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Biomedical subjects

W Kruse

Publications and source records attributed to W Kruse.

At least 19 recordsLinked to original sources
PubMed2001

Motor cortical activity during interception of moving targets.

The single-unit activity of 831 cells was recorded in the arm area of the motor cortex of two monkeys while the monkeys intercepted a moving visual stimulus (interception task) or remained immobile during presentation of the same moving stimulus (no-go task). The moving target traveled on an oblique path from either lower corner of a screen toward the vertical meridian, and its movement time (0.5, 1.0, or 1.5 sec) and velocity profile (accelerating, decelerating, or constant velocity) were pseudorandomly varied. The moving target had to be intercepted within 130 msec of target arrival at an interception point. By comparing motor cortical activity at the single-neuron and population levels between the interception and no-go tasks, we tested whether information about parameters of moving target is represented in the primary motor cortex to generate appropriate motor responses. A substantial number of neurons displayed modulation of their activity during the no-go task, and this activity was often affected by the stimulus parameters. These results suggest a role of motor cortex in specifying the timing of movement initiation based on information about target motion. In addition, there was a lack of systematic relation between the onset times of neural activity in the interception and no-go tasks, suggesting that processing of information concerning target motion and generation of hand movement occurs in parallel. Finally, the activity in the most motor cortical neurons was modulated according to an estimate of the time-to-target interception, raising the possibility that time-to-interception may be coded in the motor cortical activity.

Animals↗
PubMed2001

Neuronal clusters in the primate motor cortex during interception of moving targets.

Two rhesus monkeys were trained to intercept a moving target at a fixed location with a feedback cursor controlled by a 2-D manipulandum. The direction from which the target appeared, the time from the target onset to its arrival at the interception point, and the target acceleration were randomized for each trial, thus requiring the animal to adjust its movement according to the visual input on a trial-by-trial basis. The two animals adopted different strategies, similar to those identified previously in human subjects. Single-cell activity was recorded from the arm area of the primary motor cortex in these two animals, and the neurons were classified based on the temporal patterns in their activity, using a nonhierarchical cluster analysis. Results of this analysis revealed differences in the complexity and diversity of motor cortical activity between the two animals that paralleled those of behavioral strategies. Most clusters displayed activity closely related to the kinematics of hand movements. In addition, some clusters displayed patterns of activation that conveyed additional information necessary for successful performance of the task, such as the initial target velocity and the interval between successive submovements, suggesting that such information is represented in selective subpopulations of neurons in the primary motor cortex. These results also suggest that conversion of information about target motion into movement-related signals takes place in a broad network of cortical areas including the primary motor cortex.

Animals↗
PubMed1999

Magnetocardiographic analysis of the two-dimensional distribution of intra-QRS fractionated activation.

The spatial distribution of high-frequency components in magnetic signals during the QRS complex of the human heartbeat was investigated. Cardiomagnetic signals were recorded simultaneously using 49 first-order magnetogradiometer channels of a multi-SQUID system with a low noise power density. The QRS fragmentation score S, as a measure of the fragmentation of the bandpass-filtered QRS complex, was examined for its sensitivity and specificity to discriminate 34 healthy volunteers, 42 post-myocardial infarction patients and 43 patients with coronary heart disease and with a history of malignant sustained ventricular tachycardia or ventricular fibrillation. The multichannel information was visualized by two-dimensional mapping of the score values of the single channels. By averaging the score values for the seven central channels, S7, the score values of all 49 channels, S49, and calculating the standard deviation for all 49 channels, D49, a higher sensitivity and specificity for detecting patients with ventricular tachycardia (VT) or ventricular fibrillation (VF) was reached than by analysis of a single channel. Combination of these parameters furnishes a sensitivity of 90% and a specificity of 70% for identifying patients prone to VT/VF. The results were compared with diagnostic information obtained from the QRS duration of the signal as well as with results obtained by modified QRS integral mapping.

Adult↗
PubMed1998

Variability and correlated noise in the discharge of neurons in motor and parietal areas of the primate cortex.

We analyzed the magnitude and interneuronal correlation of the variability in the activity of single neurons that were recorded simultaneously using a multielectrode array in the primary motor cortex and parietal areas 2/5 in rhesus monkeys. The animals were trained to move their arms in one of eight directions as instructed by a visual target. The relationship between variability (SD) and mean of the discharge rate was described by a power function with a similar exponent ( approximately 0.57), regardless of the cortical area or the behavioral condition. We examined whether the deviation from mean activity between target onset and the end of the movement was correlated on a trial-by-trial basis with variability in activity during the hold period before target onset. In both cortical areas, for about a quarter of the neurons, the neuronal noise of these two periods was positively correlated, whereas significant negative correlations were seldom observed. Overall, neurons with higher signal correlation (i.e., similar directional pattern) showed higher noise correlation in both cortical areas. On the other hand, when the data were divided according to the distance between the electrode tips from which the neurons were recorded, a consistent relationship between the signal and noise correlations was found only for pairs of neurons recorded through the same electrode. These results suggest that nearby neurons with similar directional tuning carry primarily redundant messages, whereas neurons in separate cortical columns perform more independent processing.

