Microdevices for cancer stem cell culture as a predictive chemotherapeutic response platform

Microfluidic platforms for clinical use are a promising translational strategy for cancer research specially for drug screening. Identifying cancer stem cells (CSC) using sphere culture techniques in microfluidic devices (MDs) showed to be better reproducing physiological responses than other in vitro models and allow the optimization of samples and reagents. We evaluated individual sphere proliferation and stemness toward chemotherapeutic treatment (CT) with doxorubicin and cisplatin in bladder cancer cell lines (MB49-I and J82) cultured in MDs used as CSC treatment response platform. Our results confirm the usefulness of this device to evaluate the CT effect in sphere-forming efficiency, size, and growth rate from individual spheres within MDs and robust information comparable to conventional culture plates was obtained. The expression of pluripotency genetic markers (Oct4, Sox2, Nanog, and CD44) could be analyzed by qPCR and immunofluorescence in spheres growing directly in MDs. MDs are a suitable platform for sphere isolation from tumor samples and can provide information about CT response. Microfluidic-based CSC studies could provide information about treatment response of cancer patients from small samples and can be a promising tool for CSC-targeted specific treatment with potential in precision medicine. KEY MESSAGES: We have designed a microfluidic platform for CSC enriched culture by tumor sphere formation. Using MDs, we could quantify and determine sphere response after CT using murine and human cell lines as a proof of concept. MDs can be used as a tumor-derived sphere isolation platform to test the effect of antitumoral compounds in sphere proliferation.

Antimicrobial usage in farm animal practices in the UK: A mixed-methods approach

Antimicrobial resistance (AMR) is a growing One Health problem. Monitoring antimicrobial usage in farm animals is crucial for tackling AMR. A cohort study using the electronic clinical records during 2019 from 23 farm animal veterinary practices across the UK belonging to two corporate groups, with a range of 2-14 veterinarians per practice, estimated the usage of antimicrobials and highest priority critically important antimicrobials (HP-CIAs). Risk factors for using HP-CIAs were evaluated using hierarchical mixed-effects logistic regression modelling with practice ID and farm ID added as random effects. Using a qualitative approach, veterinarians from one of the participating practice groups were recruited for a qualitative study to explore the barriers and facilitators in relation to antimicrobial use. Semi-structured interviews were conducted with participants and analysed thematically. During the year 2019, 98,824 antimicrobial prescribing events overall were recorded from the treatment records of the 23 participating practices. The median count of antimicrobial events per practice was 3226 (range 263-22,159). There were 17,111/98,824 (17.3%) HP-CIAs events overall, with a median of 15.4% at practice level (range 4.8-22.1%). Penicillins were the most frequently used antimicrobials 29,539/98,824 (29.9%) followed by tetracyclines 19,015/98,824 (19.2%). HP-CIA use was strongly clustered, with more clustering seen at the farm level (intraclass correlation coefficient (ICC)= 0.56) than at the practice level (ICC= 0.32). Country, route of administration, season and practice type were significantly associated with the usage of HP-CIAs. Four main themes were identified from the analysis of the veterinarians' interviews: pressure from the industry, drug-related factors, knowledge level of veterinarians and clinical factors. Supermarket contracts and farm assurance schemes were facilitators for reducing antimicrobial use and the use of HP-CIAs. Ease of administration and the withdrawal period of the antimicrobials influenced veterinarians' choice of antimicrobials. The clinical condition and clinical signs presented on farm were reported to influence participating veterinarians' prescribing decision. Participants showed a good understanding of AMR, responsible use of antimicrobials and the term 'critically important antimicrobials'. In conclusion, integrating the quantitative and qualitative findings can inform policymaking on antimicrobials stewardship in farm practice. By estimating the relative levels of clustering of antimicrobial use at the practice and farm level, as well as identifying major risk factors for using HP-CIAs, more targeted interventions can be designed to promote responsible antimicrobial use in farm practice. Furthermore, better understanding the industry pressures on farms to reduce antimicrobials usage could reduce the barriers for responsible antimicrobial use by veterinarians.

Advanced practice physiotherapy care in emergency departments for patients with musculoskeletal disorders: a pragmatic cluster randomized controlled trial and cost analysis

BACKGROUND

Advanced practice physiotherapy (APP) models of care where physiotherapists are primary contact emergency department (ED) providers are promising models of care to improve access, alleviate physicians' burden, and offer efficient centered patient care for patients with minor musculoskeletal disorders (MSKD).

OBJECTIVES

To compare the effectiveness of an advanced practice physiotherapist (APPT)-led model of care with usual ED physician care for persons presenting with a minor MSKD, in terms of patient-related outcomes, health care resources utilization, and health care costs.

METHODS

This trial is a multicenter stepped-wedge cluster randomized controlled trial (RCT) with a cost analysis. Six Canadian EDs (clusters) will be randomized to a treatment sequence where patients will either be managed by an ED APPT or receive usual ED physician care. Seven hundred forty-four adults with a minor MSKD will be recruited. The main outcome measure will be the Brief Pain Inventory Questionnaire. Secondary measures will include validated self-reported disability questionnaires, the EQ-5D-5L, and other health care utilization outcomes such as prescription of imaging tests and medication. Adverse events and re-visits to the ED for the same complaint will also be monitored. Health care costs will be measured from the perspective of the public health care system using time-driven activity-based costing. Outcomes will be collected at inclusion, at ED discharge, and at 4, 12, and 26 weeks following the initial ED visit. Per-protocol and intention-to-treat analyses will be performed using linear mixed models with a random effect for cluster and fixed effect for time.

