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R Weber

Publications and source records attributed to R Weber.

At least 19 recordsLinked to original sources
PubMed2007

Laboratory composting of extruded starch acetate and poly lactic acid blended foams.

Composting of extruded foams made of starch acetate and poly lactic acid (PLA) with pre-conditioned yard waste was studied using a laboratory composting system. Extruded foams of high amylose starch were used as the control. Degradation was measured by analyzing the exhaust gases for carbon dioxide. There were significant differences in the amounts of carbon dioxide produced in the vessels containing foams of high amylose starch and foams of starch acetate blended with 20% or 30% PLA. The high amylose starch foams completely degraded within 15 days. The starch acetate foams with 0% PLA took longer, with evolution of carbon dioxide still measurable after 55 days. The rate of degradation was faster for foams with higher PLA contents. The starch acetate foams took even longer to degrade. The maximum time was found to be 130 days for the starch acetate foams.

Biodegradation, Environmental↗
PubMed2006

The use of the Framingham equation to predict myocardial infarctions in HIV-infected patients: comparison with observed events in the D:A:D Study.

BACKGROUND: The D:A:D (Data Collection on Adverse Events of Anti-HIV Drugs) Study, a prospective observational study on a cohort of 23 468 patients with HIV infection, indicated that the incidence of myocardial infarction (MI) increased by 26% per year of exposure to combination antiretroviral treatment (CART). However, it remains unclear whether the observed increase in the rate of MI in this population can be attributed to changes in conventional cardiovascular risk factors. OBJECTIVE: To compare the number of MIs observed among participants in the D:A:D Study with the number predicted by assuming that conventional cardiovascular risk equations apply to patients with HIV infection. METHODS: The Framingham equation, a conventional cardiovascular risk algorithm, was applied to individual patient data in the D:A:D Study to predict rates of MI by duration of CART. A series of sensitivity analyses were performed to assess the effect of model and data assumptions. Predictions were extrapolated to provide 10-year risk estimates, and various scenarios were modelled to assess the expected effect of different interventions. RESULTS: In patients receiving CART, the observed numbers of MIs during D:A:D follow up were similar to or somewhat higher than predicted numbers: 9 observed vs 5.5 events predicted, 14 vs 9.8, 22 vs 14.9, 31 vs 23.2 and 47 vs 37.0 for<1 year, 1-2 years, 2-3 years, 3-4 years and >4 years CART exposure, respectively. In patients who had not received CART, the observed number of MIs was fewer than predicted (3 observed vs 7.6 predicted). Nine per cent of the study population have a predicted 10-year risk of MI above 10%, a level usually associated with initiation of intervention on risk factors. CONCLUSIONS: A consistent feature of all analyses was that observed and predicted rates of MI increased in a parallel fashion with increased CART duration, suggesting that the observed increase in risk of MI may at least in part be explained by CART-induced changes in conventional risk factors. These findings provide guidance in terms of choosing lifestyle or therapeutic interventions to decrease those risk factors in much the same way as in persons without HIV infection.

Adult↗
PubMed2006

Prevalence of risk factors for cardiovascular disease in HIV-infected patients over time: the Swiss HIV Cohort Study.

OBJECTIVE: Metabolic changes caused by antiretroviral therapy (ART) may increase the risk of coronary heart disease (CHD). We evaluated changes in the prevalence of cardiovascular risk factors (CVRFs) and 10-year risk of CHD in a large cohort of HIV-infected individuals. METHODS: All individuals from the Swiss HIV Cohort Study (SHCS) who completed at least one CVRF questionnaire and for whom laboratory data were available for the period February 2000 to February 2006 were included in the analysis. The presence of a risk factor was determined using cut-offs based on the guidelines of the National Cholesterol Education Program (NCEP ATP III), the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7), the American Diabetes Association, and the Swiss Society for Cardiology. RESULTS: Overall, 8,033 individuals completed at least one CVRF questionnaire. The most common CVRFs in the first completed questionnaire were smoking (57.0%), low high-density lipoprotein (HDL) cholesterol (37.2%), high triglycerides (35.7%), and high blood pressure (26.1%). In total, 2.7 and 13.8% of patients were categorized as being at high (>20%) and moderate (10-20%) 10-year risk for CHD, respectively. Over 6 years the percentage of smokers decreased from 61.4 to 47.6% and the percentage of individuals with total cholesterol >6.2 mmol/L decreased from 21.1 to 12.3%. The prevalence of CVRFs and CHD risk was higher in patients currently on ART than in either pretreated or ART-naive patients. CONCLUSION: During the 6-year observation period, the prevalence of CVRFs remains high in the SHCS. Time trends indicate a decrease in the percentage of smokers and individuals with high cholesterol.

