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Practical Advantages (practical + advantage)
Selected AbstractsRegularized, fast, and robust analytical Q-ball imagingMAGNETIC RESONANCE IN MEDICINE, Issue 3 2007Maxime Descoteaux Abstract We propose a regularized, fast, and robust analytical solution for the Q-ball imaging (QBI) reconstruction of the orientation distribution function (ODF) together with its detailed validation and a discussion on its benefits over the state-of-the-art. Our analytical solution is achieved by modeling the raw high angular resolution diffusion imaging signal with a spherical harmonic basis that incorporates a regularization term based on the Laplace,Beltrami operator defined on the unit sphere. This leads to an elegant mathematical simplification of the Funk,Radon transform which approximates the ODF. We prove a new corollary of the Funk,Hecke theorem to obtain this simplification. Then, we show that the Laplace,Beltrami regularization is theoretically and practically better than Tikhonov regularization. At the cost of slightly reducing angular resolution, the Laplace,Beltrami regularization reduces ODF estimation errors and improves fiber detection while reducing angular error in the ODF maxima detected. Finally, a careful quantitative validation is performed against ground truth from synthetic data and against real data from a biological phantom and a human brain dataset. We show that our technique is also able to recover known fiber crossings in the human brain and provides the practical advantage of being up to 15 times faster than original numerical QBI method. Magn Reson Med 58:497,510, 2007. © 2007 Wiley-Liss, Inc. [source] Evaluation of biological and chemical insecticide mixture against Aedes aegypti larvae and adults by thermal fogging in SingaporeMEDICAL AND VETERINARY ENTOMOLOGY, Issue 3 2001Y. K. Chung Abstract. To improve the operational efficiency of dengue vector control in Singapore, larvicide and adulticide were applied together by thermal fog generator (Agrofog® AF40). The mixture consisted of Bacillus thuringiensis var. israelensis (Vectobac® 12 AS) as biological larvicide at 1.5 L/ha and pirimiphos-methyl (Actellic® 50 EC) as adulticide at 100 g ai/ha, diluted 10-fold with water. Aerosol of this mixture was evaluated against the mosquito Aedes aegypti (L.) (Diptera: Culicidae) in bioassays using cages of 10 adult females exposed at heights of 0.3,2.4 m and distances of 3,12 m from the hand-held generator. Cups containing 200 mL water were treated at ground level by exposure to the aerosol application at the same distances from the generator. Subsequent larval bioassays on days 1, 7, 14, 21 and 28 post-spray involved exposing 20 larvae/cup for 48 h. Droplets had VMD 57 µm and female mosquitoes were killed by 2 s exposure to the aerosol at 3 m. We obtained 92,100% mortality of the adult mosquitoes and 100% control of larvae at 3 m distance, but only 10,13% mortality at 12 m from the fogger. In treated cups, larvae showed high mortality (92%) when exposed for 48 h even 1 month post-treatment. Results demonstrate the practical advantage of using this mixture of Vectobac® 12AS and Actellic® 50 EC for simultaneous control of Aedes adults and larvae, with prolonged larvicidal efficacy in treated containers. [source] Latest news and product developmentsPRESCRIBER, Issue 6 2008Article first published online: 24 APR 200 Government responds to NICE report The Government has published its response to the Health Select Committee's report into NICE, broadly arguing that the Committee's recommendations are either already being dealt with or are not appropriate. The Committee recommended appraisals for all new drugs, shorter, rapid appraisals to coincide with their launch, and improved mechanisms for setting drug prices. The Government says its negotiations on the PPRS preclude a detailed response but suggests a rapid system may not be transparent or legally robust. It is exploring how high-cost drugs can be brought within the payment-by-results tariff. While defending NICE's reliance on QALYs, the Government accepts the need to explore how wider economic factors can be considered. As for the threshold cost per QALY by which NICE defines cost effectiveness, it says this is being validated scientifically and NICE will continue to determine the threshold. More topically, the Committee criticised the quality of clinical trial data available to NICE. The Government sees no need to compel pharmaceutical companies to disclose information and says NICE is already becoming more involved with research programmes. All clinical trials must be registered (confidentially) with the EU and the Government believes mandatory registration in the UK would be ineffective and illegal. Prescription charge up again from April The Government has raised the prescription charge by 25p to £7.10 per item with effect from 1 April. Prescription prepayment certificates will cost £27.85 for three months and £102.50 for 12 months. The