PubMed Health⌕ Search

Biomedical subjects

K Seifert

Publications and source records attributed to K Seifert.

At least 37 records · Page 2Linked to original sources
PubMed1995

Triterpenoid saponins from Verbascum songaricum.

From the aerial parts of Verbascum songaricum the two new triterpenoid saponins songarosaponin E, F and the known buddlejasaponin I have been isolated and identified as 3-O-([beta-D-glucopyranosyl-(1-->4)-beta-D- glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-beta-D- fucopyranosyl)-olea-11,13-diene-3 beta, 23,28-triol, 3-O-([beta-D- glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-[beta-D- glucopyranosyl- (1-->2)]-beta-D-fucopyranosyl)-olea-11,13-diene-3 beta, 16 beta, 23,28-tetrol and 3-O-([alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]- [beta-D-glucopyranosyl-(1-->2)]-beta-D-fucopyranosyl)-13 beta, 28-epoxyolea- 11-ene-3 beta, 16 beta, 23-triol.

Carbohydrate Conformation↗
PubMed1995

Angiotensin II induces a complex activation of transcription factors in the rat brain: expression of Fos, Jun and Krox proteins.

We investigated the effects of intracerebroventricular injection of angiotensin II on neuronal immediate early gene-encoded protein synthesis in the brain of conscious rats. The expression of seven immediate early gene-encoded transcription factors (c-Fos, FosB, c-Jun, JunB, JunD, Krox-20 (Egr-2) and Krox-24 (NGFI-A, Egr-1, Zif/268) was assessed simultaneously. Angiotensin II (1, 10, 100 ng) induced a dose-dependent expression of c-Fos and Krox-24 in the subfornical organ, the median preoptic area and in the paraventricular nucleus and supraoptic nucleus of the hypothalamus, regions known to be involved in the central osmoregulatory and neuroendocrine actions of angiotensin II. FosB expression was induced four hours after icv injection of the highest dose of angiotensin II in the median preoptic area and paraventricular nucleus, c-Jun expression was restricted to the median preoptic area, subfornical organ and paraventricular nucleus, and JunB was only induced in the median preoptic area and subfornical organ. In these above mentioned regions, JunD exhibited a high basal staining, which was not visibly altered by angiotensin II. Krox-20 was not induced by angiotensin II. Intracerebroventricular injections of isotonic saline did not induce immediate early gene expression in any of the above brain areas. The angiotensin II-AT1 receptor antagonist, losartan, applied intracerebroventricular five minutes prior to angiotensin II, prevented the angiotensin II-induced immediate early gene protein expression. Losartan alone had no effects on immediate early gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1995

[Manual medicine in otorhinolaryngology. Theoretical principles-- clinical practice--principles of therapy and prevention].

Manual medicine or ¿chirotherapy¿ has become a recognized part of medical training in Germany. In the last few decades, research in various fields has shed light on the pathoanatomic and pathophysiologic causes of functional disorders of the cervical vertebral column whose previous management was characterized by treatment of symptoms. The Arthron system provides a cybernetic model in the form of a closed-loop feedback system for visualization and training purposes. A momentary isolated disorder or recurrent exogenous disorders can be represented as reversible processes; the phases of reflex buildup, development of a vicious circle, and/or exhaustion of compensatory processes can be identified and modeled. The Arthron system focuses on neuromuscular dysfunction as the cause of reversible disturbance (and not on joint dysfunction as the did earlier theoretical models). By focussing on the ¿on-target¿ manoevre, chirotherapy aims at resolving joint dysfunction (blocks) and achieve manual and reflex mobilization. Therapy includes medical relaxation of tense musculature and transient interruption of the nerve pathway.

Cervical Vertebrae↗
PubMed1994

Songarosaponin D--a triterpenoid saponin from Verbascum songaricum.

Songarosaponin D has been isolated from the aerial parts of Verbascum songaricum. Based on spectral evidence, the structure of songarosaponin D was elucidated as 3-O-([beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-]- [beta-D-glucopyranosyl-(1-->2)]-beta-D-fucopyranosyl)-13 beta,28-++ +epoxyolea-11-ene-3 beta,16 beta,23-triol.

Carbohydrate Sequence↗
PubMed1993

Charge transport by ion translocating membrane proteins on solid supported membranes.

