The Ionospheric Connection Explorer Mission: Mission Goals and Design

The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection between our world and our space environment. This connection is made in the ionosphere, which has long been known to exhibit variability associated with the sun and solar wind. However, it has been recognized in the 21st century that equally significant changes in ionospheric conditions are apparently associated with energy and momentum propagating upward from our own atmosphere. ICON's goal is to weigh the competing impacts of these two drivers as they influence our space environment. Here we describe the specific science objectives that address this goal, as well as the means by which they will be achieved. The instruments selected, the overall performance requirements of the science payload and the operational requirements are also described. ICON's development began in 2013 and the mission is on track for launch in 2017. ICON is developed and managed by the Space Sciences Laboratory at the University of California, Berkeley, with key contributions from several partner institutions.

Effect of the combined use of enamel matrix derivative and atelocollagen sponge scaffold on osteoblastic differentiation of mouse induced pluripotent stem cells in vitro

BACKGROUND AND OBJECTIVE

Induced pluripotent stem cells (iPSCs) are a candidate cell source in periodontal regenerative therapy. Enamel matrix derivative (EMD) has been shown to regenerate periodontal tissues, and atelocollagen sponge (ACS) is considered a suitable scaffold or carrier for growth factors. This study aimed to investigate the effect of combined use of EMD and an ACS scaffold on cell behaviors and differentiation of mouse iPSCs (miPSCs) in vitro.

MATERIAL AND METHODS

Following embryonic body formation from miPSCs, dissociated cells (miPS-EB-derived cells) were seeded onto ACS with or without EMD, and cultured in osteoblast differentiation medium. Scanning electron microscopy and histological analyses were used to assess cell morphology and infiltration within the ACS. Cell viability (metabolism) was determined using an MTS assay, and expression of mRNA of osteoblastic differentiation markers was assessed by quantitative RT -PCR. Alkaline phosphatase (ALP) staining intensity and activity were evaluated. Mineralization was assessed by von Kossa staining, and calcium content was quantitated using the methylxylenol blue method.

RESULTS

By 24 hours after seeding, miPS-EB-derived cells in both the EMD and control groups had attached to and infiltrated the ACS scaffold. Scanning electron microscopy images revealed that by day 14, many cytoplasmic protrusions and extracellular deposits, suggestive of calcified matrix, were present in the EMD group. There was a time-dependent increase in cell viability up to day 3, but no difference between groups was observed at any time point. The levels expressed of ALP and osterix genes were significantly higher in the EMD group than in the control group. Expression of runt-related transcription factor 2 was increased in the EMD group compared with the control group on day 7. EMD upregulated the expression of bone sialoprotein and osteopontin on day 14, whereas expression of osteocalcin was lower at all time points. The staining intensity and activity of ALP were higher in the EMD group than in the control group. Mineralization levels and calcium contents were significantly higher in the EMD group throughout the observation period.

CONCLUSION

These data suggest that combining ACS with EMD increases levels of osteoblastic differentiation and mineralization in miPS-EB-derived cells, compared with ACS used alone.

Surfactant protein D inhibits activation of non-small cell lung cancer-associated mutant EGFR and affects clinical outcomes of patients

Tyrosine kinase inhibitor (TKI)-sensitive and TKI-resistant mutations of epidermal growth factor receptor (EGFR) are associated with lung adenocarcinoma. EGFR mutants were previously shown to exhibit ligand-independent activation. We have previously demonstrated that pulmonary surfactant protein D (SP-D, SFTPD) suppressed wild-type EGFR signaling by blocking ligand binding to EGFR. We herein demonstrate that SFTPD downregulates ligand-independent signaling in cells harboring EGFR mutations such as TKI-sensitive exon 19 deletion (Ex19del) and L858R mutation as well as TKI-resistant T790M mutation, subsequently suppressing cellular growth and motility. Lectin blotting and ligand blotting in lung cancer cell lines suggested that EGFR mutants express oligomannose-type N-glycans and interact with SFTPD directly. Cross-linking assay indicated that SFTPD inhibits ligand-independent dimerization of EGFR mutants. We also demonstrated that SFTPD reduced dimerization-independent phosphorylation of Ex19del and T790M EGFR mutants using point mutations that disrupted the asymmetric dimer interface. It was confirmed that SFTPD augmented the viability-suppressing effects of EGFR-TKIs. Furthermore, retrospective analysis of 121 patients with lung adenocarcinoma to examine associations between serum SFTPD levels and clinical outcome indicated that in TKI-treated patients with lung cancer harboring EGFR mutations, including Ex19del or L858R, high serum SFTPD levels correlated with a lower number of distant metastases and prolonged overall survival and progression-free survival. These findings suggest that SFTPD downregulates both TKI-sensitive and -resistant EGFR mutant signaling, and SFTPD level is correlated with clinical outcome. These findings illustrate the use of serum SFTPD level as a potential marker to estimate the efficacy of EGFR-TKIs.

