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Biomedical subjects

R Kunz

Publications and source records attributed to R Kunz.

At least 19 recordsLinked to original sources
PubMed2006

[Assessment of pain in advanced dementia. Construct validity of the German PAINAD].

BACKGROUND: The observation scale PAINAD (pain assessment in advanced dementia) is composed of five behavioral categories: breathing, vocalization, facial expression, body language, and consolability. The present study investigates the construct validity of the German version. PATIENTS AND METHODS: We conducted a prospective one-dimensional observation study with repeated measurements (t(1)=pretreatment, t(2)=2 h posttreatment, t(3)=24 h posttreatment). The sample consisted of 12 verbally noncommunicative demented inpatients with severe comorbidity treated in three geriatric clinics. Their age was M=84.3 years (SD=4.4) on the average. Ten of them were female. Inclusion criteria were pain-related physical illness and observed pain behavior. Every patient was treated with analgesics after t(1). After t(2) the medication was discontinued in five patients until t(3). Nurses documented the PAINAD scores after an observation period of 2 min during routine care. RESULTS: Pain behavior at t(2) diminished considerably displaying a large effect size. Scores continued to be low at t(3) only in the sample with continued medication. Scores in the other part of the sample returned to initial values. CONCLUSION: The data demonstrate that pain medication strongly impacts the pain behavior of demented patients. The outcome supports the assumption that PAINAD really measures pain.

Analgesics↗
PubMed2005

[Clinical guidelines. What do doctors and patients get from them].

Now more than ever physicians need effective management of the constantly increasing flood of medical information. The authors discuss possibilities for developing clinical guidelines as a core element of this information management and the requirements of these possibilities. The development of clinical guidelines is a process also suitable for involving patient and consumer expertise in health care. Models of involving patients are described and how these processes can build an important base for shared decision making of physicians and patients.

Drug Information Services↗
PubMed2003

[Palliative care for patients with advanced dementia: Evidence-based practice replaced by values-based practice].

For the treatment of patients with advanced dementia, we could not find any evidence based guidelines to help in decision making. Individual values and expected quality of life must be the leading goals of any intervention. Symptom control and relieving suffering are core values of palliative care, but the recognition of discomfort needs qualified assessment skills. Pain assessment with common tools like the VAS fails in patients with cognitive impairment and inability to communicate; instruments like Doloplus and ECPA can be helpful to assess behavioral changes as expression of pain. The treatment of acute and chronic pain in advanced dementia is still not sufficient and needs improvement. Oral feeding in advanced dementia becomes more and more difficult. No randomized controlled study has found evidence that tube feeding will reduce the risk of aspiration or prolong life expectancy. Eating may be the only meaningful activity that remains for the patient; artificial feeding cannot serve the same function. All final complications, like pneumonia, call for a decision making process. Those who care for and care about these patients must make decisions. The feelings of the family have to be considered, but the probable will of the patient, his dignity and quality of life must not be overridden.

Advance Directives↗
PubMed2003

Cellular neural networks (CNN) with linear weight functions for a prediction of epileptic seizures.

In this paper, we present a novel approach to the prediction of epileptic seizures using boolean CNN with linear weight functions. Three different binary pattern occurrence behaviours will be discussed and analysed for several invasive recordings of brain electrical activity. Furthermore analogic binary pattern detection algorithms will be introduced for a possible prediction of epileptic seizures.

Epilepsy↗
PubMed2002

Do short courses in evidence based medicine improve knowledge and skills? Validation of Berlin questionnaire and before and after study of courses in evidence based medicine.

OBJECTIVE: To develop and validate an instrument for measuring knowledge and skills in evidence based medicine and to investigate whether short courses in evidence based medicine lead to a meaningful increase in knowledge and skills. DESIGN: Development and validation of an assessment instrument and before and after study. SETTING: Various postgraduate short courses in evidence based medicine in Germany. PARTICIPANTS: The instrument was validated with experts in evidence based medicine, postgraduate doctors, and medical students. The effect of courses was assessed by postgraduate doctors from medical and surgical backgrounds. INTERVENTION: Intensive 3 day courses in evidence based medicine delivered through tutor facilitated small groups. MAIN OUTCOME MEASURE: Increase in knowledge and skills. RESULTS: The questionnaire distinguished reliably between groups with different expertise in evidence based medicine. Experts attained a threefold higher average score than students. Postgraduates who had not attended a course performed better than students but significantly worse than experts. Knowledge and skills in evidence based medicine increased after the course by 57% (mean score before course 6.3 (SD 2.9) v 9.9 (SD 2.8), P<0.001). No difference was found among experts or students in absence of an intervention. CONCLUSIONS: The instrument reliably assessed knowledge and skills in evidence based medicine. An intensive 3 day course in evidence based medicine led to a significant increase in knowledge and skills.

Clinical Competence↗
PubMed2001

(22)Ne(alpha,n)(25)Mg: the key neutron source in massive stars.