increase, below the annual rate of inflation for the 10th successive year, will be levied on the 12 per cent of prescriptions that are liable for the charge: 5 per cent via prepayment certificates and 7 per cent from other prescriptions. The charge will generate £435 million in England in 2008/09; this excludes money from prescriptions written by dispensing doctors, which is retained by the PCT. Following criticism of the charge by the Health Select Committee, the Government says it has reviewed the charge and is now consulting on ,cost-neutral' options. MHRA safety update The MHRA warns of possible dose errors associated with Boots Medisure Domiciliary Dosage System in its latest issue of Drug Safety Update (2008;1:issue 8). One case has been reported in which incomplete sealing allowed tablets to mix between compartments. No other cases are known and the MHRA says no harm was reported but the risk is serious. The system should be carefully sealed and inspected visually and physically. The MHRA reaffirms its plans to reclassify all pseudoephedrine and ephedrine products to prescription-only status in 2009 if the new restrictions on sales do not reduce misuse. Other topics in this month's Update include revised indications for oral ketoconazole (Nizoral), restricting its use to selected conditions unresponsive to topical therapy; reformulation of the injectable antibiotic Tazocin (piperacillin plus tazobactum); the risk of peripheral neuropathy associated with pegylated interferon and telbivudine (Sebivo) in the treatment of hepatitis B; and serious adverse events associated with modafinil (Provigil). First oral anticoagulant since warfarin In January this year the EMEA issued a positive opinion to recommend marketing authorisation of the oral, fixed-dose, direct thrombin inhibitor dabigatran etexilate (Pradaxa) for the primary prevention of venous thromboembolism (VTE) in adult patients that have undergone elective knee or hip replacement surgery. Marketing authorisation for the EU (including the UK) is expected from the European Commission in the next few weeks, making dabigatran the first oral anticoagulant since warfarin was introduced in 1954. Dabigatran etexilate has been shown to be as safe and effective as enoxaparin (Clexane) with a similar adverse event profile in the noninferiority phase III RENOVATE (Lancet 2007;370: 949-56) and RE-MODEL (J Throm Haemost 2007;5:217885) trials, which investigated the efficacy and safety of dabigatran compared to enoxaparin in reducing the risk of VTE after total hip and knee surgery respectively. Dabigatran has the practical advantage over low-molecular-weight heparin of oral postoperative administration and no risk of heparin-induced thrombocytopenia and, unlike warfarin, does not require monitoring or dose titration. Risk scale predicts anticholinergic effects US investigators have developed a scale for predicting the risk of anticholinergic side-effects from older patients' medicines (Arch Intern Med 2008;168: 508-13). The scale assigns a score from 1 (low) to 3 (high) for the risk of anticholinergic effects such as dry mouth, constipation and dizziness associated with commonly prescribed medicines. Checking the scale retrospectively in older patients in residential care, a higher score was associated with a 30 per cent increased risk of side-effects after adjustment for age and number of medicines. When this was repeated prospectively in a primary-care cohort, the increased risk was 90 per cent. HRT cancer risk persists The latest analysis of the Women's Health Initiative (WHI) trial of HRT shows that the small increase in the risk of cancer persists for up to three years after stopping treatment (J Am Med Assoc 2008;299:1036-45). WHI was stopped after 5.6 years' follow-up when it became clear the risks of HRT outweighed its benefits. This follow-up after a further three years (mean 2.4) involved 15 730 women. The annual risk of cardiovascular events was similar for HRT (1.97 per cent) and placebo (1.91 per cent). Cancers were more common among women who had taken HRT (1.56 vs 1.26 per cent), in particular breast cancer (0.42 vs 0.33 per cent). All-cause mortality was higher, but not statistically significantly so, with HRT (1.20 vs 1.06 per cent). Tight glycaemic control may increase falls Maintaining HbA1C at or below 6 per cent with insulin is associated with an increased risk of falls, a US study suggests (Diabetes Care 2008;31:391-6). The Health, Aging and Composition study involved 446 older people with type 2 diabetes (mean age 74) followed up for approximately five years. The incidence of falls ranged from 22 to 30 per cent annually. Comparing subgroups with HbA1C of ,6 per cent and >8 per cent, an increased risk of falls was associated with insulin use (odds ratio 4.4) but not oral hypoglycaemic drugs. Copyright © 2008 Wiley Interface Ltd [source] Proposing magnetic nanoparticle hyperthermia in low-field MRICONCEPTS IN MAGNETIC RESONANCE, Issue 1 2010Pádraig Cantillon-Murphy Abstract This work examines