309 research outputs found
A nonlinear dosimetric model for hemoglobin adduct formation by the neurotoxic agent acrylamide and its genotoxic metabolite glycidamide.
Hemoglobin (Hb) adducts, formed by the neurotoxic agent acrylamide (AA) and its genotoxic metabolite glycidamide (GA), were measured in the rat by means of a method for simultaneous determination of the adducts formed to cysteine. A novel, nonlinear dosimetric model was developed to describe Hb adduct formation. This model incorporates the saturable kinetics of the metabolic conversion in vivo of AA to GA. The pharmacokinetic parameters Vmax and Km and the first-order rates of elimination, k1 and k2, for AA and GA from all processes except conversion of AA to GA, were estimated directly from Hb adduct data to 19 M hr-1, 66 microM, 0.21 hr-1, and 0.48 hr-1, respectively. At low concentrations, approximately 60% of AA was metabolized to GA. The nonlinear dosimetric model for adduct formation has potential general applicability in high-to-low-dose extrapolation of genotoxic effects
Temporal increases in plasma markers of oxidized low-density lipoprotein strongly reflect the presence of acute coronary syndromes
AbstractObjectivesThis study was conducted to test the hypothesis that plasma markers of oxidized low-density lipoprotein (OxLDL) reflect acute coronary syndromes (ACS).BackgroundOxidized LDL contributes to the pathogenesis of atherosclerosis, but its role in ACS is not established.MethodsSerial plasma samples were prospectively obtained from patients with an acute myocardial infarction (MI) (n = 8), unstable angina (UA) (n = 15), stable coronary artery disease (CAD) (n = 17), angiographically normal coronary arteries (n = 8), and from healthy subjects (n = 18), at entry into the study, hospital discharge (MI group only), and at 30, 120, and 210 days. Chemiluminescent enzyme-linked immunosorbent assay was used to quantitate plasma levels of: 1) immunoglobulin (Ig)M and IgG OxLDL autoantibody titers (presented as a mean OxLDL autoantibody titer by averaging the results of four distinct epitopes); 2) LDL-autoantibody immune complexes (LDL-IC); and 3) minimally OxLDL measured by antibody E06 (OxLDL-E06), as determined by the content of oxidized phospholipids (OxPL) per apolipoprotein B-100.ResultsBaseline OxLDL IgG autoantibody levels were higher in the MI group (p < 0.0001). At 30-day follow-up, the mean IgM OxLDL titers increased by 48% (p < 0.001) and 20% (p < 0.001), and IgM LDL-IC increased by 60% (p < 0.01) and 26% (p < 0.01) in the MI and UA groups, respectively. The OxLDL-E06 levels increased by 54% (p < 0.01) in the MI group at hospital discharge and by 36% at 30 days. No significant changes in any OxLDL markers were noted in the other groups. The OxLDL-E06 levels strongly paralleled the acute rise in lipoprotein(a), or Lp(a), in the MI group, suggesting that toxic OxPL are preferentially bound to Lp(a). Oxidized LDL-E06 also correlated extremely well with Lp(a) in the entire cohort of patients (r = 0.91, p < 0.0001).ConclusionsCirculating OxLDL-specific markers strongly reflect the presence of ACS, implying immune awareness to newly exposed oxidation-specific epitopes and possible release of OxLDL in the circulation. The OxLDL-E06 measurements provide novel insights into plaque rupture and the potential atherogenicity of Lp(a)
Oxidized Phospholipids Predict the Presence and Progression of Carotid and Femoral Atherosclerosis and Symptomatic Cardiovascular Disease Five-Year Prospective Results From the Bruneck Study
ObjectivesThe purpose of this work was to determine the predictive value of oxidized phospholipids (OxPLs) present on apolipoprotein B-100 particles (apoB) in carotid and femoral atherosclerosis.BackgroundThe OxPLs are pro-inflammatory and pro-atherogenic and may be detected using the antibody E06 (OxPL/apoB).MethodsThe Bruneck study is a prospective population-based survey of 40- to 79-year-old men and women initiated in 1990. Plasma levels of OxPL/apoB and lipoprotein (a) [Lp(a)] were measured in 765 of 826 (92.6%) and 671 of 684 (98.1%) subjects alive in 1995 and 2000, respectively, and correlated with ultrasound measures of carotid and femoral atherosclerosis.ResultsThe distribution of the OxPL/apoB levels was skewed to lower levels and nearly identical to Lp(a) levels. The OxPL/apoB and Lp(a) levels were highly correlated (r = 0.87, p < 0.001), and displayed long-term stability and lacked correlations with most cardiovascular risk factors and lifestyle variables. The number of apolipoprotein (a) kringle IV-2 repeats was inversely related to Lp(a) mass (r = −0.48, p < 0.001) and OxPL/apoB levels (r = −0.46, p < 0.001). In multivariable analysis, OxPL/apoB levels were strongly and significantly associated with the presence, extent, and development (1995 to 2000) of carotid and femoral atherosclerosis and predicted the presence of symptomatic cardiovascular disease. Both OxPL/apoB and Lp(a) levels showed similar associations with atherosclerosis severity and progression, suggesting a common biological influence on atherogenesis.ConclusionsThis study suggests that pro-inflammatory oxidized phospholipids, present primarily on Lp(a), are significant predictors of the presence and extent of carotid and femoral atherosclerosis, development of new lesions, and increased risk of cardiovascular events. The OxPL biomarkers may provide valuable insights into diagnosing and monitoring cardiovascular disease
