Community-Based Participatory Research Conceptual Model: Community Partner Consultation and Face Validity

A national community-based participatory research (CBPR) team developed a conceptual model of CBPR partnerships to understand the contribution of partnership processes to improved community capacity and health outcomes. With the model primarily developed through academic literature and expert consensus building, we sought community input to assess face validity and acceptability. Our research team conducted semi-structured focus groups with six partnerships nationwide. Participants validated and expanded on existing model constructs and identified new constructs based on "real-world" praxis, resulting in a revised model. Four cross-cutting constructs were identified: trust development, capacity, mutual learning, and power dynamics. By empirically testing the model, we found community face validity and capacity to adapt the model to diverse contexts. We recommend partnerships use and adapt the CBPR model and its constructs, for collective reflection and evaluation, to enhance their partnering practices and achieve their health and research goals.

Massive lindane overdose with toxicokinetics analysis

BACKGROUND

Lindane is a possible carcinogen with known teratogenicity and immunologic and neurotoxic properties. Despite reports of seizures, coma, and death associated with its use as well as banning of its environmental use by the Environmental Protection Agency (EPA), the US Food and Drug Administration (FDA) still allows treatment with lindane as a second-line scabicide and pediculicide. We present a case of a massive suicidal ingestion of lindane in which the patient survived the ingestion, though he did expire shortly thereafter from an unrelated cause pre-discharge.

METHODS

Pharmacokinetic analysis of serum lindane concentrations was performed with Phoenix® WinNONLIN®. The estimated distribution half-life for lindane was 10.3 h, and the terminal half-life was 162.9 h, much longer than the previously reported terminal half-life of 25-36 h. Because of this long half-life, repeated lindane exposures may lead to accumulation of lindane in the tissues.

RESULT

After overdose, toxicity may be delayed and full recovery may be prolonged.

FBN-1, a fibrillin-related protein, is required for resistance of the epidermis to mechanical deformation during C. elegans embryogenesis

During development, biomechanical forces contour the body and provide shape to internal organs. Using genetic and molecular approaches in combination with a FRET-based tension sensor, we characterized a pulling force exerted by the elongating pharynx (foregut) on the anterior epidermis during C. elegans embryogenesis. Resistance of the epidermis to this force and to actomyosin-based circumferential constricting forces is mediated by FBN-1, a ZP domain protein related to vertebrate fibrillins. fbn-1 was required specifically within the epidermis and FBN-1 was expressed in epidermal cells and secreted to the apical surface as a putative component of the embryonic sheath. Tiling array studies indicated that fbn-1 mRNA processing requires the conserved alternative splicing factor MEC-8/RBPMS. The conserved SYM-3/FAM102A and SYM-4/WDR44 proteins, which are linked to protein trafficking, function as additional components of this network. Our studies demonstrate the importance of the apical extracellular matrix in preventing mechanical deformation of the epidermis during development.

DOI:http://dx.doi.org/10.7554/eLife.06565.001

For an animal embryo to develop, its cells must organize themselves into tissues and organs. For example, skin and the lining of internal organs—such as the lungs and gut—are made from cells called epithelial cells, which are tightly linked to form flat sheets.

In a microscopic worm called Caenorhabditis elegans, the outermost layer of epithelial cells (called the epidermis) forms over the surface of the embryo early on in embryonic development. Shortly afterwards, the embryonic epidermis experiences powerful contractions along the surface of the embryo. The force generated by these contractions converts the embryo from an oval shape to a roughly cylindrical form. These contractions also squeeze the internal tissues and organs, which correspondingly elongate along with the epidermis.

It has been known for decades that such ‘mechanical’ forces are important for the normal development of embryos. However, it remains poorly understood how these forces generate tissues and organs of the proper shape—partly because it is difficult to measure forces in living embryos. It is also not clear how the mechanical properties of specific tissues are controlled.

