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Biomedical subjects

Katja Schmidt

Publications and source records attributed to Katja Schmidt.

At least 19 recordsLinked to original sources
PubMed2006

Genotype-dependent activation or repression of HBV enhancer II by transcription factor COUP-TF1.

AIM: To study the expression of HBV enhancer II by transcription factor COUP-TF1. METHODS: In order to study the regulation of HBV variants in the vicinity of the NRRE we cloned luciferase constructs containing the HBV enhancer II from variants and from HBV genotypes A and D and cotransfected them together with expression vectors for COUP-TF1 into HepG2 cells. RESULTS: Our findings show that enhancer II of HBV genotype A is also repressed by COUP-TF1. In contrast, two different enhancer II constructs of HBV genotype D were activated by COUP-TF1. The activation was independent of the NRRE because a natural variant with a deletion of nt 1763-1770 was still activated by COUP-TF1. CONCLUSION: Regulation of transcription of the HBV genome seems to differ among HBV genomes derived from different genotypes. These differences in transcriptional control among HBV genotypes may be the molecular basis for differences in the clinical course among HBV genotypes.

Base Sequence↗
PubMed2005

Performance anxiety in gifted adolescent musicians.

Among professional musicians as well as among music students, performance anxiety occurs frequently and can cause considerable distress. As the professional development starts early among future musicians, younger samples are of great interest, but to date, few studies have examined adolescents. The present survey explored performance anxiety in a sample of 15-19-year-old pupils who attended a German special music school. Of those pupils, 74 participated in the study (93% response rate). In addition to frequency and expression of performance anxiety, coping strategies were assessed. Results pointed to the high frequency of performance anxiety in this sample; about one third of the group were distinctly handicapped by their anxiety. Unfavorable coping strategies, such as drug or alcohol abuse were rarely reported. Most pupils called for more support either from their teachers or from outside of school to cope with their anxiety.

Adaptation, Psychological↗
PubMed2005

A systematic review of guided imagery as an adjuvant cancer therapy.

AIM: The aim of this paper is to summarise and critically evaluate the evidence available from controlled clinical trials regarding the use of guided imagery as a sole adjuvant therapy for cancer patients. METHODS: Electronic searches for controlled clinical trials were carried out in eight databases and two clinical trial registers. Trials that featured guided imagery as a sole adjuvant therapy were included. No language restrictions were imposed. Data were extracted and validated independently by two researchers. RESULTS: Six randomised clinical trials were included. Detailed results were available for four studies only. Poor reporting and heterogeneous populations, interventions and outcome measures across trials precluded statistical pooling of results. The methodological quality was on average low. Three studies reported significant differences in measures of anxiety, comfort or emotional response to chemotherapy for patients who received guided imagery over the control groups. Two studies showed no differences between guided imagery and other interventions in any of the outcome measures. CONCLUSION: Guided imagery, as a sole adjuvant cancer therapy may be psycho-supportive and increase comfort. There is no compelling evidence to suggest positive effects on physical symptoms such as nausea and vomiting. The data seem sufficiently encouraging for the use of guided imagery as an adjuvant cancer therapy to merit further research.

Antineoplastic Agents↗
PubMed2005

Systematic literature reviews.

Systematic reviews retrieve, appraise and summarise all the available evidence on a specific health question. They are designed to reduce the effect of the reviewers' own bias, and a full protocol should be written to define and guide the process. The appropriate resources should be in place before undertaking a review. The steps of the review are: frame the question and choose appropriate methods; identify relevant work; extract relevant data on outcomes and quality; summarise the evidence; and, interpret the evidence. Reviews that combine valid, homogeneous studies of treatments that are relevant to health care, in patients who are typical, can provide good evidence to guide health care decisions.

Data Collection↗
PubMed2005

Multischool, international survey of medical students' attitudes toward "holism".

PURPOSE: Core and optional courses of study in complementary and alternative medicine (CAM) are being incorporated into medical curricula. The authors carried out this study to validate a tool to examine students' attitudes toward holism and CAM and explore the relationships between their attitudes and other demographic and education-related characteristics in a large, multischool, international sample of medical students. METHOD: In 2003 the authors used a modified version of the Integrated Medicine Attitude Questionnaire (IMAQ) to survey students at a total of six medical schools in the United Kingdom, New Zealand, Canada, the United States, and Hong Kong, China. A three-factor model was tested using confirmatory factor analysis, and the internal consistency of the factors were identified using Cronbach's alpha coefficients. A multiple-indicator multiple-cause (MIMIC) analysis was carried out to determine the relationship between IMAQ factors and student characteristics. RESULTS: The authors validated a three-factor model for the IMAQ: (1) attitudes toward holism, (2) attitudes toward the effectiveness of CAM, and (3) attitudes toward introspection and the doctor-patient relationship. Cronbach's alpha coefficients ranged from .41 to .71. The MIMIC model indicated that various background variables were associated with IMAQ factors (gender, race/ethnicity, and school), depending on whether students had previously visited a CAM practitioner and whether students were willing to undertake a special study module in CAM. CONCLUSIONS: Further development work on the IMAQ is required and qualitative research to verify and examine the reasons behind the relationships found in this study between students' attitudes to holism and their demographic and education-related characteristics.