Patient-Reported Morbidity Instruments: A Systematic Review
Objectives: Although comorbidities play an essential role in risk adjustment and outcomes measurement, there is little consensus regarding the best source of this data. The aim of this study was to identify general patient-reported morbidity instruments and their measurement properties. Methods: A systematic review was conducted using multiple electronic databases (Embase, Medline, Cochrane Central, and Web of Science) from inception to March 2018. Articles focusing primarily on the development or subsequent validation of a patient-reported morbidity instrument were included. After including relevant articles, the measurement properties of each morbidity instrument were extracted by 2 investigators for narrative synthesis. Results: A total of 1005 articles were screened, of which 34 eligible articles were ultimately included. The most widely assessed instruments were the Self-Reported Charlson Comorbidity Index (n = 7), the Self-Administered Comorbidity Questionnaire (n = 3), and the Disease Burden Morbidity Assessment (n = 3). The most commonly included conditions were diabetes, hypertension, and myocardial infarction. Studies demonstrated substantial variability in item-level reliability versus the gold standard medical record review (κ range 0.66-0.86), meaning that the accuracy of the self-reported comorbidity data is dependent on the selected morbidity. Conclusions: The Self-Reported Charlson Comorbidity Index and the Self-Administered Comorbidity Questionnaire were the most frequently cited instruments. Significant variability was observed in reliability per comorbid condition of patient-reported morbidity questionnaires. Further research is needed to determine whether patient-reported morbidity data should be used to bolster medical records data or serve as a stand-alone entity when risk adjusting observational outcomes data
Evidence in action: a Thompsonian perspective on evidence-based decision-making in social work
Evidence-based practice presupposes evidence-based decision-making. In the debate it is argued that a social work fashioned after evidence should be more rational, less authoritarian and built on scientific knowledge, respect and ethics. Yet the empirical evidence that this idea works is weak. In fact the difficulties met during efforts to implement evidence could be a sound reaction. Indeed difficulties experienced could be a defensive organizational reaction to a new, disturbing technology. In this article James D. Thompson’s classical study Organizations in Action from 1967 is applied to evidence-based decision-making in social work. It shows to date that many problems have been given, at best, tenuous attention. It is argued that a focus on evidence will raise ambiguity and complexity levels within organizations and that new professional specialists will emerge. Further, new constellations of power will appear, leading to a change of balance within the domains of social work
Scholars’ open debate paper on the World Health Organization ICD-11 gaming disorder proposal
Concerns about problematic gaming behaviors deserve our full attention. However, we claim that it is far from clear that these problems can or should be attributed to a new disorder. The empirical basis for a Gaming Disorder proposal, such as in the new ICD-11, suffers from fundamental issues. Our main concerns are the low quality of the research base, the fact that the current operationalization leans too heavily on substance use and gambling criteria, and the lack of consensus on symptomatology and assessment of problematic gaming. The act of formalizing this disorder, even as a proposal, has negative medical, scientific, public-health, societal, and human rights fallout that should be considered. Of particular concern are moral panics around the harm of video gaming. They might result in premature application of diagnosis in the medical community and the treatment of abundant false-positive cases, especially for children and adolescents. Second, research will be locked into a confirmatory approach, rather than an exploration of the boundaries of normal versus pathological. Third, the healthy majority of gamers will be affected negatively. We expect that the premature inclusion of Gaming Disorder as a diagnosis in ICD-11 will cause significant stigma to the millions of children who play video games as a part of a normal, healthy life. At this point, suggesting formal diagnoses and categories is premature: the ICD-11 proposal for Gaming Disorder should be removed to avoid a waste of public health resources as well as to avoid causing harm to healthy video gamers around the world
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Validation of the Internet Addiction Test in Students at a Pakistani Medical and Dental School
