The mediation of social influences on smoking cessation and awareness of the early signs of lung cancer.

BACKGROUND: Whilst there has been no clear consensus on the potential for earlier diagnosis of lung cancer, recent research has suggested that the time between symptom onset and consultation can be long enough to plausibly affect prognosis. In this article, we present findings from a qualitative study involving in-depth interviews with patients who had been diagnosed with lung cancer (n = 11), and people who were at heightened risk of developing the disease (n = 14). METHODS: A grounded theory methodology was drawn upon to conduct thematic and narrative based approaches to analysis. RESULTS: The paper focuses on three main themes which emerged from the study: i) fatalism and resignation in pathways to help-seeking and the process of diagnosis; ii) Awareness of smoking risk and response to cessation information and advice. iii) The role of social and other networks on help-seeking. Key findings included: poor awareness among participants of the symptoms of lung cancer; ambivalence about the dangers of smoking; the perception of lung cancer as part of a homogenisation of multiple illnesses; close social networks as a key trigger in help-seeking. CONCLUSIONS: We suggest that future smoking cessation and lung cancer awareness campaigns could usefully capitalise on the influence of close social networks, and would benefit from taking a 'softer' approach.

Knowledge and utilisation of occupational asthma guidelines in primary care.

AIMS: To develop an occupational asthma learning module, which could be used both as an educational tool and to evaluate awareness and usage of clinical guidelines in primary care. METHODS: Healthcare professionals were invited to undertake an interactive BMJ Learning module, developed from existing national occupational asthma guidelines. Participants were invited to record immediate post-module feedback, and were also sent an e-mail questionnaire six weeks later to assess the impact of the module. RESULTS: In total 1041 healthcare professionals completed the learning module within the first six months, which was associated with significant improvements in knowledge, and predominantly positive feedback. The e-mail follow-up questionnaire demonstrated improved usage and awareness of national occupational asthma guidelines. CONCLUSIONS: Significant barriers remain in ensuring that evidence-based occupational medicine guidelines are adopted in primary care. This project has demonstrated that e-learning offers one method of improving postgraduate medical education in this area, particularly where evidence-based guidelines have already been developed.

Elasticity of the living abdominal wall in laparoscopic surgery.

Laparoscopic surgery requires inflation of the abdominal cavity and this offers a unique opportunity to measure the mechanical properties of the living abdominal wall. We used a motion analysis system to study the abdominal wall motion of 18 patients undergoing laparoscopic surgery, and found that the mean Young's modulus was 27.7+/-4.5 and 21.0+/-3.7 kPa for male and female, respectively. During inflation, the abdominal wall changed from a cylinder to a dome shape. The average expansion in the abdominal wall surface was 20%, and a working space of 1.27 x 10(-3)m(3) was created by expansion, reshaping of the abdominal wall and diaphragmatic movement. For the first time, the elasticity of human abdominal wall was obtained from the patients undergoing laparoscopic surgery, and a 3D simulation model of human abdominal wall has been developed to analyse the motion pattern in laparoscopic surgery. Based on this study, a mechanical abdominal wall lift and a surgical simulator for safe/ergonomic port placements are under development.

Ferromagnetization of target tissues by interstitial injection of ferrofluid: formulation and evidence of efficacy for magnetic retraction.

During curative cancer surgery, magnetic retraction could offer advantages over retraction by graspers because of reduced tissue trauma and with the potential for noncontact retraction. To realize magnetic retraction, magnetic fluid was injected into harvested porcine stomachs and an external permanent magnet was used to retract the ferromagnetized tissue. The magnetic forces of four ferrofluids were measured. The results of these experiments showed that iron-oxide-nanoparticle-based ferrofluids do not provide the required retraction force. However, sufficient retraction force is obtained by ferromagnetic microparticles fluids (stainless steel 410, denoted MP-SS410) by virtue of their high magnetization and saturation. In ex vivo surgical retraction experiments, MP-SS410 powder was dispersed in phosphate-buffered saline and other fluids. These ferrofluids were injected into the submucosal layer of harvested porcine stomachs at different concentrations and volumes. The inoculum generated a magnetic retraction force linearly proportional to the concentration and injected volume. Ex vivo surgical retraction, and dissection and resection were possible with a simple magnetic probe. The results of this study indicate that ferromagnetization of tissue can be used to facilitate localized tissue retraction and resection.

Rapid and efficient cell labeling with a MRI contrast agent by electroporation in the presence of protamine sulfate.

AIMS: To investigate various protocols for magnetic labeling of human cancer cells with ferumoxides with a view to developing an effective and fast technique for potential clinical use in MRI. MATERIALS & METHODS: Transfection methods utilizing poly-L-lysine and protamine sulfate (PS), electroporation, and combination of PS with electroporation were evaluated in this in vitro study. RESULTS: Although transfection was more effective in terms of uptake rates (95-100%) and intracellular iron concentrations (4.01-7.34 pg/cell), all transfection agents required prolonged incubation. By contrast, electroporation yielded fast labeling but with a lower efficacy (68-75%, 1.63-2.59 pg/cell). The addition of PS to electroporation increased the labeling efficacy (80-91%, 2.84-4.16 pg/cell) and protected cell viability. This combined method also resulted in the best T(2)*-shortening effect in the in vitro cellular MRI. CONCLUSION: The combined PS-electroporation method provides a fast and efficient protocol for ferumoxide-based cellular imaging and therapeutic procedure.

Thermographic assessment of tumor growth in mouse xenografts.

