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Medical Research (medical + research)
Terms modified by Medical Research Selected AbstractsInformed Consent and Ethical Issues in Military Medical ResearchACADEMIC EMERGENCY MEDICINE, Issue 11 2005John McManus MD Abstract Informed consent in military research shares many of the same fundamental principles and regulations that govern civilian biomedical research. In fact, much of modern research ethics is grounded in events that occurred in the context of war or government-sponsored research. Despite these similarities and common origins, research in the military has additional requirements designed to preserve service members' informed consent rights. The special nature of the superior,subordinate relationship in the military necessitates careful protections to avoid perceptions of coercion or undue influence on a military subject. Additionally, current legal and regulatory requirements for advanced informed consent significantly restrict the flexibility of the military to conduct research using waiver of consent. This has implications on the ability of the nation to develop effective medical treatments for the global war on terrorism. Nevertheless, work is under way to realign defense research policy with the norms of civilian biomedical practice. Future directions include the adoption of waivers for military emergency research, and the cautious introduction of human subject studies on the battlefield. This paper discusses historical background, regulatory differences, and concerns and challenges of some of these regulatory differences for research personnel that apply to informed consent and waiver of said informed consent for emergency research conducted by the U.S. military. [source] Effect of HIV-1 infection and increasing immunosuppression on menstrual functionJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 5 2010Oliver C. Ezechi Abstract Aim:, The aim of this study was to determine the prevalence, pattern and determinants of menstrual abnormalities in HIV-positive Nigerian women. Methods:, A cross-sectional study was carried out involving 3473 (2549 HIV-seropositive and 924 seronegative) consecutive and consenting women seen at the HIV treatment centers at the Nigerian Institute of Medical Research, Lagos and the Federal Medical Centre, Markurdi. Results:, The sociodemographic characteristics of the two groups were comparable, except for body mass index (BMI): the HIV-negative women (28.1 ± 8.1) had statistically significantly (P < 0.005) higher BMI compared to the HIV-positive women (21.9 ± 7.5). Menstrual abnormalities were significantly more common in women living with HIV/AIDS (29.1%) compared to the HIV-negative (18.9%) women (P < 0.001). The proportions of women in the two groups with intermenstrual bleeding, menorrhagia, hypermenorrhea, and postcoital bleeding were similar (P > 0.005), however amenorrhea, oligomenorrhea, irregular periods and secondary dysmenorrhea were more common in the HIV-positive women (P < 0.02). Primary dysmenorrhea was less common in HIV-positive women (P < 0.03). Among the HIV-positive women, menstrual dysfunction was more common in women living with HIV/AIDS with opportunistic infections, CD4 count < 200, not undertaking therapy, symptomatic disease and BMI < 20. However, after controlling for cofounders, only CD4 < 200 (odds ratio [OR], 3.65; 95% confidence interval [CI], 1.2,9.7), BMI < 20 (OR, 2.4; 95%CI, 1.3,3.5) and not taking antiretroviral drugs (OR, 2.05; CI, 1.7,6.5) were associated with amenorrhea, oligomenorrhea, irregular periods and secondary dysmenorrhea. Conclusion:, HIV-positive women in this study experienced more menstrual abnormalities of amenorrhea, oligomenorrhea, and irregular periods compared to the HIV-negative controls. HIV-positive women with CD4 count < 200, BMI < 20 and who do not take antiretroviral drugs are at the greatest risk. [source] Global nutritional recommendations: a combination of evidence and food availability?PRACTICAL DIABETES INTERNATIONAL (INCORPORATING CARDIABETES), Issue 1 2008K Kapur BSc, PGDipDiet Dietitian/Diabetes Educator Abstract Diet and exercise are vital diabetes management strategies. Health professionals (HPs) use dietary guidelines to advise their clients but the current macronutrient recommendation in the guidelines varies. The aim of this study was to explore the similarities and differences in macronutrient dietary advice in different parts of the world and suggest some reasons for any differences identified. The study was undertaken in two phases: (1) a one-shot cross-sectional survey of HPs and global diabetes organisations using self-completed, anonymous questionnaires (n=40), and (2) a review of dietary guidelines from relevant diabetes