A new method for the investigation of ion translocating membrane proteins is presented. Protein containing membrane fragments or vesicles are adsorbed to a solid supported membrane. The solid supported membrane consists of a lipid monolayer on a gold evaporated or gold sputtered glass substrate which is coated with a long chained mercaptan (CH3(CH2)mSH, m = 15, 17). Specific conductance and specific capacitance of the solid supported membrane are comparable to those of a black lipid membrane. However, the solid supported membrane has the advantage of a much higher mechanical stability. The electrical activity of bacteriorhodopsin, Na,K-ATPase, H,K-ATPase, and Ca-ATPase on the solid supported membrane is measured and compared to signals obtained on a conventionally prepared black lipid membrane. It is shown that both methods yield similar results. The solid supported membrane therefore represents an alternative method for the investigation of electrical properties of ion translocating transmembrane proteins.

Adenosine Triphosphatases↗
PubMed1992

[Modern hearing aid treatment].

Sufficiently good hearing is the most important prerequisite for speech communications between human beings and is crucial for the quality of human life. For this reason, provision of hearing aid is a priority task of the ENT-physician in all cases of hearing impairement which are unimproveable. The following principles must be observed: when it is necessary to provide a hearing aid, this should be done as early as possible, even in monauricular hearing loss. In binauricular hearing loss, hearing aids should be provided for both ears whenever possible and always with the objective of "optimal" care. The organization of hearing aid provision, which has proved very effective in Germany, is explained. Basic types of modern hearing aids are described and a review is given on the technical possibilities of modern hearing aids in solving problems relating to disturbances of hearing.

Auditory Threshold↗
PubMed1991

Triterpene saponins from Verbascum songaricum.

Songarosaponin A, B and C isolated from the aerial parts of Verbascum songaricum were shown to be 3-O-[alpha-L-rhamnopyranosyl-(1----4)-beta-D-glucopyranosyl-(1----3)]-[b eta-D-glucopyranosyl-(1----2)-beta-D-fucopyranosyl]-olea-11,13-die ne-3 beta-23,28-triol, 3-0-[alpha-L-rhamnopyranosyl-(1----4)-beta-D-glucopyranosyl-(1----3)]-[b eta-D-glucopyranosyl-(1----2)]-beta-D-fucopyranosyl]-olea-1 1-ene-3 beta-13,23,28-tetrol and 3-O-[beta-D-glucopyranosyl-(1----4)]-[beta-D-glucopyranosyl-(1----3)]-[b eta-D-glucopyranosyl-(1----2)]-beta-D-fucopyranosyl]-13 beta,28-epoxyolea-11-ene-3 beta,23-diol.

Carbohydrate Sequence↗
PubMed1989

[Functional disorders of the craniocervical transition and ENT symptoms--a status determination].

ENT symptoms due to disorders of the cervical spine are rarely caused by pathological lesions of the cervical spine that can be demonstrated by radiography, but are mostly caused by functional disorders of the upper cervical spine. They include: globus symptoms and dysphonia; pain syndromes in the head and neck; and otoneurological disorders. ENT symptoms resolve as soon as the function of the cervical spine and vertebral joints has returned to normal.

Cervical Vertebrae↗
PubMed1987

[Peripheral vestibular vertigo and functional disorders of the craniovertebral joint].

Some vertiginous lesions producing nystagmus (e.g. acute vestibulopathy, benign paroxysmal postural vertigo and Ménière's disease) are well-defined diseases of purely labyrinthine origin. The possible place of a functional disorder of the vertebral joints on their etiology and pathogenesis, has been discussed, but is purely hypothetical. Since the lesion almost always reaches with reduced function of the vestibular apparatus, the course of the disease depends crucially on central compensation of the peripheral disorder of vestibular function. Investigations of the effect of a functional disorder of the vertebral joints on the central compensation of vestibular functional disorders have not been described previously. Our own observations show that a functional disorder of the vertebral joints can crucially impair central compensation of peripheral vestibular vertigo. The pathological mechanism of the impaired compensation is discussed, and diagnostic and therapeutic consequences explained.

Adult↗
PubMed1987

[Prescribing hearing aids in ENT practice. I. General principles of prescription and hearing aid technics].