Adult↗
PubMed2006

Oral candidosis and oral hairy leukoplakia as predictors of HAART failure in Brazilian HIV-infected patients.

INTRODUCTION: Oral candidosis (OC) and hairy leukoplakia (OHL) are important markers of Human Immunodeficiency Virus (HIV) infection immune status. OBJECTIVES: to evaluate if OC and/or OHL should be considered clinical predictors of immune and virologic failure on HIV-infected Brazilian adults undergoing Highly Active Antiretroviral Therapy (HAART). METHODS: 124 HIV-infected patients who used HAART for a minimum of six months were prospectively evaluated. All of them under-took oral examination and serum CD4+ count and viral load (VL), being divided in two groups, P and A, respectively according to the presence or absence of OC and/or OHL. During a six month period, patients belonging to group A were followed. They were re-examined for new oral lesions. New blood samples were collected and they were subdivided into groups P6 and A6. CD4+ count and VL were compared between groups at baseline and after the six months period. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and relative risk (RR) were obtained in order to assess the accuracy of using OC and OHL as predictors of immune and virologic failure, at baseline and after a six month period. RESULTS: At baseline and after six months, patients with OC and OHL have mean CD4+ count lower and mean VL higher than patients of group A and A6 (p < 0.001). OC had high PPV for immune failure and a moderated PPV for virologic failure. OHL had low PPVs for both measures. DISCUSSION AND CONCLUSIONS: OC and OHL still indicate low serum CD4+ count and high VL, but OC seems to be a better predictor of immune and virologic failure in patients undergoing HAART than OHL.

AIDS-Related Opportunistic Infections↗
PubMed2006

Medical informatics education needs information system practicums in health care settings--experiences and lessons learned from 32 practicums at four universities in two countries.

OBJECTIVES: To report about the themes and about experiences with practicums in the management of information systems in health care settings (health information management) for medical informatics students. METHODS: We first summarize the topics of the health information management practicums/projects that the authors organized between 1990 and 2003 for the medical informatics programs at Heidelberg/Heilbronn, Germany, UMIT, Austria, as well as for the informatics program at the University of Leipzig, Germany. Experiences and lessons learned, obtained from the faculty that organized the practicums in the past 14 years, are reported. RESULTS: Thirty (of 32) health information management practicums focused on the analysis of health information systems. These took place inside university medical centers. Although the practicums were time-intensive and required intensively tutoring students with regard to health information management and project management, feedback from the students and graduates was mainly positive. DISCUSSION: It is clearly recommended that students specializing in medical informatics need to be confronted with real-world problems of health information systems during their studies.

Austria↗
PubMed2005

[Multilocular large erythemas and fever].

A 44-year old man consulted our emergency room three months after returning from holidays in Sri Lanka: Following a short episode of fever, he observed rise of four large reddish skin lesions that central paling. We considered infection with Borrelia burgdorferi (erythema migrans), streptoccoci (erysipelas), or fungi (tinea corporis). Erysipelas was improbable because of slow progression with little systemic inflammatory response, fungi were not detected in direct microscopic examination. Aspect of the skin lesions was typical for erythema migrans, however, we were not familiar with multilocular appearance of this disease. Nevertheless--on the basis of clinical observations and detection of serum IgM against Borrelia burdorferi--we diagnosed multilocular erythema migrans and treated with doxycycline 200 mg daily for 10 days. The skin lesions completely disappeared within a few days. Erythema migrans may present unilocular or multilocular, depending on Borrelia species involved. In Europe (mainly B. afzelii and B. garinii), multilocular manifestation is rare and, therefore, often misinterpreted. It is important, however, to diagnose and treat multilocular erythema migrans because early hematogenic dissemination is underlying. In America B. burgdorferi sensu stricto infection more often presents with multilocular erythema migrans and systemic clinical manifestations.

Adult↗
PubMed2005

[Primary HIV-1 infection in Zurich: 2002-2004].

