Measuring laboratory-based influenza surveillance capacity: development of the 'International Influenza Laboratory Capacity Review' Tool

OBJECTIVES

The 2005 International Health Regulations (IHR 2005) emphasized the importance of laboratory capacity to detect emerging diseases including novel influenza viruses. To support IHR 2005 requirements and the need to enhance influenza laboratory surveillance capacity, the Association of Public Health Laboratories (APHL) and the Centers for Disease Control and Prevention (CDC) Influenza Division developed the International Influenza Laboratory Capacity Review (Tool).

STUDY DESIGN

Data from 37 assessments were reviewed and analyzed to verify that the quantitative analysis results accurately depicted a laboratory's capacity and capabilities.

METHODS

Subject matter experts in influenza and laboratory practice used an iterative approach to develop the Tool incorporating feedback and lessons learnt through piloting and implementation. To systematically analyze assessment data, a quantitative framework for analysis was added to the Tool.

RESULTS

The review indicated that changes in scores consistently reflected enhanced or decreased capacity. The review process also validated the utility of adding a quantitative analysis component to the assessments and the benefit of establishing a baseline from which to compare future assessments in a standardized way.

CONCLUSIONS

Use of the Tool has provided APHL, CDC and each assessed laboratory with a standardized analysis of the laboratory's capacity. The information generated is used to improve laboratory systems for laboratory testing and enhance influenza surveillance globally. We describe the development of the Tool and lessons learnt.

Sphingomyelin derivatives increase the frequency of microvesicle and granule fusion in chromaffin cells

Sphingomyelin derivatives like sphingosine have been shown to enhance secretion in a variety of systems, including neuroendocrine and neuronal cells. By studying the mechanisms underlying this effect, we demonstrate here that sphingomyelin rafts co-localize strongly with synaptosomal-associated protein of 25Kda (SNAP-25) clusters in cultured bovine chromaffin cells and that they appear to be linked in a dynamic manner. In functional terms, when cultured rat chromaffin cells are treated with sphingomyelinase (SMase), producing sphingomyelin derivatives, the secretion elicited by repetitive depolarizations is enhanced. This increase was independent of cell size and it was significant 15min after initiating stimulation. Interestingly, by evaluating the membrane capacitance we found that the events in control untreated cells corresponded to two populations of microvesicles and granules, and the fusion of both these populations is clearly enhanced after treatment with SMase. Furthermore, SMase does not increase the size of chromaffin granules. Together, these results strongly suggest that SNARE-mediated exocytosis is enhanced by the generation of SMase derivatives, reflecting an increase in the frequency of fusion of both microvesicles and chromaffin granules rather than an increase in the size of these vesicles.

MEK inhibition affects STAT3 signaling and invasion in human melanoma cell lines

Elevated activity of the mitogen-activated protein kinase (MAPK) signaling cascade is found in the majority of human melanomas and is known to regulate proliferation, survival and invasion. Current targeted therapies focus on decreasing the activity of this pathway; however, we do not fully understand how these therapies impact tumor biology, especially given that melanoma is a heterogeneous disease. Using a three-dimensional (3D), collagen-embedded spheroid melanoma model, we observed that MEK and BRAF inhibitors can increase the invasive potential of ∼20% of human melanoma cell lines. The invasive cell lines displayed increased receptor tyrosine kinase (RTK) activity and activation of the Src/FAK/signal transducers and activators of transcription-3 (STAT3) signaling axis, also associated with increased cell-to-cell adhesion and cadherin engagement following MEK inhibition. Targeting various RTKs, Src, FAK and STAT3 with small molecule inhibitors in combination with a MEK inhibitor prevented the invasive phenotype, but only STAT3 inhibition caused cell death in the 3D context. We further show that STAT3 signaling is induced in BRAF-inhibitor-resistant cells. Our findings suggest that MEK and BRAF inhibitors can induce STAT3 signaling, causing potential adverse effects such as increased invasion. We also provide the rationale for the combined targeting of the MAPK pathway along with inhibitors of RTKs, SRC or STAT3 to counteract STAT3-mediated resistance phenotypes.