feasibility, practical advantages, and disadvantages of a combined MRI/magnetic particle hyperthermia (MPH) system for cancerous tumor treatment in low perfusion tissue. Although combined MRI/hyperthermia systems have been proposed and constructed, the current proposal differs because the hyperthermia system would be specifically designed to interact with the magnetic nanoparticles injected at the tumor site. The proposal exploits the physical similarities between the magnetic nanoparticles currently employed for MPH and those used as superparamagnetic iron oxide (SPIO) contrast agents in MR imaging. The proposal involves the addition of a rotating magnetic field RF hyperthermia source perpendicular to the MRI B0 field which operates in a similar manner to the MRI RF excitation field, B1, but at significantly higher frequency and field strength such that the magnetic nanoparticles are forced to rotate in its presence. This rotation is the source of increases in temperature which are of therapeutic benefit in cancer therapy. For rotating magnetic fields with amplitudes much smaller than B0, the nanoparticles' suspension magnetization rapidly saturates with increasing B0. Therefore, the proposal is best suited to low-field MRI systems when magnetic saturation is incomplete. In addition, careful design of the RF hyperthermia source is required to ensure no physical or RF interference with the B1 field used for MRI excitation. Notwithstanding these caveats, the authors have shown that localized steady-state temperature rises in small spherical tumors of up to 10°C are conceivable with careful selection of the nanoparticle radius and concentration, RF hyperthermia field amplitude and frequency. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part A 36A: 36,47, 2010. [source] The application of structured-light illumination microscopy to hydrocarbon-bearing fluid inclusionsGEOFLUIDS (ELECTRONIC), Issue 2 2008N. J. F. BLAMEY Abstract Structured-light illumination (SLI)-based microscopy offers geologists a new perspective for screening of hydrocarbon-bearing (HCFI) and small aqueous fluid inclusion (AFI) assemblages. This optical-sectioning technique provides rapid, confocal-like imaging, using relatively simple and inexpensive instrumentation. The 3D fluorescent images of HCFI planes and large single HCFIs permit the visualization of the relationships between HCFI assemblages, examination of HCFI morphology, and volume estimates of the fluorescent components within HCFIs. By the use of normal white light illumination, SLI image capture, and varying acquisition time it is also possible to image AFI because of the random movements of vapour bubbles within the inclusions. This allows the near-simultaneous visualization of hydrocarbon and AFI which is of significant importance for the study of sedimentary basins and petroleum reservoirs. SLI is a unique and accessible 3D petrographic tool, with practical advantages over conventional epifluorescence and confocal laser scanning microscopy. [source] 3D resistivity inversion using 2D measurements of the electric fieldGEOPHYSICAL PROSPECTING, Issue 1 2001P.D. Jackson Field and ,noisy' synthetic measurements of electric-field components have been inverted into 3D resistivities by smoothness-constrained inversion. Values of electrical field can incorporate changes in polarity of the measured potential differences seen when 2D electrode arrays are used with heterogeneous ,geology', without utilizing negative apparent resistivities or singular geometrical factors. Using both the X - and Y -components of the electric field as measurements resulted in faster convergence of the smoothness-constrained inversion compared with using one component alone. Geological structure and resistivity were reconstructed as well as, or better than, comparable published examples based on traditional measurement types. A 2D electrode grid (20 × 10), incorporating 12 current-source electrodes, was used for both the practical and numerical experiments; this resulted in 366 measurements being made for each current-electrode configuration. Consequently, when using this array for practical field surveys, 366 measurements could be acquired simultaneously, making the upper limit on the speed of acquisition an order of magnitude faster than a comparable conventional pole,dipole survey. Other practical advantages accrue from the closely spaced potential dipoles being insensitive to common-mode noise (e.g. telluric) and only 7% of the electrodes (i.e. those used as current sources) being susceptible to recently reported electrode charge-up effects. [source] Using DCE and ranking data to estimate cardinal values for health states for deriving a preference-based single index from the sexual quality of life questionnaireHEALTH ECONOMICS, Issue 11 2009Julie Ratcliffe Abstract There is an increasing interest in using data derived from ordinal methods, particularly data derived from discrete choice experiments (DCEs), to estimate the cardinal values