Adolescent↗
PubMed2004

'Alternative' cures for depression--how safe are web sites?

Complementary and alternative medicine (CAM) continue to be promoted for various health conditions, recently also via the Internet. This study assessed whether patients suffering from depression might be put at risk through the advice offered by these websites. Some websites assessed offered advice with a potential to harm patients suffering from depression.

Complementary Therapies↗
PubMed2004

Impact of PCB mixture (Aroclor 1254) and TBT and a mixture of both on swimming behavior, body growth and enzymatic biotransformation activities (GST) of young carp (Cyprinus carpio).

The sensitivity of carp to chronical stress due to single and combined mixtures (each 50%) of TBT and PCB was evaluated under laboratory conditions. And concluded, mixed exposures were partially more or less toxic than single ones. Xenobiotic stress led to both decreased mean daily swimming speed and an increased mean swimming speed during darkness. Also a decreased preferred swimming depth (nearer to the surface) during nighttime was observed. We found approximately synergistic effects of TBT and PCB in swimming behavior of carp exposed to those mixtures. PCB did not affect the body growth significantly, TBT-stress led to a decreased body growth and the exposure to PCB-TBT mixture caused an approximately additive decrease of body growth. Measurement of biotransformation potential measured as GST enzyme activity showed both increasing or decreasing activity levels after exposure to single and mixture chemical combinations (approximately additive, antagonistic and synergistic). Nevertheless, we had to conclude that all methods tested were useful to screen subacute effects of single as well as mixed xenobiotic chemicals on carp, which is the prerequisite for an investigation of samples taken from the environment.

Animals↗
PubMed2004

Functional interdependence between septin and actin cytoskeleton.

BACKGROUND: Septin2 is a member of a highly conserved GTPase family found in fungi and animals. Septins have been implicated in a diversity of cellular processes including cytokinesis, formation of diffusion barriers and vesicle trafficking. Septin2 partially co-localises with actin bundles in mammalian interphase cells and Septin2-filamentmorphology depends upon an intact actin cytoskeleton. How this interaction is regulated is not known. Moreover, evidence that Septin2 is remodelled or redistributed in response to other changes in actin organisation is lacking. RESULTS: Septin2 filaments are associated with actin fibres, but Septin2 is not associated with actin at the leading edge of moving cells or in ruffles where actin is highly dynamic. Rather, Septin2 is spatially segregated from these active areas and forms O- and C-shaped structures, similar to those previously observed after latrunculin treatment. FRAP experiments showed that all assemblies formed by Septin2 are highly dynamic with a constant exchange of Septin2 in and out of these structures, and that this property is independent of actin. A combination of RNAi experiments and expression of truncated forms of Septin2 showed that Septin2 plays a significant role in stabilising or maintaining actin bundles. CONCLUSION: We show that Septin2 can form dynamic structures with differing morphologies in living cells, and that these morphologies are dependent on the functional state of the actin cytoskeleton. Our data provide a link between the different morphological states of Septin2 and functions of Septin2 in actin-dynamics, and are consistent with the model proposed by Kinoshita and colleagues, that Septin2 filaments play a role in stabilisation of actin stress fibres thus preventing actin turnover.

Actin Cytoskeleton↗
PubMed2004

Acupuncture for the relief of cancer-related pain--a systematic review.

AIMS: This systematic review summarises the existing evidence on acupuncture for cancer-related pain. METHODS: Literature searches were conducted in seven databases. All clinical studies of acupuncture, electroacupuncture and ear acupuncture in cancer patients with the main outcome measure of pain were included. Data were extracted according to pre-defined criteria by two independent reviewers and methodological quality was assessed using the Jadad scale. RESULTS: Of the seven studies included, one high quality randomised clinical trial of ear acupuncture showed statistically significant pain relief in comparison with placebo ear acupuncture. All the other studies were either non-blinded (n=2) or uncontrolled clinical trials (n=4). Most investigations suffered from methodological flaws such as inadequate study design, poor reporting of results, small sample size and overestimation of the results. CONCLUSIONS: The notion that acupuncture may be an effective analgesic adjunctive method for cancer patients is not supported by the data currently available from the majority of rigorous clinical trials. Because of its widespread acceptance, appropriately powered RCTs are needed.

Acupuncture Analgesia↗
PubMed2004

Efficacy of coenzyme Q10 for improved tolerability of cancer treatments: a systematic review.