National Ignition Facility system alignment

The National Ignition Facility (NIF) is the world's largest optical instrument, comprising 192 37 cm square beams, each generating up to 9.6 kJ of 351 nm laser light in a 20 ns beam precisely tailored in time and spectrum. The Facility houses a massive (10 m diameter) target chamber within which the beams converge onto an ∼1 cm size target for the purpose of creating the conditions needed for deuterium/tritium nuclear fusion in a laboratory setting. A formidable challenge was building NIF to the precise requirements for beam propagation, commissioning the beam lines, and engineering systems to reliably and safely align 192 beams within the confines of a multihour shot cycle. Designing the facility to minimize drift and vibration, placing the optical components in their design locations, commissioning beam alignment, and performing precise system alignment are the key alignment accomplishments over the decade of work described herein. The design and positioning phases placed more than 3000 large (2.5 m×2 m×1 m) line-replaceable optics assemblies to within ±1 mm of design requirement. The commissioning and alignment phases validated clear apertures (no clipping) for all beam lines, and demonstrated automated laser alignment within 10 min and alignment to target chamber center within 44 min. Pointing validation system shots to flat gold-plated x-ray emitting targets showed NIF met its design requirement of ±50 μm rms beam pointing to target chamber. Finally, this paper describes the major alignment challenges faced by the NIF Project from inception to present, and how these challenges were met and solved by the NIF design and commissioning teams.

Notes from the field: outbreak of 2009 pandemic influenza A (H1N1) virus at a large public university in Delaware, April-May 2009

BACKGROUND

In late April 2009, the first documented 2009 pandemic influenza A (pH1N1) virus infection outbreak in a university setting occurred in Delaware, with large numbers of students presenting with respiratory illness. At the time of this investigation, little was known about the severity of illness, effectiveness of the vaccine, or transmission factors of pH1N1 virus infection. We characterized illness, determined the impact of this outbreak, and examined factors associated with transmission.

METHODS

Health clinic records were reviewed. An online survey was administered to all students, staff, and faculty to assess influenza-like illness (ILI), defined as documented or subjective fever with cough or sore throat.

RESULTS

From 26 April-2 May 2009, the health clinic experienced a sharp increase in visits for respiratory illness, with 1080 such visits among a total of 1430 student visits, and then a return to baseline visit levels within 2 weeks. More than 500 courses of oseltamivir were distributed, and 24 cases of influenza A (pH1N1) virus infection were confirmed. Of 29,000 university students and faculty/staff, 7450 (30%) responded to the survey. ILI was reported by 604 (10%) of the students and 73 (5%) of the faculty/staff. Travel to Mexico (relative risk [RR], 2.9; 95% confidence interval [CI], 1.8-4.7) and participation in "Greek Week" activities (RR, 2.2; 95% CI, 1.8-2.8) were associated with ILI. Recipients of the 2008-2009 seasonal influenza vaccine had the same risk of ILI as nonrecipients (RR, 1.0). Four (3%) of the students with ILI were hospitalized; there were no deaths.

CONCLUSIONS

pH1N1 spread rapidly through the University of Delaware community with a surge in illness over a 2-week period. Although initial cases appear to be associated with travel to Mexico, a rapid increase in cases was likely facilitated by increased student interactions during Greek Week. No protective effect from receiving seasonal influenza vaccine was identified. Although severe illness was rare, the outbreak caused a substantial burden and challenge to the university health care system. Preparedness efforts in universities and similar settings should include enhancing health care surge capacity.

Vesicle movements are governed by the size and dynamics of F-actin cytoskeletal structures in bovine chromaffin cells

Dense vesicles can be observed in live bovine chromaffin cells using fluorescent reflection confocal microscopy. These vesicles display a similar distribution, cytoplasmic density and average size as the chromaffin granules visualized by electron microscopy. In addition, the acidic vesicles labeled with Lysotracker Red comprised a subpopulation of the vesicles that are visualized by reflection fluorescence. A combination of fluorescence reflection and transmitted light images permitted the movements of vesicles in relation to the cortical cytoskeleton to be studied. The movement of vesicles located on the outside of this structure was restricted, with an apparent diffusion coefficient of 1.0+/-0.4 x 10(-4) microm(2)/s. In contrast, vesicles located in the interior moved much more freely and escaped from the visual confocal plane. Lysotracker labeling was more appropriate to study the movement of the faster moving vesicles, whose diffusion coefficient was five times higher. Using this type of labeling we confirmed the restriction on cortical movement and showed a clear relationship between vesicle mobility and the kinetics of cytoskeletal movement on both sides of the cortical cytoskeleton. This relationship was further emphasized by studying cytoskeletal organization and kinetics. Indeed, an estimate of the size of the cytoskeletal polygonal cages present in the cortical region and in the cell interior agreed well with the calculation of the theoretical radius of the cages imprisoning vesicle movement. Therefore, these data suggest that the structure and kinetics of the cytoskeleton governs vesicle movements in different regions of chromaffin cells.