for health states to calculate quality adjusted life years (QALYs). Ordinal measurement strategies such as DCE may have considerable practical advantages over more conventional cardinal measurement techniques, e.g. time trade-off (TTO), because they may not require such a high degree of abstract reasoning. However, there are a number of challenges to deriving the cardinal values for health states using ordinal data, including anchoring the values on the full health,dead scale used to calculate QALYs. This paper reports on a study that deals with these problems in the context of using two ordinal techniques, DCE and ranking, to derive the cardinal values for health states derived from a condition-specific sexual health measure. The results were compared with values generated using a commonly used cardinal valuation technique, the TTO. This study raises some important issues about the use of ordinal data to produce cardinal health state valuations. Copyright © 2009 John Wiley & Sons, Ltd. [source] Rasagiline: defining the role of a novel therapy in the treatment of Parkinson's diseaseINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2006F. Stocchi Summary Parkinson's disease (PD) is a therapy area with considerable unmet needs. The current key targets for PD treatment include the slowing of disease progression, improved control of motor fluctuations in advanced disease and the treatment of nonmotor symptoms. In view of such major requirements, it is important to consider how new drug treatments fit into the context of PD therapy, and the practical advantages that they may offer in the management of PD in clinical practice. Rasagiline is a novel, second-generation, irreversible, selective monoamine oxidase type B inhibitor that is indicated for the treatment of idiopathic PD, either as initial monotherapy or as adjunct therapy (with levodopa) for patients experiencing end-of-dose motor fluctuations. This review assesses the outcome from several large-scale clinical studies that have investigated the use of rasagiline in early and advanced PD patient populations and discusses the role of rasagiline within the current scope of PD therapy. [source] Multilevel generalized linear models for modelling age-related gender difference in violent behaviour and associated factors in the general household populationINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 3 2005Min Yang Senior Statistician Abstract It is preferable to use longitudinal data when studying patterns of violence and antisocial behaviour over the lifespan together with the associated risk factors in the general population. From the statistical modelling perspective, random samples of cross-sectional data, representative of the population, can be a reliable alternative. Sampling, weighting, and possible geographical clustering of the behaviour must be considered in the analysis together with correct choice of model as a function of age, although cohort effects and age effects are not separated from the analysis. This paper demonstrates the use of multilevel generalized linear models in the British National Survey of Psychiatric Morbidity in 2000. A multilevel logistic model as a special case of a generalized linear model with individual weightings was adapted for a dichotomous measure of violence and extended to Poisson and negative binomial outcomes. Three types of age function, discrete age effects, continuous age effects, and piecewise polynomial function of age intervals were evaluated for goodness of fit, and for their practical advantages and disadvantages. Models were developed for possible risk factors in relation to specific age groups of interest. Copyright © 2005 John Wiley & Sons, Ltd. Copyright © 2005 John Wiley & Sons, Ltd. [source] Highly Efficient Iron(II) Chloride/N -Bromosuccinimide-Mediated Synthesis of Imides and AcylsulfonamidesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2009Feng Wang Abstract We have developed a general and highly efficient iron(II) chloride/N -bromosuccinimide (NBS)-mediated method for the synthesis of imides and acylsulfonamides via couplings of thioesters with carboxamides/sulfonamides, and the method is simple, economical and shows practical advantages. [source] An effective iodide formulation for killing Bacillus and Geobacillus spores over a wide temperature rangeJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2004N. Kida Abstract Aims:, To develop a sporicidal reagent which shows potent activity against bacterial spores not only at ambient temperatures but also at low temperatures. Methods and Results:, Suspension tests on spores of Bacillus and Geobacillus were conducted with the reagent based on a previously reported agent (N. Kida, Y. Mochizuki and F. Taguchi, Microbiology and Immunology 2003; 47: 279,283). The modified reagent (tentatively designated as the KMT reagent) was composed of 50 mmol l,1 EDTA-2Na, 50 mmol l,1 ferric chloride hexahydrate (FeCl3·6H2O), 50 mmol l,1 potassium iodide (KI) and 50% ethanol in 0·85% NaCl