associations (the American Diabetes Association [ADA], the Diabetes and Nutrition Study Group [DNSG] of the European Association for the Study of Diabetes [EASD], the Canadian Diabetes Association [CDA], the Joslin Diabetes Center, Diabetes UK, and the Indian Council of Medical Research [ICMR]). Dietary recommendations differed among countries and from the guidelines, and reflected socioeconomic factors and local food availability. With regard to macronutrient recommendations, carbohydrate ranged from 40,70%, protein 12,20% and fat 15,40% of total energy intake. Nations with higher gross domestic product (GDP) based on purchasing-power-parity (PPP) per capita tended to recommend a much lower ratio of carbohydrate than those with lower GDP PPP per capita. However, all guidelines stressed the importance of healthy eating. It was concluded that socioeconomic factors and local food availability appear to influence HPs' dietary recommendations. Copyright © 2008 John Wiley & Sons. [source] AN ASSESSMENT OF FUNDING TO SUPPORT RURAL AND REMOTE HEALTH RESEARCH IN AUSTRALIAAUSTRALIAN JOURNAL OF RURAL HEALTH, Issue 5 2000Carla Patterson ABSTRACT: A. systematic search was undertaken to ascertain the nature, source and extent of funding awarded to research projects that were directed specifically at aspects of rural health over the past decade. Comment is also made on the challenge of obtaining such information directly from databases. The sources investigated were the conventional research funding bodies, hospital trusts and foundations, university funding schemes and government sources. The results of these searches revealed a crude average of 3 million dollars per year from conventional research funding with the remaining sources adding a similar amount in total. Analysis of the data using a framework modified from the Strategic Review of Health and Medical Research in Australia shows that funding is concentrated in the health services and public health areas with a preponderance of funding being directed towards the description of conditions and interventions. Significant levels of funding have been directed towards the National Health Priority Areas. [source] Herbizide , Neue Wirkstoffe gegen die Malaria?BIOLOGIE IN UNSERER ZEIT (BIUZ), Issue 4 2007Article first published online: 30 JUL 200 Die Tropenkrankheit Malaria gehört zu den zehn häufigsten Todesursachen weltweit. Unser Titelbild zeigt Merozoiten , die Vermehrungsform des einzelligen Malaria-Erregers Plasmodium , die gerade rote Blutkörperchen eines Menschen infizieren. Möglicherweise kann man mit Herbiziden gegen den Parasiten vorgehen. Mehr dazu lesen Sie in dem Artikel, der auf Seite 228 beginnt. Bild: Drew Berry, The Walter und Eliza Hall Institute of Medical Research, Melbourne, Australien. [source] Survival Analysis for Epidemiologic and Medical Research.BIOMETRICAL JOURNAL, Issue 2 2009No abstract is available for this article. [source] Tutorial: Using Confidence Curves in Medical ResearchBIOMETRICAL JOURNAL, Issue 2 2005Ralf Bender Abstract Confidence intervals represent a routinely used standard method to document the uncertainty of estimated effects. In most cases, for the calculation of confidence intervals the conventional fixed 95% confidence level is used. Confidence curves represent a graphical illustration of confidence intervals for confidence levels varying between 0 and 100%. Although such graphs have been repeatedly proposed under different names during the last 40 years, confidence curves are rarely used in medical research. In this paper, we introduce confidence curves and present a short historical review. We draw attention to the different interpretation of one- and two-sided statistical inference. It is shown that these two options also have influence on the plotting of appropriate confidence curves. We illustrate the use of one- and two-sided confidence curves and explain their correct interpretation. In medical research more emphasis on the choice between the one- and two-sided approaches should be given. One- and two-sided confidence curves are useful complements to the conventional methods of presenting study results. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Survival Analysis for Epidemiologic and Medical Research by SELVIN, S.BIOMETRICS, Issue 2 2009M. G. Valsecchi No abstract is available for this article. [source] Bladder neck mobility is a heritable traitBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 3 2005H.P. Dietz Objective Congenital connective tissue dysfunction may partly be responsible for female pelvic organ prolapse and urinary incontinence. We undertook a heritability study to determine whether mobility of the bladder neck, one of the main determinants of stress urinary incontinence, is genetically influenced. Design Heritability study using a twin model and structural equation modelling. Setting Queensland Institute of Medical Research, Brisbane, Australia. Population One hundred and seventy-eight nulliparous Caucasian female twins and their sisters (46 monozygotic pairs, 24 dizygotic pairs and 38 sisters) aged 18,24 years. Methods We performed translabial ultrasound, supine and after bladder emptying, for pelvic organ mobility. Urethral rotation and bladder neck descent were calculated using the best of three effective Valsalva manoeuvres. Main outcome measures Bladder and urethral mobility on Valsalva assessed by urethral rotation, vertical and oblique bladder neck descent. Results Genetic modelling indicated that additive genes accounted for up to 59% of the variance for bladder neck descent. All remaining variance appeared due to environmental influences unique to the individual, including measurement error. Conclusion A significant genetic contribution to the phenotype of bladder neck mobility appears likely. [source] Exception from Informed Consent Enrollment in Emergency Medical Research: Attitudes and AwarenessACADEMIC EMERGENCY MEDICINE, Issue 2 2007Wayne Triner DO Objectives To explore attitudes surrounding exception from informed consent enrollment into research studies. In addition, the authors sought to determine the level of awareness of such an ongoing study among potential subjects, as defined by their presence in an emergency department (ED). Methods A convenience sample of urban academic ED patients and visitors was surveyed during a visit regarding their attitudes and awareness of an emergency exception from informed consent, blood-substitute trial ongoing in the community. Results There was a 13% refusal rate, and 32% of those approached had characteristics that met exclusion criteria. There were 497 surveys analyzed. There was a predominance of women, Caucasians, and persons with at least some college education. Only 39 (8%) of respondents reported awareness of the ongoing blood substitute trial, and only 19 (4%) were able to list a risk or benefit of participation. Education, income, and age were not associated with reported awareness. Male gender, younger age, awareness of the existing exception from informed consent study, and being married were associated with greater acceptability for such enrollment practices. Conclusions The overall awareness of an ongoing exception from informed consent trial after community consultation and notification was low. A population with potential for enrollment in such a study did not demonstrate a high degree of acceptance of such practices. There were differences among certain demographic groups in the degree of acceptance. These differences may guide institutional review boards and investigators in community-consultation strategies for future waiver of or exception from informed consent studies. [source] Direct Visualization of Deformation in VolumesCOMPUTER GRAPHICS FORUM, Issue 3 2009Stef Busking Abstract Deformation is a topic of interest in many disciplines. In particular in medical research, deformations of surfaces and even entire volumetric structures are of interest. Clear visualization of such deformations can lead to important insight into growth processes and progression of disease. We present new techniques for direct focus+context visualization of deformation fields representing transformations between pairs of volumetric datasets. Typically, such fields are computed by performing a non-rigid registration between two data volumes. Our visualization is based on direct volume rendering and uses the GPU to compute and interactively visualize features of these deformation fields in real-time. We integrate visualization of the deformation field with visualization of the scalar volume affected by the deformations. Furthermore, we present a novel use of texturing in volume rendered visualizations to show additional properties of the vector field on surfaces in the volume. [source] An appreciation of Ronnie Mac Keith (1978)DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 2 2008Martin Bax DM It is 100 years since Ronnie Mac Keith's birth and 50 years since he started the Journal Developmental Medicine & Child Neurology (DMCN; initially called The Cerebral Palsy Bulletin), the first number being a reprint of William Little's original article. Scope, then The Spastics Society, had just begun to raise significant sums of money and Ronnie persuaded them not only to put some money into medical research, which they did, funding the research laboratories at Guy's, but also, uniquely, to spend some money on educating and informing doctors. This led to financial backing, happily still continuing, to the publishers of DMCN, now the