DISCUSSION

MSKD have a significant impact on health care systems. By providing innovative efficient pathways to access care, APP models of care could help relieve pressure in EDs while providing efficient care for adults with MSKD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05545917 . Registered on September 19, 2022.

Social Isolation in Community-Dwelling Older Adults During COVID-19: Understanding the Role of Resilience

The COVID-19 pandemic increased social isolation for many older adults, causing concern for their health and well-being. To enhance understanding of how community-dwelling older adults were impacted by prolonged social isolation during COVID-19, a qualitative descriptive study was conducted to: (1) explore the self-reported factors supporting their resilience during COVID-19 related social isolation, and (2) to help understand the intentional and unintentional outcomes of the government mandated health measures. A total of 19 community dwelling older adults were sampled. Factors that supported older adults' resilience during COVID-19 included maintaining positivity, drawing on historical experiences of resilience and finding opportunities to connect with their community. However, collective safety came with losses: such as time, freedom, opportunity, engagement, and initiative. The findings provide insight on contributing factors to resilience against social isolation in older adults and suggest the value of collective, community-based approaches to build resilience across variable contexts in this population.

Bioremediation on a chip: A portable microfluidic device for efficient screening of bacterial biofilm with polycyclic aromatic hydrocarbon removal capacity

Polycyclic aromatic hydrocarbons (PAHs) are pollutants of critical environmental and public health concern and their elimination from contaminated sites is significant for the environment. Biodegradation studies have demonstrated the ability of bacteria in biofilm conformation to enhance the biodegradation of pollutants. In this study, we used our newly developed microfluidic platform to explore biofilm development, properties, and applications of fluid flow, as a new technique for screening PAHs-degrading biofilms. The optimization and evaluation of the flow condition in the microchannels were performed through computational fluid dynamics (CFD). The formation of biofilms by PAHs-degrading bacteria Pseudomonas sp. P26 and Gordonia sp. H19, as pure cultures and co-culture, was obtained in the developed microchips. The removal efficiencies of acenaphthene, fluoranthene and pyrene were determined by HPLC. All the biofilms formed in the microchips removed all tested PAHs, with the higher removal percentages observed with the Pseudomonas sp. P26 biofilm (57.4% of acenaphthene, 40.9% of fluoranthene, and 28.9% of pyrene). Pseudomonas sp. P26 biofilm removed these compounds more efficiently than planktonic cultures. This work proved that the conformation of biofilms enhances the removal rate. It also provided a new tool to rapid and low-cost screen for effective pollutant-degrading biofilms.

Large Area Microfluidic Bioreactor for Production of Recombinant Protein

To produce innovative biopharmaceuticals, highly flexible, adaptable, robust, and affordable bioprocess platforms for bioreactors are essential. In this article, we describe the development of a large-area microfluidic bioreactor (LM bioreactor) for mammalian cell culture that works at laminar flow and perfusion conditions. The 184 cm² 32 cisterns LM bioreactor is the largest polydimethylsiloxane (PDMS) microfluidic device fabricated by photopolymer flexographic master mold methodology, reaching a final volume of 2.8 mL. The LM bioreactor was connected to a syringe pump system for culture media perfusion, and the cells’ culture was monitored by photomicrograph imaging. CHO-ahIFN-α2b adherent cell line expressing the anti-hIFN-a2b recombinant scFv-Fc monoclonal antibody (mAb) for the treatment of systemic lupus erythematosus were cultured on the LM bioreactor. Cell culture and mAb production in the LM bioreactor could be sustained for 18 days. Moreover, the anti-hIFN-a2b produced in the LM bioreactor showed higher affinity and neutralizing antiproliferative activity compared to those mAbs produced in the control condition. We demonstrate for the first-time, a large area microfluidic bioreactor for mammalian cell culture that enables a controlled microenvironment suitable for the development of high-quality biologics with potential for therapeutic use.

Removal of uterine polyps: clinical management and surgical approach

Endometrial polyps have a reported prevalence from 7.8% up to 30% and are one of the most cost-consuming gynecological conditions for our specialty. There are strong practitioner beliefs that surgical removal of endometrial polyps is highly beneficial, particularly for those with abnormal uterine bleeding and infertility. Additionally, polypectomy is indicated to reduce the risk of malignancy. Transvaginal ultrasound is the first-line diagnostic option for detection of endometrial polyps, while sonohysterography has similar accuracy as hysteroscopy in the diagnostic confirmation. Blind dilatation and curettage is not recommended for polyp removal; rather, hysteroscopy in the operating room and office setting using small-diameter hysteroscopic equipment is the standard approach. This can be performed without anesthesia in most women. While hysteroscopy is an effective method for polypectomy with a low complication rate, it is unknown whether this is truly beneficial for reproductive-age women with infertility and prior assisted reproduction therapy. The risk of malignancy in women with postmenopausal bleeding justifies the necessity of polypectomy with histologic tissue examination. In asymptomatic women, the risk of malignancy is low, and there are no known benefits of polyp removal in the prevention of malignant transformation. Cost-effective studies remain to be done to provide us with the optimal approach to endometrial polyps including the management of asymptomatic and/or infertile women, ideal location including office-based or the operating room setting, complication prevention including intrauterine adhesions, and recurrence issues.