Acute HIV-infection mostly presents with unspecifc symptoms. Thus the acute retroviral syndrome is often not readily recognized. Here we present an interim analysis of a prospective study from 62 patients with documented acute HIV infection acquired between January 2002-August 2004 in the greater Zurich area. 61.5% of patients were infected by homosexual contacts, mostly with HIV-1 subtype B, 34% acquired infection by heterosexual contacts, often with non-B-virus subtypes. Transmission occurred in all sexually active age groups (18-72 years). Clinical symptoms presented as follows: fever (77%), pharyngitis (56%), fatigue (52%), gastrointestinal symptoms (45%), rash (39%). On first physician contact, an ARS was only suspected in 27% of the cases. Patients primarily called on their family doctors (37.5%), went to see larger walk in clinics or emergency rooms (37.5%), and 16% were hospitalised. In 16% of patients other sexually transmitted diseases were diagnosed contemporaneously. Drug resistant virus (single class resistance) was transmitted in only one patient.

Acute Disease↗
PubMed2005

Cerebrovascular manifestations of Takayasu arteritis in Europe.

OBJECTIVES: Takayasu arteritis is well known as a cause of stroke in Asia but has rarely been described in the Western world. Here we report the clinical and neuroimaging follow-up of a series of patients with Takayasu arteritis from Europe. METHODS: Seventeen consecutive patients who fulfilled the diagnostic criteria for Takayasu arteritis of the American College of Rheumatology were evaluated on follow-up by standardized neurological examination, sonography and MRI. RESULTS: At follow-up almost 20 yr after onset of symptoms, the subclavian artery and the common carotid artery were often affected. In addition, evidence of intracranial pathology was found in seven patients. In contrast to the severe vessel involvement, the neurological state was stable. Two patients had suffered from stroke before the diagnosis was made and therapy was initiated, and one patient had recurrent transient ischaemic attacks. Intermittent dizziness was associated with pathology of the vertebral and basilar arteries. However, clinical symptoms of subclavian steal syndrome were rare. CONCLUSION: This case series shows that the clinical neurological course of Takayasu arteritis on treatment is benign in most cases despite the severe vascular involvement.

Adolescent↗
PubMed2005

[Thrombophilias in patients with ischemic stroke. Indication and calculated costs for evidence-based diagnostics and treatment].

Patients with ischemic stroke are sometimes found to have an underlying inherited (deficiency of protein C, protein S, antithrombin III, activated protein C resistance, prothrombin gene mutation, hyperhomocysteinemia) or acquired thrombophilia (lupus anticoagulant and anticardiolipin antibodies, hyperhomocysteinemia). Patient selection for thrombophilia screening is, therefore, a frequent question in managing patients with ischemic stroke. In this review we discuss patient selection and timing for laboratory tests for thrombophilia screening in stroke patients based on a literature review and we calculated overall costs per year in Germany for testing patients older than 18 years with an ischemic stroke of undetermined cause. As there is a lack of studies comparing anticoagulation with antiplatelet therapy in patients with diagnosed thrombophilia, laboratory screening for thrombophilia even in a selected group of patients with cryptogenic ischemic stroke remains of questionable value at present. An exception appears to be testing for lupus anticoagulant and anticardiolipin antibodies in younger patients with suspected antiphospholipid syndrome (two positive test results necessary), because anticoagulation seems to be superior to aspirin in patients with antiphospholipid syndrome.

Brain Ischemia↗
PubMed2005

Interferon alpha-2a plus ribavirin 1,000/1,200 mg versus interferon alpha-2a plus ribavirin 600 mg for chronic hepatitis C infection in patients on opiate maintenance treatment: an open-label randomized multicenter trial.

BACKGROUND: Many intravenous opiate users are infected with hepatitis C virus (HCV) but few are treated. Although this complies with various guidelines, virtually no published evidence supports such a recommendation. PATIENTS AND METHODS: In a multicenter study, HCV-infected patients in opiate maintenance treatment programs received interferon plus high- or low-dose ribavirin (1,000/1,200 mg or 600 mg). HIV-coinfected patients were not included. Endpoints were feasibility, efficacy, side effects, and reasons for dropout. RESULTS: Of the 420 patients who tested positive for HCV, 27 (6%) were enrolled; 393 (94%) either failed to meet the inclusion criteria or refused treatment. Virologic end-of-treatment response was achieved in 12/27 patients, and sustained response in 13/27 (48%). Response depended on viral genotype, not ribavirin dose. The two doses of ribavirin did not differ in their side effects. CONCLUSION: In a small fraction of HCV-infected intravenous drug users in an opiate maintenance treatment program, antiviral therapy was feasible, safe, and effective. The success rate was comparable to that achieved in controlled studies that excluded drug users.

Antiviral Agents↗
PubMed2005

TERMTrial--terminology-based documentation systems for cooperative clinical trials.

