A PTK7-targeted antibody-drug conjugate reduces tumor-initiating cells and induces sustained tumor regressions.

Disease relapse after treatment is common in triple-negative breast cancer (TNBC), ovarian cancer (OVCA), and non-small cell lung cancer (NSCLC). Therapies that target tumor-initiating cells (TICs) should improve patient survival by eliminating the cells that can drive tumor recurrence and metastasis. We demonstrate that protein tyrosine kinase 7 (PTK7), a highly conserved but catalytically inactive receptor tyrosine kinase in the Wnt signaling pathway, is enriched on TICs in low-passage TNBC, OVCA, and NSCLC patient-derived xenografts (PDXs).

A DLL3-targeted antibody-drug conjugate eradicates high-grade pulmonary neuroendocrine tumor-initiating cells in vivo.

The high-grade pulmonary neuroendocrine tumors, small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC), remain among the most deadly malignancies. Therapies that effectively target and kill tumor-initiating cells (TICs) in these cancers should translate to improved patient survival. Patient-derived xenograft (PDX) tumors serve as excellent models to study tumor biology and characterize TICs.

Anti-EFNA4 Calicheamicin Conjugates Effectively Target Triple-Negative Breast and Ovarian Tumor-Initiating Cells to Result in Sustained Tumor Regressions.

Purpose: Triple-negative breast cancer (TNBC) and ovarian cancer each comprise heterogeneous tumors, for which current therapies have little clinical benefit. Novel therapies that target and eradicate tumor-initiating cells (TIC) are needed to significantly improve survival.

Experimental Design: A panel of well-annotated patient-derived xenografts (PDX) was established, and surface markers that enriched for TIC in specific tumor subtypes were empirically determined.

Heart structure-specific transcriptomic atlas reveals conserved microRNA-mRNA interactions.

MicroRNAs are short non-coding RNAs that regulate gene expression at the post-transcriptional level and play key roles in heart development and cardiovascular diseases. Here, we have characterized the expression and distribution of microRNAs across eight cardiac structures (left and right ventricles, apex, papillary muscle, septum, left and right atrium and valves) in rat, Beagle dog and cynomolgus monkey using microRNA sequencing. Conserved microRNA signatures enriched in specific heart structures across these species were identified for cardiac valve (miR-let-7c, miR-125b, miR-127, miR-199a-3p, miR-204, miR-320, miR-99b, miR-328 and miR-744) and myocardium (miR-1, miR-133b, miR-133a, miR-208b, miR-30e, miR-499-5p, miR-30e*).

Pdx1 and Ngn3 overexpression enhances pancreatic differentiation of mouse ES cell-derived endoderm population.

In order to define the molecular mechanisms regulating the specification and differentiation of pancreatic β-islet cells, we investigated the effect of upregulating Pdx1 and Ngn3 during the differentiation of the β-islet-like cells from murine embryonic stem (ES) cell-derived activin induced-endoderm. Induced overexpression of Pdx1 resulted in a significant upregulation of insulin (Ins1 and Ins2), and other pancreas-related genes. To enhance the developmental progression from the pancreatic bud to the formation of the endocrine lineages, we induced the overexpression express of Ngn3 together with Pdx1.

Antitumor therapy mediated by 5-fluorocytosine and a recombinant fusion protein containing TSG-6 hyaluronan binding domain and yeast cytosine deaminase.

Matrix attachment therapy (MAT) is an enzyme prodrug strategy that targets hyaluronan in the tumor extracellular matrix to deliver a prodrug converting enzyme near the tumor cells. A recombinant fusion protein containing the hyaluronan binding domain of TSG-6 (Link) and yeast cytosine deaminase (CD) with an N-terminal His(x6) tag was constructed to test MAT on the C26 colon adenocarcinoma in Balb/c mice that were given 5-fluorocytosine (5-FC) in the drinking water. LinkCD was expressed in Escherichia coli and purified by metal-chelation affinity chromatography.

Notch signaling respecifies the hemangioblast to a cardiac fate.

To efficiently generate cardiomyocytes from embryonic stem (ES) cells in culture it is essential to identify key regulators of the cardiac lineage and to develop methods to control them. Using a tet-inducible mouse ES cell line to enforce expression of a constitutively activated form of the Notch 4 receptor, we show that signaling through the Notch pathway can efficiently respecify hemangioblasts to a cardiac fate, resulting in the generation of populations consisting of >60% cardiomyocytes. Microarray analyses reveal that this respecification is mediated in part through the coordinated regulation of the BMP and Wnt pathways by Notch signaling.

Modeling the impact of sea-spray on particle concentrations in a coastal city.