The role of intra-operative cell salvage in patient blood management for revision hip arthroplasty: a prospective cohort study

Cell salvage is an important component of blood management in patients undergoing revision hip arthroplasty surgery. However concerns regarding efficacy and patient selection remain. The aims of this study were to describe intra-operative blood loss, cell salvage re-infusion volumes and red blood cell transfusion rates for revision hip procedures and to identify factors associated with the ability to salvage sufficient blood intra-operatively to permit processing and re-infusion. Data were collected from a prospective cohort of 664 consecutive patients undergoing revision hip surgery at a single tertiary centre from 31 March 2015 to 1 April 2018. Indications for revision surgery were aseptic (n = 393 (59%)) fracture (n = 160 (24%)) and infection (n = 111 (17%)). Salvaged blood was processed and re-infused when blood loss exceeded 500 ml. Mean (SD) intra-operative blood loss was 1038 (778) ml across all procedures. Salvaged blood was re-infused in 505 of 664 (76%) patients. Mean (SD) re-infusion volume was 253 (169) ml. In total, 246 of 664 (37%) patients received an allogeneic red blood cell transfusion within 72 h of surgery. Patients undergoing femoral component revision only (OR (95%CI) 0.41 (0.23-0.73)) or acetabular component revision only (0.53 (0.32-0.87)) were less likely to generate sufficient blood salvage volume for re-infusion compared with revision of both components. Compared with aseptic indications, patients undergoing revision surgery for infection (1.87 (1.04-3.36)) or fracture (4.43 (2.30-8.55)) were more likely to generate sufficient blood salvage volume for re-infusion. Our data suggest that cell salvage is efficacious in this population. Cases where the indication is infection or fracture and where both femoral and acetabular components are to be revised should be prioritised.

Hybrid microchannel-solid state micropore device for fast and optical cell detection

This paper presents a methodology for cell detection and counting using a device that combines PDMS (polydimethylsiloxane) microfluidic multilayer channels with a single solid state micropore. Optimal conditions of solid-state micropore fabrication from crystalline silicon wafers are presented. Micropores of varying size can be obtained by directly etching using an etchant agent concentration of 50 wt% KOH, at varying temperatures (40, 60, 80 °C) and voltages (100, 500, 1000 mV). Scanning Electron Microscopy (SEM), and profilometry techniques have been used for the micropore characterization. In order to find optimal conditions for cell detection a COMSOL Multiphysics simulation was performed. Pressure drop, shear stress, fluid viscosities and flow rates parameters were evaluated. The potential viability of the device for cell detection and counting, avoiding cellular damage, is demonstrated.

This paper presents a methodology for cell detection and counting using a device that combines PDMS (polydimethylsiloxane) microfluidic multilayer channels with a single solid state micropore.

Risk factors and mitigation of influenza among Indigenous children in Australia, Canada, United States, and New Zealand: a scoping review

AIM

This review considers prominent risk factors and mitigation strategies of influenza among Indigenous children.

METHODS

Seven electronic databases were searched from the period of 2004-2017 to locate articles discussing influenza among Indigenous children in the developed circumpolar nations of Australia, Canada, United States, and New Zealand. Articles selected for inclusion discussed influenza among Indigenous children as either individuals or as a part of a community. Ancestry searches of articles meeting the review criteria were also undertaken to discern seminal research in this topic area.

RESULTS

From the 39 primary research studies included, marked risk factors and mitigation strategies of influenza among Indigenous children were identified using inductive analysis. Notable risk factors included age under 2 years, cigarette smoke exposure, presence of a chronic illness, and crowded living conditions. Successful mitigation of influenza for Indigenous children included strategies to improve vaccine coverage, provision of health education, and policy change.

CONCLUSION

In the past, the impact of influenza upon Indigenous communities has been devastating for both children and their families. By utilizing existing public health infrastructure and collaborating with culturally unique Indigenous groups, preventive action for Indigenous children at significant risk of contracting influenza can be realized.

Abstract LB-316: Dynamic live cell imaging of tumor migration and invasion

Migration and invasion activities of metastasizing cancer cells are of immense significance to the field of cancer research, often leading to fatal spread of the disease. While much understanding has been gained regarding the underlying molecular and cellular mechanisms governing these processes, the direct observations of associate morphological and biochemical features are limited by the current methodologies which largely rely on endpoint micro-porous membrane-based assays or various live cell imaging assays performed on 2D/3D substrates- neither of which enable dynamic control over the tumor microenvironment. Microfluidic technologies enable high-resolution time-lapse imaging while providing exceptional experimental control to maintain a physiologically relevant microenvironment. Here we demonstrate the value of the CellASIC ONIX2 “dynamic live cell imaging system”, where microenvironmental parameters such as flowrates, the perfusion of nutrients and reagents, and temperature and gas compositions can be precisely controlled on demand by software during the entire duration of a given experiment. We now show the value of this system for imaging of metastatic processes with a novel microfluidic design comprising two parallel chambers separated by a micro-porous wall. One chamber contains MDA-MB-231 breast cancer cells embedded in 3D hydrogel culture or simply grown in 2D fashion, and the other chamber contains HUVEC endothelial cells in a monolayer. The device enables exceptionally clear real-time imaging of the migration of MDA-MB-231 cells, as well as invasion of these cells through and out of the gel into the “vascular” channel, enabling the monitoring of the adhesion and interaction of these cells with the HUVEC cells once the tumor cells had left the gel. Unlike the state-of-the-art endpoint or static culture imaging assays, the microfluidics system described herein enables the investigation of wider microenvironmental parameters and their interplay with cellular processes in unprecedented precision and permutations, and is also suitable for the studies of wider biological applications outside of cancer biology.

