Chitosan adhesive for laser tissue repair: In vitro characterization

Background and Objectives Laser tissue repair usually relies on hemoderivate protein solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited tensile strength of repaired tissue, poor solder solubility, and brittleness prior to laser denaturation. Furthermore, the required activation temperature of albumin solders (between 65 and 70°C) can induce significant thermal damage to tissue. In this study, we report on the design of a new polysaccharide adhesive for tissue repair that overcomes some of the shortcomings of traditional solders. Study Design/Materials and Methods Flexible and insoluble strips of chitosan adhesive (elastic modulus ~6.8 Mpa, surface area ~34 mm2, thickness ~20 µm) were bonded onto rectangular sections of sheep intestine using a diode laser (continuous mode, 120 ± 10 mW, = λ 808 nm) through a multimode optical fiber with an irradiance of ~15 W/cm2. The adhesive was based on chitosan and also included indocyanin green dye (IG). The temperature between tissue and adhesive was measured using a small thermocouple (diameter ~0.25 mm) during laser irradiation. The repaired tissue was tested for tensile strength by a calibrated tensiometer. Murine fibroblasts were cultured in extracted media from chitosan adhesive to assess cytotoxicity via cell growth inhibition in a 48 hours period. Results Chitosan adhesive successfully repaired intestine tissue, achieving a tensile strength of 14.7 ± 4.7 kPa (mean ± SD, n = 30) at a temperature of 60-65°C. Media extracted from chitosan adhesive showed negligible toxicity to fibroblast cells under the culture conditions examined here. Conclusion A novel chitosan-based adhesive has been developed, which is insoluble, flexible, and adheres firmly to tissue upon infrared laser activation.

Closed system isolation and scalable expansion of human placental mesenchymal stem cells

Mesenchymal stem cells (MSC) are emerging as a leading cellular therapy for a number of diseases. However, for such treatments to become available as a routine therapeutic option, efficient and cost-effective means for industrial manufacture of MSC are required. At present, clinical grade MSC are manufactured through a process of manual cell culture in specialized cGMP facilities. This process is open, extremely labor intensive, costly, and impractical for anything more than a small number of patients. While it has been shown that MSC can be cultivated in stirred bioreactor systems using microcarriers, providing a route to process scale-up, the degree of numerical expansion achieved has generally been limited. Furthermore, little attention has been given to the issue of primary cell isolation from complex tissues such as placenta. In this article we describe the initial development of a closed process for bulk isolation of MSC from human placenta, and subsequent cultivation on microcarriers in scalable single-use bioreactor systems. Based on our initial data, we estimate that a single placenta may be sufficient to produce over 7,000 doses of therapeutic MSC using a large-scale process.

Porosity of serially sectioned interplanetary dust particles

The application of epoxy embedding and microtomy to individual chondritic interplanetary dust particles (lOP's)(Bradley and Brownlee, 1986a) provides not only higher precision in thin-film elemental analyses (Bradley and Brownlee, 19861:1), but also allows a wealth of other important techniques for the micro-characterization of these primitive extraterrestrial materials. For example, individual sections (e.g. 100 nm thick) or a series of sections, can be examined using image analysis techniques which utilize either transmitted or scanned secondary electron images, or alternatively, secondary X-ray spectra collected concurrently from a given region of sample. Individual particles, or groups of particles with similar image characteristics can then be rapidly identified using conventional grey-scale/particle recognition techniques for each microtomed section of lOP. This type of image analysis provides a suitable method for determination of particle size and shape distribution as well as porosity throughout the aggregate.

Trace phases in CI chondrites Alais and Orgueil

Minor phases in meteorites are important indicators of parent-body processing conditions. For example, Kerridge and others (1, 2) have shown that the presence of sulphates and carbonates in CI chondrites provides evidence for aqueous alteration on the parent body. Carbonates and sulphates are relatively prominent components of CI chondrites (e.g., -11.6 wt.% of total mass' and> 10 um diameter) compared to minor phases in most other classes of meteorite and thus, have been amenable to macro scale characterisation using optical petrography and electron microprobe analysis. These minor phases account for significant accumulations of low abundance elements, such as Na, S, K, Ca, and Ni within the bulk meteorite. The fine grained matrix, which consists mostly oflizardite- and montmorillonite-like clays (3), is the...

Development and testing of an iPad application for teaching self-management to heart failure patients. (Nursing/Allied Health Professional Investigator Award)- Abstract

Purpose: Heart failure (HF) is the leading cause of hospitalization and significant burden to the health care system in Australia. To reduce hospitalizations, multidisciplinary approaches and enhance self-management programs have been strongly advocated for HF patients globally. HF patients who can effectively manage their symptoms and adhere to complex medicine regimes will experience fewer hospitalizations. Research indicates that information technologies (IT) have a significant role in providing support to promote patients' self-management skills. The iPad utilizes user-friendly interfaces and to date an application for HF patient education has not been developed. This project aimed to develop the HF iPad teaching application in the way that would be engaging, interactive and simple to follow and usable for patients' carers and health care workers within both the hospital and community setting. Methods: The design for the development and evaluation of the application consisted of two action research cycles. Each cycle included 3 phases of testing and feedback from three groups comprising IT team, HF experts and patients. All patient education materials of the application were derived from national and international evidence based practice guidelines and patient self-care recommendations. Results: The iPad application has animated anatomy and physiology that simply and clearly teaches the concepts of the normal heart and the heart in failure. Patient Avatars throughout the application can be changed to reflect the sex and culture of the patient. There is voice-over presenting a script developed by the heart failure expert panel. Additional engagement processes included points of interaction throughout the application with touch screen responses and the ability of the patient to enter their weight and this data is secured and transferred to the clinic nurse and/or research data set. The application has been used independently, for instance, at home or using headphones in a clinic waiting room or most commonly to aid a nurse-led HF consultation. Conclusion: This project utilized iPad as an educational tool to standardize HF education from nurses who are not always heart failure specialists. Furthermore, study is currently ongoing to evaluate of the effectiveness of this tool on patient outcomes and to develop several specifically designed cultural adaptations [Hispanic (USA), Aboriginal (Australia), and Maori (New Zealand)].