solution at pH 0·3. The KMT reagent showed significant sporicidal activity against three species of Bacillus and Geobacillus spores over a wide range of temperature. The KMT reagent had many practical advantages, i.e. activity was much less affected by organic substances than was sodium hypochlorite, it did not generate any harmful gas and it was stable for a long period at ambient temperatures. The mechanism(s) of sporicidal activity of the KMT reagent was considered to be based on active iodine species penetrating the spores with enhanced permeability of the spore cortex by a synergistic effect of acid, ethanol and generated active oxygen. Conclusions:, The data suggest that the KMT reagent shows potent sporicidal activity over a wide range temperatures and possesses many advantages for practical applications. Significance and Impact of the Study:, The results indicate development of a highly applicable sporicidal reagent against Bacillus and Geobacillus spores. [source] The Role of Enoxaparin in Interventional Management of Patients with Acute Coronary SyndromesJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 5 2003CINDY L. GRINES M.D., F.A.C.C. Interventional management strategies involving early angiography and percutaneous coronary intervention (PCI) are increasingly widespread in the management of patients with acute coronary syndromes (ACS). Notwithstanding the benefits of early intervention, there is a significant risk of postprocedural thrombotic complications and a need to optimize antithrombotic regimens for use before and during PCI. It is clear that the current standard therapy with unfractionated heparin (UFH) and aspirin can be improved upon, in terms of both efficacy and safety. The low-molecular-weight heparin(s) (LMWHs) offer pharmacologic and practical advantages over UFH. The LMWH enoxaparin has recently emerged as the anticoagulant of choice for the acute management of ACS. Enoxaparin has also demonstrated sustained benefits over UFH in patients proceeding to PCI, and as a procedural anticoagulant. Combination therapy with enoxaparin and a glycoprotein IIb/IIIa inhibitor may further improve the efficacy and safety of antithrombotic treatment during coronary interventions, as a result of the drugs' complementary mechanisms of action. Early clinical evidence supports the use of enoxaparin in combination with glycoprotein IIb/IIIa inhibitors in high-risk patients with ACS. Ongoing, large-scale, randomized controlled studies will help to clarify the role of enoxaparin in interventional cardiology, either as the primary anticoagulant or as part of a combination regimen, and to define optimal regimens for treatment. (J Interven Cardiol 2003;16:357,366) [source] Potential of ,flat' fibre evanescent wave spectroscopy to discriminate between normal and malignant cells in vitroJOURNAL OF MICROSCOPY, Issue 2 2007Z. HAMMODY Summary The present study focuses on evaluating the potential of flattened AgClBr fibre-optic evanescent wave spectroscopy (FTIR-FEWS) technique for detection and identification of cancer cells in vitro using cell culture as a model system. The FTIR-FEWS results are compared to those from FTIR-microspectroscopy (FTIR-MSP) method extensively used to identify spectral properties of intact cells. Ten different samples of control and malignant cells were measured in parallel by the above two methods. Our results show a significant similarity between the results obtained by the two methodologies. The absorbance level of Amide I/Amide II, phosphates and carbohydrates were significantly altered in malignant compared to the normal cells using both systems. Thus, common biomarkers such as Amide I/Amide II, phosphate and carbohydrate levels can be derived to discern between normal and cancer cells. However, marked differences are also noted between the two methodologies in the protein bands due to CH3 bending vibration (1480,1350 cm,1). The spectral differences may be attributed to the variation in the penetration depth of the two methodologies. The use of flattened fibre rather than the standard cylindrical fibre has several practical advantages and is considered as an important step towards in vivo measurements in real time, such as that of skin nevi and melanoma using special designs of fibre-optic,based sensors. [source] Constrained process monitoring: Moving-horizon approachAICHE JOURNAL, Issue 1 2002Christopher V. Rao Moving-horizon estimation (MHE) is an optimization-based strategy for process monitoring and state estimation. One may view MHE as an extension for Kalman filtering for constrained and nonlinear processes. MHE, therefore, subsumes both Kalman and extended Kalman filtering. In addition, MHE allows one to include constraints in the estimation problem. One can significantly improve the quality of state estimates for certain problems by incorporating prior knowledge in the form of inequality constraints. Inequality constraints provide a flexible tool for complementing process knowledge. One also may use