Citation Format: Ross Booth, Cindy Chen, Victor Yeh, Deepika Verma, Jun Park. Dynamic live cell imaging of tumor migration and invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-316.

Dynamic live cell imaging of immune cell interactions using microfluidics cell trap

While providing indispensable insight into immune processes, the live cell imaging of immune cells poses unique challenges due to their non-adherent nature. Suspension cells such as immune cells can easily move away from the FOV (field of view) during imaging by any physical perturbations such as introduction of agonist or even simple media change, often necessitating the use of surface coating to artificially immobilize cells. In addition, unlike adherent cells, interacting suspension cells form aggregates, making it very difficult to track and analyze individual cells during imaging. Previously, we have described the novel microfluidic-based dynamic live cell imaging platform CellASIC ONIX2, where microenvironmental parameters such as the perfusion of media/reagent, temperature, and gas compositions can be precisely controlled on demand via software during the entire imaging experiment. We now report further utility of the system with a new non-adherent cell trap culture plate comprising an array of walled ~100μm square pads with a 12μm height restriction and 3μm wall gap, allowing physical trapping of immune cells within FOV while enabling their natural movement, and preventing vertical cell stacking of aggregated cells while preserving cell-cell interactions. Using Jurkat T cells and super antigen loaded Raji B cells, we demonstrate dynamic live cell imaging of immune cell interactions. Unlike systems where cells are artificially immobilized, we show that these cells are extremely motile and behave in much more complex and dynamic fashion during their interactions. The technology should benefit live cell imaging of any suspension cells and is amendable for wider applications in addition to immune cell imaging.

Analysis of tumoral spheres growing in a multichamber microfluidic device

Lab on a Chip (LOC) farming systems have emerged as a powerful tool for single cell studies combined with a non-adherent cell culture substrate and single cell capture chips for the study of single cell derived tumor spheres. Cancer is characterized by its cellular heterogeneity where only a small population of cancer stem cells (CSCs) are responsible for tumor metastases and recurrences. Thus, the in vitro strategy to the formation of a single cell-derived sphere is an attractive alternative to identify CSCs. In this study, we test the effectiveness of microdevices for analysis of heterogeneity within CSC populations and its interaction with different components of the extracellular matrix. CSC could be identify using specific markers related to its pluripotency and self-renewal characteristics such as the transcription factor Oct-4 or the surface protein CD44. The results confirm the usefulness of LOC as an effective method for quantification of CSC, through the formation of spheres under conditions of low adhesion or growing on components of the extracellular matrix. The device used is also a good alternative for evaluating the individual growth of each sphere and further identification of these CSC markers by immunofluorescence. In conclusion, LOC devices have not only the already known advantages, but they are also a promising tool since they use small amounts of reagents and are under specific culture parameters. LOC devices could be considered as a novel technology to be used as a complement or replacement of traditional studies on culture plates.

Dynamic characterization of the phagocytic process utilizing an automated microfluidic platform

Phagocytosis is a complex pathway that involves removal of pathogens, foreign particles, or cell debris through engulfment by unique cell types. Such innate responses provide the first line of immune defense with evidence showing their critical involvement in prevention of chronic inflammation or autoimmune disease, tissue remodeling and removal of apoptotic tumor cells following therapeutic intervention. Traditional tools evaluate cell behavior in bulk context thus masking inherent cellular heterogeneity or employ end-point assays thus losing temporal process dynamics. Moreover, non-adherent immune cells are mobile complicating single cell analysis. Characterizing functional changes with single cell resolution requires precise spatial cell positioning, controlled micro-environment and high-throughput multiplexed measurement. We developed a novel microfluidic approach to trap single non-adherent immune cells in a microfluidic platform capable of perfusion-based media supply with gas and temperature control. The device is comprised of a controller system and optically transparent microfluidic plates, each with four culture chambers. Each chamber [dimension: 3mm × 3mm × 40μm (L × W × H)] contains a trap array tailored to the dimensions of the cells of interest. Each unit can be addressed by programmable manipulation of up to six reagents, enabling uninterrupted real-time live cell imaging assays in response to changing conditions. To demonstrate utility, the platform was used in conjunction with fluorescent markers to monitor the phagocytic process in real-time via, including temporal changes in morphology and the rate of phagosome formation/inhibition in the presence of different stimuli and concentration.

Randomised positive control trial of NSAID and antimicrobial treatment for calf fever caused by pneumonia

One hundred and fifty-four preweaning calves were followed between May and October 2015. Calves were fitted with continuous monitoring temperature probes (TempVerified FeverTag), programmed so a flashing light emitting diode (LED) light was triggered following six hours of a sustained ear canal temperature of ≥39.7°C. A total of 83 calves (61.9 per cent) developed undifferentiated fever, with a presumptive diagnosis of pneumonia through exclusion of other calf diseases. Once fever was detected, calves were randomly allocated to treatment groups. Calves in group 1 (NSAID) received 2 mg/kg flunixin meglumine (Allevinix, Merial) for three consecutive days and group 2 (antimicrobial) received 6 mg/kg gamithromycin (Zactran, Merial). If fever persisted for 72 hours after the initial treatment, calves were given further treatment (group 1 received antimicrobial and group 2 received NSAID). Calves in group 1 (NSAID) were five times more likely (P=0.002) to require a second treatment (the antimicrobial) after 72 hours to resolve the fever compared with the need to give group 2 (antimicrobial) calves a second treatment (NSAID). This demonstrates the importance of ongoing monitoring and follow-up of calves with respiratory disease. However, of calves with fever in group 1 (NSAID), 25.7 per cent showed resolution following NSAID-only treatment with no detrimental effect on the development of repeated fever or daily live weight gain. This suggests that NSAID alone may be a useful first-line treatment, provided adequate attention is given to ongoing monitoring to identify those cases that require additional antimicrobial treatment.