Assessing the progression of chronic periodontitis using subgingival pathogen levels: a 24-month prospective multicenter cohort study

BACKGROUND

The diagnosis of the progression of periodontitis presently depends on the use of clinical symptoms (such as attachment loss) and radiographic imaging. The aim of the multicenter study described here was to evaluate the diagnostic use of the bacterial content of subgingival plaque recovered from the deepest pockets in assessing disease progression in chronic periodontitis patients.

METHODS

This study consisted of a 24-month investigation of a total of 163 patients with chronic periodontitis who received trimonthly follow-up care. Subgingival plaque from the deepest pockets was recovered and assessed for bacterial content of Porphyromonas gingivalis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans using the modified Invader PLUS assay. The corresponding serum IgG titers were measured using ELISA. Changes in clinical parameters were evaluated over the course of 24 months. The sensitivity, specificity, and prediction values were calculated and used to determine cutoff points for prediction of the progression of chronic periodontitis.

RESULTS

Of the 124 individuals who completed the 24-month monitoring phase, 62 exhibited progression of periodontitis, whereas 62 demonstrated stable disease. The P. gingivalis counts of subgingival plaque from the deepest pockets was significantly associated with the progression of periodontitis (p < 0.001, positive predictive value = 0.708).

CONCLUSIONS

The P. gingivalis counts of subgingival plaque from the deepest pockets may be associated with the progression of periodontitis.

Functional status of the articularis genus muscle in individuals with knee osteoarthritis

OBJECTIVES

To clarify the functional status of the articularis genus muscle (AGM) in individuals with knee osteoarthritis (OA) and to analyze the muscle's relationship with knee OA.

METHODS

Fifty-two individuals with knee OA (mean age, 73.4 years), 50 elderly individuals without knee OA changes (mean age, 71.2 years) and 75 young individuals (mean age, 20.2 years) were observed the AGM using ultrasonography. The thickness of the AGM, the anteroposterior distance of the suprapatellar bursa, and moving distance of the muscle insertion were measured both at rest and during isometric contraction, and values during contraction were expressed as percentages of the values at rest (%Muscle-Increase, %Bursa-Increase).

RESULTS

Muscle thickness at rest, %Muscle-Increase, %Bursa-Increase, and moving distance of the muscle insertion were significantly lower and anteroposterior distance of the suprapatellar bursa was significantly higher in the OA group than in the controls (p<0.001, all). In the OA group, these values for the AGM were significantly correlated with knee range of motion, knee pain, and Kellgren and Lawrence grade.

CONCLUSIONS

Individuals with knee OA exhibited atrophic changes and dysfunctions of the AGM, and these were associated with symptoms. Atrophic changes and dysfunctions of the AGM may be specific changes associated with knee OA.

Role of mitogen-activated protein kinase pathways in migration of gingival epithelial cells in response to stimulation by cigarette smoke condensate and infection by Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

Previous studies have shown that cigarette smoke (CS) and periodontal pathogens could alter wound healing responses of gingival epithelial cells. To elucidate molecular mechanisms leading to these epithelial changes, we studied the signaling pathway involved in the modulation of cell migration by CS condensate (CSC) and the infection by a prominent periodontal pathogen, Porphyromonas gingivalis.

MATERIAL AND METHODS

Human gingival epithelial cells (Ca9-22) were treated with CSC or vehicle control for 24 h. Activation of mitogen-activated protein kinases (MAPK) in cells with or without infection by P. gingivalis was assessed by polymerase chain reaction array and immunoblotting using phospho-specific antibodies. Cell migration was assessed using in vitro wound closure model, and specific pharmacologic inhibitors of MAPK pathways were used to characterize further the extent of involvement of the MAPK pathways.

RESULTS

Polymerase chain reaction array showed that gene expression of several members of the MAPK, particularly p38 and JNK, was upregulated more than twofold in Ca9-22 cells stimulated with 10 μg/mL CSC. Coincubation with P. gingivalis induced a different pattern of gene expression for MAPK pathways, but it did not suppress the MAPK-related genes upregulated by CSC. A significant phosphorylation of ERK1/2 and p38 was observed in cells stimulated with 10 μg/mL CSC (p < 0.05), whereas coincubation with a higher concentration of CSC (250 μg/mL) evoked no such activation. P. gingivalis infection resulted in a tendency to reduce the phosphorylation of ERK1/2 and p38, which had been enhanced by stimulation with 10 μg/mL CSC. Incubation with ERK1/2 and p38 inhibitors significantly reduced the wound closure of CSC-stimulated cells, by approximately 43% and 46%, respectively (p < 0.05).

CONCLUSION

CSC exerts effects on the migration of human gingival epithelial cells through the activation of the MAPK ERK1/2 and p38 signaling pathways. P. gingivalis infection attenuates the CSC-induced migration at least partly by suppressing the phosphorylation of ERK1/2 and p38, but other pathways are likely to be involved in this modulatory process.