Action Potentials↗
PubMed1998

[The serologic detection of virus-induced infections in the domestic goose (Anser anser dom.)].

The most important virus-induced diseases associated with heavy losses in the domestic goose are Derzsy's disease which is caused by a goose parvovirus and duck plague (duck viral enteritis) which is caused by an avian herpesvirus. Both diseases still occur but can be prevented by timely vaccinations. Antibodies against Influenza A viruses of the subtypes H1, H5, and H7 as well as against avian paramyxoviruses of the serogroups 4, 6, and 8, respectively, were not detected in any of the examined sera. However, antibodies against paramyxovirus type 1 were detected in sera of one source. Haemagglutination inhibition or neutralizing antibodies against avian adenoviruses (EDS76 virus and goose adenovirus of the serotypes 1, 2, and 3) were quite often detected. Based on the present knowledge their pathogenic potential is minor. Neutralizing antibodies against a reovirus originating from Muscovy ducks and against a chicken reovirus (strain U Con S 1133) were quite frequently detected. In 35 of 564 examined geese sera hepatitis B virus was found.

Animals↗
PubMed1996

Inhibition of sustained gamma oscillations (35-80 Hz) by fast transient responses in cat visual cortex.

Interactions between stimulus-induced oscillations (35-80 Hz) and stimulus-locked nonoscillatory responses were investigated in the visual cortex areas 17 and 18 of anaesthetized cats. A single square-wave luminance grating was used as a visual stimulus during simultaneous recordings from up to seven electrodes. The stimulus movement consisted of a superposition of a smooth movement with a sequence of dynamically changing accelerations. Responses of local groups of neurons at each electrode were studied on the basis of multiple unit activity and local slow field potentials (13-120 Hz). Oscillatory and stimulus-locked components were extracted from multiple unit activity and local slow field potentials and quantified by a combination of temporal and spectral correlation methods. We found fast stimulus-locked components primarily evoked by sudden stimulus accelerations, whereas oscillatory components (35-80 Hz) were induced during slow smooth movements. Oscillations were gradually reduced in amplitude and finally fully suppressed with increasing amplitudes of fast stimulus-locked components. It is argued that suppression of oscillations is necessary to prevent confusion during sequential processing of stationary and fast changing retinal images.

Animals↗
PubMed1996

Elderly patients' problems with medication. An in-hospital and follow-up study.

OBJECTIVES: To examine medication problems during a stay in hospital and after discharge and to identify risk factors that contribute to poor compliance with medication a prospective observational study was carried out in an university-affiliated geriatric hospital and a patients' home. PATIENTS: One hundred and nineteen patients admitted from home to the geriatric hospital underwent a comprehensive geriatric assessment. They were also tested in opening and removing tablets from various common medicine containers. Drug prescriptions before, during and after the hospital stay were recorded. Medication use at home was observed by a member of a hospital-based home intervention team. The patients' reports of their drug therapy was compared with those by their family doctors. RESULTS: Of all tested patients 10.1% failed to open at least one container. This inability was associated with poor vision, impaired cognitive function and low manual dexterity. Compliance with prescribed medication was associated with cognitive function, ability to handle medication containers, number of prescribed drugs and recent changes in drug prescriptions. Of the patients only 39.5% had stable drug prescriptions during the 3-month study period. Doctor/patient agreement concerning drug therapy was low in all age groups. The agreement rate and patients' knowledge of their treatment was correlated with cognitive function and the number of prescribed drugs. CONCLUSION: Patients' ability to open and remove tablets from common commercial packages/containers should be tested routinely during a stay in hospital. Management of medication should be taught and supervised within the first few days after discharge from hospital.

Aged↗
PubMed1995

[Role of the family physician in treatment of alcoholic patients].

In Western countries alcohol is a socially accepted drug and its use is on the increase. Accordingly, the number of alcoholics is also increasing. An important task of the general practitioner is first to recognize that a patient has a drinking problem, and then to help him/her to acknowledge and come to terms with the situation. Additionally he must motivate the patients to accept the need for suitable treatment and initiate it. Prevention of alcoholism, however, is not a matter of the medical profession alone, but is first and foremost a problem of our society. For a remedial approach to be effective, interdisciplinary cooperation between internists, psychologists, psychiatrists and social workers is a must, and here the general practitioner has a coordinating function to fulfill.

