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Biomedical subjects

J Gehrke

Publications and source records attributed to J Gehrke.

At least 19 recordsLinked to original sources
PubMed2003

[What kind of information is expected to be provided by medical information services?].

OBJECTIVE: The improvement of health-related information services is one major issue in reforming the German health care system to provide more transparency in health care services for patients and persons covered by the German statutory health insurance system. To meet the general need for specific medical information a telephone-based health information service may give individual advice and provide a helpful selection of information. The study aims at users expectations and preferences with regard to health information services. More particularly, users perception concerning the type of health information and the ways of choosing the information were to be explored. METHOD: The study included 160 participants of different ages. Prototypical medical advice conversations were presented to the participants consisting of/identifying the consumer's inquiry, followed by the expert's answering sequence. The answers were based on typical inquiries from medical information providers focussing on treatment methods and illnesses. Health information from these conversations with its special contents were ranked by preference judgements resulting in Thurstone scalings. RESULTS: In terms of different health questions, the participants' judgements showed general preference structures for special health information, independent from any personal attitude towards medical information services. Great emphasis was placed on the medical conversation competence of the service provider, which is evident from recognising the specific needs and selection of information of a caller. Overall such health information was preferred that strengthened the patient's and user's autonomy and ability for decision making. CONCLUSION: Patients and persons covered by German statutory health insurance are characterised as users of information by special preferences. Identifying these preferences permits a reasonable selection of information and individual advice. Therefore, these services provide a major advantage over non-interactive health information services (print media, internet sites).

Adult↗
PubMed2001

Tapping with peripheral nerve block. a role for tactile feedback in the timing of movements.

This study examines the impact of peripheral nerve block, that is, the elimination of tactile feedback on synchronization performance. In a tapping experiment in which subjects were instructed to tap in synchrony with an auditory pacing signal, three different tasks were studied under conditions with and without peripheral nerve block: standard tapping with tactile contact, isometric tapping, and contact-free tapping. In addition, the maximum tapping rate was registered both with and without peripheral nerve block. It was found that the anticipatory error, usually observed in synchronization tasks, was affected by the peripheral nerve block in the standard tapping and the isometric tapping task. In both tasks, local anesthesia led to an increase in asynchrony between the pacing signal and the tap. Performance remained unimpaired in those tasks in which tactile information was assumed to play a minor role (maximum tapping rate and contact-free tapping). The results clearly demonstrate the importance of tactile feedback for the timing of movements. The predictions of a model assuming a strong correlation between the amount of sensory feedback and the size of the negative asynchrony in synchronization tasks were examined and discussed.

Adult↗
PubMed2001

Multicentre evaluation of a new point-of-care test for the quantitative determination of D-dimer.

Imprecision studies, interference testing and multicentre method comparisons using patient samples were carried out with of a new point-of-care test for D-dimer (CARDIAC D-Dimer). The CV of the within-series and the day-to-day imprecision with blood samples and control materials were between 7% and 13%. Compared with Tina-quant D-Dimer, CARDIAC D-Dimer showed a good correlation and accuracy (n=353; r=0.91; y=1.06x-0.03), compared with STA LIATEST D-Dimer some poorer accuracy (n=304; r=0.91; y=1.12x-0.03). No interference was detected for different hematocrit values (16% to 51%) and in investigations with hemoglobin (up to 0.13 mmol/l), biotin (up to 30 microg/l), bilirubin (up to 340 micromol/l), intralipid (up to 31.1 mmol/l) and rheumatic factor (up to 79 IU/ml). Overdosing or underdosing by 10 microl did not affect the test result. The diagnostic sensitivity of CARDIAC D-Dimer for the detection of acute venous thromboembolic diseases was 100% in our study. With CARDIAC D-Dimer reliable quantitative D-dimer results can be easily obtained. Because of the good analytical and clinical agreement with Tina-quant D-Dimer, it should be suitable for ruling out venous thromboembolic diseases.

Clinical Chemistry Tests↗
PubMed2000

Hierarchical coding in the perception and memory of spatial layouts.

