Home About us Contact
|
Home About us Contact | ||
|
|
||
Large Study (large + study)
Selected AbstractsOptimizing flow cytometric DNA ploidy and S-phase fraction as independent prognostic markers for node-negative breast cancer specimensCYTOMETRY, Issue 3 2001C.B. Bagwell Abstract Developing a reliable and quantitative assessment of the potential virulence of a malignancy has been a long-standing goal in clinical cytometry. DNA histogram analysis provides valuable information on the cycling activity of a tumor population through S-phase estimates; it also identifies nondiploid populations, a possible indicator of genetic instability and subsequent predisposition to metastasis. Because of conflicting studies in the literature, the clinical relevance of both of these potential prognostic markers has been questioned for the management of breast cancer patients. The purposes of this study are to present a set of 10 adjustments derived from a single large study that optimizes the prognostic strength of both DNA ploidy and S-phase and to test the validity of this approach on two other large multicenter studies. Ten adjustments to both DNA ploidy and S-phase were developed from a single node-negative breast cancer database from Baylor College (n = 961 cases). Seven of the adjustments were used to reclassify histograms into low-risk and high-risk ploidy patterns based on aneuploid fraction and DNA index optimum thresholds resulting in prognostic P values changing from little (P < 0.02) or no significance to P < 0.000005. Other databases from Sweden (n = 210 cases) and France (n = 220 cases) demonstrated similar improvement of DNA ploidy prognostic significance, P < 0.02 to P < 0.0009 and P < 0.12 to P < 0.002, respectively. Three other adjustments were applied to diploid and aneuploid S-phases. These adjustments eliminated a spurious correlation between DNA ploidy and S-phase and enabled them to combine independently into a powerful prognostic model capable of stratifying patients into low, intermediate, and high-risk groups (P < 0.000005). When the Baylor prognostic model was applied to the Sweden and French databases, similar significant patient stratifications were observed (P < 0.0003 and P < 0.00001, respectively). The successful transference of the Baylor prognostic model to other studies suggests that the proposed adjustments may play an important role in standardizing this test and provide valuable prognostic information to those involved in the management of breast cancer patients. Cytometry (Comm. Clin. Cytometry) 46:121,135, 2001. © 2001 Wiley-Liss, Inc. [source] The DPT-1 trial: a negative result with lessons for future type 1 diabetes preventionDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 4 2002Professor Paolo Pozzilli Abstract The author comments on the DPT-1 Trial and why the observed negative outcome in preventing diabetes in first-degree relatives of type 1 diabetic patients by parenteral insulin administration may have occurred and what can be gathered from this large study. There were three main lessons to be learned from the DPT-1 Trial as follows. (1) Large preventive trials of type 1 diabetes are feasible in first-degree relatives of type 1 diabetic patients and other preventive approaches may be now envisaged. (2) The natural history of type 1 diabetes, at least in its final years before clinical onset, has been elucidated and reiterates the relevance of our present predictive tools (autoantibodies) for identifying individuals at risk for the disease. (3) Strict follow-up of enrolled subjects in trials permits an earlier diagnosis of the disease with less frequency of ketoacidosis and implementation of insulin therapy when higher C-peptide levels are present. DPT-1 has paved the way on how to proceed and new trials will be planned benefiting from such experience. Copyright © 2002 John Wiley & Sons, Ltd. [source] Haplotype Analysis Confirms the Association Between the HCRTR2 Gene and Cluster HeadacheHEADACHE, Issue 7 2008Innocenzo Rainero MD Background., Several studies suggested that genetic factors play a role in cluster headache (CH) susceptibility. We found a significant association between the 1246 G>A polymorphism of the hypocretin receptor-2 (HCRTR2) gene and the disease. This association was confirmed in a large study from Germany but was not replicated in a dataset of CH patients from Northern Europe. Objective., The purpose of this study was to further evaluate the association between CH and the HCRTR2 gene using new polymorphisms, estimating the frequency of different gene haplotypes, searching for gene mutations, and evaluating the effects of the examined polymorphisms on hypocretin binding sites. Methods., We genotyped 109 CH patients and 211 healthy controls for 5 new polymorphisms of the HCRTR2 gene and we inferred different gene haplotypes. Complete HCRTR2 sequencing was undertaken for 11 independent CH patients, 5 of whom had a positive family history. The