most species, the motor can turn either CW or CCW, and reversals in direction are the basis of regulated movement such as chemotaxis (4,5). Although more than two-dozen proteins are needed for assembly and operation of the flagellum, only five are thought to function closely in rotation. FliG, FliM, and FliN form the "switch complex" on the rotor that determines the direction of rotation (6,7). MotA and MotB are membrane proteins that form the stator, functioning to conduct protons across the membrane and couple proton flow to rotation (8-12) (Figure 1, left). While structural studies of the rotor proteins are fairly advanced (13-16), less is known about the structure of the stator. The stator complexes have subunit composition MotA 4 MotB 2 (17,18). MotA has four TM segments, relatively large domains in the cytoplasm, and only short segments in the periplasm (9,19). MotB has a short segment in the cytoplasm, a single TM segment, and a large periplasmic domain that includes features believed to bind peptidoglycan (10,20,21 In a current model for the rotation mechanism, torque is produced as the stator undergoes conformational changes driven by proton association/dissociation at Asp 32 (23). In support of this model, mutations that neutralized the charge of Asp 32 (e.g., replace...

The bacterial flagellum contains a specialized secretion apparatus in its base that pumps certain protein subunits through the growing structure to their sites of installation beyond the membrane. A related apparatus functions in the injectisomes of gram-negative pathogens to export virulence factors into host cells. This mode of protein export is termed type-III secretion (T3S). Details of the T3S mechanism are unclear. It is energized by the proton gradient; here, a mutational approach was used to identify proton-binding groups that might function in transport. Conserved proton-binding residues in all the membrane components were tested. The results identify residues R147, R154, and D158 of FlhA as most critical. These lie in a small, well conserved cytoplasmic domain of FlhA, located between trans-membrane segments 4 and 5. Two-hybrid experiments demonstrate self-interaction of the domain, and targeted cross-linking indicates that it forms a multimeric array. A mutation that mimics protonation of the key acidic residue (D158N) was shown to trigger a global conformational change that affects the other, larger cytoplasmic domain that interacts with the export cargo. The results are discussed in the framework of a transport model based on proton-actuated movements in the cytoplasmic domains of FlhA.