Two experiments were performed to investigate the organization of spatial information in perception and memory. Participants were confronted with map-like configurations of objects which were grouped by color (Experiment 1) or shape (Experiment 2) so as to induce cognitive clustering. Two tasks were administered: speeded verification of spatial relations between objects and unspeeded estimation of the Euclidean distance between object pairs. In both experiments, verification times, but not distance estimations, were affected by group membership. Spatial relations of objects belonging to the same color or shape group were verified faster than those of objects from different groups, even if the spatial distance was identical. These results did not depend on whether judgments were based on perceptually available or memorized information, suggesting that perceptual, not memory processes were responsible for the formation of cognitive clusters.

Adult↗
PubMed1998

Advancements toward magneto immunoassays.

Recently, a magneto binding assay was conducted. The operational principle is based on a 'sandwich' mode of detection, where the target analyte (Concanavalin A) becomes bound nonselectively by protein adsorption between the solid support (silica carrier particles) and the ferromagnetic label (magneto markers). A magnetic transducer was employed for the detection. The binding assay gave a linear response in the dynamic range of 0-1.9 microM and proved to be sensitive by having a limit of detection at 250 nM. Furthermore, the relative standard deviation observed was 6.2% (n = 3). The demonstration of the 'sandwich' approach is a step toward achieving magneto immunoassays (MIA).

Animals↗
PubMed1997

The clinical utility of duplicate readings for musculoskeletal radiographs.

It is a common practice in many hospitals to have all skeletal radiographs read by a second physician, usually a radiologist, as well as by the treating physician. A two-part study was performed in order to examine the cost and clinical benefit of this practice for plain films ordered by orthopedists. In the first part of this study, the attending orthopedic surgeons were surveyed about the clinical usefulness and effect on patient care of 1000 radiologic reports from plain films ordered on orthopedic patients. In the second part, the charts of 272 patients who had 704 radiographs were reviewed with the goal of identifying any discrepancies between the orthopedic interpretation and the radiologic reading. Thirty-eight reports were discarded because they were not reports of plain skeletal films. One hundred twenty-nine of the remaining 962 radiologic reports were never read by the attending orthopedist. The average time between the taking of the film and an orthopedic attending reading the printed report was 6.1 days. Three radiology reports contained findings that were incorrect. Only one report contained findings that the orthopedist was unaware, and one report may have led to an alteration in treatment. No reports resulted in an unplanned trip to the operating room or a patient being called back to the clinic. Of the 272 chart reviews (704 reports), 70 had no orthopedic interpretation recorded and 94 had no radiologic report in the chart. Twelve discrepancies were noted in the cases that had both reports. Four fracture displacements were identified by orthopedists, but not on the written radiology report; three of these required a return to the operating room. Four instances of hardware displacement or breakage were noted by orthopedists, but not commented on by the radiologists. Three incidental injuries (two fractures and an acromioclavicular injury) were noted on printed reports of films taken for other reasons, but not commented on by the orthopedist, and not treated. A dorsal bunion was noted on one film by the orthopedist, but not by the radiologist. From this study, one can conclude that the benefit of routine duplicate radiograph interpretation by a second physician does not justify its cost.

Cost-Benefit Analysis↗
PubMed1996

Irreducible fracture of the calcaneus due to flexor hallucis longus tendon interposition.

An unusual fracture-dislocation of the calcaneus is presented in which tendinous interposition in the subtalar joint prevented the possibility of closed reduction. This situation has been reported in the literature in only five previous patients. The position of the flexor hallucis tendon in the joint could be visualized on the preoperative computed tomographic scan. The patient was treated operatively with reduction through a lateral approach without a supplemental medial incision.

Adult↗
PubMed1991

[Use of a computer in a clinical-toxicological laboratory with a fuzzy search].

If a clinician is faced with acute intoxications a rapid toxicological test is essential. The toxic substances are identified by a combined use of various systems of analysis such as gas chromatography, thin-layer chromatography or UV-spectroscopy. As the result of the analysis a data pattern is obtained which can be interpreted by comparing it with substance-related reference patterns. This paper describes a computer-program which allows more efficient reference comparisons and which gives a support of the decisions. The algorithms of the comparisions are based on fuzzy-theory.

Diagnosis, Computer-Assisted↗
PubMed1983

Classification of mitral valve prolapse.