Mac Keith Press. Initially, it was published under the title Spastics International Medical Publications but this was a clumsy and difficult title because of the unfortunate use of the word 'spastics'and soon after Ronnie's death, who was then senior editor, the Mac Keith Press Board were delighted that his family agreed that the Press would be named after him. In the late 1950s and early 1960s, Ronnie was collecting a team around him to develop the Journal and the books, and contacted me because he knew I had literary interests. I didn't really want to edit a medical journal but I was interested in paediatrics so in the end I got involved! I worked very closely with Ronnie, both clinically and at the Mac Keith Press, and also with the Medical Education Information Unit of the Spastics Society on the meetings he ran. When he died, I tried to pull together something of Ronnie's nature in this personal memoir below, which supplemented the more formal statements about his life and career which can be found in the relevant number of the Journal.1 One hopes that Ronnie would be pleased with what we have done and I know that he would be hoping that we would continue for another 50 years developing ideas and approaches which were essentially developed by Ronnie Mac Keith. [source] Political abuse of psychiatryACTA PSYCHIATRICA SCANDINAVICA, Issue 399 2000J. L. T. Birley The abuse of psychiatry in Nazi Germany 60 years ago was the abuse of the ,duty to care'. Its scale was enormous; 300,000 people were sterilized and 100,000 killed in Germany alone and many thousands further afield, mainly in eastern Europe. This episode occurred in a country with a high reputation for its medicine, including psychiatry, and for its interest in the ethics of medical research. The economic conditions which preceded the violent political upheaval had led to increasing concern about ,the burden on the State' of the mentally ill and disabled. These preoccupations are still with us today. There may still be lessons to be learnt from the Nazi episode. [source] Miniaturization of Fluorescence Microscopes Using Fibre OpticsEXPERIMENTAL PHYSIOLOGY, Issue 6 2002Fritjof Helmchen In both medical research and diagnostics characterization of biological tissue on the cellular level relies on high-resolution optical microscopy. In most cases, however, tissue is excised for microscopic investigation, in part because conventional microscopes are bulky instruments. Imaging of cells in the intact living organism has been difficult. Over the last decade several groups have developed miniature confocal microscopes that use fibre optics to deliver light to the specimen and to measure either reflected or excited fluorescence light. In addition, two-photon excitation recently has been employed in a small portable ,fibrescope'. A potential clinical application of these microscope probes is their endoscopic use for optical biopsy of inner organs or guidance of conventional biopsy. As a mobile research tool they may permit imaging of neuronal activity in the brain of awake, behaving animals. Here, we review technological approaches to build miniaturized fluorescence microscopes and discuss their potential applications. [source] The thrombotic thrombocytopenic purpura registry: a new national resource to inform patient care and medical researchINTERNAL MEDICINE JOURNAL, Issue 1 2009M. N. Polizzotto No abstract is available for this article. [source] Misconduct in medical research: ethics and democracyINTERNAL MEDICINE JOURNAL, Issue 4 2003P. A. Komesaroff No abstract is available for this article. [source] Misconduct in medical research: whose responsibility?INTERNAL MEDICINE JOURNAL, Issue 4 2003K. J. Breen Abstract Examples of many types of misconduct in medical research continue to be reported. The true incidence is unknown because there is strong evidence of under-reporting as well as suggestions of increased detection. Risks to research participants may also be increasing, with contributing factors such as increased pressure on researchers to publish and to produce commercialization of their research. Institutions are perceived to typically respond slowly and inadequately to allegations of research misconduct. More could be done to try to prevent such misconduct, such as: (i) educating researchers about research ethics, (ii) assisting and protecting whistleblowers and (iii) instituting processes to adequately and promptly investigate and deal with allegations. In addition, a debate needs to take place as to whether research misconduct allegations should be dealt with at the institutional level or at a national level and whether medical boards should be routinely involved in the more serious breaches of ethical standards by medical practitioners engaged