2,163 research outputs found
Scleral contact lenses for visual rehabilitation in keratoconus and irregular astigmatism after refractive surgery
AbstractThis study aims to report our experience of using fluid-ventilated, gas-permeable scleral contact lenses (SCLs) for visual rehabilitation of patients with keratoconus and irregular astigmatism after refractive surgery. This is a noncomparative interventional case series reporting eight consecutive patients fitted with SCLs because of irregular astigmatism following the failure of other optical corrections. Retrospective chart review and data analysis included age, sex, etiology prior to lens fitting, visual outcomes, follow-up time, and complications. Twelve eyes of eight patients were studied. All eyes were fitted with SCLs due to unsatisfactory vision with spectacle correction or other contact lens modalities. Five eyes had keratoconus and seven had irregular corneas post refractive surgery. The mean follow-up period was 14.4 ± 1.3 months (range 11–17 months). The mean age was 32.63 ± 7.68 years (range 18–48 years). The average steepest keratometry(Kmax) of our series was 49.56 ± 12.2 D. The mean refractive astigmatism was 5.50 ± 5.3 D. The mean best corrected visual acuity (BCVA) in logarithm of the minimum angle of resolution improved from 0.71 ± 0.50 (range 0.10–1.40) to 0.05 ± 0.07 (range 0.00–0.15) after SCL fitting (p < 0.001). All reported eyes achieved significant improvement in the BCVA with SCL fitting. None of the patients discontinued to wear SCLs. SCLs should be considered lenses of choice in irregular corneas refractory to conventional optical correction
Fly-DPI: database of protein interactomes for D. melanogaster in the approach of systems biology
BACKGROUND: Proteins control and mediate many biological activities of cells by interacting with other protein partners. This work presents a statistical model to predict protein interaction networks of Drosophila melanogaster based on insight into domain interactions. RESULTS: Three high-throughput yeast two-hybrid experiments and the collection in FlyBase were used as our starting datasets. The co-occurrences of domains in these interactive events are converted into a probability score of domain-domain interaction. These scores are used to infer putative interaction among all available open reading frames (ORFs) of fruit fly. Additionally, the likelihood function is used to estimate all potential protein-protein interactions. All parameters are successfully iterated and MLE is obtained for each pair of domains. Additionally, the maximized likelihood reaches its converged criteria and maintains the probability stable. The hybrid model achieves a high specificity with a loss of sensitivity, suggesting that the model may possess major features of protein-protein interactions. Several putative interactions predicted by the proposed hybrid model are supported by literatures, while experimental data with a low probability score indicate an uncertain reliability and require further proof of interaction. Fly-DPI is the online database used to present this work. It is an integrated proteomics tool with comprehensive protein annotation information from major databases as well as an effective means of predicting protein-protein interactions. As a novel search strategy, the ping-pong search is a naïve path map between two chosen proteins based on pre-computed shortest paths. Adopting effective filtering strategies will facilitate researchers in depicting the bird's eye view of the network of interest. Fly-DPI can be accessed at . CONCLUSION: This work provides two reference systems, statistical and biological, to evaluate the reliability of protein interaction. First, the hybrid model statistically estimates both experimental and predicted protein interaction relationships. Second, the biological information for filtering and annotation itself is a strong indicator for the reliability of protein-protein interaction. The space-temporal or stage-specific expression patterns of genes are also critical for identifying proteins involved in a particular situation
Illuminating the diversity of aromantic polyketide synthases in Aspergillus nidulans
This document is the Accepted Manuscript version of a Published Work that appeared in final form in the Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/ja3016395.Genome sequencing has revealed that fungi have the ability to synthesize many more natural products (NPs) than are currently known, but methods for obtaining suitable expression of NPs have been inadequate. We have developed a successful strategy that bypasses normal regulatory mechanisms. By efficient gene targeting, we have replaced, en masse, the promoters of non-reducing polyketide synthase (NR-PKS) genes, key genes in NP biosynthetic pathways and other genes necessary for NR-PKS product formation or release. This has allowed us to determine the products of eight NR-PKSs of A. nidulans, including seven novel compounds, as well as the NR-PKS genes required for the synthesis of the toxins, alternariol (8) and cichorine (19)