effects of the 1246 G>A polymorphism on the hypocretin binding sites were evaluated using different computer-assisted analyses. Results., Three new polymorphisms of the HCRTR2 gene resulted significantly associated with CH. The GTAAGG haplotype resulted more frequent in cases than in controls (OR: 3.68; 95% CI: 1.85-7.67). No point mutation of the HCRTR2 gene was found. Binding analyses showed that the 1246 G>A polymorphism (substitution of valine at position 308 by isoleucine) has no effect on the hypocretin binding sites but could influence the dimerization process of the receptor. Conclusion., Our data confirm previous studies suggesting that the HCRTR2 gene or a linked locus significantly modulates the risk for CH. In addition, we suggest that the V308I substitution of the HCRTR2 may interfere with the dimerization process of the receptor, thereby influencing its functional activity. [source] Older patients and delayed discharge from hospitalHEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 6 2000Christina R. Victor BA M Phil PhD Hon MFPHM Abstract Older people (those aged 65 years and over) are the major users of health care services, especially acute hospital beds. Since the creation of the NHS there has been concern that older people inappropriately occupy acute hospital beds when their needs would be best served by other forms of care. Many factors have been associated with delayed discharge (age, sex, multiple pathology, dependency and administrative inefficiencies). However, many of these factors are interrelated (or confounded) and few studies have taken this into account. Using data from a large study of assessment of older patients upon discharge from hospital in England, this paper examines the extent of delayed discharge, and analyses the factors associated with such delays using a conceptual model of individual and organisational factors. Specifically, this paper evaluates the relative contribution of the following factors to the delayed discharge of older people from hospital: predisposing factors (such as age), enabling factors (availability of a family carer), vulnerability factors (dependency and multiple pathology), and organisational/administrative factors (referral for services, type of team undertaking assessments). The study was a retrospective patient case note review in three hospitals in England and included four hundred and fifty-six patients aged 75 years and over admitted from their own homes, and discharged from specialist elderly care wards. Of the 456 patients in the sample, 27% had a recorded delay in their discharge from hospital of three plus days. Multivariate statistical analysis revealed that three factors independently predicted delay in discharge: absence of a family carer, entry to a nursing/residential home, and discharge assessment team staffing. Delayed discharge was not related to the hypothesised vulnerability factors (multiple dependency and multiple pathology) nor to predisposing factors (such as age or whether the older person lived alone). The delayed discharge of older people from hospital is a topic of considerable policy relevance. Our study indicated that delay was independently related to two organisational issues. First, entry into long-term care entailed lengthy assessment procedures, uncertainty over who pays for this care, and waiting lists. Second, the nature of the team assessing people for discharge was associated with delay (the nurse-coordinated team made the fewest referrals for multidisciplinary assessments and had the longest delays). Additionally, the absence of a family carer was implicated in delay, which underlines the importance of family and friends in providing posthospital care and in maintaining older people in the community. Our study suggests that considerable delay in discharging older people from hospital originates from administrative/organisational issues; these were compounded by social services resource constraints. There is still much to be done therefore to improve coordination of care in order to provide a truly ,seamless service'. [source] Geographic Pathology of Helicobacter pylori GastritisHELICOBACTER, Issue 2 2005Yi Liu ABSTRACT Background and aim.,Helicobacter pylori is etiologically associated with gastritis and gastric cancer. There are significant geographical differences between the clinical manifestation of H. pylori infections. The aim of this study was to compare gastric mucosal histology in relation to age among H. pylori -infected patients from different geographical areas using the same grading system. The prevalence of atrophy and intestinal metaplasia were also compared with the respective gastric cancer incidence in the different countries. Methods., A total of 1906 patients infected with H. pylori from seven countries were evaluated. Entry criteria included H. pylori positive cases with antral and corpus biopsies between the ages of 18 and 75 years. The minimum number of cases