in research. (Intern Med J 2003; 33: 186,191) [source] A review of recent studies in China on the possible beneficial health effects of teaINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2006Yong-xing Zhu Summary Tea is one of the most heavily consumed beverages in the world. The relationship between tea drinking and human health is becoming a subject of intense study by scientists throughout the world. In this paper, we first provide a comprehensive analysis of the medical literature on tea published in China during the past 20 years, and then highlight some recent studies in China on the relationship between tea and several human diseases. During the period 1982,2002, 691 research papers related to tea and health have been published in 290 Chinese journals. These studies showed that tea and tea constituents have various biological activities and suggested that tea drinking might be beneficial to human health. Tea has potential in the prevention or adjuvant treatment of several diseases including cancer, cardiovascular diseases and obesity. The trend and future direction in medical research on tea in China are also briefly discussed. [source] Cryopreservation of fish sperm: applications and perspectivesJOURNAL OF APPLIED ICHTHYOLOGY, Issue 5 2010E. Cabrita Summary Cryopreservation is of interest not only for fish farming but also for the conservation and genetic improvement of resources. This technique has been well established in some freshwater fish species mainly, salmonid, sturgeons and carps, however, only in the last decade research was focused in marine fish species. The benefits of sperm cryopreservation include: (i) synchronization of gamete availability of both sexes, (ii) sperm economy; (iii) simplification of broodstock management, (iv) transport of gametes from different fish farms, and (v) germplasm storage for genetic selection programs or conservation of species. These issues would certainly benefit the aquaculture industry. The tremendous impact that biotechnology is having in aquaculture has been particularly obvious in recent years. Several species are being used as research models not only for aquaculture development applications but also for medical research. Sperm cryopreservation can give an important contribution in the germ storage of all transgenic lines. However, in all applications in fish sperm, cryopreservation needs to overcome a lack in standardization of methodologies and procedures, a correct assay of seminal quality and the development of tools to characterize cryoinjury. Many efforts have recently been made in the study of DNA using different approaches such as the comet assay (single cell gel electrophoresis), TUNEL (terminal deoxynucleotidyl transferase-nick-end-labelling), SCSA (sperm chromatin structure assay) and the analysis of specific DNA sequences using RT-PCR, since DNA damage may impair fertility or embryo development. Cryopreservation of gametes would certainly benefit from a higher concern on male improvement, basically through nutrition or selection of resistant stocks (e.g. stress resistant individuals or highly adapted to captivity) producing gametes of higher quality. There is a huge window of opportunities for improve the resistance of cells to cryopreservation through diet supplementation of certain compounds such as amino acids (taurine and hypotaurine), vitamins (Vit. E and C) and lipids or through a direct supplementation of the extender media. An equilibrium of those compounds will improve spermatozoa and seminal plasma composition protecting cells against oxidative stress (lipid peroxidation, protein oxidation, DNA fragmentation, enzyme protection) that is gaining each day more importance in cryodamage research. [source] Biomedical applications of protein chipsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2002Jocelyn H. Ng Abstract The development of microchips involving proteins has accelerated within the past few years. Although DNA chip technologies formed the precedent, many different strategies and technologies have been used because proteins are inherently a more complex type of molecule. This review covers the various biomedical applications of protein chips in diagnostics, drug screening and testing, disease monitoring, drug discovery (proteomics), and medical research. The proteomics and drug discovery section is further subdivided to cover drug discovery tools (on-chip separations, expression profiling, and antibody arrays), molecular interactions and signaling pathways, the identification of protein function, and the identification of novel therapeutic compounds. Although largely focused on protein chips, this review includes chips involving cells and tissues as a logical extension of the type of data that can be