Individuals with current suicidal ideation demonstrate implicit "fearlessness of death"

BACKGROUND AND OBJECTIVES

Suicidal behaviour has proved to be difficult to predict, due in part to the particular limitations of introspection within suicidality. In an effort to overcome this, recent research has demonstrated the utility of indirect measures of "implicit" attitudes within the study of suicidality. However, research to date has focused predominantly on implicit self-evaluations and self-death associations. No work has examined implicit evaluations of death, despite the theoretical importance of such evaluations; "fearlessness of death" is central to both the Interpersonal Theory of Suicide and the Integrated Motivational-Volitional model of suicide..

METHODS

Twenty-three psychiatric patients with current suicidal ideation and twenty-five normative university students completed two versions of the Implicit Relational Assessment Procedure (IRAP) that targeted evaluations of death. One task specified personal death (i.e., was self-focused) and the other targeted death in the abstract.

RESULTS

Self-focused evaluations of death reliably distinguished between the two groups, correctly classifying 74% of cases, but evaluations of death in the abstract did not. The suicidal group produced specific biases indicating a rejection of the negativity of death. Results are consistent with the definition of suicidality as involving a self-focused wish to die..

LIMITATIONS

For ethical reason, suicidal behaviours were not assessed in the normative group. Groups were therefore not mutually exclusive. This may have decreased the specificity of the IRAP.

CONCLUSIONS

Suicidal ideation is associated with an implicit "fearlessness of death". The utility of implicit death-evaluations should therefore be considered alongside self-evaluations and self-death associations in the future..

Permeability analysis of neuroactive drugs through a dynamic microfluidic in vitro blood-brain barrier model

This paper presents the permeability analysis of neuroactive drugs and correlation with in vivo brain/plasma ratios in a dynamic microfluidic blood-brain barrier (BBB) model. Permeability of seven neuroactive drugs (Ethosuximide, Gabapentin, Sertraline, Sunitinib, Traxoprodil, Varenicline, PF-304014) and trans-endothelial electrical resistance (TEER) were quantified in both dynamic (microfluidic) and static (transwell) BBB models, either with brain endothelial cells (bEnd.3) in monoculture, or in co-culture with glial cells (C6). Dynamic cultures were exposed to 15 dyn/cm(2) shear stress to mimic the in vivo environment. Dynamic models resulted in significantly higher average TEER (respective 5.9-fold and 8.9-fold increase for co-culture and monoculture models) and lower drug permeabilities (average respective decrease of 0.050 and 0.052 log(cm/s) for co-culture and monoculture) than static models; and co-culture models demonstrated higher average TEER (respective 90 and 25% increase for static and dynamic models) and lower drug permeability (average respective decrease of 0.063 and 0.061 log(cm/s) for static and dynamic models) than monoculture models. Correlation of the resultant logP e values [ranging from -4.06 to -3.63 log(cm/s)] with in vivo brain/plasma ratios (ranging from 0.42 to 26.8) showed highly linear correlation (R (2) > 0.85) for all model conditions, indicating the feasibility of the dynamic microfluidic BBB model for prediction of BBB clearance of pharmaceuticals.

A multiple-channel, multiple-assay platform for characterization of full-range shear stress effects on vascular endothelial cells

Vascular endothelial cells (VECs), which line blood vessels and are key to understanding pathologies and treatments of various diseases, experience highly variable wall shear stress (WSS) in vivo (1-60 dyn cm(-2)), imposing numerous effects on physiological and morphological functions. Previous flow-based systems for studying these effects have been limited in range, and comprehensive information on VEC functions at the full spectrum of WSS has not been available yet. To allow rapid characterization of WSS effects, we developed the first multiple channel microfluidic platform that enables a wide range (~15×) of homogeneous WSS conditions while simultaneously allowing trans-monolayer assays, such as permeability and trans-endothelial electrical resistance (TEER) assays, as well as cell morphometry and protein expression assays. Flow velocity/WSS distributions between channels were predicted with COMSOL simulations and verified by measurement using an integrated microflow sensor array. Biomechanical responses of the brain microvascular endothelial cell line bEnd.3 to the full natural spectrum of WSS were investigated with the platform. Under increasing WSS conditions ranging from 0 to 86 dyn cm(-2), (1) permeabilities of FITC-conjugated dextran and propidium iodide decreased, respectively, at rates of 4.06 × 10(-8) and 6.04 × 10(-8) cm s(-1) per dyn cm(-2); (2) TEER increased at a rate of 0.8 Ω cm(2) per dyn cm(-2); (3) increased alignment of cells along the flow direction under increasing WSS conditions; and finally (4) increased protein expression of both the tight junction component ZO-1 (~5×) and the efflux transporter P-gp (~6×) was observed at 86 dyn cm(-2) compared to static controls via western blot. We conclude that the presented microfluidic platform is a valid approach for comprehensively assaying cell responses to fluidic WSS.