The excitation function of the reaction (22)Ne(alpha,n)(25)Mg, the key neutron source in the astrophysical s process in massive stars, has been determined from threshold at E(alpha) = 570 up to 1450 keV with an experimental sensitivity of 10(-11) b. For all resonances in this energy range new resonance parameters have been measured. For a possible resonance at about 635 keV a new upper limit omega gamma < 60 neV for the strength was obtained. Based on the new data, improved reaction rates were calculated as a function of temperature. The new uncertainty limits are considerably smaller than in previous determinations, ruling out the large enhancement factors, up to 500, assumed in some stellar model calculations.

Journal Article↗
PubMed2001

12C(alpha,gamma)16O: the key reaction in stellar nucleosynthesis.

The angular distributions of gamma rays from the 12C(alpha,gamma)16O reaction have been measured at 20 energy points in the energy range E(cm) = 0.95 to 2.8 MeV. The sensitivity of the present experiment compared to previous direct investigations was raised by 1-2 orders of magnitude, by using an array of highly efficient ( 100%) Ge detectors shielded actively with BGOs, as well as high beam currents of up to 500 microA that were provided by the Stuttgart Dynamitron accelerator. The S(E1) and S(E2) factors deduced from the gamma angular distributions have been extrapolated to the range of helium burning temperatures applying the R-matrix method, which yielded S(300)(E1) = (76+/-20) keV b and S(300)(E2) = (85+/-30) keV b.

Journal Article↗
PubMed2001

[Severely injured patients after the initial phase--vegetative state or remaining cognitive functions?].

BACKGROUND: We wanted to quantify improvements in the subacute rehabilitation phase in patients with severe brain injuries classified as vegetative or minimal brain consciousness. MATERIAL AND METHODS: Five patients were studied during a 12 months period using a method called Coma Recovery Scale (CRS) as described by Giacino et al. (1991). The parameters measured included visual and hearing functions, motor functioning, oromotor/verbal function, communication, and arousal. The observations of the patients and commandos given were standardised in a manual, and the responses achieved from the patients were recorded according to a scale for each parameter. RESULTS: This procedure for measuring closely the progress over time in these severely brain injured patients, was used for planning a realistic rehabilitation program. It was found to be very practical in communication with relatives of the patients and with the other therapists involved. INTERPRETATION: By decomposing the cognitive functions by this method using all the available possibilities for inputs, even minimal improvement in the cognitive functions mentioned could be uncovered and recorded.

Adolescent↗
PubMed2001

Studies of symptoms in primary care.

Publications on the frequency of defined symptoms in the practice setting, underlying conditions and prognosis have been rare in the past. Also, studies addressing these questions have suffered from several methodological problems. We therefore developed criteria to help investigators improve the quality of study design, implementation and publication. Studies evaluating symptoms in practice can make an important contribution to a more rational approach to diagnostic decision making especially in primary care.

Diagnosis↗
PubMed2001

[Development of quality assurance criteria for continuing education in evidence-based medicine].

OBJECTIVE: To develop a set of core contents for teaching evidence-based medicine (EBM). METHOD: Description of basic principles from clinical epidemiology, medical statistics and literature search essential for health care practitioners to perform critical appraisal of the medical literature. Based on textbooks for EBM and clinical epidemiology and guided by the EBM courses at McMaster university and the Oxford Centre for EBM, core contents were defined. Decision on inclusion was made by consensus. RESULTS: The core contents for the Berlin curriculum in EBM covers 3 areas: 1. General information on the methods of experimental and observational clinical studies, principles of EMB, basic statistical concepts, and literature search. 2. Tools for critical appraisal of primary studies required for medical decision making: therapy, diagnosis, prognosis, and harm. 3. Evidence-based summary reports: meta-analysis and guidelines. CONCLUSIONS: The contents of EBM can be precisely defined. They are transparent, explicit and communicable and present a reproducible basis for the different forms of teaching EBM.

Education, Medical, Continuing↗
PubMed2000

Practice variations in the evaluation of adult candidates for cadaveric kidney transplantation: a survey of the European Transplant Centers.

BACKGROUND: This survey was conducted to investigate similarities and differences in the diagnostic evaluation of adult candidates for cadaveric renal transplantation and the criteria for acceptance to the cadaveric renal transplant waiting-list in the European transplant centers. METHODS: A questionnaire listing 45 diagnostic procedures (consultations of 9 specialties, 18 imaging techniques and 18 laboratory investigations), 45 medical conditions constituting possible reasons for exclusion from renal transplantation, and 10 properties characterizing the responding transplant center was sent to 214 European transplant centers. RESULTS: A completed questionnaire was returned by 154 of 214 centers (72%). Significant disagreement (P<0.001) exists about the necessity of 28 of the 45 surveyed diagnostic procedures and about the acceptability of transplant candidates for 15 of the 45 surveyed medical conditions. The influence of center characteristics on the observed practice variations was examined by multinomial logistic regression (factors: Center size, waiting-list pressure, responsibility for organizing the diagnostic work-up, status of transplant center, responsibility for decision about acceptance of candidates and geographic location of center): In 13 of 28 controversial diagnostic procedures, geographic location of the centers turned out to be the only significant determining factor (P<0.001), whereas the dissent about medical conditions is not influenced significantly by the analyzed factors. CONCLUSION: The detected significant practice variations in the evaluation of renal transplant candidates may either indicate where scientific evidence is missing and more clinical research is needed or where the existing evidence has not been adequately disseminated and convincing guidelines should be established.