Alcoholism↗
PubMed1994

[Hormone profile of elderly women and potential modifiers].

In 136 women with a median age of 78 (60-98) years the serum concentrations of FSH, LH, prolactin, estradiol-17 beta, testosterone and DHEA-S were determined completed by GnRH and ACTH stimulation tests in a subgroup. This resulted in median values for FSH of 15.8 ng/ml, LH 6.4 ng/ml, prolactin 6.9 ng/ml, estradiol 16 pg/ml, testosterone 270 pg/ml and 306 ng/ml for DHEA-S. No correlation with age in this population was found for gonadotropins as well as the other hormones for an age level of up to 98 years. Determination of multiple general clinical and laboratory parameters demonstrate the significance particularly in a geriatric group of patients to consider these patient characteristics when interpreting the serum hormone levels. In summary, the results of this prospective study underline the importance for health, of the secretion of gonadotropic and sexual hormones even at a very advanced age.

Adrenocorticotropic Hormone↗
PubMed1994

Patterns of drug compliance with medications to be taken once and twice daily assessed by continuous electronic monitoring in primary care.

Adherence to drug treatment is difficult to assess in routine medical practice. Therefore, electronic compliance monitoring and a new computer software program, the PC-RDP (Reader, Display, Printer) system was used. It allows instant evaluation of a patient's dosing record, at the patient's return to the practice. Compliance was measured in 24 patients on antihypertensive treatment, either continuous (n = 8) or newly prescribed treatment (n = 16) in primary care, for a total period of 5144 patient days. Fifteen patients received compliance feedback by their physician, 9 did not receive feedback. The drugs prescribed were triamterene plus hydrochlorothiazide, as a single dose, once daily (QD), and nifedipine twice daily (BID). The mean percentages of prescribed doses taken were 89% (QD) and 88% (BID). Partial compliance was 10 times more often (1243 days) than overcompliance (114 days), and days without dosing were observed twice as frequently with the QD than the BID regimen. Omissions of doses occurred more often on weekends than any other day of the week. With the BID regimen, evening doses were omitted twice as often as morning doses. When treatment was initiated, compliance was consistently high until the end of the study period, whereas in patients on continuous treatment, it decreased over time. Both compliance feedback (n = 11/16) and the beginning of treatment may be important factors to explain the difference in compliance behavior. An implementation of compliance monitoring into practical patient care seems to be feasible and promising.

Aged↗
PubMed1993

Compliance and adverse drug reactions: a prospective study with ethinylestradiol using continuous compliance monitoring.

This study examined the relationship between adverse reactions and patient compliance with ethinylestradiol at 40 micrograms twice daily versus 20 micrograms four times daily. In a randomized study 61 female patients with primary infertility were prescribed the drug twice daily (n = 31) or four times daily (n = 30). Ethinylestradiol was administered for 7 days before the sperm cervical mucus penetration-test was performed for hormonal standardization of the cervical mucus quality. Drug compliance was measured by continuous monitoring using the Medication Event Monitoring System. Two parameters were evaluated: percentage of prescribed doses taken (administration compliance) and adherence to the prescribed dose schedule (regimen compliance, number of days with two or four dosing events recorded). Adverse drug reactions were assessed using a standardized questionnaire. Fourty-four women experienced side effects, of which 81% were rated by patients as being mild. Patient compliance was higher with the twice daily than with the four times daily regimen: 85% versus 65% prescribed doses taken (P < 0.05). There was no significant difference in compliance comparing patients with and without adverse reactions (82% versus 72%, respectively), but compliance was lower and more irregular with at least 3 versus one or two adverse reactions reported: 54% versus 84% in administration compliance and 31% versus 58% in regimen compliance (P < 0.05). Compliance was also lower in patients with nausea and vomiting than in those without these symptoms, 59% versus 91% and 34% versus 66% (P < 0.005), respectively, and lower with moderate or severe compared to mild side effects; 48% versus 85% and 25% versus 59% (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Actual versus prescribed timing of lovastatin doses assessed by electronic compliance monitoring.