required from a country was 100. Hematoxylin-eosin stained biopsies from antrum and corpus were scored semiquantitatively using the parameters suggested by the Sydney Classification System. Statistical evaluation was performed using Krusakal-Wallis test and Spearman's rank correlation test. Results., The severity of gastric atrophy varied among the different groups with the highest scores being present in Japan. The lowest scores were found in four European countries and in Thailand. The scores for intestinal metaplasia were low in general except for Xi-an, Japan, and Shanghai. For all the countries, the presence of atrophy in the antrum correlated well (r = 0.891) with the incidence of gastric cancer. Conclusion., Using a standardized grading system in a large study of H. pylori -related geographic pathology, we found major differences in the overall prevalence and severity of H. pylori gastritis in relation to age. These differences mirrored the respective incidences of gastric cancer in those geographical areas. [source] Ethnic skin types: are there differences in skin structure and function?,INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2006A. V. Rawlings Synopsis People of skin of colour comprise the majority of the world's population and Asian subjects comprise more than half of the total population of the earth. Even so, the literature on the characteristics of the subjects with skin of colour is limited. Several groups over the past decades have attempted to decipher the underlying differences in skin structure and function in different ethnic skin types. However, most of these studies have been of small scale and in some studies interindividual differences in skin quality overwhelm any racial differences. There has been a recent call for more studies to address genetic together with phenotypic differences among different racial groups and in this respect several large-scale studies have been conducted recently. The most obvious ethnic skin difference relates to skin colour which is dominated by the presence of melanin. The photoprotection derived from this polymer influences the rate of the skin aging changes between the different racial groups. However, all racial groups are eventually subjected to the photoaging process. Generally Caucasians have an earlier onset and greater skin wrinkling and sagging signs than other skin types and in general increased pigmentary problems are seen in skin of colour although one large study reported that East Asians living in the U.S.A. had the least pigment spots. Induction of a hyperpigmentary response is thought to be through signaling by the protease-activated receptor-2 which together with its activating protease is increased in the epidermis of subjects with skin of colour. Changes in skin biophysical properties with age demonstrate that the more darkly pigmented subjects retaining younger skin properties compared with the more lightly pigmented groups. However, despite having a more compact stratum corneum (SC) there are conflicting reports on barrier function in these subjects. Nevertheless, upon a chemical or mechanical challenge the SC barrier function is reported to be stronger in subjects with darker skin despite having the reported lowest ceramide levels. One has to remember that barrier function relates to the total architecture of the SC and not just its lipid levels. Asian skin is reported to possess a similar basal transepidermal water loss (TEWL) to Caucasian skin and similar ceramide levels but upon mechanical challenge it has the weakest barrier function. Differences in intercellular cohesion are obviously apparent. In contrast reduced SC natural moisturizing factor levels have been reported compared with Caucasian and African American skin. These differences will contribute to differences in desquamation but few data are available. One recent study has shown reduced epidermal Cathepsin L2 levels in darker skin types which if also occurs in the SC could contribute to the known skin ashing problems these subjects experience. In very general terms as the desquamatory enzymes are extruded with the lamellar granules subjects with lowered SC lipid levels are expected to have lowered desquamatory enzyme levels. Increased pores size, sebum secretion and skin surface microflora occur in Negroid subjects. Equally increased mast cell granule size occurs in these subjects. The frequency of skin sensitivity is quite similar across different racial groups but the stimuli for its induction shows subtle differences. Nevertheless, several studies indicate that Asian skin maybe more sensitive to exogenous chemicals probably due to a thinner SC and higher eccrine gland density. In conclusion, we know more of the biophysical and somatosensory characteristics of ethnic skin types but clearly, there is still more to learn and especially about the inherent underlying biological differences in ethnic skin types. Résumé, Les gens qui ont une peau de