With the worlds population becoming increasingly focused on coastal locations there is a need to better understand the interactions between anthropogenic emissions and marine atmospheres. Herein an atmospheric chemistry-transport model is used to assess the impacts of sea-spray chemistry on the particle composition in and downwind of a coastal city--Vancouver, British Columbia. It is shown that the model can reasonably represent the average features of the gas phase and particle climate relative to in situ measurements.

Expression analysis of secreted and cell surface genes of five transformed human cell lines and derivative xenograft tumors.

Background: Since the early stages of tumorigenesis involve adhesion, escape from immune surveillance, vascularization and angiogenesis, we devised a strategy to study the expression profiles of all publicly known and putative secreted and cell surface genes. We designed a custom oligonucleotide microarray containing probes for 3531 secreted and cell surface genes to study 5 diverse human transformed cell lines and their derivative xenograft tumors. The origins of these human cell lines were lung (A549), breast (MDA MB-231), colon (HCT-116), ovarian (SK-OV-3) and prostate (PC3) carcinomas.

Functional identification of kinases essential for T-cell activation through a genetic suppression screen.

Activation of T-cells by antigens initiates a complex series of signal-transduction events that are critical for immune responses. While kinases are key mediators of signal transduction networks, several of which have been well characterized in T-cell activation, the functional roles of other kinases remain poorly defined. To address this deficiency, we developed a genetic screen to survey the functional roles of kinases in antigen mediated T-cell activation.

Identification of cell surface and secreted proteins essential for tumor cell survival using a genetic suppressor element screen.

Survival factors play critical roles in regulating cell growth in normal and cancer cells. We designed a genetic screen to identify survival factors which protect tumor cells from apoptosis. A retroviral expression library of random cDNA fragments was constructed from cancer cells and used to transduce the colon carcinoma cell line HCT116.

Simultaneous flow cytometric analyses of enhanced green and yellow fluorescent proteins and cell surface antigens in doubly transduced immature hematopoietic cell populations.

Background: Cell transduction with multiple genes offers opportunities to investigate specific gene interactions on cell function. Detection of multiple transduced genes in hematopoietic cells requires strategies to combine measurements of gene expression with phenotypic cell discriminants. We describe simultaneous flow cytometric detection of two green fluorescent protein (GFP) variants in immunophenotypically defined human hematopoietic subpopulations using only a minor physical adjustment to a standard FACSCalibur.

An in vitro messenger RNA binding assay as a tool for identifying hybridization-competent antisense oligonucleotides.

The apparent dissociation constants for 32 phosphodiester and 5 phosphorothioate antisense oligodeoxyribonucleotides (ODN) targeted to murine tumor necrosis factor-alpha (mTNF-alpha) mRNA were determined using a gel-shift binding assay. In this assay, radiolabeled ODN were hybridized in solution to a structured mRNA transcript generated in vitro. Free ODN was resolved from bound ODN on a two-phase discontinuous polyacrylamide gel.

Antigene, ribozyme and aptamer nucleic acid drugs: progress and prospects.

Nucleic acids are increasingly being considered for therapeutic uses, either to interfere with the function of specific nucleic acids or to bind specific proteins. Three types of nucleic acid drugs are discussed in this review: aptamers, compounds which bind specific proteins; triplex forming (antigene) compounds; which bind double stranded DNA; and ribozymes (catalytic RNA), which bind and cleave RNA targets. The binding of aptamers to protein may involve specific sequence recognition, although this is not always the case.

Low-volume whole bowel irrigation and salicylate absorption: a comparison with ipecac-charcoal.

Study Objective: To evaluate two methods of gastrointestinal decontamination, low-volume whole bowel irrigation (WBI) and activated charcoal, for their ability to prevent absorption of salicylate.

Design: Randomized, two-phase crossover study.

Setting: A clinical research unit in a university-based teaching hospital.

Single-stranded phosphodiester and phosphorothioate oligonucleotides bind actinomycin D and interfere with tumor necrosis factor-induced lysis in the L929 cytotoxicity assay.

Antisense oligonucleotides may prove useful tools to elucidate the biological functions of cytokines and to address regulatory control of cytokine expression. The functional activity of cytokines generally is determined by biological assays, and a standard biological assay for TNF activity measures the cytotoxic effect of TNF on actinomycin D-sensitized L929 cells (Matthews and Neale, 1987). We observed that phosphorothioate and phosphodiester oligonucleotides, at concentrations > 100 nM in supernatants tested in this bioassay, prevented TNF-induced lysis of L929 cells.

Predicting antisense oligonucleotide inhibitory efficacy: a computational approach using histograms and thermodynamic indices.

