ObjectivesTo examine whether the extent of fibroproliferative changes on high-resolution CT (HRCT) scan influences prognosis, ventilator dependency and the associated outcomes in patients with early acute respiratory distress syndrome (ARDS).DesignA prospective observational cohort study.SettingIntensive care unit in a teaching hospital.Participants85 patients with ARDS who met American-European Consensus Conference Criteria and eligible criteria.InterventionsHRCT scans were performed and prospectively evaluated by two independent observers on the day of diagnosis and graded into six findings according to the extent of fibroproliferation. An overall HRCT score was obtained by previously published method.Primary and secondary outcomesThe primary outcome was 60-day mortality. Secondary outcomes included the number of ventilator-free days, organ failure-free days, the incidence of barotraumas and the occurrence of ventilator-associated pneumonia.ResultsHigher HRCT scores were associated with statistically significant decreases in organ failure-free days as well as ventilator-free days. Multivariate Cox proportional hazards model showed that the HRCT score remained an independent risk factor for mortality (HR 1.20; 95% CI 1.06 to 1.36; p=0.005). Multivariate analysis also revealed that the CT score had predictive value for ventilator weaning within 28 days (OR 0.63; 95% CI 0.48 to 0.82; p=0.0006) as well as for an incidence of barotraumas (OR 1.61; 95% CI 1.08 to 2.38; p=0.018) and for an occurrence of ventilator-associated pneumonia (OR 1.46; 95% CI 1.13 to 1.89; p=0.004). A HRCT score <210 enabled prediction of 60-day survival with 71% sensitivity and 72% specificity and of ventilator-weaning within 28 days with 75% sensitivity and 76% specificity.ConclusionsPulmonary fibroproliferation assessed by HRCT in patients with early ARDS predicts increased mortality with an increased susceptibility to multiple organ failure, including ventilator dependency and its associated outcomes.

Dendritic cells (DCs) play critical roles in innate immunity and adaptive immunity (4). Immature DCs reside in peripheral tissues, where they serve as sentinels for foreign antigens and microbial pathogens. Upon activation, immature DCs undergo maturation and migrate to the lymph nodes. During maturation, DCs acquire an enhanced capacity to form and accumulate peptides, major histocompatibility complex (MHC) class II molecules, costimulatory molecules (such as CD40, CD80, and CD86), and antigens of unknown functions (such as CD83 and DC-LAMP) (10). Mature DCs can prime naïve T cells and initiate primary T-cell-mediated immune responses (4). In addition, there is increasing evidence that DCs in situ induce antigen-specific unresponsiveness or tolerance in central lymphoid organs and in peripheral tissues (4, 31). Thus, DCs play a crucial role during the initiation and regulation of immune responses. Recently, we and others reported that DCs are essential for granuloma formation against bacterial antigens in animal models (12,33,36).Osteopontin (OPN), also known as early T-lymphocyte activation-1 (Eta-1), is a phosphoprotein that contains arginineglycine-aspartate (RGD). Although OPN is classified as an extracellular matrix (ECM) protein, OPN has only recently been shown to be an important component of early cellular immune responses (18). OPN has various functions in chemotaxis for immune cells, tumor metastasis, neovascularization, and host defense, including control of nitric oxide production, control of infection, and control of cell adhesion (3,5,9,21,25). These mechanisms are regulated by posttranslational modifications, such as cleavage by thrombin, addition of a glucose chain, and phosphorylation. Various immunological disorders are associated with high levels of OPN expression (8,15). Analyses of OPN-deficient mice revealed that OPN plays an important immunological role in granuloma formation (23), acid-fast bacillus disease (21), and carcinoma metastasis (5). The role of OPN in inflammation suggests that ECM-related proteins may function as pleiotropic cytokines to regulate immune responses. Activated macrophages, lymphocytes, and natural killer (NK) cells produce OPN in response to various stimuli (23). However, there are no reports of the effects of OPN on DCs, with the exception of a single report of the migratory effect of OPN on cutaneous Langerhans cells and DCs in a mouse allergic cutaneous hypersensitivity model (34). The direct effect of OPN on the development and activation of DCs has not been clarified. Thus, we sought to characterize the functional interaction between OPN and DCs by examining the effects of OPN on differentiation, maturation, and function of human monocyte-derived immature and mature DCs. We report here that human monocyte-derived dendritic cell (Mo-DC) can produce OPN that enhances differentiation, maturation, and survival of DCs by autocrine and/or paracrine pathways. MATERIALS AND METHODSReagents. Recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) ...

Amelogenesis imperfecta (AI) is a group of commonly inherited defects of dental enamel formation, which exhibits marked genetic and clinical heterogeneity. The genetic basis of this heterogeneity is still poorly understood. Enamelin, the affected gene product in one form of AI (AIH2), is an extracellular matrix protein that is one of the components of enamel. We isolated three ENU-induced dominant mouse mutations, M100395, M100514 and M100521, which caused AI-like phenotypes in the incisors and molars of the affected individuals. Linkage analyses mapped each of the three mutations to a region of chromosome 5 that contained the genes encoding enamelin (Enam) and ameloblastin (Ambn). Sequence analysis revealed that each mutation was a single-base substitution in Enam. M100395 (Enam(Rgsc395)) and M100514 (Enam(Rgsc514)) were putative missense mutations that caused S to I and E to G substitutions at positions 55 and 57 of the translated protein, respectively. Enam(Rgsc395) and Enam(Rgsc514) heterozygotes showed severe breakage of the enamel surface, a phenotype that resembled local hypoplastic AI. The M100521 mutation (Enam(Rgsc521)) was a T to A substitution at the splicing donor site in intron 4. This mutation resulted in a frameshift that gave rise to a premature stop codon. The transcript of the Enam(Rgsc521) mutant allele was degraded, indicating that Enam(Rgsc521) is a loss-of-function mutation. Enam(Rgsc521) heterozygotes showed a hypomaturation-type AI phenotype in the incisors, possibly due to haploinsufficiency of Enam. Enam(Rgsc521) homozygotes showed complete loss of enamel on the incisors and the molars. Thus, we report here that the Enam gene is essential for amelogenesis, and that mice with different point mutations at Enam may provide good animal models to study the different clinical subtypes of AI.

No abstract

Mammal-fish-conserved-sequence 1 (MFCS1) is a highly conserved sequence that acts as a limb-specific cis-acting regulator of Sonic hedgehog (Shh) expression, residing 1 Mb away from the Shh coding sequence in mouse. Using gene-driven screening of an ENU-mutagenized mouse archive, we obtained mice with three new point mutations in MFCS1: M101116, M101117, and M101192. Phenotype analysis revealed that M101116 mice exhibit preaxial polydactyly and ectopic Shh expression at the anterior margin of the limb buds like a previously identified mutant, M100081. In contrast, M101117 and M101192 show no marked abnormalities in limb morphology. Furthermore, transgenic analysis revealed that the M101116 and M100081 sequences drive ectopic reporter gene expression at the anterior margin of the limb bud, in addition to the normal posterior expression. Such ectopic expression was not observed in the embryos carrying a reporter transgene driven by M101117. These results suggest that M101116 and M100081 affect the negative regulatory activity of MFCS1, which suppresses anterior Shh expression in developing limb buds. Thus, this study shows that gene-driven screening for ENU-induced mutations is an effective approach for exploring the function of conserved, noncoding sequences and potential cis-regulatory elements.