couleur représentent la majorité de la population mondiale et les sujets asiatiques en représentent plus de la moitié. Pourtant la littérature consacrée aux caractéristiques de ces sujets est limitée. Plusieurs groupes de travail ont essayé au cours des dernières années de comprendre les différences sous-jacentes de la structure et de la fonction de la peau de différentes ethnies. Maisla plupart de ces études ont été réalisées à petite échelle et dans certains cas les différences observées entre les individus au niveau de la qualité de la peau ne font pas ressortir de différence entre races. Récemment, un besoin d'études reliant les diffèrences génétiques et phénotypiques entre différents groupes raciaux s'est fait sentir et de ce fait beaucoup d'études à grande èchelle ont été entreprises. La différence la plus évidente, entre les peaux ethniques, est leur couleur liée à la présence de la mélanine. La photoprotection induite par ce polymère influence le taux de vieillissement de la peau entre les différents groupes raciaux qui finalement sont tous sujets au processus de photovieillissement. Généralement, les caucasiens ont des signes plus précoces et plus importants de formation de rides et de relâchement de la peau; en général, les problèmes d'augmentation de la pigmentation sont observés sur les peaux de couleur, bien qu'une grande étude ait rapporté que des sujets originaires de l'Asie de l'Est vivant aux U.S.A. avaient le moins de taches pigmentaires. On pense que la réponse d'une induction hyperpigmentaire est due à un signal envoyé par le récepteur 2 activé par une protéase. Le récepteur 2 augmente en même temps que la protéase activatrice dans l'épiderme des sujets ayant une peau de couleur. Les changements dans les propriètés biophysiques de la peau en fonction de l'âge montrent que les sujets qui ont la pigmentation la plus sombre gardent une peau plus jeune par comparaison aux groupes qui possèdent une pigmentation moins forte. Toutefois, bien qu'ayant un stratum corneum plus compact, il existe des rapports divergents sur la fonction barrière de ces sujets. Dans le cas d'agression chimique ou mécanique, la fonction barrière du stratum corneum est considérée plus forte chez les sujets à peau plus foncée, malgré leurs taux plus faibles encéramide. On doit garder à l'esprit que la fonction barrière du stratum corneum dépend de toute son architecture et pas seulement de sa teneur en lipides. On considère que la peau asiatique à unePIE (TEWL) basale similaire à la peau caucasienne, ainsi que des taux en céramides comparables, mais on constate que dans le cas d'agression mécanique, elle possède un effet barrière le plus faible. Des différences dans la cohésion intercellulaire sont évidentes. A contrario, on a mis en évidence des taux d'hydratation (NMF) plus faibles dans son stratum corneum, comparativement à la peau caucasienne et afro-américaine. Ces différences expliquent les variations au niveau de la desquamation, mais on a très peu de données sur ce sujet. Une étude récente a mis en évidence des taux réduits de Cathepsin L2 dans l'épiderme des types de peau plus sombre, ce qui, si cela se produisait dans le stratum corneum, expliquerait les problèmes biens connus de cendrage de la peau que ces sujets connaissent. En terme très gènéral, étant donné que les enzymes liées à la desquamation sont libérées avec les granules lamellaires, on s'attend à ce que les sujets ayant des taux de lipides faibles dans le stratum corneum aient des taux d'enzymes liés à la desquamation faibles. On constate chez les sujets noirs une augmentation de la taille des pores, de la sécrétion du sébum et de la microflore cutanée. On observe également chez ces sujets une augmentation de la taille des granules mastocellulaires. Le phénomène de peau sensible se retrouve à une fréquence similaire dans les différents groupes raciaux, mais il existe des différences subtiles dans lesstimuli nécessaires pour l'induire. En tout cas, plusieurs études montrent que la peau asiatique est peut-être plus sensible aux produits chimiques exogènes, ce qui probablement est dûà un stratum corneum plus mince et à une densité de glandes eccrines plus élevées. En conclusion, c'est sur les caractéristiques biophysiques et somato-sensorielles des différents types de peaux ethniques que nous en savons plus, mais il est clair qu'il nous reste à comprendre encore beaucoup de choses principalement sur leurs différences biologiques. [source] Religious Market Share and Intensity of Church Involvement in Five DenominationsJOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 1 2000Paul Perl graduate student Proponents of the supply side approach to religion theorize that religious market share,the proportion of people in a geographical area who belong to a given denomination,is inversely related to religious commitment in that denomination. They argue that a small market share motivates religious leaders to compete harder in the religious market