generated from these microchips. [source] Bayesian statistics in medical research: an intuitive alternative to conventional data analysisJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 2 2000AStat, Lyle C. Gurrin BSc (Hons) Summary Statistical analysis of both experimental and observational data is central to medical research. Unfortunately, the process of conventional statistical analysis is poorly understood by many medical scientists. This is due, in part, to the counter-intuitive nature of the basic tools of traditional (frequency-based) statistical inference. For example, the proper definition of a conventional 95% confidence interval is quite confusing. It is based upon the imaginary results of a series of hypothetical repetitions of the data generation process and subsequent analysis. Not surprisingly, this formal definition is often ignored and a 95% confidence interval is widely taken to represent a range of values that is associated with a 95% probability of containing the true value of the parameter being estimated. Working within the traditional framework of frequency-based statistics, this interpretation is fundamentally incorrect. It is perfectly valid, however, if one works within the framework of Bayesian statistics and assumes a ,prior distribution' that is uniform on the scale of the main outcome variable. This reflects a limited equivalence between conventional and Bayesian statistics that can be used to facilitate a simple Bayesian interpretation based on the results of a standard analysis. Such inferences provide direct and understandable answers to many important types of question in medical research. For example, they can be used to assist decision making based upon studies with unavoidably low statistical power, where non-significant results are all too often, and wrongly, interpreted as implying ,no effect'. They can also be used to overcome the confusion that can result when statistically significant effects are too small to be clinically relevant. This paper describes the theoretical basis of the Bayesian-based approach and illustrates its application with a practical example that investigates the prevalence of major cardiac defects in a cohort of children born using the assisted reproduction technique known as ICSI (intracytoplasmic sperm injection). [source] Preparing for "diastole": Advanced training opportunities for academic hospitalistsJOURNAL OF HOSPITAL MEDICINE, Issue 6 2006Vineet Arora MD Abstract Academic hospital medicine can be described as comprising periods of "systole," during which hospitalists provide clinical care, and periods of "diastole," the portion of a hospitalist's time spent in nonclinical activities. Far from being a period of relaxation, diastole is an active component of a hospitalist's work, the time devoted to the pursuit of career advancement. This period is a critical opportunity for career development in terms of medical research, education, quality improvement, or administration. An appropriate balance of systole and diastole may potentially prevent burnout and allow hospitalists opportunities to focus on academic advancement. Although an increasing number of residency graduates opt for a career in academic hospital medicine, few are prepared for the period of diastole. This article describes several career options in academic hospital medicine, specifically, opportunities in education, research, quality improvement, and administrative opportunities. By informing future hospitalists about the career opportunities within academic hospital medicine possible through managing their diastolic time, we hope that future generations of trainees will be better prepared to enter this field. Journal of Hospital Medicine 2006;1:368,377. © 2006 Society of Hospital Medicine. [source] The evolution of the randomized controlled trial and its role in evidence-based decision makingJOURNAL OF INTERNAL MEDICINE, Issue 2 2003P. J. Devereaux Abstract., Devereaux PJ, Yusuf S (McMaster University, Hamilton, Ontario, Canada). The evolution of the randomized controlled trial and its role in evidence-based decision making (Clinical Trials). J Intern Med 2003; 254: 105,113. The randomized controlled trial has been used in medical research for a little over half a century. This manuscript provides an overview of some of the history and evolution of the randomized controlled trial during this period. There exists hierarchies of evidence for therapeutic, diagnostic and prognostic questions, and the randomized controlled trial is at the top of the therapeutic hierarchy. Despite being at the top of the therapeutic hierarchy randomization in itself does not guarantee the trial results approximate the true effect. Issues that result in systematic and nonsystematic