Despite growing concerns over pathological internet usage, studies based on validated psychometric instruments are still lacking in Pakistan. This study aimed to examine the psychometric properties of the Internet Addiction Test (IAT) in a sample of Pakistani students. A total of 522 students of medicine and dentistry completed the questionnaire, which consisted of four sections: (a) demographics, (b) number of hours spent on the Internet per day, (c) English version of the IAT, and (d) the Defense Style Questionnaire-40. Maximum likelihood analysis and principal axis factoring were used to validate the factor structure of the IAT. Convergent and criterion validity were assessed by correlating IAT scores with number of hours spent online and defense styles. Exploratory and confirmatory factor analysis reflected the goodness of fit of a unidimensional structure of the IAT, with a high alpha coefficient. The IAT had good face and convergent validity and no floor and ceiling effects, and was judged easy to read by participants
An integrated model of care to counter high incidence of HIV and sexually transmitted diseases in men who have sex with men – initial analysis of service utilizers in Zurich
BACKGROUND: As other countries, Switzerland experiences a high or even rising incidence of HIV and sexually transmitted infections (STI) among men who have sex with men (MSM). An outpatient clinic for gay men ("Checkpoint") was opened in 2006 in Zurich (Switzerland) in order to provide sexual health services. The clinic provides counselling, testing, medical treatment and follow-up at one location under an "open-door-policy" and with a high level of personal continuity. We describe first experiences with the new service and report the characteristics of the population that utilized it. METHODS: During the 6-month evaluation period, individuals who requested counselling, testing or treatment were asked to participate in a survey at their first visit prior to the consultation. The instrument includes questions regarding personal data, reasons for presenting, sexual behaviour, and risk situations. Number and results of HIV/STI tests and treatments for STI were also recorded. RESULTS: During the evaluation period, 632 consultations were conducted and 247 patients were seen by the physician. 406 HIV tests were performed (3.4% positive). 402 men completed the entry survey (64% of all consultations). The majority of respondents had 4 and more partners during the last 12 months and engaged in either receptive, insertive or both forms of anal intercourse. More than half of the responders used drugs or alcohol to get to know other men or in conjunction with sexual activity (42% infrequently, 10% frequently and 0.5% used drugs always). The main reasons for requesting testing were a prior risk situation (46.3%), followed by routine screening without a prior risk situation (24.1%) and clarification of HIV/STI status due to a new relationship (29.6%). A fifth of men that consulted the service had no history of prior tests for HIV or other STIs. CONCLUSION: Since its first months of activity, the service achieved high levels of recognition, acceptance and demand in the MSM community. Contrary to common concepts of "testing clinics", the Checkpoint service provides post-exposure prophylaxis, HIV and STI treatment, psychological support and counselling and general medical care. It thus follows a holistic approach to health in the MSM community with the particular aim to serve as a "door opener" between the established system of care and those men that have no access to, or for any reason hesitate to utilize traditional health care
酸化物ガラスの塩基度と XPS による O1s 化学シフトの相関に関する考察
O1s binding energy measured by X-ray photoelectron spectroscopy (XPS) is candidate as a new tool to determine a new scale of Lewis basicity of oxide ions in glass. Some mathematical expressions for the basicity or XPS chemical shift, such as charge parameter and optical basicity, were compared with the experimental O1s binding energy in binary alkali oxide glasses. The expressions so far in use needed some modification in parameters. A new empirical expression introduced in this paper gives a new concept and universal scale of basicity
A weak scientific basis for gaming disorder: let us err on the side of caution
We greatly appreciate the care and thought that is evident in the 10 commentaries that discuss our debate paper, the
majority of which argued in favor of a formalized ICD-11 gaming disorder. We agree that there are some people
whose play of video games is related to life problems. We believe that understanding this population and the nature
and severity of the problems they experience should be a focus area for future research. However, moving from
research construct to formal disorder requires a much stronger evidence base than we currently have. The burden of
evidence and the clinical utility should be extremely high, because there is a genuine risk of abuse of diagnoses. We
provide suggestions about the level of evidence that might be required: transparent and preregistered studies, a better
demarcation of the subject area that includes a rationale for focusing on gaming particularly versus a more general
behavioral addictions concept, the exploration of non-addiction approaches, and the unbiased exploration of clinical
approaches that treat potentially underlying issues, such as depressive mood or social anxiety first. We acknowledge
there could be benefits to formalizing gaming disorder, many of which were highlighted by colleagues in their
commentaries, but we think they do not yet outweigh the wider societal and public health risks involved. Given the
gravity of diagnostic classification and its wider societal impact, we urge our colleagues at the WHO to err on the side
of caution for now and postpone the formalization
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