Molecular-based allergy diagnosis of allergic bronchopulmonary aspergillosis in Aspergillus fumigatus-sensitized Japanese patients

BACKGROUND

Distinguishing between patients with allergic bronchopulmonary aspergillosis (ABPA) and Aspergillus fumigatus (Af)-sensitized asthmatic patients without ABPA is sometimes difficult owing to the IgE-cross-reactivity between Af and other fungal allergens.

OBJECTIVE

To establish the usefulness of molecular-based allergy diagnostics using allergen components from Af in distinguishing ABPA from Af-sensitized asthma without ABPA.

METHODS

Sera from Japanese patients with ABPA (n = 53) and Af-sensitized asthma without ABPA (n = 253) were studied. The levels of IgE and IgG antibodies to allergen components from Af and IgE antibodies to different fugal allergen extracts were measured by ImmunoCAP. Comorbid atopic dermatitis (AD) was taken into consideration in the sensitization profile analysis.

RESULTS

Patients with ABPA possessed significantly higher levels of IgE antibodies to Asp f 1, and Asp f 2 than asthmatic patients without ABPA. The areas under the receiver operating characteristic curves for the levels of IgE to Asp f 1 and Asp f 2 as diagnostic markers of ABPA were 0.75 and 0.78, respectively. The presence of IgE positivity to Asp f 1 and/or Asp f 2 resulted in increased sensitivity while losing little specificity. Comorbid AD was associated with higher levels of IgE to Asp f 6 (manganese superoxide dismutase from Af, a ubiquitous pan-allergen in fungi) and low but positive levels of IgE to other Af-components, which hampered the serological discrimination of ABPA.

CONCLUSIONS AND CLINICAL RELEVANCE

The levels of IgE to Asp f 1 and/or Asp f 2 can effectively differentiate ABPA from Af-sensitized asthma, suggesting that the amounts of IgE specific for these molecules are markers for genuine Af-sensitization in ABPA. However, comorbid AD must be taken into consideration in the interpretation of high IgE to Asp f 6. Establishing of IgE-sensitization profiles using panel of Af-allergen components provides valuable information for distinguishing genuine vs. cross-reactive sensitization in Af-sensitized patients.

Detection of occult metastatic lymph nodes in the neck with gray-scale and power doppler us

Purpose: To determine the most accurate criterion for predicting malignancy of small cervical lymph nodes with gray-scale ultrasound (GSUS) and power Doppler ultrasound (PDUS).

Material and Methods: Findings of 69 pathologically verified cervical nodes (38 benign, 31 malignant) in 57 patients without wide echogenic hilum on GSUS that measured less than 10 mm in minimal axial diameter were prospectively studied. Minimal and maximal axial diameters, ratios of minimal to maximal axial diameters, and presence or absence of calcification or necrosis of the nodes were assessed. On PDUS, vascularity in the node was classified into 4 pattern groups. A logistic model was used to evaluate the significant factors for predicting malignancy.

Results: The logistic model revealed that the minimal axial diameter and vascularity patterns were the only significant factors for malignancy. Using the minimal axial diameter, a node larger than 8 mm showed the highest accuracy (73%) with 45% sensitivity and 93% specificity. Of the vascularity patterns, spotted or peripheral pattern had the highest accuracy (80%) with 61% sensitivity and 93% specificity. A combined criterion of the minimal axial diameter larger than 8 mm and spotted or peripheral pattern increased the accuracy to 82% and sensitivity to 77% but specificity decreased to 86%.

Conclusion: A combined criterion of minimal axial diameter and vascular patterns was most accurate for diagnosing occult metastatic lymph nodes in the neck.

Effects of JPEG and wavelet compression of spiral low-dose CT images on detection of small lung cancers

Purpose: To compare the effect of compression of spiral low-dose CT images by the Joint Photographic Experts Group (JPEG) and wavelet algorithms on detection of small lung cancers.

Material and Methods: Low-dose spiral CT images of 104 individuals (52 with peripheral lung cancers smaller than 20 mm and 52 control subjects) were used. The original images were compressed using JPEG or wavelet algorithms at a ratio of 10:1 or 20:1. Five radiologists interpreted these images and evaluated the image quality on a high-resolution CRT monitor. Observer performance was studied by receiver operating characteristic (ROC) analysis.

Results: There was no significant difference in the detection of cancers measuring 6 to 15 mm in uncompressed images and in those compressed by either of the algorithms, although the quality of images compressed at 20:1 with the wavelet algorithm was somewhat inferior. A lower diagnostic accuracy was noted using images compressed by the JPEG or wavelet algorithms at 20:1 in detecting lung cancers measuring 6 to 10 mm and cancers measuring from 6 to 15 mm with ground-glass opacity.

Conclusion: Compression of low-dose CT images at a ratio of 10:1 using JPEG and wavelet algorithms does not compromise the detection rate of small lung cancers.