Contraception in sea-going service personnel

The right to make an informed choice about contraception should be afforded to every individual serving within the United Kingdom (UK) Armed Forces. This article looks at the responsibilities and approach that healthcare professionals should take within a Primary Care setting, summarises the common contraceptive options available, discusses the associated advantages and disadvantages of each technique, and considers operational factors in a military environment that combine to influence the final contraceptive choice an individual makes. Case Study. A 19-year old Able Rate joined the Royal Navy (RN) and at her joining medical it was noted that she had been on Microgynon™ combined oral contraceptive pill for approximately three years. During this time, her menstrual periods remained light; she never experienced adverse effects, demonstrated good compliance, and was happy to remain on this contraceptive regimen. Over the course of the next eighteen months, she was reviewed by a number of Medical Officers and Civilian Medical Practitioners on a quarterly basis, with Microgynon™ re-prescribed on each occasion. The appropriate Defence Medical Information Capability Programme (DMICP) template was used, with weight, smoking status, compliance and any issues or comments documented accordingly. In December 2010, a discussion regarding long-acting reversible contraception (LARC) was documented for the first time. The patient agreed to give LARC some thought and a review appointment was made for one month. She was subsequently started on the progestogen-only pill Cerazette™. It was noted by the consulting doctor that both the patient's mother and grandmother had a positive history of cerebrovascular events and the combined oral contraceptive pill was discontinued. Upon review at two months, the patient reported that she was content on Cerazette™ and wished to continue with this medication. She was amenorrhoeic, highly compliant, had given up smoking and her weight and blood pressure were stable. However, due to supply issues, it was explained that Cerazette™ was no longer a viable option for her. She had no plans to start a family, and was keen to investigate other contraceptive options. Furthermore, she expressed a particular desire to remain amenorrhoeic, as she was due to deploy overseas in the coming months, and not only wanted to avoid the inconvenience of having her period, but also felt it preferable not to have to take a daily pill when considering the constantly changing time zones. She subsequently had the etonogestrel-releasing subdermal implant Nexplanon™ fitted without complication. She has remained amenorrhoeic throughout and this form of long-acting reversible contraception has particularly suited her busy working role and active lifestyle.

Assessment of two essential elements of BVDV control on selected Flemish dairy and beef farms

Bovine viral diarrhea virus (BVDV) is one of the most important viruses to cause disease in cattle worldwide. The virus is endemically present in Belgium. Clinical diagnosis of BVDV infection is difficult. Therefore, monitoring through testing is necessary to detect the presence of the virus on farms. As vaccination alone does not suffice for eradication, a combination of measures is required for successful control. Via a questionnaire, the BVDV policy on 241 selected Flemish cattle farms was investigated. This revealed some striking results. For the majority of the herds, the BVDV status was unknown (63%), and only 23% had a monitoring program in place. Furthermore, on seven out of ten (71%) BVDV-vaccinating farms, vaccination against BVDV was implemented as a strategy without knowing the actual BVDV status.

Characterization of a microfluidic in vitro model of the blood-brain barrier (μBBB)

The blood-brain barrier (BBB), a unique selective barrier for the central nervous system (CNS), hinders the passage of most compounds to the CNS, complicating drug development. Innovative in vitro models of the BBB can provide useful insights into its role in CNS disease progression and drug delivery. Static transwell models lack fluidic shear stress, while the conventional dynamic in vitro BBB lacks a thin dual cell layer interface. To address both limitations, we developed a microfluidic blood-brain barrier (μBBB) which closely mimics the in vivo BBB with a dynamic environment and a comparatively thin culture membrane (10 μm). To test validity of the fabricated BBB model, μBBBs were cultured with b.End3 endothelial cells, both with and without co-cultured C8-D1A astrocytes, and their key properties were tested with optical imaging, trans-endothelial electrical resistance (TEER), and permeability assays. The resultant imaging of ZO-1 revealed clearly expressed tight junctions in b.End3 cells, Live/Dead assays indicated high cell viability, and astrocytic morphology of C8-D1A cells were confirmed by ESEM and GFAP immunostains. By day 3 of endothelial culture, TEER levels typically exceeded 250 Ω cm(2) in μBBB co-cultures, and 25 Ω cm(2) for transwell co-cultures. Instantaneous transient drop in TEER in response to histamine exposure was observed in real-time, followed by recovery, implying stability of the fabricated μBBB model. Resultant permeability coefficients were comparable to previous BBB models, and were significantly increased at higher pH (>10). These results demonstrate that the developed μBBB system is a valid model for some studies of BBB function and drug delivery.

OZSPEC-2: an improved broadband high-resolution elliptical crystal x-ray spectrometer for high-energy density physics experiments (invited)

A novel time, space, and energy-resolved x-ray spectrometer has been developed which produces, in a single snapshot, a broadband and relatively calibrated spectrum of the x-ray emission from a high-energy density laboratory plasma. The opacity zipper spectrometer (OZSPEC-1) records a nearly continuous spectrum for x-ray energies from 240 to 5800 eV in a single shot. The second-generation OZSPEC-2, detailed in this work, records fully continuous spectra on a single shot from any two of these three bands: 270-650, 660-1580, and 1960-4720 eV. These instruments thus record thermal and line radiation from a wide range of plasmas. These instruments' single-shot bandwidth is unmatched in a time-gated spectrometer; conversely, other broadband instruments are either time-integrated (using crystals or gratings), lack spectral resolution (diode arrays), or cover a lower energy band (gratings). The OZSPECs are based on the zipper detector, a large-format (100x35 mm) gated microchannel plate detector, with spectra dispersed along the 100 mm dimension. OZSPEC-1 and -2 both use elliptically bent crystals of OHM, RAP, and/or PET. Individual spectra are gated in 100 ps. OZSPEC-2 provides one-dimensional spatial imaging with 30-50 microm resolution over a 1500 microm field of view at the source. The elliptical crystal design yields broad spectral coverage with resolution E/DeltaE>500, strong rejection of hard x-ray backgrounds, and negligible source broadening for extended sources. Near-term applications include plasma opacity measurements, detailed spectra of inertial fusion Hohlraums, and laboratory astrophysics experiments.