Elimination of head and neck cancer initiating cells through targeting glucose regulated protein78 signaling
<p>Abstract</p> <p>Background</p> <p>Head and neck squamous cell carcinoma (HNSCC) is a highly lethal cancer that contains cellular and functional heterogeneity. Previously, we enriched a subpopulation of highly tumorigenic head and neck cancer initiating cells (HN-CICs) from HNSCC. However, the molecular mechanisms by which to govern the characteristics of HN-CICs remain unclear. GRP78, a stress-inducible endoplasmic reticulum chaperone, has been reported to play a crucial role in the maintenance of embryonic stem cells, but the role of GRP78 in CICs has not been elucidated.</p> <p>Results</p> <p>Initially, we recognized GRP78 as a putative candidate on mediating the stemness and tumorigenic properties of HN-CICs by differential systemic analyses. Subsequently, cells with GRP78 anchored at the plasma membrane (<sup>mem</sup>GRP78<sup>+</sup>) exerted cancer stemness properties of self-renewal, differentiation and radioresistance. Of note, xenotransplantation assay indicated merely 100 <sup>mem</sup>GRP78<sup>+ </sup>HNSCCs resulted in tumor growth. Moreover, knockdown of GRP78 significantly reduced the self-renewal ability, side population cells and expression of stemness genes, but inversely promoted cell differentiation and apoptosis in HN-CICs. Targeting GRP78 also lessened tumorigenicity of HN-CICs both <it>in vitro </it>and <it>in vivo</it>. Clinically, co-expression of GRP78 and Nanog predicted the worse survival prognosis of HNSCC patients by immunohistochemical analyses. Finally, depletion of GRP78 in HN-CICs induced the expression of Bax, Caspase 3, and PTEN.</p> <p>Conclusions</p> <p>In summary, <sup>mem</sup>GRP78 should be a novel surface marker for isolation of HN-CICs, and targeting GRP78 signaling might be a potential therapeutic strategy for HNSCC through eliminating HN-CICs.</p
Chromogranin A (CgA) as Poor Prognostic Factor in Patients with Small Cell Carcinoma of the Cervix: Results of a Retrospective Study of 293 Patients
BACKGROUND: Small cell carcinoma of the cervix (SCCC) is a very rare tumor. Due to its rarity and the long time period, there is a paucity of information pertaining to prognostic factors associated with survival. The objective of this study was to determine whether clinicopathologic finings or immunohistochemical presence of molecular markers predictive of clinical outcome in patients with SCCC. METHODOLOGY AND FINDINGS: We retrospectively reviewed a total of 293 patients with SCCC (47 patients from Cancer Center of Sun Yat-sen University in china, 71 patients from case report of china journal, 175 patients from case report in PubMed database). Of those 293 patients with SCCC, the median survival time is 23 months. The 3-year overall survival rates (OS) and 3-year disease-free survival rates (DFS) for all patients were 34.5% and 31.1%, respectively. Univariate and multivariate analysis showed that FIGO stage (IIb-IV VS I-IIa, Hazard Ratio (HR) = 3.08, 95% confidence interval (CI) of ratio = [2.05, 4.63], P<0.001), tumor mass size (≥ 4 cm VS <4 cm, HR = 2.37, 95% CI = [1.28, 4.36], P = 0.006) and chromogranin A (CgA) (Positive VS Negative, HR = 1.81, 95% CI = [1.12, 2.91], P = 0.015) were predictive of poor prognosis. CgA stained positive was found to be highly predictive of death in early-stage (FIGO I-IIa) patient specifically. CONCLUSIONS: Patients with SCCC have poor prognosis. FIGO stage, tumor mass size and CgA stained positive may act as a surrogate for factors prognostic of survival. CgA may serve as a useful marker in prognostic evaluation for early-stage patients with SCCC
Evidence for Dynamically Important Magnetic Fields in Molecular Clouds
Recent observational evidence that magnetic fields are dynamically important
in molecular clouds, compared to self-gravity and turbulence, is reviewed and
illustrated with data from the NGC 2024 region. One piece of evidence,
turbulence anisotropy, was found in the diffuse envelope of a cloud (Av~1;
Heyer et al. 2008); our data further suggests turbulence anisotropy in the
cloud (Av >7) and even near the cloud core (Av~100). The data also shows that
magnetic fields can channel gravitational contraction even for a region with
super-critical N(H2)/2Blos ratio (the ratio between the observed column density
and two times the line-of-sight observed field strength), a parameter which has
been widely used by observers to estimate core mass-to-flux ratios. Although
the mass-to-flux ratio is constant under the flux-freezing condition, we show
that N(H2)/2Blos grows with time if gravitational contraction is anisotropic
due to magnetic fields.Comment: accepted by MNRA
Concomitant Active Tuberculosis Prolongs Survival in Non-Small Cell Lung Cancer: A Study in a Tuberculosis-Endemic Country