If it is no longer possible to improve hearing by conservative or surgical measures, provision of a hearing aid to the deaf patient remains an important task for the Otorhinolaryngologist. 98% of hearing aids are prescribed at the expense of the Statutory Health Insurance, 90-95% of them by Otorhinolaryngologists in private practice. The limits of the indication for the provision of hearing aids are explained, with attention to the principles of cash limits or by the Social Security system. The contractually regulated division of responsibility between the Otorhinolaryngologist and the hearing aid specialist are explained. The most important principles of hearing aid technology are described: the knowledge of these principles is a pre-requisite for correct prescription of hearing aids by the Otorhinolaryngologist.

Audiometry↗
PubMed1987

[Hearing aid prescription in ENT practice. II. Forms of hearing aid construction and prescription of bilateral hearing aids].

The fundamental constructional types of hearing aids are box or pocket hearing aids, behind-the-ear devices and in-the-ear devices. Other special forms include hearing aid spectacles. The indications for prescription of the various constructional types are described with consideration of their advantages and disadvantages, supplemented by a comment on the legal aspects of prescription of in-the-ear aids. In binaural deafness, provision of hearing aids for both ears is to be regarded as the normal approach with careful observation of the limits of the indications. The advantages of hearing in both ears compared with monaural hearing, and the contra-indications to binaural provision of hearing aids are described in detail. The legal basis of binaural hearing aid provision is explained.

Auditory Threshold↗
PubMed1985

Structural changes of hair after incorporation of the proline analogue L-azetidine-2-carboxylic acid. A model of hair disease by alteration of primary structure.

In order to correlate biochemical changes of the hair with physical properties we present a model for the examination techniques. L-azetidine was incorporated into the hair keratin complex and the resulting mechanoelastic properties were determined using the ultramicrohardness testing system on scanning electron microscopy. Structure was investigated by X-ray diffraction and incorporation of L-azetidine was detected by thin-layer chromatography. This system could possibly be introduced for examination of hair changes in humans. 8 white mice, 3 weeks of age, were given L-azetidine-2-carboxylic acid in water (0.1 g/100 ml) as only source of fluid over a period of 5 weeks. They had free access to dry mouse cake only. 8 animals of the same strain, who had free access to tap water and mouse cake and were kept under the same conditions, served as controls. After 5 weeks, the animals were sacrificed and hair was obtained for analyses. 2 dimensional thin-layer chromatography of hair hydrolyzed with 6N HCl at 105 degrees C for 12 hours revealed 2 additional spots in the chromatographic pattern in the experimental animals in comparison with the control group. 1 of the spots was identified as L-azetidine-2-carboxylic acid, while the second spot was possibly a degradation product of L-azetidine on acid hydrolysis at a high temperature. Hair of the animals was put into Mark capillaries and subjected to X-ray diffraction, which showed a markedly disordered orientation of keratin. Impression studies using scanning electron microscopy revealed a remarkably reduced elasticity of hair with incorporated L-azetidine. These findings may be explained on the basis of qualitative or quantitative changes in the helical structure of the keratin complex of hair, which is responsible for the elastic properties, whereas the globular matrix is responsible for the firmness of the hair.

Animals↗
PubMed1983

[Brief acoustic stimuli for the recording of brain stem potentials by computer controlled system analysis].

Brief acoustic stimuli are used in the objective assessment of the auditory threshold and in topodiagnosis of pathological processes in the auditory path via registration of brain stem potentials. The type of stimulus, duration, frequency and phase are decisive for the evocation of the brain stem potentials. However, it is still a somewhat unsolved problem as to how to obtain an optimally reproducible kind of stimulation. The pattern of progression of acoustic stimuli is of crucial importance for the recording of early acoustic evoked potentials (EAEP). Using an artificial auditory canal, a measurement device was constructed for recording acoustic stimulus sequences in the auditory meatus. With the help of electronic monitoring it became possible to produce digitally controlled stimulation resulting in utilizing forms of electrical stimuli which cannot be produced in the audiometer, for obtaining suitable electric stimuli. Whereas the curves of the acoustic pressures largely deviate from those of the electrical stimuli, as shown by measurements in the artificial auditory canal (the deviations depending on the headphones used in each case), the transmission properties of the electro-acoustic transducers are processed mathematically on the basis of Fourier's transformation, and such processing makes it possible to electrically produce any desired sequences of acoustic stimuli, taking the transmission properties of the headphones into account. In this manner, synchronous discharging of the sensory cells by brief acoustic stimuli, which is required for EAEP recording, can be optimized.

Acoustic Stimulation↗