201 research outputs found
Exploring collaborative culture and leadership in large high schools
The purpose of this exploratory study was to analyze how high school principals approach developing a collaborative culture and providing collaborative leadership in a large high school setting. The population sample for this study were 82 principals of large comprehensive high schools of grades 9 through 12 or some combination thereof with student populations of more than 1700 students from nine states in the middle region of the United States including Colorado, Missouri, Kansas, Iowa, Nebraska, Illinois, Indiana, Oklahoma, and Wisconsin. The study through an analysis of variance and bivariate correlations analyzed differences sorted by degree of collaboration and relationships among variables correlated with collaborative learning and leadership of principals in a large high school setting. The study found principals in large high schools their learning practices, their beliefs about collaborative leadership, examples of their work, and their perceptions about the degree of collaborative learning were evident. The study found significant differences in leadership practices and beliefs for schools that are perceived as more collaborative compared to those perceived as less collaborative. However the study found there is no significant relationship between demographic characteristics of professional experiences and background were related to collaborative leadership and learning practices and beliefs. Overall, the findings from this study create awareness about the uniqueness of collaborative leadership among principal beliefs and practices in a large high school setting
Resilience: nitrogen limitation, mycorrhiza and long-term palaeoecological plant–nutrient dynamics
Biomarker analyses of clinical outcomes in patients with advanced hepatocellular carcinoma treated with Sorafenib with or without Erlotinib in the SEARCH Trial
Purpose: Sorafenib is the current standard therapy for advanced HCC, but validated
biomarkers predicting clinical outcomes are lacking. This study aimed to identify biomarkers
predicting prognosis and/or response to sorafenib, with or without erlotinib, in HCC patients from
the phase 3 SEARCH trial.
Experimental Design: 720 patients were randomized to receive oral sorafenib 400 mg BID plus
erlotinib 150 mg QD or placebo. Fifteen growth factors relevant to the treatment regimen and/or
to HCC were measured in baseline plasma samples.
Results: Baseline plasma biomarkers were measured in 494 (69%) patients (sorafenib plus
erlotinib, n=243; sorafenib plus placebo, n=251). Treatment arm–independent analyses showed
that elevated HGF (HR, 1.687 [high vs low expression]; endpoint multiplicity adjusted [e-adj]
P=0.0001) and elevated plasma VEGF-A (HR, 1.386; e-adj P=0..0377) were significantly
associated with poor OS in multivariate analyses, and low plasma KIT (HR, 0.75 [high vs low];
P=0.0233; e-adj P=0.2793) tended to correlate with poorer OS. High plasma VEGF-C
independently correlated with longer TTP (HR, 0.633; e-adj P=0.0010) and trended toward
associating with improved disease control rate (univariate:OR, 2.047; P=0.030; e-adj P=0.420).
In 67% of evaluable patients (339/494), a multimarker signature of HGF, VEGF-A, KIT, epigen,
and VEGF-C correlated with improved median OS in multivariate analysis (HR, 0.150;
P<0.00001). No biomarker predicted efficacy from erlotinib.