inequality constraints as a strategy for model simplification. The ability to include constraints and nonlinear dynamics is what distinguishes MHE from other estimation strategies. Both the practical and theoretical issues related to MHE are discussed. Using a series of example monitoring problems, the practical advantages of MHE are illustrated by demonstrating how the addition of constraints can improve and simplify the process monitoring problem. [source] High-energy femtosecond fiber lasers based on pulse propagation at normal dispersionLASER & PHOTONICS REVIEWS, Issue 1-2 2008F.W. Wise Abstract The generation and stable propagation of ultrashort optical pulses tend to be limited by accumulation of excessive nonlinear phase shifts. The limitations are particularly challenging in fiber-based devices, and as a result, short-pulse fiber lasers have lagged behind bulk solid-state lasers in performance. This article will review several new modes of pulse formation and propagation in fiber lasers. These modes exist with large normal cavity dispersion, and so are qualitatively distinct from the soliton-like processes that have been exploited effectively in modern femtosecond lasers but which are also quite limiting. Self-similar evolution can stabilize high-energy pulses in fiber lasers, and this leads to order-of-magnitude increases in performance: fiber lasers that generate 10 nJ pulses of 100 fs duration are now possible. Pulse-shaping based on spectral filtering of a phase-modulated pulse yields similar performance, from lasers that have no intracavity dispersion control. These new modes feature highly-chirped pulses in the laser cavity, and a theoretical framework offers the possibility of unifying our view of normal-dispersion femtosecond lasers. Instruments based on these new pulse-shaping mechanisms offer performance that is comparable to that of solid-state lasers but with the major practical advantages of fiber. [source] Spin-echo MRI using ,/2 and , hyperbolic secant pulses,MAGNETIC RESONANCE IN MEDICINE, Issue 1 2009Jang-Yeon Park Abstract Frequency-modulated (FM) pulses have practical advantages for spin-echo experiments, such as the ability to produce a broadband , rotation, with an inhomogeneous radiofrequency (RF) field. However, such use leads to a nonlinear phase of the transverse magnetization, which is why FM pulses like the hyperbolic secant (HS) pulse are not commonly used for multislice spin-echo magnetic resonance imaging (MRI). Here, a general theory and methods are described for conventional spin-echo imaging using a , HS pulse for refocusing. Phase profiles produced by the HS pulse are analytically described. The analysis is extended to yield the specific relationships between pulse parameters and gradients, which must be satisfied to compensate the nonlinear phase variation produced with a spin-echo sequence composed of ,/2 and , HS pulses (the ,/2 HS , , HS sequence). The latter offers advantages for multislice spin-echo MRI, including excellent slice-selection and partial compensation for RF inhomogeneity. Furthermore, it can be implemented with a shorter echo time and lower power deposition than a previously described method using a pair of , HS pulses. Magn Reson Med 61:175,187, 2009. © 2008 Wiley-Liss, Inc. [source] The Application of Microreactors in Combinatorial ChemistryMOLECULAR INFORMATICS, Issue 6 2005Paul Watts Abstract The miniaturisation of chemical reactors offers many fundamental and practical advantages of relevance to the pharmaceutical and fine chemicals industries, which are constantly searching for controllable, information-rich, high-throughput and environmentally friendly methods of producing products with a high degree of chemical selectivity. This review explores how miniaturisation may revolutionise chemical synthesis, highlighting in particular the commercial and environmental benefits of this new technology in combinatorial synthesis. [source] Practical aspects of sharing controls between case-control studies,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 8 2005Greta R. Bunin PhD Abstract Purpose We discuss the practical advantages and challenges of sharing controls among two or more concurrently conducted case-control studies. Methods We conducted two case-control studies, one of breast cancer and the other of endometrial cancer, with overlapping, shared control groups. The studies had overlapping geographic areas, identical telephone questionnaires and biosample collection, and identical age and race eligibility. Results Sharing controls reduced the number of potential controls that had to be identified by random-digit dialing by 25% and the number of eligible controls that had to be interviewed by 32%. The cost savings were approximately $296,000, or 7% of the program project that funded the studies. Conclusions The disadvantage of sharing controls was the complexity of the design and the additional investigator time required to plan, monitor, and adjust the design. In the situation