Within cooperative groups of multi-center clinical trials a standardized documentation is a prerequisite for communication and sharing of data. Standardizing documentation systems means standardizing the underlying terminology. The management and consistent application of terminology systems is a difficult and fault-prone task, which should be supported by appropriate software tools. Today, documentation systems for clinical trials are often implemented as so-called Remote-Data-Entry-Systems (RDE-systems). Although there are many commercial systems, which support the development of RDE-systems there is none offering a comprehensive terminological support. Therefore, we developed the software system TERMTrial which consists of a component for the definition and management of terminology systems for cooperative groups of clinical trials and two components for the terminology-based automatic generation of trial databases and terminology-based interactive design of electronic case report forms (eCRFs). TERMTrial combines the advantages of remote data entry with a comprehensive terminological control.

Clinical Trials as Topic↗
PubMed2005

Costs of treatment of Swiss patients with HIV on antiretroviral therapy in hospital-based and general practice-based care: a prospective cohort study.

Some ambulant people with HIV are cared for primarily by their general practitioner and some in an outpatient clinic. Costs and patterns of care in these settings were studied in 65 such patients based in Zürich, from a limited societal perspective (excluding patient costs) based on medical resource use. Antiretroviral therapy (ART), other medications and patient variables were collected prospectively, and non-medication resources (professional time and investigations) and treatment history data were collected from medical records and by record linkage to the Swiss HIV Cohort Study database. Cost differences between the settings were estimated using multiple regression, controlling for differences in case-mix. ART comprised 80% of the total cost, non-medication costs 15% and non-ART medications 5%. Total costs were higher in the outpatient clinic (estimated additional cost after controlling for case-mix = 3489 Swiss Francs per year at 1999 prices, 95% confidence interval 742 to 6236, p=0.017). The difference was accounted for by higher ART costs in the outpatient clinic, not through a tendency to use more expensive drugs or higher doses but rather through the use of more drugs concurrently. Differences in ART prescribing patterns between the doctors in the outpatient clinic and the general practitioners were considerable and appear worthy of further investigation.

Adult↗
PubMed2004

Surface roughness of supercooled polymer melts.

We report on in situ x-ray reflectivity measurements of the surface roughness of supercooled glass forming polymers in a temperature range from 190 to 330 K. The experimentally determined rms roughness has been found to obey the capillary wave model of a single liquid/vapor interface over the entire temperature range. An expression for the surface roughness below the bulk glass transition (T(G) approximately equal to 200 K) is deduced from the viscoelastic theory of surface fluctuations; however, no indication of a frozen-in surface roughness has been observed in the experiment. Additionally, it is shown that precise values of the surface tension of highly viscous liquids in the supercooled state can be determined by x-ray reflectivity.

Journal Article↗
PubMed2004

Cardio- and cerebrovascular events in HIV-infected persons.

OBJECTIVE: Recent results from the D:A:D Study indicated that the incidence of myocardial infarction (MI) increased by 26% per year of exposure to combination antiretroviral treatment (CART). The present study was performed to investigate whether this risk was similar when including other cardio- and cerebro-vascular disease events (CCVE). DESIGN: D:A:D is an international collaboration of 11 cohorts, following 23 468 HIV-infected patients prospectively at 188 clinics in 21 countries situated in Europe, USA and Australia. METHODS: The end-point was the occurrence of a first CCVE during prospective follow-up, defined as the first of: acute MI, invasive cardiovascular procedures, stroke, or death from other cardiovascular disease. Relative rates (RR) for CCVE from Poisson regression models and 95% confidence intervals (CI) are reported. All models are adjusted for other risk factors for CCVE, including age, gender, ethnicity, family history, body mass index, and smoking status as well as cohort and HIV transmission group. RESULTS: Over 36 145 person-years of follow-up, 207 patients experienced at least one CCVE (23.7% fatal). The first event was MI in 126 patients, invasive cardiovascular procedure in 39 patients, stroke in 38 patients, and death from other cardiovascular disease in four patients. The incidence of first CCVE was 5.7 per 1000 person-years [95% confidence interval (CI) 5.0-6.5] and increased with longer exposure to CART (RR per year of exposure, 1.26; 95% CI, 1.14-1.38; P < 0.0001). CONCLUSION: CART increases the risk of CCVD, and this increase is comparable with how CART affects the risk of MI. This finding is consistent with the hypothesis that atherosclerosis is a side-effect of CART.

Anti-Retroviral Agents↗