Conclusions: Baseline plasma HGF, VEGF-A, KIT, and VEGF-C correlated with clinical
outcomes in HCC patients treated with sorafenib with or without erlotinib. These biomarkers
plus epigen constituted a multimarker signature for improved OS
Differential effects of class I isoform histone deacetylase depletion and enzymatic inhibition by belinostat or valproic acid in HeLa cells
<p>Abstract</p> <p>Background</p> <p>Histone acetylation is an epigenetic modification involved in the regulation of gene expression, balanced by histone acetyl transferases and histone deacetylase (HDAC) enzymes. HDAC inhibitors (HDACi) induce growth arrest and cell death in transformed cells, and are currently in many clinical cancer trials. The transcriptional response to HDACi is complex, as is the response to HDAC isoform knockdown (KD). Here, we describe for the first time in a human cancer cell line, a transcriptional comparison of treatment by two structurally unrelated HDACi; belinostat and valproic acid with the KD of HDAC1, 2 and 3 isoforms.</p> <p>Results</p> <p>HDAC KD showed anti-proliferative effects, although to a lesser extent than HDACi treatment. Moreover, we found a 2-fold increased resistance of HDAC1 knockdown cells to belinostat, suggesting this isoenzyme as a selective target. While both HDACi treatment and individual class I HDAC KD produce significant transcriptional effects, three-times higher for HDACi, the gene-expression profiles of class I HDAC KD compared with that obtained by HDACi treatment exhibited less than 4% of altered genes in common between the two modes of inhibition. Further, cell-specific effects of HDAC KD are evident by comparison with a recent study in a different cell line.</p> <p>Conclusion</p> <p>The increased resistance to belinostat in response to HDAC1 depletion indicates the possibility of using this isoform as a predictive biomarker of response to HDACi treatment. Further, the transcriptional response to chemical inhibition of HDACs is very different from that of KD of individual class I HDAC isoforms. These data suggest that the anti-tumor effect of HDACi is indeed linked to class I inhibition, but may be more complex than simply targeting individual HDAC enzymes.</p
Sequence and the Developmental and Tissue-Specific Regulation of the First Complete Vitellogenin Message From Ticks
The first full-length mRNA for vitellogenin (Vg) from ticks was sequenced. This also represents the first complete sequence of Vg from the Chelicerata and of a heme binding Vg. The Vg cDNA from the American dog tick, Dermacentor variabilis was 5744nt in length (GenBank Accession number AY885250), which coded for a protein of 1843aa with a calculated molecular weight of 208kD. This protein had an 18 aa signal sequence, a single RXXR cleavage signal that would generate two subunits (49.5 and 157K in molecular weight) and lipoprotein N-terminal and carboxy von Willebrand factor type D domains. Tryptic digest MS analysis of vitellin protein confirmed the function of the cDNA as the tick yolk protein. Apparently, vitellin in D. variabilis is oligomeric (possibly dimeric) and is comprised of a mixture of the uncleaved monomer and subunits that were predicted from the single RXXR cleavage signal. The highly conserved GL/ICG motif close to the C-terminus in insect Vg genes was different in the tick Vg message, i.e., GLCS. This variant was also present in a partial sequence of Vg from Boophilus microplus. Phylogenic analysis showed that the full length Vg cDNA from D. variabilis and the partial cDNA from B. microplus were distinct from insects and Crustacea. The Vg message was not found in whole body RNA from unfed or fed males or in unfed and partially fed (virgin) females as determined by Northern blotting. The message was found in replete (mated) pre-ovipositional females, increased to higher levels in ovipositing females and was absent after egg laying was complete. The endocrine regulation of the Vg mRNA is discussed. The tissue sources of the Vg message are both the gut and fat body. Tryptic digest MS fingerprinting suggests that a second Vg mRNA might be present in the American dog tick, which needs further study
AKT1 (E17K) mutation profiling in breast cancer: prevalence, concurrent oncogenic alterations, and blood-based detection.
BACKGROUND: The single hotspot mutation AKT1 [G49A:E17K] has been described in several cancers, with the highest incidence observed in breast cancer. However, its precise role in disease etiology remains unknown.
METHODS: We analyzed more than 600 breast cancer tumor samples and circulating tumor DNA for AKT1 (E17K) and alterations in other cancer-associated genes using Beads, Emulsions, Amplification, and Magnetics digital polymerase chain reaction technology and targeted exome sequencing.
RESULTS: Overall AKT1 (E17K) mutation prevalence was 6.3 % and not correlated with age or menopausal stage. AKT1 (E17K) mutation frequency tended to be lower in patients with grade 3 disease (1.9 %) compared with those with grade 1 (11.1 %) or grade 2 (6 %) disease. In two cohorts of patients with advanced metastatic disease, 98.0 % (n = 50) and 97.1 % (n = 35) concordance was obtained between tissue and blood samples for the AKT1 (E17K) mutation, and mutation capture rates of 66.7 % (2/3) and 85.7 % (6/7) in blood versus tissue samples were observed. Although AKT1-mutant tumor specimens were often found to harbor concurrent alterations in other driver genes, a subset of specimens harboring AKT1 (E17K) as the only known driver alteration was also identified. Initial follow-up survival data suggest that AKT1 (E17K) could be associated with increased mortality. These findings warrant additional long-term follow-up.
