Dual-keel electrodynamic maglev system

A propulsion and stabilization system with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle

The diagnosis of colorectal cancer in patients with symptoms: finding a needle in a haystack

Patients often see primary care physicians with symptoms that might signal colorectal cancer but are also common in adults without cancer. Physicians and patients must then make a difficult decision about whether and how aggressively to evaluate the symptom. Favoring referral is that missed diagnoses lead to unnecessary testing, prolonged uncertainty, and continuing symptoms; also, the physician will suffer chagrin. It is not clear that diagnostic delay leads to progression to a more advanced stage. Against referral is that proper evaluation includes colonoscopy, with attendant inconvenience, discomfort, cost, and risk. The article by Hamilton et al, published this month in BMC Medicine, provides strong estimates of the predictive value of the various symptoms and signs of colorectal cancer and show how much higher predictive values are with increasing age and male sex. Unfortunately, their results also make clear that most colorectal cancers present with symptoms with low predictive values, < 1.2%. Models that include a set of predictive variables, that is, risk factors, age, sex, screening history, and symptoms, have been developed to guide primary prevention and clinical decision-making and are more powerful than individual symptoms and signs alone. Although screening for colorectal cancer is increasing in many countries, cancers will still be found outside screening programs so primary care physicians will remain at the front line in the difficult task of distinguishing everyday symptoms from life-threatening cancer

The mortality of colorectal cancer in relation to the initial symptom at presentation to primary care and to the duration of symptoms: a cohort study using medical records

The association between the staging of colorectal cancer and mortality is well known. Much less researched is the relationship between the duration of symptoms and outcome, and whether particular initial symptoms carry a different prognosis. We performed a cohort study of 349 patients with primary colorectal cancer in whom all their prediagnostic symptoms and investigation results were known. Survival data for 3–8 years after diagnosis were taken from the cancer registry. Six features were studied: rectal bleeding, abdominal pain, diarrhoea, constipation, weight loss, and anaemia. Two of these were significantly associated with different staging and mortality. Rectal bleeding as an initial symptom was associated with less advanced staging (odds ratio from one Duke's stage to the next 0.50, 95% confidence interval 0.31, 0.79; P=0.003) and with reduced mortality (Cox's proportional hazard ratio (HR) 0.56 (0.41, 0.79); P=0.001. Mild anaemia, with a haemoglobin of 10.0–12.9 g dl−1, was associated with more advanced staging (odds ratio 2.2 (1.2, 4.3); P=0.021) and worse mortality (HR 1.5 (0.98, 2.3): P=0.064). When corrected for emergency admission, sex, and the site of the tumour, the HR for mild anaemia was 1.7 (1.1, 2.6); P=0.015. No relationship was found between the duration of symptoms and staging or mortality

Environmental toxicity, redox signaling and lung inflammation:the role of glutathione

Glutathione (γ-glutamyl-cysteinyl-glycine, GSH) is the most abundant intracellular antioxidant thiol and is central to redox defense during oxidative stress. GSH metabolism is tightly regulated and has been implicated in redox signaling and also in protection against environmental oxidant-mediated injury. Changes in the ratio of the reduced and disulfide form (GSH/GSSG) can affect signaling pathways that participate in a broad array of physiological responses from cell proliferation, autophagy and apoptosis to gene expression that involve H(2)O(2) as a second messenger. Oxidative stress due to oxidant/antioxidant imbalance and also due to environmental oxidants is an important component during inflammation and respiratory diseases such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, acute respiratory distress syndrome, and asthma. It is known to activate multiple stress kinase pathways and redox sensitive transcription factors such as Nrf2, NF-κB and AP-1, which differentially regulate the genes for pro-inflammatory cytokines as well as the protective antioxidant genes. Understanding the regulatory mechanisms for the induction of antioxidants, such as GSH, versus pro-inflammatory mediators at sites of oxidant-directed injuries may allow for the development of novel therapies which will allow pharmacological manipulation GSH synthesis during inflammation and oxidative injury. This article features the current knowledge about the role of GSH in redox signaling, GSH biosynthesis and particularly the regulation of transcription factor Nrf2 by GSH and downstream signaling during oxidative stress and inflammation in various pulmonary diseases. We also discussed the current therapeutic clinical trials using GSH and other thiol compounds, such as N-acetyl-L-cysteine, fudosteine, carbocysteine, erdosteine in environment-induced airways disease

Comparison of immunohistochemistry with immunoassay (ELISA) for the detection of components of the plasminogen activation system in human tumour tissue

Enzyme-linked immunosorbent assay (ELISA) methods and immunohistochemistry (IHC) are techniques that provide information on protein expression in tissue samples. Both methods have been used to investigate the impact of the plasminogen activation (PA) system in cancer. In the present paper we first compared the expression levels of uPA, tPA, PAI-1 and uPAR in a compound group consisting of 33 cancer lesions of various origin (breast, lung, colon, cervix and melanoma) as quantitated by ELISA and semi-quantitated by IHC. Secondly, the same kind of comparison was performed on a group of 23 melanoma lesions and a group of 28 breast carcinoma lesions. The two techniques were applied to adjacent parts of the same frozen tissue sample, enabling the comparison of results obtained on material of almost identical composition. Spearman correlation coefficients between IHC results and ELISA results for uPA, tPA, PAI-1 and uPAR varied between 0.41 and 0.78, and were higher for the compound group and the breast cancer group than for the melanoma group. Although a higher IHC score category was always associated with an increased median ELISA value, there was an overlap of ELISA values from different scoring classes. Hence, for the individual tumour cases the relation between ELISA and IHC is ambiguous. This indicates that the two techniques are not directly interchangeable and that their value for clinical purposes may be different. © 1999 Cancer Research Campaig