PURPOSE: The aim of this systematic review was to summarize and evaluate the evidence available for oral supplementation with coenzyme Q10 (CoQ10) to improve the tolerability of cancer treatments. MATERIALS AND METHODS: Searches for all published and unpublished controlled trials were carried out on seven databases. Manufacturers of CoQ10 were identified and contacted. Controlled clinical trials of monopreparations of CoQ10 administered orally to cancer patients were included. No language restrictions were imposed. Data were extracted independently by two authors according to predefined criteria. RESULTS: Six studies were included in the review, including three randomized clinical trials and three nonrandomized clinical trials. Patients in five of six studies received anthracyclines. The results suggested that CoQ10 provides some protection against cardiotoxicity or liver toxicity during cancer treatment. However, because of inadequate reporting and analysis, as well as questionable validity of outcome measures, the results are not conclusive. CONCLUSION: Suggestions that CoQ10 might reduce the toxicity of cancer treatments have not been tested by rigorous trials. Further investigations are necessary to determine whether CoQ10 can improve the tolerability of cancer treatments.

Antineoplastic Agents↗
PubMed2004

Reporting of ethical standards: differences between complementary and orthodox medicine journals?

OBJECTIVES: This study aimed at assessing whether there are differences in the reporting of ethical aspects of complementary and alternative medicine (CAM) and mainstream medical research. DESIGN: Review of published literature. SETTING: Research department of medical school. MAIN OUTCOME MEASURES: Reports of ethical aspects including adherence to clinical guidelines, ethical approval from ethics committees, consent of the patient, declaration of conflict of interest, and declaration of funding for a study. RESULTS: We included 21 articles from CAM journals, as well as 16 from equal impact factor mainstream (EIF) journals and 27 from high impact factor (HIF) journals. A statistically significant difference was found in the reporting of ethical approval: 62% of all CAM articles, 75% of the EIF and 93% of the HIF journal articles reported approval from ethics committees [chi2 = (2, n = 64) 6.631, p<0.05]. Regarding the reporting of obtaining patients' consent there were no statistically significant differences: 48% of all CAM articles, 38% of the EIF mainstream and 67% of the HIF mainstream journal articles explicitly stated that patients signed a consent form [chi2 = (2, n = 64) 3.813, p>.05]. High impact factor journals were more likely to report on ethical standards than other journals on conflicts of interests and sponsorship. However, they were less likely to report a reference to ethical guidelines. Articles from CAM journals had more strict reporting requirements than mainstream medicine journals with comparable impact factors. CONCLUSIONS: Differences exist between complementary and orthodox medical journals in the reporting of ethical aspects of trial design.

Codes of Ethics↗
PubMed2004

A barrier to lateral diffusion in the cleavage furrow of dividing mammalian cells.

Barriers to diffusion of proteins and lipids play an important role in generating functionally specialized regions of the plasma membrane. Such barriers have been reported at the base of axons, at the bud neck in Saccharomyces cerevisiae, as well as at the tight junctions of epithelia. How diffusion barriers are formed and how they effect behavior of both inner and outer leaflets of the bilayer are not fully understood. Here, we provide evidence for a cortical barrier to diffusion within the cleavage furrow of mammalian cells. Photobleaching-based assays were used to measure diffusion of three membrane proteins with differing topologies and putative lipid raft association, as well as the lipid analog dialkylindocarbocyanine (DiI C18, ), across the cleavage furrow. There was a block in diffusion of proteins with a cytosolic domain, but not of proteins anchored in the outer leaflet of the PM or of DiI. Diffusion of lipid raft proteins in the inner and outer leaflets of the membrane was not directly coupled. The distribution of Septin proteins, as opposed to cortical actin, was consistent with a functional role in limiting diffusion.

Biological Transport↗
PubMed2004

Xenobiotic substances such as PCB mixtures (Aroclor 1254) and TBT can influence swimming behavior and biotransformation activity (GST) of carp (Cyprinus carpio).

Different groups of carp were treated with polychlorinated biphenyl (PCB) or tributyltin (TBT), and possible effects of the chemicals on the swimming behavior of the carp were examined using the BehavioQuant system. By evaluating quantitative behavioral parameters of the animals, it became evident that exposure to high concentrations of chemicals (organotin, 7 microg L(-1), or polychlorinated biphenyl, 22 microg L(-1)) severely affected the carp, causing a significant change in their swimming speed. TBT stress led to a rapid decrease in mean swimming activity. A decrease in the preferred swimming depth was observed in TBT- and PCB-exposed fish. Animals exposed to PCB reduced their mean daily activity and increased their mean swimming speed in the nighttime during the second week of exposure. Therefore, our findings imply that the fish were adapted to cope with the chemicals after the second week of exposure. Furthermore, our results showed that low concentrations (TBT, 0.3 and 2 microg L(-1), or PCB, 14 microg L(-1)) did not significantly alter any quantified parameters of swimming behavior. In addition, the direct effects of chemicals on enzyme activity (GST) were determined. Measurement of soluble glutathione-S-transferase activity of fish liver or gills showed a significant elevation after exposure to PCB (0.1 or 22 microg L(-1)) or TBT (0.8 or 7 microg L(-1)). We had to conclude that the two different end points tested generally are useful as biomarkers of exposure and for investigations of energy resources in organisms under the influence of toxic stress.

