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Biomedical subjects

H Feldmann

Publications and source records attributed to H Feldmann.

At least 163 records · Page 9Linked to original sources
PubMed1989

[The status of psychogenic hearing disorder today].

The general symptoms of psychogenic hearing disorders are pointed out and exemplified by 16 own cases seen by the author in 1987 to 1988. Psychogenic hearing disorders imitate various constellations of findings and histories of genuine organic hearing disorders. The individual's experience and the contemporary consciousness of hearing disorders seem to enter into the individual manifestation. The 16 cases can clearly be divided into 3 groups of equal size: 1. The unilateral acute hearing loss, imitating either an acute traumatic damage or an idiopathic sudden hearing loss. This was seen almost exclusively in children. 2. The bilateral chronic hearing loss. This, too, was seen mainly in children and youths. 3. The acute bilateral recurring or progressing hearing disorder. This was seen predominantly in adults, mimicking dramatic courses ending up in bilateral profound deafness. In part of the cases the psychological background of the neurotic reaction could be explored quite easily. Knowledge of the various manifestations of psychogenic hearing disorders is important, because otherwise, as the reported cases demonstrate, misleading interpretation of findings entails costly diagnostic procedures (computerized tomography, arteriography) and expensive therapeutic measures (hospitalization, fitting of hearing aids).

Adolescent↗
PubMed1989

[Martin Luther's seizure disorder].

Martin Luther's diseases are well documented, because he used to discuss them freely in his letters. There is also a wealth of evidence through reports by his friends. Most of his diseases were common and well known to the contemporary physicians, who accordingly interpreted them correctly: bladder stones, chronic constipation, hemorrhoids. Luther's death obviously was due to a coronary thrombosis. During the last 19 years of his life, in addition to these "natural diseases", Luther also suffered from recurring attacks of a peculiar symptomatology. Luther himself and his friends considered these seizures to be no "natural disease", but Satan punching his flesh, and he compared them to St. Paul's disease (2. Cor. 12). The first of these attacks occurred on July 6, 1527, when Luther was 43 years of age. It began with a roaring tinnitus in his left ear, which increased dramatically and seemed to occupy the left half of his head. Then a state of sickness and collapse followed, however, consciousness was retained throughout the whole period. After a night's rest all the symptoms had subsided, except the tinnitus, which, from that day on, continued for all the following years in varying intensity. Similar attacks with increase of the tinnitus and vertigo as the leading symptoms, seized Luther at irregular intervals and distressed him extremely. Former investigators of Luther's diseases interpreted these attacks as manifestations of a psychiatric disorder and a chronic inflammatory disease of the middle ear. The present detailed study reveals that it was a typical case of Menière's disease of the left ear manifesting itself more than 330 years before Menière's classical observation.

Christianity↗
PubMed1988

Analysis of yeast chromosomal regions carrying members of the glutamate tRNA gene family: various transposable elements are associated with them.

We carried out an analysis on the genomic organisation of the tRNA(Glu) family in S. cerevisiae; eight clones were characterized by restriction mapping, hybridization and sequencing. These data taken together with our earlier findings show that the individual tRNA(Glu3) copies are identical only in their structural part but embedded in entirely different genomic environments. All of the tRNA genes identified here are flanked by elements such as Ty, delta, sigma, and tau. In some cases, sequences from different elements form complex patterns indicating a sophisticated history of these chromosomal regions. A novel observation is that Ty and delta in the regions analyzed are exclusively associated with the tRNA genes. The observed patterns imply that the tRNA genes mark regions of multiple transposition and subsequent excision events, but that these have occurred after the individual tRNA gene copies had been fixed in their present locations. Transcription experiments by the use of micro-injection into Xenopus oocytes suggest that the elements flanking the tRNA genes exert a modulating effect on their expression.

Animals↗
PubMed1988

A series of shuttle vectors using chloramphenicol acetyltransferase as a reporter enzyme in yeast.