place, increasing the participation of members. Another perspective, often associated with secularization theory, make the opposite prediction. It argues that people find it difficult to remain religiously committed in social environments where they are numerical minoritiesbecause other people do not reinforce their beliefs and practices. We use data from a large study of financial giving to analyze the relationship between market share and commitment for five denominations in the United States. We find that market share has a negative effect on church financial giving within all five denominations and a weaker negative effect on attendance in threeof the denominations. We explore whether these effects are the spurious byproducts of pro-religious cultural norms associated with either the South or the presence of conservative Protestants in local areas. In models pooling all denominations, the negative effect of market share on financial giving and attendance cannot be explained away by either of these factors. However, the effect on attendance can be accounted for by congregational size. [source] Western Australian cigarette smokers have fewer small lung nodules than North Americans on CT screening for lung cancerJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2009CP Murray Summary To determine the prevalence of small lung nodules on low-dose helical computed tomography (CT) in a Western Australian cohort of asymptomatic long-term cigarette smokers and to compare this with a large, similarly derived cohort of North Americans from the Mayo Clinic Lung Cancer Screening Trial. Forty-nine asymptomatic long-term cigarette smokers of minimum age 50 years underwent a low-dose 64-slice helical CT of the lungs. Images were viewed on a soft copy reporting station with thin section axial and coronal images, maximum intensity projection images, and advanced image manipulation tools. The prevalence of all nodules was 39%, significantly lower than the Mayo Clinic cohort prevalence of 51% (P < 0.01, Fisher's exact test), despite the use of more advanced imaging technology and image manipulation designed to increase the sensitivity for nodules. The prevalence of small nodules in asymptomatic long-term cigarette smokers in Western Australia is high, though significantly less than that found in a large study in North America. The authors postulate this is due to the relatively low rates of mycobacterium tuberculosis and soil-derived fungal pulmonary infections in Western Australia, as well as a lower degree of urban air pollution. [source] Severe hypoglycemia during intensive insulin therapyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2009K.-M. KAUKONEN Background: Tight glycemic control reduces mortality in surgical intensive care patients and in long-term medical intensive care patients. A large study on intensive insulin therapy was prematurely discontinued due to safety issues. As the safety of intensive insulin therapy has been questioned, we screened all patients during a 17-month period to reveal the incidence of hypoglycemia and its effects on the outcome of the patients. Methods: All patients treated between February 2005 and June 2006 in two intensive care units (ICUs) of a tertiary care teaching hospital were included in the study. A nurse-driven intensive insulin therapy with a target blood glucose level of 4,6 mmol/l had been introduced earlier. The patients were divided into two groups according to the presence of severe hypoglycemia (,2.2 mmol/l). Results: One thousand two hundred and twenty-four patients (1124 treatment periods) were included. During the study period, 61,203 blood glucose measurements were performed, 2.6% of which were below and 52.6% above the target range. Severe hypoglycemia (glucose ,2.2 mmol/l) occurred in 25 patients (36 measurements). The incidence was 0.06% of the measurements and 2.3% of the patients. The median age, sex, Acute Physiology And Chronic Health Evaluation II, Simplified Acute Physiology Score II, diagnosis category, ICU or hospital length of stay did not differ between the groups. The hospital mortalities were 25% and 15% in patients with or without severe hypoglycemia, respectively (P=0.16). Conclusion: Severe hypoglycemia during intensive insulin therapy is rare in clinical practice compared with previous clinical trials. [source] Examining the effects of a highly rated science curriculum unit on diverse students: Results from a planning grantJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 8 2005Sharon Lynch This article reports on the results of a planning grant studying the effects of a highly rated curriculum unit on a diverse student population. The treatment was introduced to 1500 eighth grade students in five middle schools selected for their ethnic, linguistic, and socioeconomic diversity. Students were given pre-, post-, and delayed posttests on a Conservation of Matter Assessment and measures of motivation and engagement. This