Now, Kelley, Yochem, Krieg et al. have analyzed the development of C. elegans' embryos and discovered a novel mechanical interplay between the feeding organ (called the pharynx) and the worm's epidermis. The experiments involved studying several mutant worms that perturb epidermal contractions and disrupt the attachment of the pharynx to the epidermis. These studies suggested that the pharynx exerts a strong inward pulling force on the epidermis during development. Using recently developed methods, Kelley, Yochem, Krieg et al. then measured mechanical forces within intact worm embryos and demonstrated that greater forces were experienced in cells that were being pulled by the pharynx.

Kelley, Yochem, Krieg et al. further analyzed how the epidermis normally resists this pulling force from the pharynx and implicated a protein called FBN-1. This worm protein is structurally related to a human protein that is affected in people with a disorder called Marfan Syndrome. Worm embryos without the FBN-1 protein become severely deformed because they are unable to withstand mechanical forces at the epidermis. FBN-1 is normally synthesized and then transported to the outside of the worm embryo by epidermal cells, where it is thought to assemble into a meshwork of long fibers. This provides a strong scaffold that attaches to the epidermis to prevent the epidermis from undergoing excessive deformation while it experiences mechanical forces.

The work of Kelley, Yochem, Krieg et al. provides an opportunity to understand how FBN-1 and other fiber-forming proteins are produced and transported to the cell surface. Moreover, these findings may have implications for human diseases and birth defects that result from an inability of tissues to respond appropriately to mechanical forces.

DOI:http://dx.doi.org/10.7554/eLife.06565.002

The stress-induced heat shock protein 70.3 expression is regulated by a dual-component mechanism involving alternative polyadenylation and HuR

Heat shock protein 70.3 (Hsp70.3) expression increases in response to cellular stress and plays a cytoprotective role. We have previously shown that Hsp70.3 expression is controlled through coordinated post-transcriptional regulation by miRNAs and alternative polyadenylation (APA), and APA-mediated shortening of the Hsp70.3 3'-UTR facilitates increased protein expression. A stress-induced increase in Hsp70.3 mRNA and protein expression is accompanied by alternative polyadenylation (APA)-mediated truncation of the 3'UTR of the Hsp70.3 mRNA transcript. However, the role that APA plays in stress-induced expression of Hsp70.3 remains unclear. Our results show that APA-mediated truncation of the Hsp70.3 3'UTR increases protein expression through enhanced polyribosome loading. Additionally, we demonstrate that the RNA binding protein HuR, which has been previously shown to play a role in mediating APA, is necessary for heat shock mediated increase in Hsp70.3 mRNA and protein. However, it is somewhat surprising to note that HuR does not play a role in APA of the Hsp70.3 mRNA, and these two regulatory events appear to be mutually exclusive regulators of Hsp70.3 expression. These results not only provide important insight to the regulation of stress response genes following heat shock, but also contribute an enhanced understanding of how alternative polyadenylation contributes to gene regulation.

Dynamics of heavy-Rydberg ion-pair formation in K(14p,20p)-SF6, CCl4 collisions

The dynamics of formation of heavy-Rydberg ion-pair states through electron transfer in K(np)-SF6, CCl4 collisions is examined by measuring the velocity, angular, and binding energy distributions of the product ion pairs. The results are analyzed with the aid of a Monte Carlo collision code that models both the initial electron capture and the subsequent evolution of the ion pairs. The model simulations are in good agreement with the experimental data and highlight the factors such as Rydberg atom size, the kinetic energy of relative motion of the Rydberg atom and target particle, and (in the case of attaching targets that dissociate) the energetics of dissociation that can be used to control the properties of the product ion-pair states.