Reports from numerous laboratories have shown that the gene coding for the bacterial enzyme chloramphenicol-3-O-acetyltransferase can be used as a reporter gene (cat) in mammalian and plant systems to analyze gene activity at the transcriptional level when combined with endogenous regulatory signals; the enzyme activity can be quantified by a chromatographic or a photometric assay. To adapt this simple and highly sensitive test for the yeast system, we constructed a series of yeast vectors containing the cat gene together with selectable markers for Escherichia coli and yeast; integrating, autonomously replicating and centromere-carrying plasmids were used. We show that the cat gene lacking the endogenous promoter is expressed at low levels in yeast transformants. To demonstrate functional expression of the cat gene placed under the control of a yeast promoter, we chose the PHO5 regulatory region. We found that cat expression was induced via the PHO5 promoter in a manner as observed for the endogenous PHO5 gene, whereas in the repressed state cat expression remained low. Using these vectors, it should be feasible to analyze other sequences conferring promoter activity or other control functions in yeast.

Chloramphenicol O-Acetyltransferase↗
PubMed1988

The structure of serotype H10 hemagglutinin of influenza A virus: comparison of an apathogenic avian and a mammalian strain pathogenic for mink.

The primary structure of the hemagglutinin of the apathogenic avian influenza virus A/chick/Germany/N/49 (H10N7) and of the serologically related strain A/mink/Sweden/84 (H10N4) pathogenic for mink has been elucidated by nucleotide sequence analysis, and the carbohydrates attached to the polypeptide have been determined. The H10 hemagglutinin has 65, 52, 46, 45, and 44% amino acid sequence homology with serotypes H7, H3, H1, H2, and H5, respectively. H10 and H7 hemagglutinins are also most closely related in their glycosylation patterns. There is a high sequence homology between both H10 strains supporting the concept that the mink virus has obtained its hemagglutinin from an avian strain. The sequence homology includes the cleavage site which consists of a single arginine as is the case with most other hemagglutinins exhibiting low susceptibility to proteolytic activation. The similarity in hemagglutinin structure between both H10 strains is discussed in light of the distinct differences in the pathogenicity of both viruses.

Amino Acid Sequence↗
PubMed1988

[Quantitative evaluation of hearing disorders in expert assessment. A recent recommendation for calculating the percentage of hearing loss].

A short historical survey is given of grading the severity of hearing disorders and assessing the relevant disability for recompensation purposes according to the tables of Boenninghaus, Röser, and Feldmann. The present situation and the reasons giving rise to dissatisfaction with this procedure are analysed. They are the high threshold of 20% disability for recompensation, the rigidity of the tables, and the technical development of speech audiometry without concomitant adaptation of the tables. The following possible solutions are discussed and rejected: changing the tables, substituting speech audiometry by tone audiometry, speech audiometry with interfering noise, filtered speech audiometry, special bonus for recruitment. The following feasible solution is proposed: Retaining all tables in use up to this time, however, instead of using the sum of discrimination scores which simply adds the scores at 60, 80 and 100 dB SRL, weighting factors are introduced according to the formula [3 x (% at 60 dB) + 2 x (% at 80 dB) + 1 x (% at 100 dB)]: 2 The advantages and the effect of this procedure on calculating hearing loss and disability are discussed.

Audiometry, Pure-Tone↗
PubMed1988

[Listening to music in hearing loss with and without a hearing aid].

By means of a questionnaire it was investigated how in individuals who had previously had normal hearing deafness influences their pleasure and habits in listening to music, and which role a hearing aid can play in this respect. Out of 330 questionnaires returned, 206 could be statistically evaluated. 95% reported that formerly they had liked music, light music coming from the radio being the most frequently mentioned type of music and medium. 36% had formerly played an instrument or had enjoyed singing. 79% feel that their deafness has affected their pleasure in listening to music. Most common complaints refer to the fact that everything sounds distorted and wrong, melodies cannot be recognised any longer, the text of songs is not understood. 60% are fitted with one hearing aid, 40% have binaural hearing aids. 67% report that the hearing aid has rendered listening to music again more pleasurable, and 74% use their hearing aid more or less regularly when listening to music. The distorted sound and the fast alternating between "too soft" and "too loud", forcing the subject to continually adjusting his hearing aid, seem to be among the most annoying features.