quasi-experiment found statistically significant posttest results for achievement, basic learning engagement, and goal orientation. Analyses of disaggregated data showed that subgroups of students in the treatment condition outscored their comparison group peers (n,=,1500) in achievement in all cases, except for students currently enrolled in ESOL. Analysis of video data of a diverse group of four students as the unit was enacted suggests that students entered a learning environment that permitted them to function in different, but consistent ways over time; that is, the frequency of students' manipulation of objects showed a different pattern of engagement for each of the four students compared with patterns of verbal responses such as the use of scientific terms. The results of this planning grant paved the way for a large study of the scale-up of highly rated curriculum units. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 42: 912,946, 2005 [source] Methodological challenges when monitoring the diet of pregnant women in a large study: experiences from the Norwegian Mother and Child Cohort Study (MoBa)MATERNAL & CHILD NUTRITION, Issue 1 2008Helle Margrete Meltzer Abstract The aim of this article is to describe the main methodological challenges in the monitoring of dietary intake in the Norwegian Mother and Child Cohort Study (MoBa), a pregnancy cohort aiming to include 100 000 participants. The overall challenge was to record dietary patterns in sufficient detail to support future testing of a broad range of hypotheses, while at the same time limiting the burden on the participants. The main questions to be answered were: which dietary method to choose, when in pregnancy to ask, which time period should the questions cover, which diet questions to include, how to perform a validation study, and how to handle uncertainties in the reporting. Our decisions were as follows: using a semi-quantitative food frequency questionnaire (FFQ) (in use from 1 March 2002), letting the participants answer in mid-pregnancy, and asking the mother what she has eaten since she became pregnant. The questions make it possible to estimate intake of food supplements, antioxidants and environmental contaminants in the future. Misreporting is handled by consistency checks. Reports with a calculated daily energy intake of <4.5 and >20 MJ day,1 are excluded, about 1% in each end of the scale. A validation study confirmed that the included intakes are realistic. The outcome of our methodological choices indicates that our FFQ strikes a reasonable balance between conflicting methodological and scientific interests, and that our approach therefore may be of use to others planning to monitor diet in pregnancy cohorts. [source] Clinical correlates of depressive symptoms in familial Parkinson's disease,,MOVEMENT DISORDERS, Issue 15 2008Nathan Pankratz PhD Abstract Depression is one of the most common nonmotor complications of Parkinson's disease (PD) and has a major impact on quality of life. Although several clinical factors have been associated with depression in PD, the relationship between depression and stage of illness as well as between depression and degree of disability remains controversial. We have collected clinical data on 1,378 PD cases from 632 families, using the Unified Parkinson's Disease Rating Scale (UPDRS) Parts II (activities of daily living) & III (motor), the Mini-Mental State Exam, the Geriatric Depression Scale (GDS), and the Blessed Functional Activity Scale (Blessed). Analyses were performed using the 840 individuals with verified PD and without evidence of cognitive decline. Logistic regression was used to identify study variables that individually and collectively best predicted the presence of depressive symptoms (GDS , 10). After correcting for multiple tests, depressive symptoms were significantly associated with Hoehn and Yahr stage and other clinical measures but not with any genetic variant (parkin, LRRK2, APOE). The Blessed score, education, presence of a first degree relative with signs of depression, and UPDRS Part II were found to best predict depressive symptomatology (R2 = 0.33; P = 4 × 10,48). Contrary to several reports, the results from this large study indicate that stage of illness, motor impairment, and functional disability are strongly correlated with depressive symptoms. © 2008 Movement Disorder Society [source] Closing the gate: Part-Time faculty instruction in gatekeeper courses and first-year persistenceNEW DIRECTIONS FOR TEACHING & LEARNING, Issue 115 2008M. Kevin Eagan This chapter reports the results of a large study on the effects of part-time faculty on student persistence and suggests that administrators give careful consideration when trying to reduce expenses through the use of such faculty in large beginning courses. [source] Ineffectiveness of Precordial Thump for Cardioversion of Malignant Ventricular TachyarrhythmiasPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2007OFFER