In human breast tumors, a 1-2 degrees C increase in skin surface temperature is usually observed at the periphery; it has been proposed that this change is due to the hypervascularity and increased blood flow resulting from tumor-associated angiogenesis. Here we tested the hypothesis that thermal imaging might represent a useful adjunctive technique in monitoring the growth dynamics of human tumor xenografts. Xenografts were established in immunocomprised nude mice using MDA-MB-231 or MCF7 breast cancer cells. We exploited the inherent noncontact and noninvasive advantages of infrared thermography to detect skin surface temperature changes. Continuous thermographic investigation was performed to detect and monitor tumor growth in vivo and high resolution digital images were analyzed to measure the tumor temperature dynamics. In contrast to the skin temperature increases associated with human breast cancer, a consistent temperature decrease was found in the xenograft mice. In one case, a smaller secondary tumor, otherwise undetectable, was clearly evident by thermal imaging. The tumors were cooler than the surrounding tissue with a maximum temperature reduction of 1.5 degrees C for MDA-MB-231 tumor and 3 degrees C for MCF7 tumors observed on day 14. In addition, the temperature of the xenograft tumors decreased progressively as they grew throughout the observation period. It was demonstrated that thermographic imaging could detect temperature changes as small as 0.1 degrees C on the skin surface at an early stage of tumor development. The findings of the study indicate that thermographic imaging might have considerable potential in monitoring human tumor xenografts and their response to anticancer drugs.

Shape memory alloy clip for compression colonic anastomosis.

This study was setup to investigate the design and performance of a shape memory alloy clip for colonic anastomosis. The thermo-mechanical properties of the shape memory alloy material were studied and the data were used to derive a nonlinear material model. This enabled the development of computer computer aided design models and finite element analysis of the clip and tissue compression. The maximum strain of the anastomosis clip was within the recoverable range, and it exerted parallel compression of the colonic walls with a uniform pressure distribution. The design of the anastomosis clip was optimized for safe, simple, and effective use in colon surgery.

The perceptions of occupational health in primary care.

AIM: A random sample of general practitioners (GPs), practice nurses (PNs) and practice managers (PMs) in Sheffield and Manchester was recruited into a study to evaluate the perceptions of occupational health (OH) in primary care. METHODS: Qualitative data were collected using focus groups with three groups of primary care sector professionals. Quantitative data were collected nationally from 295 GPs using a postal questionnaire. RESULTS: GPs and PNs had minimal OH training, and 60% of GPs reported constraints in addressing OH matters with patients. The lack of referral routes (63 and 67%, respectively) was also seen as a barrier. OH was regarded as a speciality, and primary care professionals preferred to refer patients with OH problems to specialist centres because they perceived barriers to their dealing with the issues. A total of 74% of GPs surveyed thought that speedier access to secondary care would help them to address OH problems. CONCLUSIONS: This study has identified some of the problems associated with delivering OH through primary care. It also demonstrated a need for greater emphasis on OH education in medical and nurse training, and a need for better advice for GPs, PNs and PMs regarding support services for OH.

Evolution of a percutaneous fetoscopic access system for single-port tracheal occlusion.

BACKGROUND/PURPOSE: Prenatal tracheal occlusion currently is being assessed as a treatment modality for congenital diaphragmatic hernia (CDH). The development of a totally percutaneous fetoscopic access system would help avoid the need for maternal laparotomy and reduce the morbidity rate of fetal surgical procedures for the mother. Laparoscopic radial expansion sheaths and Seldinger technique-based vascular catheters both have been advocated as means of achieving amniotic cavity access. The authors have investigated these 2 systems in an attempt to develop a reliable method for achieving safe percutaneous fetoscopic access and present the first successful attempt to deploy an intratracheal balloon using an entirely percutaneous approach through a single port in an ovine model. METHODS: A number of prototype systems were evaluated sequentially over a 3-year period in an ovine model: (1) the radially expanding InnerDyne step port system, (2) a new rigid cannula with a bulbous/sharp end preloaded onto the radially expanding InnerDyne port, (3) a conical removable addition to the rigid cannula in 2, (4) a modified bulbous/sharp ended cannula incorporating a circumferential protective insert, (5) a rigid split sheath with the radially expanding port placed through the lumen of the split sheath, (6) a flexible introducer and dilator with the split sheath (used in the Seldinger placement of central lines), and (7) a 2-needle approach using a superelastic shape-memory alloy Nickel-Titanium wire with the flexible dilator and sheath, incorporating a side perfusion port. For balloon tracheal occlusion, live anaesthetized time-mated pregnant ewes were used at 110 days' gestation. Tracheobronchoscopy was achieved using a 3-mm 0 degrees telescope, and the cutaneotracheal tract was secured by a 3.3-mm sheath incorporating a side-perfusion port. The rigid telescope was replaced by a flexible choledochoscope preloaded with a silicone balloon. The balloon was deployed 2 cm above the carina proximal to the right upper lobe bronchus. RESULTS: The many problems encountered in the evolution of the preferred system related mainly to separation and tenting of the chorioamniotic membranes in the ovine uterus and inconsistent access to the fetal parts of interest. Each resulted in significant modifications to our approach. Furthermore, the use of rigid access devices commonly caused fetal injury. Successful access to the intrauterine cavity and cannulation of the trachea was achieved consistently with minimal trauma, irrespective of fetal position by method 7. Multiple port placement allowed visualization of the entry of all components of the system confirming minimal chorioamniotic membrane separation and tenting. Single port tracheal occlusion was undertaken first on 6 cadavers before being performed successfully on 3 live anaesthetized ewes. Fetoscopic access and cannulation of the trachea was achieved consistently in all live animals irrespective of fetal position. CONCLUSIONS: This modified Seldinger technique using the unique properties of the memory-shaped alloy wire for initial uterine access offers a safe method for the percutaneous placement of fetoscopic ports in the ovine model for prenatal intervention. Successful placement of a tracheal balloon entirely through a single percutaneously placed port represents a further advance in prenatal therapy for CDH.