deviations from the truth in randomized controlled trials must also be considered. We present a model for evidence-based decision making that includes the following components: the clinical state, patient preferences, research evidence from a range of studies and clinical expertise. We discuss the role of the randomized controlled trial within evidence-based decision making. [source] Emerging drugs: mechanism of action, mass spectrometry and doping control analysisJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 4 2009Mario Thevis Abstract The number of compounds and doping methods in sports is in a state of constant flux. In addition to ,traditional' doping agents, such as anabolic androgenic steroids or erythropoietin, new therapeutics and emerging drugs have considerable potential for misuse in elite sport. Such compounds are commonly based on new chemical structures, and the mechanisms underlying their modes of action represent new therapeutic approaches arising from recent advances in medical research; therefore, sports drug testing procedures need to be continuously modified and complementary methods developed, preferably based on mass spectrometry, to enable comprehensive doping controls. This tutorial not only discusses emerging drugs that can be categorized as anabolic agents (selective androgen receptor modulators, SARMs), gene doping [hypoxia-inducible factor stabilizers, peroxisome-proliferator-activated receptor (PPAR),-agonists] and erythropoietin-mimetics (Hematide) but also compounds with potentially performance-enhancing properties that are not classified in the current list of the World Anti-Doping Agency. Compounds such as ryanodine-calstabin-complex modulators (benzothiazepines) are included, their mass spectrometric properties discussed, and current approaches in sports drug testing outlined. Copyright © 2009 John Wiley & Sons, Ltd. [source] Liquid and gas chromatography coupled to isotope ratio mass spectrometry for the determination of 13C,valine isotopic ratios in complex biological samplesJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 10 2008Jean-Philippe Godin Abstract On-line gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) is commonly used to measure isotopic ratios at natural abundance as well as for tracer studies in nutritional and medical research. However, high-precision 13C isotopic enrichment can also be measured by liquid chromatography-isotope ratio mass spectrometry (LC-IRMS). Indeed, LC-IRMS can be used, as shown by the new method reported here, to obtain a baseline separation and to measure 13C isotopic enrichment of underivatised amino acids (Asp, Thr,Ser, Glu, Pro, Gly, Ala, Cys and Val). In case of Val, at natural abundance, the SD(,13C) reported with this method was found to be below 1, . Another key feature of the new LC-IRMS method reported in this paper is the comparison of the LC-IRMS approach with the conventional GC-C-IRMS determination. To perform this comparative study, isotopic enrichments were measured from underivatised Val and its N(O, S)-ethoxycarbonyl ethyl ester derivative. Between 0.0 and 1.0 molar percent excess (MPE) (,13C = , 12.3 to 150.8,), the calculated root-mean-square (rms) of SD was 0.38 and 0.46, and the calculated rms of accuracy was 0.023 and 0.005 MPE, respectively, for GC-C-IRMS and LC-IRMS. Both systems measured accurately low isotopic enrichments (0.002 atom percent excess (APE)) with an SD (APE) of 0.0004. To correlate the relative (,13C) and absolute (atom%, APE and MPE) isotopic enrichment of Val measured by the GC-C-IRMS and LC-IRMS devices, mathematical equations showing the slope and intercept of the curves were established and validated with experimental data between 0.0 to 2.3 MPE. Finally, both GC-C-IRMS and LC-IRMS instruments were also used to assess isotopic enrichment of protein-bound 13C,Val in tibial epiphysis in a tracer study performed in rats. Isotopic enrichments measured by LC-IRMS and GC-C-IRMS were not statistically different (p > 0.05). The results of this work indicate that the LC-IRMS was successful for high-precision 13C isotopic measurements in tracer studies giving 13C isotopic enrichment similar to the GC-C-IRMS but without the step of GC derivatisation. Therefore, for clinical studies requiring high-precision isotopic measurement, the LC-IRMS is the method of choice to measure the isotopic ratio. Copyright © 2008 John Wiley & Sons, Ltd. [source] The Principle of Assumed Consent: The Ethics of GatekeepingJOURNAL OF PHILOSOPHY OF EDUCATION, Issue 3 2001Roger Homan The obligation to inform and obtain the consent of human subjects is axiomatic in social and medical research. Yet educational researchers are often reluctant to inform their subjects: class teachers and headteachers, for