Animals↗
PubMed2003

Mistletoe for cancer? A systematic review of randomised clinical trials.

Mistletoe extracts are widely used in the treatment of cancer. The results of clinical trials are however highly inconsistent. We therefore conducted a systematic review of all randomised clinical trials of this unconventional therapy. Eight databases were searched to identify all studies that met our inclusion/exclusion criteria. Data were independently validated and extracted by 2 authors and checked by the 3rd according to predefined criteria. Statistical pooling was not possible because of the heterogeneity of the primary studies. Therefore a narrative systematic review was conducted. Ten trials could be included. Most of the studies had considerable weaknesses in terms of study design, reporting or both. Some of the weaker studies implied benefits of mistletoe extracts, particularly in terms of quality of life. None of the methodologically stronger trials exhibited efficacy in terms of quality of life, survival or other outcome measures. Rigorous trials of mistletoe extracts fail to demonstrate efficacy of this therapy.

Clinical Trials as Topic↗
PubMed2003

Hawthorn extract for treating chronic heart failure: meta-analysis of randomized trials.

The aim of this meta-analysis was to assess the evidence from rigorous clinical trials of the use of hawthorn extract to treat patients with chronic heart failure. We searched the literature using MEDLINE, EMBASE, the Cochrane Library, CINAHL, CISCOM, and AMED. Experts on and manufacturers of commercial preparations containing hawthorn extract were asked to contribute published and unpublished studies. There were no restrictions about the language of publication. Two reviewers independently performed the screening of studies, selection, validation, data extraction, and the assessment of methodological quality. To be included, studies were required to state that they were randomized, double-blind, and placebo controlled, and used hawthorn extract monopreparations. Thirteen trials met all inclusion criteria. In most of the studies, hawthorn was used as an adjunct to conventional treatment. Eight trials including 632 patients with chronic heart failure (New York Heart Association classes I to III) provided data that were suitable for meta-analysis. For the physiologic outcome of maximal workload, treatment with hawthorn extract was more beneficial than placebo (weighted mean difference, 7 Watt; 95% confidence interval [CI]: 3 to 11 Watt; P < 0.01; n = 310 patients). The pressure-heart rate product also showed a beneficial decrease (weighted mean difference, -20; 95% CI: -32 to -8; n = 264 patients) with hawthorn treatment. Symptoms such as dyspnea and fatigue improved significantly with hawthorn treatment as compared with placebo. Reported adverse events were infrequent, mild, and transient; they included nausea, dizziness, and cardiac and gastrointestinal complaints. In conclusion, these results suggest that there is a significant benefit from hawthorn extract as an adjunctive treatment for chronic heart failure.

Crataegus↗
PubMed2003

MMR vaccination advice over the Internet.

We wanted to investigate what advice UK homeopaths, chiropractors and general practitioners give on measles, mumps and rubella vaccination programme (MMR) vaccination via the Internet. Online referral directories listing e-mail addresses of UK homeopaths, chiropractors and general practitioners and private websites were visited. All addresses thus located received a letter of a (fictitious) patient asking for advice about the MMR vaccination. After sending a follow-up letter explaining the nature and aim of this project and offering the option of withdrawal, 26% of all respondents withdrew their answers. Homeopaths yielded a final response rate (53%, n = 77) compared to chiropractors (32%, n = 16). GPs unanimously refused to give advice over the Internet. No homeopath and only one chiropractor advised in favour of the MMR vaccination. Two homeopaths and three chiropractors indirectly advised in favour of MMR. More chiropractors than homeopaths displayed a positive attitude towards the MMR vaccination. Some complementary and alternative medicine (CAM) providers have a negative attitude towards immunisation and means of changing this should be considered.

Attitude of Health Personnel↗
PubMed2003

Associative processes in repetition priming.

Three experiments that investigated alternative accounts of repetition priming are reported. All 3 experiments used semantic comparison tasks and included trials in which each of the 2 words being compared had previously occurred on separate trials. In the re-pair match condition, the response required matched that on the 2 previous trials in which the words had occured. In there-pair mismatch condition, the response required was opposite to that on the previous trials containing the words forming the critical pair. In all 3 experiments, responses were faster and more accurate in the re-pair match condition than in the re-pair mismatch condition. Possible accounts of this effect within the frameworks of instance theory and of transfer appropriate processing are considered.

Association↗