CONCLUSIONS: The data suggest that AKT1 (E17K) is the most likely disease driver in certain breast cancer patients. Blood-based mutation detection is achievable in advanced-stage disease. These findings underpin the need for a further enhanced-precision medicine paradigm in the treatment of breast cancer
Image analysis as an adjunct to manual HER-2 immunohistochemical review: a diagnostic tool to standardize interpretation
Dobson L, Conway C, Hanley A, Johnson A, Costello S, O’Grady A, Connolly Y, Magee H, O’Shea D, Jeffers M & Kay E (2010) Histopathology57, 27–38 Image analysis as an adjunct to manual HER-2 immunohistochemical review: a diagnostic tool to standardize interpretatio
Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma Treated with Radiation Therapy: A Case Report and Review of the Literature
Introduction: Mucosa-associated lymphoid tissue lymphoma (MALT lymphoma or MALToma) is a prevalent type of primary pulmonary lymphoma. Typically, the primary therapeutic approaches involve surgery or chemotherapy, although there have been instances of radiation therapy being employed. Case Report: We present a case of pulmonary MALToma that exhibited progression despite rituximab therapy. Subsequently, the patient demonstrated a positive response to radiation therapy. Conclusion: This case highlights the potential efficacy of radiation therapy as a treatment option for pulmonary MALToma, especially in cases where other conventional treatments like rituximab have proven ineffective. Further research and studies are warranted to better understand the role of radiation therapy in managing pulmonary MALToma and to determine optimal treatment strategies for patients with this condition
In Vivo Role of 20-hydroxyecdysone in the Regulation of the Vitellogenin mRNA and Egg Development in the American Dog Tick, Dermacentor variabilis (Say)
Injection of the hormone 20-hydroxyecdysone (20-E) into partially fed (virgin) female adults of the American dog tick, Dermacentor variabilis, while they are attached and feeding on the rabbit host, initiated the expression of the vitellogenin (Vg) gene, and Vg protein secretion and uptake by the ovary. The induction of egg production by 20-E in this bioassay was dose dependent in the range of 1-50 times the concentration normally found in a replete, vitellogenic female. Ticks examined 4d after the 50x treatment were still attached to the host, had numerous enlarged vitellin-filled (brown) oocytes in their ovaries, but had not engorged to repletion. The ovaries reached weights similar to those found in untreated, replete (mated) females (pre-oviposition) while solvent-injected controls demonstrated no increase in oocyte size or increase in ovary weight. An increase in the levels of a putative Vg protein was observed in hemolymph samples collected 1, 2 and 3d post-20-E injection but was not observed in the corresponding solvent controls as determined by native PAGE. Analysis of the ecdysteroid-induced protein by tryptic digestion-mass fingerprinting and BLASTP found that the putative Vg had the strongest match to GP80 (U49934), the partial sequence for the vitellogenin protein from Boophilus microplus. A partial Vg cDNA was cloned and sequenced from replete females of D. variabilis with a high similarity to GP80. Using this message as a probe, Northern blots conducted with RNA collected from partially fed, virgin females 1, 2 and 3d post-20-E injection showed upregulation of the Vg mRNA on all 3 days. Controls injected with solvent only showed no Vg mRNA. Injections with juvenile hormone III did not stimulate Vg expression, oocyte growth or full engorgement. These studies indicate that ecdysteroids and not JH can initiate expression of the Vg gene, Vg protein synthesis and release into hemolymph, and Vg uptake into developing oocytes under bioassay conditions mimicking normal feeding on the host
WindCube: A CubeSat Thermospheric Wind Instrument Utilizing Fabry-Pérot Interferometry
WindCube is a 6U CubeSat mission selected for implementation through NASA’s HFORT program. Starting in 2022 and following ~36 months of development, integration and testing, the spacecraft will operate for ~12 months in low earth orbit to study the influence of thermospheric winds on the earth’s ionosphere. Its scientific payload is a limb viewing Fabry Pérot Interferometer (étalon) specially designed to fit into a 10cm x 10cm cross-sectional assembly. WindCube will make global maps of wind speed derived from the doppler shifted emission of the 630.0nm oxygen line (1D \u3e 3P), at altitudes near 250km. Projected performance includes wind speed retrievals every 10 seconds with an accuracy of 5m/s, a vertical resolution of 63km, and a horizontal resolution of 100km. We present an overview of the mission design and observation plan for WindCube as well as a top-level description of the payload design
- …