Family-based programmes for preventing smoking by children and adolescents

BACKGROUND: There is evidence that children's decisions to smoke are influenced by family and friends. OBJECTIVES: To assess the effectiveness of interventions to help family members to strengthen non-smoking attitudes and promote non-smoking by children and other family members. SEARCH STRATEGY: We searched 14 electronic bibliographic databases, including the Cochrane Tobacco Addiction Group specialized register, MEDLINE, EMBASE, PsycINFO and CINAHL. We also searched unpublished material, and the reference lists of key articles. We performed both free-text Internet searches and targeted searches of appropriate websites, and we hand-searched key journals not available electronically. We also consulted authors and experts in the field. The most recent search was performed in July 2006. SELECTION CRITERIA: Randomized controlled trials (RCTs) of interventions with children (aged 5-12) or adolescents (aged 13-18) and family members to deter the use of tobacco. The primary outcome was the effect of the intervention on the smoking status of children who reported no use of tobacco at baseline. Included trials had to report outcomes measured at least six months from the start of the intervention. DATA COLLECTION AND ANALYSIS: We reviewed all potentially relevant citations and retrieved the full text to determine whether the study was an RCT and matched our inclusion criteria. Two authors independently extracted study data and assessed them for methodological quality. The studies were too limited in number and quality to undertake a formal meta-analysis, and we present a narrative synthesis. MAIN RESULTS: We identified 19 RCTs of family interventions to prevent smoking. We identified five RCTs in Category 1 (minimal risk of bias on all counts); nine in Category 2 (a risk of bias in one or more areas); and five in Category 3 (risks of bias in design and execution such that reliable conclusions cannot be drawn from the study).Considering the fourteen Category 1 and 2 studies together: (1) four of the nine that tested a family intervention against a control group had significant positive effects, but one showed significant negative effects; (2) one of the five RCTs that tested a family intervention against a school intervention had significant positive effects; (3) none of the six that compared the incremental effects of a family plus a school programme to a school programme alone had significant positive effects; (4) the one RCT that tested a family tobacco intervention against a family non-tobacco safety intervention showed no effects; and (5) the one trial that used general risk reduction interventions found the group which received the parent and teen interventions had less smoking than the one that received only the teen intervention (there was no tobacco intervention but tobacco outcomes were measured). For the included trials the amount of implementer training and the fidelity of implementation are related to positive outcomes, but the number of sessions is not. AUTHORS' CONCLUSIONS: Some well-executed RCTs show family interventions may prevent adolescent smoking, but RCTs which were less well executed had mostly neutral or negative results. There is thus a need for well-designed and executed RCTs in this area.

Community wide interventions for increasing physical activity (protocol)

This is the protocol for a review and there is no abstract. The objectives are as follows: Primary research objective To determine the effects of community wide, multi-strategic interventions upon community levels of physical activity. Secondary research objectives 1. To explore whether any effects of the intervention are different within and between populations, and whether these differences form an equity gradient. 2. To describe other health (e.g. cardiovascular disease morbidity) and behavioural effects (e.g. diet) where appropriate outcomes are available. 3. To explore the influence of context in the design, delivery, and outcomes of the interventions. 4. To explore the relationship between the number of components, duration, and effects of the interventions. 5. To highlight implications for further research and research methods to improve knowledge of the interventions in relation to the primary research objective.

A chance for diversity? Australian online journalism

Australia’s mainstream media landscape has long been recognised as highly limited – media ownership in the country has traditionally been concentrated in the hands of a very few, and (except for Sydney and Melbourne) it is common for major Australian cities to be served by only one local newspaper, usually produced by Rupert Murdoch’s News Ltd. This can be seen also to affect the quality and diversity of Australian journalism; additionally, the global decline of newspaper publishers’ revenues and overall adverse economic conditions exert further pressure on journalistic operations in the country. At the same time, and possibly in response to the increasing stresses on industrial journalism in the country and the implications they have for the quality of journalistic products, a vibrant and dynamic ecosystem of Australian industrial and citizen journalism publications has emerged online. Existing media organisations have built strong news brands online, while citizen journalists and political bloggers have given voice to issues, concerns, and opinions hitherto underrepresented in Australian mainstream journalism; of particular interest, however, is the increasing level of engagement and interaction between the two. While such interaction has been characterised by deep animosity at times (especially also in the context of the Australian federal election in November 2007), Australia has also seen the emergence and establishment of a number of new, intermediary online publications which act as spaces for public debate and analysis – from the public intellectualism of Online Opinion through the muckraking of Crikey to the progressive politics of New Matilda. The rise of social media as spaces for the discussion of news and politics further changes the media environment, potentially leading both to renewed conflict between professional and citizen journalists and to a greater level of engagement between journalists and audiences. Overall, then, such online developments offer a chance for a greater diversity of opinion and representation in Australian journalism, but also remain under a cloud from uncertain long-term business models and funding arrangements. This chapter outlines current trends in Australian online journalism, and speculates about their effect on the Australian news media landscape.