Increased fibrosis and progression to heart failure in MRL mice following ischemia/reperfusion injury

The cardiac regenerative capacity of MRL/MpJ mouse remains a controversy. Although the MRL mouse has been reported to exhibit minimal scarring and subsequent cardiac regeneration after cryoinjury of the right ventricle, multiple studies have been unable to replicate this cardiac regenerative capacity after both cryogenic and coronary ligation cardiac injury. Therefore, we evaluated the cardiac regenerative wound-healing response and functional recovery of MRL mice compared to C57 mice, in response to a clinically relevant left ventricular (LV) coronary ligation. Male MRL/MpJ+/+ and C57BL/6 mice underwent left coronary artery ligation followed by reperfusion. Cardiac function was evaluated by echocardiography [LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV mass, wall thickness] at 24 hours post-ischemia and weekly for 13 weeks thereafter. Hearts were also analyzed histologically for individual cardiomyocyte hypertrophy and cardiac fibrosis. Our results show that contrary to prior reports of cardiac regenerations, MRL mice progress to heart failure more rapidly following I/R injury as marked by a significant decrease in LVEF, increase in LVEDV, LV mass, individual myocyte size, and fibrosis in the post-ischemic myocardium. Therefore, we conclude that MRL mice do not exhibit regeneration of the LV or enhanced functional improvement in response to coronary ligation. However, unlike prior studies, we matched initial infarct size in MRL and C57 mice, used high frequency echocardiography, and histological analysis to reach this conclusion. The prospect of cardiac regeneration after ischemia in MRL mice seems to have attenuated interest, given the multiple negative studies and the promise of stem cell cardiac regeneration. However, our novel observation that MRL may possess an impaired compensated hypertrophy response makes the MRL mouse strain an interesting model in the study of cardiac hypertrophy.

Venous thrombosis in an ALS population over four years

We conducted a retrospective chart review of all ALS patients seen at our institution over four years to determine the incidence of venous thromboembolism and to identify risk factors in this population. Events occurred in 13 of 438 patients (2.97%), yielding an annual incidence rate of 33.1 events per 1,000 patients (95% CI 17.5-55.3). ALS patients have a risk of venous thromboembolism that is higher than the general population but lower than the population of patients with acute stroke or spinal cord injury. Immobility was significantly associated with increased risk of venous thrombosis (RR = 4.96; 95% CI 1.39-17.78).

Effects of the Perfluorochemical Emulsion FMIQ on the Radiation Response of EMT6 Tumours

The effects of FMIQ, a perfluorochemical emulsion based on perfluoro-N-methyldecahydroisoquinoline, were examined using BALB/c mice and EMT6 mammary carcinomas. The radiobiological effects of FMIQ were similar to those found previously for Fluosol in the same tumour/host system. Although the perfluorochemical content (20% w/v) and oxygen-carrying capacity of FMIQ are similar to those of Fluosol, the formulation of FMIQ offers some advantages over that of Fluosol. For example, FMIQ has greater stability during storage. FMIQ also is formulated without pluronic F-68 and is based on a perfluorochemical (FMIQ) having a shorter tissue dwell time than the perfluorotripropylamine in Fluosol; it therefore may produce fewer side-effects than Fluosol. The lifetime of the circulating perfluorochemical droplets in BALB/c mice was longer than FMIQ than for Fluosol; this could offer an advantage in fractionated radiotherapy. These findings give reason to expect that FMIQ may prove to be a better emulsion than Fluosol for clinical use as an adjunct to cancer therapy.

Genomewide clonal analysis of lethal mutations in the Drosophila melanogaster eye: comparison of the X chromosome and autosomes

Using a large consortium of undergraduate students in an organized program at the University of California, Los Angeles (UCLA), we have undertaken a functional genomic screen in the Drosophila eye. In addition to the educational value of discovery-based learning, this article presents the first comprehensive genomewide analysis of essential genes involved in eye development. The data reveal the surprising result that the X chromosome has almost twice the frequency of essential genes involved in eye development as that found on the autosomes.