Automatic methods for characterization of sexual dimorphism of adult femora: distal femur

Quantifying sex differences in femoral size and shape has extensive applications in forensics and prosthesis design. By applying strong statistical techniques such as principal component analysis (PCA), certain three-dimensional (3D) morphological variations of adult femora can be quantified over various femoral sizes. Coupling this statistical approach with a novel feature generation and extraction technique, localization of statistically significant (p<0.05) features are automatically defined and measured. Also, predefined anatomical landmarks and surgical axes have been calculated automatically. In all methods, femoral scale is controlled as a possible parameter of shape. By extensively comparing measurements across 92 male and 74 female femora, the dimorphic characteristics of the distal femur are shown. These differences have not been accounted for in many prosthetic systems and consequently these systems have limited sizing accuracy.

Admissible and Restrained Revision

As partial justification of their framework for iterated belief revision Darwiche and Pearl convincingly argued against Boutilier's natural revision and provided a prototypical revision operator that fits into their scheme. We show that the Darwiche-Pearl arguments lead naturally to the acceptance of a smaller class of operators which we refer to as admissible. Admissible revision ensures that the penultimate input is not ignored completely, thereby eliminating natural revision, but includes the Darwiche-Pearl operator, Nayak's lexicographic revision operator, and a newly introduced operator called restrained revision. We demonstrate that restrained revision is the most conservative of admissible revision operators, effecting as few changes as possible, while lexicographic revision is the least conservative, and point out that restrained revision can also be viewed as a composite operator, consisting of natural revision preceded by an application of a "backwards revision" operator previously studied by Papini. Finally, we propose the establishment of a principled approach for choosing an appropriate revision operator in different contexts and discuss future work.

Screening of some Australian Flacourtiaceae species for in vitro antioxidant, cytotoxic and antimicrobial activity

A total of 27 methanol extracts obtained from different plant parts of 10 species of rain forest trees belonging to four genera of the Flacourtiaceae and originating from Australia were investigated. In vitro cytotoxicity was measured by an ATP Lite-M assay method against the mouse P388 lymphocytic leukemia cell line. The total antioxidant activity has been assessed based on scavenging activity of stable ABTS free radicals. The minimum inhibition concentration (MIC) was determined by the dilution method performed in 96 well plates against four different microbes. The leaf extract of Casearia sp. (RB 3051), mature stem extract of Casearia grayi and stem extract of Scolopia braunii were found to have most antioxidant activity (IC50 = 2.9 microg/ml), cytotoxic activity (LC50 = 0.89 microg/ml) and antimicrobial activity against all four different microbes, respectively. The results obtained suggested that among the four genera studied Casearia is the most promising in respect of finding significant antioxidant, cytotoxic and also antimicrobial activity.

Initiation of salvage therapy for prostate cancer

Physicians and patients have variable and individual levels of comfort regarding when to begin salvage therapy for rising prostate specific antigen (PSA) after definitive treatment of prostate cancer. The decision to start salvage therapy is a multifactorial process for which few rigorous data or guidelines exist. A questionnaire survey of urologists of the Department of Defense (DoD) Center for Prostate Disease Research (CPDR) was undertaken to obtain current perspectives on when to begin salvage therapy for biochemical failure after definitive therapy. Variables of age, grade, T-stage, nodal status, performance status, latency since prior therapy, PSA velocity, and ploidy were prioritized in four clinical situations; subsequent questions assessed consensus PSA cut-offs for beginning adjuvant therapy in 84 clinical scenarios. Consensus on PSA cut-off points was limited to postoperative radiotherapy (RT), where values of 1.0-1.5 were the mean cut-off points. CPDR urologists consider salvage prostatectomy post-RT only for patients <70-y-old with node negative, grade 2-7 disease and excellent performance status. Ploidy was not generally considered useful in any scenario. Many variables in addition to PSA level are involved in the decision of when to commence adjuvant therapy for initial biochemical failure. These are strikingly interdependent, and few clear absolutes are evident from this questionnaire. This is a point of necessary further research and continued discussion among physicians caring for these patients.