presented here, the complexities would have been reduced greatly if we had not attempted to frequency match on age in both studies. Generally, sharing controls is likely to work well when strict frequency matching is not required and there is a large overlap of interview questions, other data to be collected, and eligibility criteria among the studies. Copyright © 2005 John Wiley & Sons, Ltd. [source] Airway hyperresponsiveness: the usefulness of airway hyperresponsiveness testing in epidemiology, in diagnosing asthma and in the assessment of asthma severityTHE CLINICAL RESPIRATORY JOURNAL, Issue 1 2007Celeste Porsbjerg MD Abstract The present PhD thesis was conducted at the Respiratory Research Unit at the Pulmonary Department L in Bispebjerg Hospital, Copenhagen, Denmark and describes airway hyperresponsiveness in asthma patients in four studies. The first study concerned risk factors for the development of asthma in young adults in a 12-year prospective follow-up study of a random population sample of 291 children and adolescents from Copenhagen, who were followed up from the age of 7,17 years (1986) until the age of 19,29 years (1998). During follow-up, 16.1% developed asthma, and in these subjects, the most important predictor of asthma development was airway hyperresponsiveness to histamine at baseline. Airway hyperresponsiveness is associated with more severe asthma and a poorer prognosis in terms of more exacerbations and less chance of remission of the disease. The second study described the relation between airway hyper-responsiveness to methacholine and the quality of life in 691 asthma patients: In asthma patients with airway hyperresponsiveness to methacholine, the quality of life measured with a validated questionnaire (Junipers Asthma Quality of Life Questionnaire) was significantly reduced compared to asthma patients who did not respond to bronchial provocation with methacholine. Airway hyperresponsiveness is not uncommonly observed in non-asthmatics, and the response to bronchial provocation with methacholine is therefore relatively non-specific. The mannitol test is a relatively new bronchial provocation test that acts indirectly on the smooth airway muscle cells through the release of mediators from inflammatory cells in the airways; the mannitol could consequently be a more specific test compared with methacholine. The third study showed that out of 16 non-asthmatics with airway hyperresponsiveness to methacholine, 15 did not respond to bronchial provocation with mannitol Because of the mechanism of action of mannitol, it seems plausible that the response to mannitol is more closely correlated to airway inflammation in asthma compared with the response to methacholine. The fourth study showed that in 53 adult asthma patients, who did not receive treatment with inhaled steroids, there was a positive correlation between the degree of airway inflammation and the degree of airway responsiveness to mannitol as well as to methacholine. The mannitol does, however, have the advantage of being a faster and simpler test to perform, requiring no additional equipment apart from a spirometer. Conclusions:, Airway hyperresponsiveness in children and in adolescents without asthma predicts asthma development in adulthood. Asthma patients with airway hyperresponsiveness to methacholine have a poorer quality of life as well as more severe disease and a poorer prognosis compared with asthma patients without airway hyperresponsiveness. Bronchial provocation with mannitol as well as with methacholine were useful for evaluating the severity of asthma and the degree of airway inflammation, and accordingly for determining the need for steroid statement. The mannitol test does, however, have practical advantages over the methacholine test that make it preferable for clinical use. [source] In vivo gene marking of rhesus macaque long-term repopulating hematopoietic cells using a VSV-G pseudotyped versus amphotropic oncoretroviral vectorTHE JOURNAL OF GENE MEDICINE, Issue 4 2004Patricia A. Shi Abstract Background Gene transfer efficiency into primitive hematopoietic cells may be limited by their expression of surface receptors allowing vector entry. Vectors pseudotyped with the vesicular stomatitis virus (VSV-G) envelope do not need receptors to enter cells, and therefore may provide superior transduction efficiency. Methods Using a competitive repopulation model in the rhesus macaque, we examined in vivo gene marking levels of blood cells transduced with two vectors: (i) a VSV-G pseudotyped retrovirus and (ii) a conventional amphotropic retrovirus. The VSV-G vector, containing the human glucose-6-phosphate dehydrogenase (G6PD) gene, was constructed for treatment of severe hemolytic anemia caused by G6PD deficiency. Three myeloablated animals were transplanted with peripheral blood CD34+ cells, half of which were transduced with the VSV-G vector and the other half with the amphotropic vector. Results In all animals post-transplantation, levels of in vivo marking