Perforin polymorphism A91V and susceptibility to B-precursor childhood acute lymphoblastic leukemia: a report from the Children's Oncology Group

Perforin plays a key role in the cytotoxicity of natural killer and cytotoxic T cells. Genetic mutations in the perforin gene (PRF1) give rise to approximately 30% cases of familial hemophagocytic lymphohistiocytosis. A frequent polymorphism, A91V (C to T transition at position 272), may impair processing of perforin protein to the active form, and has been suggested to increase susceptibility to childhood acute lymphoblastic leukemia (ALL). To investigate the role of A91V in ALL, we genotyped 2272 children with de novo ALL registered on the Pediatric Oncology Group ALL Classification study P9900 and 655 normal controls. Allele frequencies in the controls showed a very low frequency of the variant allele in blacks, 0.7% compared to 4% in white controls. In light of this, analysis was restricted to a comparison of white cases and controls only. Overall genotype frequencies were similar in white ALL cases and normal white controls (P=0.58), indicating that in contrast to the previous report, A91V polymorphism is not associated with increased risk of childhood ALL. PRF1 A91V frequency was significantly increased in children with BCR-ABL positive ALL (24 vs 8.5%; P=0.0048); however, this observation includes a relatively small number of cases and needs further exploration.

Preliminary results of a randomized phase II study comparing two schedules of temozolomide in combination with sorafenib in patients with advanced melanoma

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Background: Sorafenib (SO) is an oral Raf kinase/VEGFR-2 inhibitor that has anti-melanoma activity when given with carboplatin/paclitaxel. The primary objective of this study is to estimate the duration of progression-free survival (PFS) for patients with metastatic melanoma (MM) taking SO + temozolomide (TEM). Secondary objectives are to determine the optimal dosing of TEM when given with SO, response, and toxicity rates. Correlative studies include BRAF genotyping and assessment of intratumoral Raf inhibition. Methods: Patients with MM and ECOG PS<2 are eligible. Prior therapy is allowed. Accrual is designed for 167 patients in one stage. All patients receive SO 400 mg po bid continuously. After one week of SO alone, patients without brain metastasis and no prior TEM are randomized to receive either extended daily dosing (EDD): TEM 75 mg/m2 po qd for 6 /8 weeks (Arm A), or standard dosing (STD): TEM 150 mg/m2 po qd for days1–5/28 (Arm B). Patients with prior TEM use are treated with EDD (Arm C) and patients with brain metastasis without prior TEM are treated with STD (Arm D). Responses are assessed using RECIST criteria. Results: 65 patients were evaluated for toxicity. Of these, 58 received SO + TEM and were evaluable for response (Table). SO + TEM resulted in a 24% overall response rate (ORR) [95% CI 11–41%] in patients without brain metastasis or prior TEM and 20% ORR [95% CI 3–56%] in patients with brain metastasis and no prior TEM. Observed grade 3 toxicities attributable to study medication were: hand-foot syndrome (12%), rash (8%), nausea (5%), anorexia (8%), and hypertension (3%). Nausea and anorexia were more prevalent with STD. Tumor blocks and 8 paired biopsy samples have been collected for correlative studies. Conclusions: Initial phase II results demonstrate encouraging antitumor activity and safety profile for SO + TEM in MM. Updated PFS data, response and toxicity rates, and correlative results will be presented.