The objective of the study was to compare compliance with and the hypocholesterolaemic effect of lovastatin given once daily as a morning or an evening dose. Twenty-four out-patients with familial hypercholesterolaemia were randomly assigned to receive placebo first, then lovastatin 20 mg, to be taken once daily for 4 weeks, either with the breakfast or evening meal, in a single-blind fashion. Drug compliance was assessed by pill counts and continuous electronic monitoring. Two compliance parameters were evaluated, consumption, defined as percentage of prescribed doses taken, and time compliance, the percentage of total dosing events recorded within defined intervals (6.00-10.00 h, and 17.00-21.00 h), for the morning and evening regimes. Both regimes satisfactorily reduced the total and LDL-cholesterol concentrations, and there was no significant difference in the extent of the reductions. Pill counts overestimated compliance, as revealed by the monitoring method. The times of actual consumption of doses by the patients often differed from that prescribed, predominantly in patients who were told to take the evening dose. Partial time compliance may have confounded the efficacy of the drugs. Electronic compliance monitoring appears to be particularly useful in chronopharmacological studies.

Adult↗
PubMed1992

[Ethical problems in geriatrics from the family physician's viewpoint].

The picture of the 'youthful elderly' will develop further in a positive way because elderly people will not only experience a further increase of their average life-expectancy but also of their physical and psychic health and efficiency. Strict adhesion to calendar data means for the elderly that he is easily excluded from social performance and functionality of life. In order to meet the needs and expectations of the elder generation we need more overlapping linking of the different life periods, i.e. more sensitivity for individual arrangements. Increasing burden on the younger generation by increasing multimorbidity and needs for nursing may evoke responsibility for our patients. Therefore we practitioners should readily fulfill our duty to be in charge for the wellbeing of our aging patients. Social sensitivity for dignity in borderline situations depends on the acceptance of illness and needs for nursing as a natural part of our human existence.

Aged↗
PubMed1992

[The early rehospitalization of elderly patients. Causes and prevention].

The causes of early rehospitalization (within 3 weeks) of very elderly patients, its possible avoidance and appropriate preventive measures were analysed retrospectively in patients of a geriatric hospital. Included were all those patients who had been admitted to the hospital from their home several (mean: five) times between 1987 and 1990 (48 women, 19 men; mean age 81.3 +/- 7.2 years--a total of 331 re-admissions). The most frequent diagnoses were heart failure (38.8%), acute cerebrovascular accident or its sequelae (31.3%), dementia (23.9%), fall or its sequelae (22.3%) and diabetes (20.9%). Of the 331 re-admissions 87 (26.3%) occurred during the first 3 weeks after discharge. The most important reasons of this early re-admissions were inadequate home care (41.4%), undesirable drug effects and non-compliance (25.3%), as well as rapid progression of the basic disease (14.9%). In the judgement of the hospital team more than 40% of the early re-admissions were avoidable, among those re-admitted because of inadequate home care and those in connection with drug intake even more than half. Early hospitalization is frequently avoidable, if individual geriatric assessment is undertaken and discharge carefully planned.

Acute Disease↗
PubMed1992

Patient compliance with drug treatment--new perspectives on an old problem.

Compared to other variables being considered in therapeutics, patient compliance has long been given minor attention although it affects every aspect of medical care. Limited methodology of compliance measurement, in particular, has hampered major progress in research, and pre-conceptions have been reiterated. However, there is a recent surge in interest derived from new data revealed by reliable methods, i.g. continuous medication (compliance) monitoring. The visualization of dynamics in drug regimen compliance over time offers unique opportunities, both to scientific drug evaluation and therapeutics in medical practice. New perspectives related to the descriptive and explanatory side of the problem are outlined by giving examples from various therapeutic fields.

Drug Administration Schedule↗
PubMed1992

[Therapy for smoking: consensus in German-speaking countries].

The german speaking countries (Austria, Germany, Switzerland) are not the most advanced in the world when it comes to the control of tobacco related diseases. The medical system in these countries has yet to be convinced that smoking cessation is not only necessary but feasible. In order to provide a basic document for further activities, a consensus development process was initiated. The consensus development process forms part of the activities performed by the UICC (International Union Against Cancer) Project Smoking Cessation, which is a project within the framework of the UICC Tobacco and Cancer Programme. The 1988 Report of the US Surgeon General states very clearly, that the use of tobacco products is not a matter of free choice, but is the result of an addiction as scientifically valid as the addiction to heroin and other narcotics. The scientific literature provides informations on many methods and techniques for a smoking cessation, both pharmacological and non-pharmacological. Many pharmacological approaches have been tried to treat nicotine dependence in man. According to scientific standards and many controlled studies, nicotine has been the only drug found to be effective in treating nicotine dependence. Many techniques, ranging from self help to sophisticated combined therapeutic approaches including pharmacological interventions, are now available to deal with the nicotine addiction. Smoking cessation treatment uses time, effort and other resources and the question of reimbursement for these services has to be considered. As with any other form of treatment, costs needed to be paid either by the individual patient/client and/or by other sources including private and national health insurance systems.(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture Therapy↗