in circulating granulocytes and mononuclear cells were similar: 1% or less with both vectors. In one animal, the human G6PD enzyme transferred by the VSV-G vector was expressed in erythrocytes, early after transplantation, at a level of 45% of the endogenous rhesus G6PD protein. Conclusions In a clinically relevant animal model, we found similar in vivo marking with a VSV-G pseudotyped and a standard amphotropic oncoretroviral vector. Amphotropic receptor expression may not be a limiting factor in transduction efficiency, but VSV-G pseudotypes possess other practical advantages that may make them advantageous for clinical use. Copyright © 2004 John Wiley & Sons, Ltd. [source] Generalized X-ray and neutron crystallographic analysis: more accurate and complete structures for biological macromoleculesACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2009Paul D. Adams X-ray and neutron crystallographic techniques provide complementary information on the structure and function of biological macromolecules. X-ray and neutron (XN) crystallographic data have been combined in a joint structure-refinement procedure that has been developed using recent advances in modern computational methodologies, including cross-validated maximum-likelihood target functions with gradient-based optimization and simulated annealing. The XN approach for complete (including hydrogen) macromolecular structure analysis provides more accurate and complete structures, as demonstrated for diisopropyl fluorophosphatase, photoactive yellow protein and human aldose reductase. Furthermore, this method has several practical advantages, including the easier determination of the orientation of water molecules, hydroxyl groups and some amino-acid side chains. [source] An evaluation of a hand-held electrical resistance meter for the diagnosis of bovine subclinical mastitis in late lactation under Australian conditionsAUSTRALIAN VETERINARY JOURNAL, Issue 9 2000AG SEGUYA Objective To assess the ability of a hand-held device to differentiate between infected and noninfected bovine mammary glands according to the electrical resistance of milk, under Australian conditions. Design A cross-sectional study. Procedure Milk samples were collected from 236 quarters of 60 cows selected from a commercial dairy herd with a high prevalence of mastitis. The true infection status of these quarters was determined using bacteriology. Various methods were used in an attempt to relate the electrical resistance of milk from each quarter to the presence or absence of infection in that quarter. Results Although the electrical resistance of milk from infected quarters was generally lower than that of noninfected quarters, the overlap of readings between the two populations limited the ability of this device to indicate accurately whether a quarter was infected. The use of methods comparing the readings from each of the four quarters of a single cow did not allow the reliable detection of infected cows. Conclusion Although this device may have some practical advantages in comparison with some other methods of diagnosing subclinical mastitis, the predictive value of the method was generally poor. [source] Treatment of vesico-ureteric reflux: a new algorithm based on parental preferenceBJU INTERNATIONAL, Issue 3 2003N. Capozza Authors from Rome evaluated parental preference for treatment in children with grade III VUR. Parents were provided with detailed information about the three treatment options: antibiotic treatment, open surgery, endoscopic treatment. Most parents chose endoscopic management; with this in mind, the authors proposed a new treatment algorithm for VUR. OBJECTIVE To assess parental preference (acknowledged in treatment guidelines as important when choosing therapy) about treatments for vesico-ureteric reflux (VUR, commonly associated with urinary tract infection and which can cause long-term renal damage if left untreated), as at present there is no definitive treatment for VUR of moderate severity (grade III). SUBJECTS AND METHODS The parents of 100 children with grade III reflux (38 boys and 62 girls, mean age 4 years, range 1,15) were provided with detailed information about the three treatment options available for treating VUR (antibiotic prophylaxis, open surgery and endoscopic treatment), including the mode of action, cure rate and possible complications, and the practical advantages and disadvantages. They were then presented with a questionnaire asking them to choose their preferred treatment. RESULTS Most parents preferred endoscopic treatment (80%), rather than antibiotic prophylaxis (5%) or open surgery (2%); 13% could not decide among the three options and endoscopic treatment was recommended. CONCLUSION Given the strong preference for endoscopic treatment we propose a new algorithm for treating VUR; endoscopic treatment would be considered as the first option for persistent VUR, except in severe cases where open surgery would still be recommended. [source] | |||||||||||||||||||