Adult↗
PubMed2000

Cationic ruthenium allenylidene complexes as catalysts for ring closing olefin metathesis

A series of well accessible cationic ruthenium allenylidene complexes of the general type [(eta6-arene)(R3P)RuCl(=C=CR'2)]+ X- is described which constitute a new class of pre-catalysts for ring closing olefin metathesis reactions (RCM) and provide an unprecedented example for the involvement of metal allenylidenes in catalysis. They effect the cyclization of various functionalized dienes and enynes with good to excellent yields and show a great tolerance towards an array of functional groups. Systematic variations of their basic structural motif have provided insights into the essential parameters responsible for catalytic activity which can be enhanced further by addition of Lewis or Bronsted acids, by irradiation with UV light, or by the adequate choice of the "non-coordinating" counterion X-. The latter turned out to play a particularly important role in determining the rate and selectivity of the reaction. A similarly pronounced influence is exerted by remote substituents on the allenylidene residue which indicates that this ligand (or a ligand derived thereof) may remain attached to the metal throughout the catalytic process. X-ray crystal structures of the catalytically active allenylidene complexes 3b.PF6 and 15.OTf as well as of the chelate complex 10 required for the preparation of the latter catalyst are reported.

Journal Article↗
PubMed2000

Influence of cold ischemia time, pretransplant anti-porcine antibodies, and donor/recipient size matching on hyperacute graft rejection after discordant porcine to cynomolgus kidney transplantation.

Organs transplanted between phylogenetically disparate species, such as from the pig into the primate, are subject to hyperacute rejection (HAR). This form of xenograft rejection is mediated by preformed natural antibodies and is believed to occur invariably in discordant xenografts thus leading to rapid destruction and complete thrombosis of the graft. Recent data, however, have shown that in the porcine to cynomolgus monkey setting, HAR is not inevitably seen after porcine kidney transplantation. The influence of preoperative antiporcine antibody levels in the recipient, cold ischemia time, and donor organ weight on the onset of HAR was investigated by using unmodified large white pigs (aged 3-12 weeks) as organ donors and adult cynomolgus monkeys (aged 1.5-3.5 years) as recipients. Porcine kidney xenotransplantation was performed in either a non-life-supporting model (n=7) or in a life-supporting model (n=8). In both models, no correlation was found between cold ischemia time and HAR. When preoperative anti-porcine antibody levels were investigated, a significant increase in incidence of HAR was observed in animals with elevated anti-porcine IgM (P<0.05) but not IgG levels (P=NS). Interestingly, although 5 of 12 grafts with an organ weight of less than 50 g underwent HAR, none of three grafts with a donor organ weight of more than 70 g showed signs of HAR. In addition, all three larger grafts showed intraoperative and postoperative urine production, although only in 1 (48 g) of the 12 grafts weighing less than 50 g primary graft function was observed. In one animal, a second porcine kidney (23 g) was successfully transplanted (without HAR) immediately after HAR and subsequent removal of a first porcine kidney (20 g). These results indicate that in the porcine to cynomolgus monkey setting anti-porcine IgM rather than IgG anti-porcine antibody levels seem to be of predominant importance for the induction of HAR. By increasing the donor organ size and weight the frequency of the onset of HAR can be at least reduced. This is most likely due to immunoabsorption of the recipients preformed antibodies in the porcine kidney without lethal damage for the graft.

Acute Disease↗
PubMed2000

[Evidence-based medicine--from evidence production to its implementation].

Evidence-based medicine (EBM) and evidence-based health care (EBHC) is one answer to the increasing need for quality and transparency in the care of individual patients as well as health care services. Using explicit and sound methodological criteria, EBM and EBHC question current management strategies for their effectiveness and usefulness to individual patients and patient groups. This approach therefore supports the implementation of rational patient-oriented care.

Clinical Trials as Topic↗
PubMed2000

[Goals and methods of clinical studies].

The validity of clinical patient-oriented research is always threatened by the influence of bias, confounding factors or random effects that might distort the results. However, the susceptibility to distortion varies between different study designs. The best protection against spurious relationships or distorted results are specific focused research questions and rigorous integration of sound study methodology during the design and performance phase.

Alcohol Drinking↗