The scope of diagnosing mitral valve prolapse (MVP) has been enlarged by the earlier reported real-time B-scan criteria of small or "localised MVP". This form is believed to be the precursor of the overt MVP which is then readily diagnosed by angiocardiography and 1- and 2-dimensional echocardiography (1- and 2-dE). Rheumatic heart disease (RHD) is believed to be recognisable much earlier as well, by the previously reported 1- and 2-dE features of "early commissural fusion" (ECF). 30 patients in whom overt or localised MVP were diagnosed previously were reviewed for overt or early signs of ECF. In all patients early or overt echo features of RHD could be visualised. Thus RHD may be the most important cause of acquired MVP, even though it is rarely considered in recent classifications. It is proposed that RHD is perhaps the unifying link for all forms of MVP. GOTTLIEB and CHUNG were asking for such a unifying link "since the present classification is dubious at best. It offers nothing to use clinically and may actually be in error, since the primary form may be a less overt expression of the secondary form." It is proposed that mostly unrecognised rheumatic fever may be the underlying first lesion leading to the various different mechanisms described for MVP. If this can be confirmed, a new approach to primary prevention of rheumatic fever and its subclinical forms may be necessary. There is also some evidence to suggest that RHD may be the early and unrecognised microlesion in the coronary arteries as well and thus the important early factor in the development of macroscopic coronary artery disease.

Coronary Disease↗
PubMed1977

[M- and real-time b-scan diagnostic criteria and pit-falls in right ventricular volume overload (author's transl)].

The observation of a characteristic "see-saw" motion of the interventricular septum (IVS) in real-time B-scan (RTBS) in right ventricular volume overload (RVVO) reveals features which have not been taken into account in diagnostic M-scan echocardiography. From an investigation of 20 patients it became apparent that the criteria (1) increase in right ventricular internal diameter and (2) "paradoxical" septal motion, so far used for the M-scan diagnosis of RVVO, should be complemented by further criteria: (3) hypertrophy of the IVS in longstanding RVVO, (4) increase in septal amplitude of motion towards the cardiac apex, (5) selective increasing apical septal hypertrophy and (6) an apparent random septal motion without any resultant main direction as an indication of a displaced fulcrum of the septal "see-saw". All features may be visualised by carrying out a continuous sweep in M-scanning. The criteria 2-5 may be understood as a result of increased apical work load compensating for the haemodynamic loss of the reversed upper septal motion ("RUSM"). The diagnosis of RVVO can be made more readily and reliably with RTBS echocardiography, underlining the utility of a combined use of one- and two-dimensional ultrasonography in diagnostic cardiology.

Blood Volume↗
PubMed1977

[Interventricular septal motion in hypertrophic cardiomyopathy. Additonal knowledge from real-time b-scan echocardiography (author's transl)].

M-scan echocardiography had suggested that interventricular septal motion in patients with Hypertrophic Cardiomyopathy is immobile. In this study special attention was paid to this septal motion during Real-time B-scan (RTBS) investigations of 15 patients with proven Hypertrophic Cardiomyopathy. RTBS recordings have shown that the basal part of the interventricular septum (IVS), which bulges into the left ventricular outflow tract (LVOT), exhibits a forceful contraction towards the cardiac apex, while the more apical portion moves normally towards the left ventricular posterior wall. The direction of the basal septal motion is more or less at right angles to the single ultrasonic beam in M-scanning. The amplitude of this motion, therefore, can only be appreciated with M-mode according to that component of motion which moves parallel to the ultrasonic beam. According to the angle of incidence of the ultrasound waves, septal motion may be recorded as mobile or apparently immobile, and the transition zone from apical to posterior septal motion can be appreciated in a semiquantitative manner by using a Continuous Sweep Technique. From these observations and considerations it has emerged that the left ventricular internal diameter and the rate of change of this dimension in the region of the "immobile" basal septum does not allow conclusions to be drawn about the overall haemodynamic situation of the left ventricle in patients with Hypertrophic Cardiomyopathy. Furthermore, this study is another demonstration of the importance of the combined application of M-and RTBS echocardiography for optimal non-invasive clinical cardiac diagnosis.

Adolescent↗