Antisense oligonucleotides (ASOs) are designed to bind to a specific mRNA and selectively suppress its translation. To facilitate selection of optimal ASO targets, we have developed three thermodynamic indices to evaluate putative structural complexes important in ASO action. These indices are: a secondary structure score (Sscore), which estimates the strength of local mRNA secondary structures at the ASO target site; a duplex score (Dscore), which estimates the delta Gformation for the ASO:mRNA target sequence duplex; and a competition score (Cscore), which is the difference between the Dscore and the Sscore.

Cerebrospinal fluid and serum levels of dopa, catechols, and monoamine metabolites in patients with epilepsy.

We measured CSF and serum concentrations of monoamines and monoamine metabolites in normal control subjects and in patients with partial epilepsy between and less than 2 h after complex partial seizures (CPS) or secondarily generalized tonic-clonic seizures (SGTCs). After SGTCs, concentrations of norepinephrine in CSF were significantly higher (p less than 0.05) than interictal concentrations, concentrations after PSs, and concentrations in control subjects.

HCMR interview: Richard Stull. Interview by Montague Brown.

The career of Richard J. Stull, II, president and chief executive officer of North Broward Hospital in Fort Lauderdale, FL, reflects the solid grounding he received, literally starting on his father's knee. Dick's career is unusual from another perspective; he moved through the ranks to a distinguished career in one location.

Learning theory and knowledge structures in computer-aided instruction.

The development of computer-aided instructional (CAI) systems suffers from a lack of a cohesive theory of learning--how do students acquire and store knowledge? From studies of computer systems that learn and tutor, we can infer generic activities that appear to be integral parts of the learning process, such as aggregation, clustering, characterization, and storage for later retrieval. Learning is faster and more efficient if the goal of a task is made explicit. Hints should be given with the correct timing in relation to an objective so that students can advance in their own problem-solving strategies with the prerequisites in mind.

Tumor necrosis factor: immune endocrine interaction.

Tumor necrosis factor (TNF), a peptide produced by macrophages in response to endotoxin, has been implicated as a mediator of septic shock. This study examined the effects of injections of recombinant (r) human TNF on circulating levels of metabolic substrates and hormones in conscious, unrestrained rats and the effects of TNF on cortisol secretion from human adrenocortical cells in vitro. Sublethal doses of rTNF--doses that did not produce hemodynamic changes in previous work--produced rapid (1 hour), significant increases in blood levels of glucose, lactate, and triglycerides and decreases in plasma levels of branched chain amino acids.

Effects of a peripherally acting alpha 2-adrenoceptor antagonist (L-659,066) on hemodynamics and plasma levels of catechols in conscious rats.

L-659,066 is a new alpha 2-adrenoceptor antagonist which does not enter the central nervous system after systemic administration and therefore can be used to examine effects of blockade of peripheral alpha 2-receptors on hemodynamics and plasma levels of catechols. After i.v.

Patterns of plasma levels of catechols in neurogenic orthostatic hypotension.

Patients with neurogenic orthostatic hypotension can have deficits in sympathetic neural function at any of several levels of the sympathetic neuraxis. We determined whether patterns of plasma levels of dopa, norepinephrine, dihydroxyphenylglycol, and dihydroxyphenylacetic acid would distinguish patients with orthostatic hypotension associated with multiple system atrophy, pure autonomic failure, or deficiency of dopamine-beta-hydroxylase. Plasma levels of catechols were normal in most patients with multiple system atrophy, consistent with relatively intact peripheral sympathetic neurons; in contrast, most patients with pure autonomic failure had decreased levels of all four catechols, consistent with degenerative loss of sympathetic nerve endings.

Epinephrine suppresses stress-induced increases in plasma immunoreactive beta-endorphin in humans.

The present study evaluated the hypothesis that increased plasma levels of epinephrine (EPI) stimulate immunoreactive beta-endorphin (i beta END) secretion in humans experiencing a mild stress. The stressor consisted of intraoral injections of a local anesthetic solution (with or without EPI) just before the surgical extraction of impacted third molars in 26 awake unsedated patients. The EPI group experienced a 30-fold increase in plasma EPI levels by 2 min after injection; these concentrations were physiologically active, as evidenced by increased pulse rate and systolic blood pressure.

Application of teaching and learning principles to computer-aided instruction.

Many authors of software providing computer-aided instruction (CAI) have no background in educational theories. This paper reviews teaching theories and ways in which instructional principles can be applied to CAI. While the lecture form of teaching has often been maligned, there are techniques for enhancing lectures that can also apply to CAI.