AMIR M.D. Background:The Precordial Thump (PT) is commonly used for cardiopulmonary resuscitations both in and out of hospitals. However, the support for its efficiency relies mainly on sporadic cases. In this current prospective large study, we tested the effectiveness and safety of PT in a wide range of malignant ventricular tachyarrhythmias. Methods: The study included 80 patients who underwent electrophysiological study and/or implantation of a cardiodefibrillator device. During these procedures, once a malignant ventricular tachyarrhythmia was induced, PT was used as the first treatment option. If the PT failed, other means were used to discontinue the arrhythmia. Results: Polymorphic ventricular tachycardia occurred in 32 (40%) patients, ventricular fibrillation in 28 (35%) patients, and 20 (25%) patients had sustained monomorphic ventricular tachycardia. Except in one patient with monomorphic ventricular tachycardia, the PT was unsuccessful in terminating any of the other malignant tachyarrhythmias, and internal or external defibrillation was eventually required in all other 79 (99%) patients. The PT was not associated with any damage either to the sternal bone, ribs, or to the cardiodefibrillator device. Conclusions: PT is not effective in terminating malignant ventricular tachyarrhythmia and should be reserved to a situation in which a defibrillator is not available. [source] The effect of GSM and TETRA mobile handset signals on blood pressure, catechol levels and heart rate variability ,BIOELECTROMAGNETICS, Issue 6 2007Anthony T. Barker Abstract An acute rise in blood pressure has been reported in normal volunteers during exposure to signals from a mobile phone handset. To investigate this finding further we carried out a double blind study in 120 healthy volunteers (43 men, 77 women) in whom we measured mean arterial pressure (MAP) during each of six exposure sessions. At each session subjects were exposed to one of six different radio frequency signals simulating both GSM and TETRA handsets in different transmission modes. Blood catechols before and after exposure, heart rate variability during exposure, and post exposure 24 h ambulatory blood pressure were also studied. Despite having the power to detect changes in MAP of less than 1 mmHg none of our measurements showed any effect which we could attribute to radio frequency exposure. We found a single statistically significant decrease of 0.7 mmHg (95% CI 0.3,1.2 mmHg, P,=,.04) with exposure to GSM handsets in sham mode. This may be due to a slight increase in operating temperature of the handsets when in this mode. Hence our results have not confirmed the original findings of an acute rise in blood pressure due to exposure to mobile phone handset signals. In light of this negative finding from a large study, coupled with two smaller GSM studies which have also proved negative, we are of the view that further studies of acute changes in blood pressure due to GSM and TETRA handsets are not required. Bioelectromagnetics 28:433,438, 2007. © 2007 Wiley-Liss, Inc. [source] A standardized photographic method for evaluating enamel opacities including fluorosisCOMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 2004Judith A. Cochran Abstract,-,Objectives: The objective of this study was to demonstrate the reproducibility of a standardized photographic technique for recording fluorosis when used by a group of epidemiologists as part of a large multicentred European study. Methods: Studies were first carried out to develop the equipment specification and photographic method. The author (JAC) was then trained and calibrated in this method. She was then responsible for the training and calibration of examiners from a further six European study sites. The method involved taking two transparencies of the permanent maxillary central incisors of 8-year-old children, the first after 8 s while the teeth were still wet and the second after 105 s when the teeth had been allowed to dry out naturally. Data were collected at a central location during a training/calibration exercise and subsequently, during the conduct of a large study to measure fluorosis prevalence, at the seven sites. Intra- and interexaminer reproducibility of the photographic method were measured by grading the transparencies produced by all the examiners according to the DDE and TF indices. Results: The time period in which the transparencies were taken was to within 4 s among the examiners. Transparencies scored according to the TF index gave a range of Kappa values of 0.45-0.66 for intraexaminer reliability and 0.32-0.55 for interexaminer reliability. When using the DDE index Kappa values ranged from 0.43 to 0.70 for intraexaminer reliability and from 0.34 to 0.69 for interexaminer reliability. Conclusion: The photographic method was mostly robust and reproducible when used by epidemiologists from seven European study sites. [source] | ||||||||||||||||