Gene expression patterns of oncogenic signaling pathways provide a novel approach to targeted therapeutics in advanced non-small cell lung cancer (NSCLC)

7503

Gene expression profiles reflect unique aspects of individual tumors and may characterize tumor heterogeneity in NSCLC. We used gene expression signatures that reflect the deregulation of major oncogenic signaling pathways (Ras, PI3 kinase, Akt, Src, β-catenin, E2F, and Myc) to identify patterns of pathway activation in 118 samples from patients with recurrent (n = 69) and metastatic (n = 49) NSCLC. These individuals, in particular, the patients with metastatic disease are likely to be resistant to standard chemotherapy pointing to the need for alternative therapeutic options. As one approach to this challenge, we used Affymetrix expression data to identify patterns of pathway deregulation in patients with advanced (recurrent/metastatic) disease and compared them to our previously described data on early stage NSCLC (n = 91). Unique to the recurrent and metastatic disease cohorts, a majority of the tumors (greater than 80%) had deregulation of multiple signaling pathways. In particluar, NSCLC tumors with deregulated Src and Myc pathways had a much worse prognosis than those with deregulated Ras and Akt pathways [median survival: 15.5 months vs. 55.3 months, hazard ratio: 2.6, p < 0.01]. Further, using cell proliferation assays, we have shown that the predicted deregulation of Ras, Src and PI3K pathways was directly proportional (p < 0.01, log rank test) to the sensitivity of NSCLC cell lines (n = 17) to agents that specifically target these pathways, suggesting that an ability to profile the status of oncogenic pathways in a tumor sample provides an opportunity to better characterize the oncogenic process in patients with recurrent and advanced NSCLC. More importantly, such a strategy provides a novel approach to targeted therapeutics in NSCLC by guiding the appropriate use of pathway specific inhibitors. Finally, data on gene expression patterns involving other signatures representing unique cancer biology relevant to NSCLC (e.g. hypoxia, chromosomal instability, and angiogenesis) will be also be presented.

No significant financial relationships to disclose.

A multicenter phase II study of erlotinib and bevacizumab in patients with metastatic melanoma

8539

Background: Erlotinib and bevacizumab have demonstrated activity in a number of malignancies by virtue of interrupting interdependent signaling pathways thought important in tumorigenesis. Melanoma may be an appropriate target based on its expression of EGFR and VEGF. We conducted a phase II multi-institutional trial evaluating erlotinib and bevacizumab in advanced melanoma patients. Methods: Eligibility included measurable disease, ECOG PS = 0–1, adequate organ function, no more than one prior therapy for metastatic disease, and CNS metastases were allowed if limited and controlled. Patients received oral erlotinib 150 mg/day and bevacizumab 10 mg/kg IV Q 2 weeks with tumor evaluation every 8 weeks. The primary outcomes were response rate (RR), response duration, and frequency of PFS >6 months. Secondary outcomes included overall survival, safety, and tolerability. A two-stage accrual design was employed ensuring that = 3/21 patients had PFS >6 months before additional patients were accrued. Results: As of Nov 2006, 29 patients with metastatic melanoma were enrolled. A total of 23 patients were evaluable for response. The majority was male 19/29 (65%) and had a median age = 62 yrs (range 35–78 years). Fifteen of the 29 had stage M1c disease (51.7%) and 18/29 (62.1%) had a PS = 1. Ten patients (34%) had prior adjuvant therapy and 6 patients (21%) prior therapy for metastatic disease. There were 2/23 (9%) partial responses lasting < 6 months and 5/23 (22%) had stable disease lasting > 6 months. The median progression free survival of evaluable patients was 96 days (95% CI: 50 - 142 days). A total of 25 grade III toxicities were observed with the most common being rash/pruritis (n=4), pain (n=4), fatigue (n=3), hypertension (n=2) and diarrhea (n=2). Two grade IV toxicities were observed (myocardial infarction and bowel perforation) both thought to be due to bevacizumab. Conclusion: The combination of erlotinib (150 mg/day) and bevacizumab (10 mg/kg) appears potentially active in patients with metastatic melanoma with largely tolerable toxicities. Accrual of a total of 41 patients will be completed shortly.

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