Adolescent↗
PubMed1987

One member of the tRNA(Glu) gene family in yeast codes for a minor GAGtRNA(Glu) species and is associated with several short transposable elements.

During characterization of the whole tRNA-(Glu) family from the yeast, Saccharomyces cerevisiae, we isolated one cosmid clone bearing a tRNA(Glu) gene copy that is deviant from the major tRNA(Glu3) gene members in only five positions. This divergent tRNA-(Glu) is a minor species and is represented by a single gene copy. One of the nucleotide exchanges concerns the anticodon which is modified from T-T-C in the tRNA(Glu3) gene to C-T-C which implies that this tRNA serves the codon triplet G-A-G. Two other minor yeast tRNA species have been reported which appear to be particularly designed for the translation of those codons that have a G in its third (Wobble) position. The low abundance of such minor tRNA species correlates positively to the low occurrence of most of the N-N-G codons in yeast. Furthermore, the GAGtRNA-(Glu) locus represents another case of the general phenomenon in which the majority of the tRNA genes in yeast are associated with one or several transposable elements forming complex patterns. In this particular case, divergent segments of delta and tau are present in the 5' flanking region of the tRNA gene and arranged in a novel configuration. The sequence data lend support to the view that tau is not an evolutionary young element as was earlier anticipated.

Base Sequence↗
PubMed1987

[Late sequelae following laterobasal fractures, therapeutic and forensic viewpoints].

Report on two cases of temporal bone fracture with unilateral profound deafness and vestibular dysfunction. The other ear was apparently not involved. After 4, respectively 18 years, a sudden hearing loss occurred in the second ear, fluctuating and associated with acute vestibular symptoms. On operation we found in the first case a perilymph fistula in the round window, in the second case a gaping fracture in the promontory. A retrospective study of 527 cases of "sudden hearing loss" revealed 11 more cases with similar histories that must be regarded as sequelae of the head trauma. The latency between trauma and onset of hearing loss in the second ear ranged from 4 to 33 years. Discussion of the pathomechanism of the trauma, therapeutic and medico-legal issues.

Adult↗
PubMed1986

Conserved and non-conserved features among the yeast Ty elements.

We have isolated and characterized a Ty element from a yeast cosmid library which exhibits several unusual features: it is flanked by non-homologous delta elements and directly associated with a singular delta element. A tRNA(Glu3) gene and tRNA(Cys) gene are found in conjunction with this element, located in opposite orientation on either end of it. The sequence information now available for several Ty elements has been used in a detailed comparative analysis to determine conserved features among the Ty elements, preferably between class I elements and a class II element. Highly conserved sequence motifs appear to be located at the borders of particular segments that correspond to the putative protein domains of the Tys. Furthermore, we include a comparison of the best-conserved amino acid homologies for these putative proteins of Ty elements, transposable elements from other organisms and several retroviral proviruses to confirm their close structural resemblance.

Amino Acid Sequence↗
PubMed1986

Enhancer-like stimulation of yeast tRNA gene expression by a defined region of the Ty element micro-injected into Xenopus oocytes.

In the yeast Saccharomyces cerevisiae, the majority of the tRNA genes are found associated with transposable elements one of which is the Ty element. We noticed that the transcriptional activity of several of these genes was rather different depending on the type of the accompanying element(s) [Nelböck et al. (1985) Biol. Chem. Hoppe-Seyler 366, 1041-1051]. In order to study the influence of a Ty element on tRNA gene expression, we used the method of micro-injection into Xenopus oocytes taking advantage of a Ty+/Ty- allelic pair of a tRNALys1 gene recently isolated in our laboratory. A direct comparison showed that the expression of the plus allele was c. sixfold higher than that of the minus allele. In order to determine sequences of the Ty responsible for this effect, we constructed a number of variants in which distinct segments of the Ty were deleted or rearranged. The activating ability was localized to a 590-bp segment of the Ty containing the 'promoter delta', independent of its orientation or location towards the tRNA gene thus resembling the effects described for transcriptional enhancers. This is the first time that a long-range effect has been observed on the expression of a gene transcribed by RNA polymerase III.

Animals↗