example, are often used as gatekeepers, and investigators sometimes do not so much seek consent as assume it. This chapter discusses the principle of informed consent, in particular that of children. It proposes guidelines for gatekeepers who may be called upon to authorise research and to grant to investigators access to children in their care. [source] Science versus Human Welfare?JOURNAL OF SOCIAL ISSUES, Issue 3 2009Understanding Attitudes toward Animal Use Scientists have been portrayed as having an uncaring attitude toward the use of animals and being inclined to reject the possibility of animal mind (Baldwin, 1993; Blumberg & Wasserman, 1995), yet there is little empirical research to support these claims. We examined why disparate attitudes toward animal use are held. Scientists, animal welfarists, and laypersons (N = 372) were compared on questionnaire responses that measured attitudes toward four types of animal use, and factors that might underlie these views (including belief in animal mind). As expected, scientists and animal welfarists held polarized views on all measures, whereas laypersons fell between the two. Animal welfarists were consistently opposed to all types of animal use, whereas scientists expressed support for the use of animals for medical research, but not for dissection, personal decoration, and entertainment. Animal welfarists showed high levels of belief in animal mind for 13 animal types, and scientists believed some of the 13 animals to have at least a moderate capacity for cognition and most to have at least a moderate capacity for sentience. Hence, the negative image of the science community that is often portrayed was not supported by our data. Findings were discussed in relation to external (group membership) and internal (belief systems) factors, and it is concluded that some people hold fixed attitudes toward animal use, whereas others are more influenced by context. [source] Near-optimal designs for dual channel microarray studiesJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 5 2005Ernst Wit Summary., Much biological and medical research employs microarray studies to monitor gene expression levels across a wide range of organisms and under many experimental conditions. Dual channel microarrays are a common platform and allow two samples to be measured simultaneously. A frequently used design uses a common reference sample to make conditions across different arrays comparable. Our aim is to formulate microarray experiments in the experimental design context and to use simulated annealing to search for near-optimal designs. We identify a subclass of designs, the so-called interwoven loop designs, that seems to have good optimality properties compared with the near-optimal designs that are found by simulated annealing. Commonly used reference designs and dye swap designs are shown to be highly inefficient. [source] Structure and function of the Mur enzymes: development of novel inhibitorsMOLECULAR MICROBIOLOGY, Issue 1 2003Ahmed El Zoeiby Summary One of the biggest challenges for recent medical research is the continuous development of new antibiotics interacting with bacterial essential mechanisms. The machinery for peptidoglycan biosynthesis is a rich source of crucial targets for antibacterial chemotherapy. The cytoplasmic steps of the biosynthesis of peptidoglycan precursor, catalysed by a series of Mur enzymes, are excellent candidates for drug development. There has been growing interest in these bacterial enzymes over the last decade. Many studies attempted to understand the detailed mechanisms and structural features of the key enzymes MurA to MurF. Only MurA is inhibited by a known antibiotic, fosfomycin. Several attempts made to develop novel inhibitors of this pathway are discussed in this review. Three novel inhibitors of MurA were identified recently. 4-Thiazolidinone compounds were designed as MurB inhibitors. Many phosphinic acid derivatives and substrate analogues were identified as inhibitors of the MurC to MurF amino acid ligases. [source] How to make your article more acceptable for the statistical reviewer,NEUROUROLOGY AND URODYNAMICS, Issue 3 2007Peter Herbison Abstract Many medical articles have problems with methodological aspects. To help prevent this, medical statisticians should be more involved in all aspects of medical research. Having more statistical reviewing of manuscripts submitted to journals should also help, but will not cure the problem. This paper makes some suggestions that may help authors make manuscripts more acceptable methodologically, but there is no substitute for statistical involvement throughout the research process. Neurourol. Urodynam. 26:318,322, 2007. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||