Cellular determinants of the mutational specificity of 1-nitroso-6-nitropyrene and 1-nitroso-8-nitropyrene in the lacI gene of Escherichia coli

We have characterized 202 lacI(-) mutations, and 158 dominant lacI(-d) mutations following treatment of Escherichia coli strains NR6112 and EE125 with 1-nitroso-6-nitropyrene (1,6-NONP), an activated metabolite of the carcinogen 1,6-dinitropyrene. In all, 91% of the induced point mutations occurred at G:C residues. The -(G:C) frameshifts were the dominant mutational class in the lacI(-) collections of both NR6112 and EE125, and in the lacI(-d) collection of NR6112. Frameshift mutations occurred preferentially in runs of guanine residues, and their frequency increased with the length of the reiterated sequence. In strain EE125, which contained the plasmid pKM101, there was a marked stimulation in the frequency of base substitution mutations that was particularly apparent in the lacI(-d) collection. This study completes a comprehensive analysis of 1194 lacI(-) and 348 lacI(-d) mutations induced by either 1,6-NONP or its positional isomer 1-nitroso-8-nitropyrene (1,8-NONP) in strains of E. coli that differ with regard to their ability to carry out nucleotide excision repair and/or their ability to express the translesion synthesis DNA polymerase RI (MucAB) encoded by plasmid pKM101. Among the mutations are 763 frameshift mutations, 367 base substitutions and 47 deletions; these mutations have been characterized at more than 300 distinct sites in the lacI gene. Our studies provide detailed insight into the DNA sequence alterations and mutational mechanisms associated with dinitropyrene mutagenesis. We review the mutational spectra, and discuss cellular lesion repair or tolerance mechanisms that modulate the observed mutational specificity.

RHO-associated protein kinase alpha potentiates insulin-induced MAP kinase activation in Xenopus oocytes

We recently identified Xenopus Rho-associated protein kinase alpha (xROKalpha) as a Xenopus insulin receptor substrate-1 binding protein and demonstrated that the non-catalytic carboxyl terminus of xROKalpha binds Xenopus insulin receptor substrate-1 and blocks insulin-induced MAP kinase activation and germinal vesicle breakdown in Xenopus oocytes. In the current study we further examined the role of xROKalpha in insulin signal transduction in Xenopus oocytes. We demonstrate that injection of mRNA encoding the xROKalpha kinase domain or full length xROKalpha enhanced insulin-induced MAP kinase activation and germinal vesicle breakdown. In contrast, injection of a kinase-dead mutant of xROKalpha or pre-incubation of oocytes with an xROKalpha inhibitor significantly reduced insulin-induced MAP kinase activation. To further dissect the mechanism by which xROKalpha may participate in insulin signalling, we explored a potential function of xROKalpha in regulating cellular Ras function, since insulin-induced MAP kinase activation and germinal vesicle breakdown is known to be a Ras-dependent process. We demonstrate that whereas injection of mRNA encoding c-H-Ras alone induced xMAP kinase activation and GVBD in a very low percentage (about 10%) of injected oocytes, co-injection of mRNA encoding xROKalpha and c-H-Ras induced xMAP kinase activation and germinal vesicle breakdown in a significantly higher percentage (50-60%) of injected oocytes. These results suggest a novel function for xROKalpha in insulin signal transduction upstream of cellular Ras function.

Folate receptor type beta is a neutrophilic lineage marker and is differentially expressed in myeloid leukemia

BACKGROUND

The membrane-associated folate receptor (FR) type beta is elevated in the spleen in patients with chronic myeloid leukemia (CML) and acute myeloid leukemia (AML). In this study, the authors investigated possible cell type and differentiation stage specificity of expression of FR-beta in normal and leukemic hematopoietic cells.

METHODS

An affinity-purified rabbit polyclonal antibody specific for FR-beta was employed for immunostaining representative bone marrow smears and peripheral blood smears from normal individuals and from a limited number of patients with various leukemias. Multiple samples of normal bone marrow and peripheral blood were analyzed for the expression of FR-beta and selected CD antigens by two- or three-color flow cytometry.

RESULTS

Of the morphologically identifiable cells, only neutrophils were positive for FR-beta. The leukemic blasts in CML patients showed expression of FR-beta with no apparent relation to the occurrence of the Philadelphia chromosome. Among acute nonlymphocytic leukemias, FR-beta was expressed in promyelocytic leukemia, in the myeloblast populations of myelomonocytic and erythroleukemias, and variably in M1/M2 AML. Neither the blasts of acute lymphocytic leukemia nor the more mature cells of chronic lymphocytic and hairy cell leukemias expressed FR-beta. The less differentiated FR-beta positive AML samples also were positive for CD34 and HLA-DR. Flow cytometric analysis of normal bone marrow and peripheral blood revealed low or insignificant coexpression of FR-beta with CD34, CD19, and CD3, whereas significant coexpression was observed with high levels of CD33, CD13, and CD11b; coexpression of FR-beta with CD14 was high in the immature bone marrow cells, comparable to that in myeloid cells, but relatively low in peripheral blood.

CONCLUSIONS

The results of this study suggest a narrow expression pattern of FR-beta marking the neutrophilic lineage and the possibility of defining a subtype or subtypes of myeloid leukemia based on FR-beta expression. The identification of FR-beta positive leukemias and the absence of the receptor in normal CD34 positive cells may enable selective receptor-mediated targeting of leukemic cells.

Sex partners of Native American drug users

This study describes patterns of sexual behavior and condom use in a sample of Native American drug-using men and women (N = 114). Data are self-reports of sexual behavior in the last 30 days, including descriptions of the most recent sex partners up to five. These data provided information on 157 sex partner pairs, of which at least one partner was a drug user. Native American women (55%) were more likely than Native American men (23%) to report never using condoms for vaginal and anal sex in the last 30 days. Compared with other ethnic pair combinations, sex partner pairs composed of Native American women and white men (n = 18) were the least likely to use condoms (6% of pairs) and the most likely to report an injection drug user (IDU) sex partner (33% of pairs). These results suggest a potential vector of HIV and other sexually transmitted disease (STD) transmission between white male IDUs and Native American women and highlight the need for further qualitative and quantitative research to examine the factors underlying this pattern of sexual risk behavior.