BACKGROUND: Adjuvant tumor cell vaccine with chemotherapy against non-small cell lung cancer (NSCLC) shows limited clinical response. Whether it provokes effective cellular immunity in tumor microenvironment is questionable. Concomitant active tuberculosis in NSCLC (TBLC) resembles locoregional immunotherapy of tumor cell vaccine; thus, maximally enriches effective anti-tumor immunity. This study compares the survival and immunological cell profile in TBLC over NSCLC alone. METHODS: Retrospective review of NSCLC patients within 1-year-period of 2007 and follow-up till 2010. RESULTS: A total 276 NSCLC patients were included. The median survival of TBLC is longer than those of NSCLC alone (11.6 vs. 8.8 month, p<0.01). Active tuberculosis is an independent predictor of better survival with HR of 0.68 (95% CI, 0.48 ~ 0.97). Squamous cell carcinoma (SCC) (55.8 vs. 31.7%, p<0.01) is a significant risk factor for NSCLC with active TB. The median survival of SCC with active tuberculosis is significantly longer than adenocarcinoma or undetermined NSCLC with TB (14.2 vs. 6.6 and 2.8 months, p<0.05). Active tuberculosis in SCC increases the expression of CD3 (46.4 ± 24.8 vs. 24.0 ± 16.0, p<0.05), CXCR3 (35.1 ± 16.4 vs. 19.2 ± 13.3, p<0.01) and IP-10 (63.5 ± 21.9 vs. 35.5 ± 21.0, p<0.01), while expression of FOXP3 is decreased (3.5 ± 0.5 vs. 13.3 ± 3.7 p<0.05, p<0.05). Survival of SCC with high expression of CD3 (12.1 vs. 3.6 month, p<0.05) and CXCR3 (12.1 vs. 4.4 month, p<0.05) is longer than that with low expression. CONCLUSIONS: Active tuberculosis in NSCLC shows better survival outcome. The effective T lymphocyte infiltration in tumor possibly underlies the mechanism. Locoregional immunotherapy of tumor cell vaccine may deserve further researches
Influence of Various Polymorphic Variants of Cytochrome P450 Oxidoreductase (POR) on Drug Metabolic Activity of CYP3A4 and CYP2B6
Cytochrome P450 oxidoreductase (POR) is known as the sole electron donor in the metabolism of drugs by cytochrome P450 (CYP) enzymes in human. However, little is known about the effect of polymorphic variants of POR on drug metabolic activities of CYP3A4 and CYP2B6. In order to better understand the mechanism of the activity of CYPs affected by polymorphic variants of POR, six full-length mutants of POR (e.g., Y181D, A287P, K49N, A115V, S244C and G413S) were designed and then co-expressed with CYP3A4 and CYP2B6 in the baculovirus-Sf9 insect cells to determine their kinetic parameters. Surprisingly, both mutants, Y181D and A287P in POR completely inhibited the CYP3A4 activity with testosterone, while the catalytic activity of CYP2B6 with bupropion was reduced to approximately ∼70% of wild-type activity by Y181D and A287P mutations. In addition, the mutant K49N of POR increased the CLint (Vmax/Km) of CYP3A4 up to more than 31% of wild-type, while it reduced the catalytic efficiency of CYP2B6 to 74% of wild-type. Moreover, CLint values of CYP3A4-POR (A115V, G413S) were increased up to 36% and 65% of wild-type respectively. However, there were no appreciable effects observed by the remaining two mutants of POR (i.e., A115V and G413S) on activities of CYP2B6. In conclusion, the extent to which the catalytic activities of CYP were altered did not only depend on the specific POR mutations but also on the isoforms of different CYP redox partners. Thereby, we proposed that the POR-mutant patients should be carefully monitored for the activity of CYP3A4 and CYP2B6 on the prescribed medication
Characterization of Epstein-Barr Virus miRNAome in Nasopharyngeal Carcinoma by Deep Sequencing
Virus-encoded microRNAs (miRNAs) have been shown to regulate a variety of biological processes involved in viral infection and viral-associated pathogenesis. Epstein-Barr virus (EBV) is a herpesvirus implicated in nasopharyngeal carcinoma (NPC) and other human malignancies. EBV-encoded miRNAs were among the first group of viral miRNAs identified. To understand the roles of EBV miRNAs in the pathogenesis of NPC, we utilized deep sequencing technology to characterize the EBV miRNA transcriptome in clinical NPC tissues. We obtained more than 110,000 sequence reads in NPC samples and identified 44 EBV BART miRNAs, including four new mature miRNAs derived from previously identified BART miRNA precursor hairpins. Further analysis revealed extensive sequence variations (isomiRs) of EBV miRNAs, including terminal isomiRs at both the 5′ and 3′ ends and nucleotide variants. Analysis of EBV genomic sequences indicated that the majority of EBV miRNA nucleotide variants resulted from post-transcriptional modifications. Read counts of individual EBV miRNA in NPC tissue spanned from a few reads to approximately 18,000 reads, confirming the wide expression range of EBV miRNAs. Several EBV miRNAs were expressed at levels similar to highly abundant human miRNAs. Sequence analysis revealed that most of the highly abundant EBV miRNAs share their seed sequences (nucleotides 2–7) with human miRNAs, suggesting that seed sequence content may be an important factor underlying the differential accumulation of BART miRNAs. Interestingly, many of these human miRNAs have been found to be dysregulated in human malignancies, including NPC. These observations not only provide a potential linkage between EBV miRNAs and human malignancy but also suggest a highly coordinated mechanism through which EBV miRNAs may mimic or compete with human miRNAs to affect cellular functions
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