[Table: see text]

[Table: see text]

Non-linear effects in the determination of paleotemperature Uk′37 alkenone ratios by chemical ionization mass spectrometry

The performance of gas chromatography coupled to mass spectrometry in the positive chemical ionization mode using ammonia as reagent gas (GC-PCI-MS) in the analysis of C37 alkenones for paleotemperature estimation has been re-evaluated. In some conditions, the discrepancies observed in the measurement of the U37(k') index with this technique as compared with GC equipped with flame ionization detection (GC-FID) cannot be explained by differences in sensitivity between the tri- and diunsaturated alkenones. Thus, at low (currently <0.3) or high (currently >0.4) U37(k') values the GC-PCI-MS determinations may be observed to be lower or higher, respectively, than those measured with GC-FID. As shown by analysis of a series of synthetic C37 alkenone standards these discrepant results can be explained by non linear effects in the GC-PCI-MS response factors. Second-order polynomial functions provide equations that describe better the signal to amount of analyte ratios. Users of GC-PCI-MS should calibrate their instruments with standards of known C37 alkenone composition in order to minimize non-linear effects.

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) up-regulates death receptor 5 (DR5) mediated by NFkappaB activation in epithelial derived cell lines

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL/APO-2L) activates nuclear factor kappaB (NFkappaB). This activation is regulated by the recruitment of an adaptor protein Fas associating death domain (FADD) to TRAIL death receptors, death receptor 4 (DR4, TRAIL-R1) and death receptor 5 (DR5 TRAIL-R2). This leads to recruitment of caspase 8 and receptor interacting protein (RIP) to the receptor complex. Upon recruitment of caspase 8 and RIP, NFkappaB inducing kinase (NIK) becomes activated causing NFkappaB activation. The role of TRAIL induced NFkappaB activation in epithelial cells is unknown. Herein we demonstrate that TRAIL increases expression of DR5 in human embryonic kidney (HEK) 293, MCF-7 and MDA MB 231 epithelial cell lines while DR4 expression remains unchanged. Blockage of NFkappaB activation either by expression of dominant negative IkappaB or treatment with proteasome inhibitor lactacystin eliminates TRAIL induced DR5 expression. Expression of FADD dominant negative in HEK 293 cells that prevents the recruitment of caspase 8 and RIP to TRAIL death receptors also eliminates this increase. By over expression of the p65 subunit of NFkappaB that increases NFkappaB transcriptional activity, DR5 expression was increased compared to vector alone expressing cells. By blocking TRAIL induced NFkappaB activation, the sensitivity of cells to undergo TRAIL induced apoptosis was significantly decreased. Conversely, the amount of TRAIL induced apoptosis was increased in HEK 293 cells over expressing p65 subunit of NFkappaB. Finally blockage of NFkappaB activation eliminates the synergistic apoptotic response of TRAIL and etoposide. Thus, TRAIL mediated NFkappaB activation increases DR5 expression thereby amplifying the apoptotic response of TRAIL in epithelial derived cells.

Timing of cyclin D1 expression within G1 phase is controlled by Rho

The expression of cyclin D1 in mid-G1 phase is associated with sustained ERK activity, and we show here that Rho is required for the sustained ERK signal. However, we also report that Rho inhibits an alternative Rac/Cdc42-dependent pathway, which results in a strikingly early G1-phase expression of cyclin D1. Thus, cyclin D1 is induced in mid-G1 phase because a Rho switch couples its expression to sustained ERK activity rather than Rac and Cdc42. Our results show that Rho is crucial for maintaining the correct timing of cyclin D1 expression in G1 phase and describe a new role for cytoskeletal integrity in the regulation of cell cycle progression.

Monitoring the expression and purification of recombinant proteins by MALDI-TOF mass spectrometry

1Samples coming from biologic sources usually contain several contaminants that interfere seriously with Mass Spectrometry (MS) measurements. In this paper we report the application of MALDI-TOF MS to monitor recombinant protein expression and purification. The technique is based on the use of a C18 resin to clean and concentrate proteins in batch. The utility of this method is demonstrated for samples coming from different bacterial cultures expressing secreted and intracellular proteins ranging from 4 to 53 kDa. MALDI-TOF MS of peptide and proteins can be accomplished directly from complex bacterial cultures or from any purification step in a few minutes using the conventional stainless steel sample targets, allowing for a nearly instantaneous monitoring of the nature and integrity of recombinant expression products.