Factors influencing time from presentation to treatment of colorectal and breast cancer in urban and rural areas

Stage at diagnosis and survival from cancer vary according to where people live, suggesting some may have delays in diagnosis. The aim of this study was to determine if time from presentation to treatment was longer for colorectal and breast cancer patients living further from cancer centres, and identify other important factors in delay. Data were collected on 1097 patients with breast and 1223 with colorectal cancer in north and northeast Scotland. Women with breast cancer who lived further from cancer centres were treated more quickly than those living closer to cancer centres (P = 0.011). Multilevel modelling found that this was largely due to them receiving earlier treatment at hospitals other than cancer centres. Breast lump, change in skin contour, lymphadenopathy, more symptoms and signs, and increasing age predicted faster treatment. Screen detected cancers and private referrals were treated more quickly. For colorectal cancer, time to treatment was similar for people in rural and urban areas. Quicker treatment was associated with palpable rectal or abdominal masses, tenesmus, abdominal pain, frequent GP consultations, age between 50 and 74 years, tumours of the transverse colon, and iron medication at presentation. Delay was associated with past anxiety or depression. There was variation between general practices and treatment appeared quicker at practices with more female general practitioners

A 3D individual-based model to investigate the spatially heterogeneous response of bacterial biofilms to antimicrobial agents

The response of bacterial biofilms to treatment with antimicrobial agents is often characterized by the emergence of recalcitrant cellular microcolonies. We present an individual-based model to investigate the biophysical mechanisms of the selective resistance that arises within the biofilm and leads to a spatially heterogeneous response upon treatment with antibiotics. The response occurs in 3 distinct phases. In the first phase, the subpopulation of metabolically active cells diminishes due to antibiotic-induced cell death. Subsequently, in the second phase, increased nutrient availability allows dormant cells in the lower layers of the biofilm to transform into metabolically active cells. In the third phase, survival of the biofilm is governed by the interplay between 2 contrasting factors: (1) rate of antibiotic-induced cell death and (2) rate of transformation of dormant cells into active ones. Metabolically active cells at the distal edge of the biofilm sacrifice themselves to protect the dormant cells in the interior by (1) reducing local antibiotic concentrations and (2) increasing nutrient availability. In the presence of quorum sensing, biofilms exhibit increased tolerance compared with the quorum sensing-negative strains. Extracellular polymeric substance (EPS) forms a protective layer at the top of the biofilm, thereby limiting antibiotic penetration. The surviving cells, in turn, produce EPS resulting in a feedback-like mechanism of resistance. Whereas resistance in QS- biofilms occurs because of transformation of dormant cells into metabolically active cells, this transformation is less pronounced in QS+ biofilms, and resistance is a consequence of the sequestration of the antibiotic by EPS

Unmeasured improvement work: the lack of routinely collected, service-related data in NHS endoscopy units in England involved in "modernisation"

Contains fulltext : 70532.pdf (publisher's version ) (Open Access)BACKGROUND: The availability of routinely collected service-related endoscopy data from NHS endoscopy units has never been quantified. METHODS: This retrospective observational study asked 19 endoscopy units to submit copies of all in-house, service-related endoscopy data that had been routinely collected by the unit - Referral numbers, Activity, Number of patients waiting and Number of lost slots. Nine of the endoscopy units had previously participated in the Modernising Endoscopy Services (MES) project during 2003 to redesign their endoscopy services. These MES sites had access to additional funding and data collection software. The other ten (Control sites) had modernised independently. All data was requested in two phases and corresponded to eight specific time points between January 2003 and April 2006. RESULTS: Only eight of 19 endoscopy units submitted routinely collected, service-related data. Another site's data was collected specifically for the study. A further two units claimed to routinely collect service-related data but did not submit any to the study. The remaining eight did not collect any service-related endoscopy data routinely and liaised with their Trust for data. Of the eight sites submitting service-related data, only three were MES project sites. Of these three, the data variables collected were limited and none collected the complete set of endoscopy data variables requested. Of the other five sites, two collected all four endoscopy data types. Data for the three MES project sites went back as far as January 2003, whilst the five Control sites were only able to submit data from December 2003 onwards. CONCLUSION: There was a lack of service-related endoscopy data routinely collected by the study sites, especially those who had participated in the MES project. Without this data, NHS endoscopy services cannot have a true understanding of their services, cannot identify problems and cannot measure the impact of any changes. With the increasing pressures placed on NHS endoscopy services, the need to effectively inform redesign plans is paramount. We recommend the compulsory collection of service-related endoscopy data by all NHS endoscopy units using a standardised format with rigorous guidelines