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Biomedical subjects

U Heller

Publications and source records attributed to U Heller.

9 recordsLinked to original sources
PubMed2001

Enabling guidelines for computer-based decision support--process and tools.

Many guideline only implicitly or vaguely define the process of health care delivery. However, an explicit model of the medical tasks comprising this process is needed before active decision support at the patient encounter can take place. We propose to use a structured, but semi-formal representation as intermediate step in the process of enacting a guideline. This allows for the application independent representation of the content of a guideline enabled for decision support. The process and the tools of the methodology have been applied to enable guidelines from the field of Diabetes mellitus.

Decision Making, Computer-Assisted↗
PubMed1998

[Incidence and clinical relevance of antibodies to phospholipids, serotonin and ganglioside in patients with sudden deafness and progressive inner ear hearing loss].

Immunoserological assays of patients with sudden deafness and progressive hearing losses have revealed the presence of different antibodies, leading to the assumption that immunological processes may be involved. Recent investigations have demonstrated that these patients have phospholipid antibodies that can cause venous or arterial vasculopathies. In the present study we analyzed the incidence of these antibodies in patients with inner ear disorders. Sera of 55 patients with sudden deafness and 80 patients with progressive hearing loss were tested. Phospholipid antibodies were demonstrable in 49% of the patients with sudden hearing loss and 50% of the patients with progressive hearing loss. Serotonin and ganglioside antibodies were found in 53% of the patients with sudden hearing loss and 63% of the patients with progressive hearing loss. Since these three antibodies are also frequently found in patients with fibromyalgia syndrome (FMS) and chronic fatigue syndrome (CFS), 28 of the patients studied displayed symptoms typical for these disorders, including fatigue, myalgia, arthralgia, depressions, sicca symptoms and diarrhea. We now recommend questioning patients suffering from inner ear disorders for symptoms typical for FMS or CFS, since these diseases are often closely related to inner ear disorders. If symptoms are present, antibodies should be tested against phospholipids, serotonin and gangliosides. If present, the antibodies are diagnostic for each syndrome. Additionally these immunologic and serologic findings show that these antibodies may play a role in the etiology of hearing loss disorders.

Adolescent↗
PubMed1989

Evidence for cholinergic participation in frontal cortical potentials evoked by single impulse stimulation in the locus coeruleus area of freely moving rats.

Single impulse stimulation in the area of locus coeruleus (LC) in freely moving rats evokes bilateral symmetrical potentials (EP) in the frontal cortex. Threshold intensity for this potential was higher when the stimulus electrode was in the LC than in the cholinergic dorsal parabrachial nucleus lateral of LC. Amplitudes and peak times of this EP were constant during relaxed wakefulness, exploratory behavior and unaffected by beta-blockade (propranolol, 2.5 mg/kg i.p.). Their amplitudes were strongly decreased and the peak times of later negativity (N50) were prolonged during slow wave sleep and by muscarinic blockade with scopolamine (0.5 mg/kg i.p.) which induced active behavior and synchronized EEG. These data suggest a direct participation of cholinergic structures in cortical potential evoked by electrical LC stimulation. Relations between stimulus effect and behavior regulating systems are discussed.

Animals↗
PubMed1989

Modulatory effect of locus coeruleus stimulation on visually evoked potentials in freely moving rats.

Interactions between light-flash stimulation and electrical single impulse stimulation of locus coeruleus (LC) were investigated in 9 freely moving rats with chronically implanted electrodes during different behavioral states. The interaction of both showed different immediate and long-lasting effects. Simultaneous visual and electrical stimulation caused a clear decrease of trigger rate of photically evoked after-discharges from 60% to 15% and a reduction of the early primary component of visually evoked potentials (VEP) in area 17 compared with the values without LC stimulation during relaxed wakefulness (RW). On the contrary, the simultaneous LC stimulation was ineffective during exploratory behavioral states (E). At 100 ms stimulus interval and more there was no detectable LC stimulus effect on VEP components during RW, whereas the LC stimulation under beta-blockade (2.5 mg/kg propranolol i.p.) during RW-like behavior clearly reduced the early VEP component to 75% compared with values without LC stimulation. On the other hand, LC stimulation facilitated mainly the primary VEP component to about 160% during E compared with the flash response alone. This effect was observed from 100 to 300 ms after LC stimulus and was unaffected by muscarinic blockade (0.5 mg/kg scopolamine i.p.). We conclude from these data that the short-time effects are comparable with the influence of spontaneous behavioral activation and probably result from a costimulation of cholinergic neurons around LC, whereas the long-lasting effects may be attributed to the influence of noradrenergic LC cells. The noradrenergic-dependent facilitation of early VEP component counteracts the cholinergically-induced reduction.

Animals↗
PubMed1987

[Further development of pneumatization of the mastoid apophysis in long-term drainage of the tympanum].

Tubal insufficiency evoked by inflammation or mechanical obstruction due to enlarged adenoids plays an important role in the pathogenesis of chronic serous otitis media. Serous and mucous tympanic effusions in the presence of immature middle ear mucosa and pneumatisation follow. An adhesive process can be the result. Secretory outflow as well as constant pressure compensation between the tympanic cavity and the auditory meatus can only be achieved by a long-term tympanic drainage. Progression of pneumatisation is achieved by recovery of the middle ear mucosa and in most cases an adhesive process can be prevented.

Child↗