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Biomedical subjects

M Giesen

Publications and source records attributed to M Giesen.

At least 19 recordsLinked to original sources
PubMed1990

Papillomavirus common antigen in Bowen's disease.

We studied 173 biopsies of histologically determined Bowen's disease and looked for the presence of papillomavirus antigen using immunoperoxidase staining. Fifty-nine of the lesions were located at the head, 49 at the extremities, 36 at the trunk and 29 originated from the genital region. Papillomavirus capsid antigen could be clearly identified in 39 (22.5%) cases. Eleven (38%) of the 29 lesions located on genital skin were positive for papillomavirus capsid antigen while 28 (19.4%) of the 144 biopsies from other skin regions contained viral antigen. Our findings are suggestive of an etiologic relationship between the virus and this dermatosis which represents a special variant of squamous cell carcinoma. They indicate that human papillomaviruses may play an important role in the development of cutaneous malignancies.

Adolescent↗
PubMed1988

Phenotypic selection on the dentition in a Late Archaic population of Ohio.

Significant phenotypic selection acting on the buccolingual diameters of the permanent first and second molars is established for a Late Archaic population in Ohio. Directional selection appears to be acting on an index that increases the size of the maxillary first (UM1) and mandibular second (LM2) molars and decreases the size of the maxillary second (UM2) and mandibular first (LM1) molars. Variance selection is fundamentally disruptive but results in a more integrated (highly correlated) set of characteristics in the after-selection sample.

Adolescent↗
PubMed1979

Chronic and acute transtentorial herniation with tumours of the posterior cranial fossa.

In patients with expanding lesions of the posterior fossa general hyper-reflexia (and bilateral latency shifts of auditory evoked brain stem potentials) have been noted as possible symptoms of chronic ascending transtentorial herniation. After ventricular tap, this chronic herniation may evolve into acute herniation with progressive reduction of consciousness which in our experience can only be survived by decompression of the compressed brain stem. The chronic transtentorial herniation is related morphologically to demyelination of the pyramidal tracts and the auditory pathways, whereas the acute transtentorial herniation is related to microcirculatory disturbances in the reticular formation of the mesencephalo-pontine junction.

Auditory Pathways↗
PubMed1979

[Objective diagnosis of recruitment by brainstem audiometry (author's transl)].

The differential diagnosis in cochlear damage with brainstem potentials is easily done by looking for normal latencies that coincide with substantial hearing loss. Further validation can now be achieved with methods representing Fowler and SISI test equivalents. Amplitudes of brainstem potential were compared in 28 patients with marked differences of hearing loss in either ear. Amplitudes are balanced at the stimulus intensity corresponding to subjective loudness balance (Fig. 3). Intersubject comparison of input/output function steepness is not advisable because of the greater interindividual variation of amplitudes (Fig. 2). Amplitude modulation by short Gauss-shaped increments (Fig. 1) or by decrements of a continuous tone evokes clear brainstem potentials at thresholds of about 5dB above subjective detection, but it also depends upon stimulus duration or steepness (Fib. 4), frequency (Fig. 5) and the degree of modulation (Fig. 6). With a cochlear hearing loss of more than 40dB, a 1 dB increment evokes potentials for continuous tone intensities higher than 20 dB above subjective thresholds (Fig. 7). This test is mainly useful for children with retarded language development and lacking a stapedius reflex, for adults, who cannot sufficiently cooperate, and where there is a prolonged latency due to middle ear damage or a steep high frequency loss.

Audiometry↗
PubMed1979

[The complex tympanic membrane impedance in various middle ear disturbances (author's transl)].

Clinical experience with two-component registration (Susceptance and Conductance) of the tympanic membrane impedance at two frequencies (220 and 660 Hz) is reported. More than 1000 results of the last 6 years have been evaluated. The normal tympanometric shape is confirmed by computer simulation. More information about mass and elasticity relations of the middle ear is obtained by the complex registration at 660 Hz. Clinical examples are presented to demonstrate the influence of scars on the ear drum and of a disruption of the ossicular chain. In 77 cases of otosclerosis with stapes fixation, as confirmed by operation, the shape of the pressure-dependent admittance is significantly narrower than in normal hearing ears. For a glomus tumor a pulsation of the oto-admittance following the electro-cardiogram can be shown. In a classification of the tympanometric types the different shapes correspond well to the set of functional finding (normal) ears, otosclerosis, Eustachian tube malfunction, processes of the middle ear cavity, post operation state). The extreme sensitivity of the method, however, produces a small group of unpredictable results for each type. So differential diagnosis is to be done by usual audiometric methods or microscopy of the ear drum.

Acoustic Impedance Tests↗
PubMed1978

[Quantitative results of the brainstem audiometry in middle ear, cochlear, and retrocochlear hearing damage (author's transl)].

After a discussion of the technique and validity of the objective audiometry using acoustically evoked brainstem potentials, we demonstrate the shape of potentials at various locations of the scalp. We compare the objective findings for middle and inner ear hearing losses with the subjective audiogram. Disturbances in the middle ear are marked through a letency shift corresponding to the hearing loss with normal bone conducted reaction. When the cochlea is damaged we notice a quick decrease in amplitude from the loudnesscompensation to the threshold with normal latencies. As examples for retro-cochlear damages we give the cases of a child, retarded after encephalitis, of an infant and of a patient with stato-acoustic neurinoma, whereby also the cochlear, subcortical and cortical potentials are evaluated.

Acoustic Stimulation↗
PubMed1978

[Ventilation measurings before, during and after treatment of tracheal stenosis due to long term intubation (author's transl)].

17 patients with post-intubation stenosis of the trachea were studied. By the extrathoracic stenosis the relative forced expiratory volume in the first second (FEV1,0) and in and expiratory flow were decreased, total airway resistance (Rt) was increased. After implantation of an endoprothesis the obstruction was significantly lowered (p less than 0,05). After removal of the tracheal endoprothesis further improvement occurred as was demonstrated by an increase in FEV1,0 an flow and by a decrease in Rt.

Adolescent↗
PubMed1978

[Early and late functional hearing results from a modified technique for tympanoplasty (author's transl)].

This paper is a comparative study of the early and late functional results of tympanoplastic operations, as modified by Khan. Following such surgery, we examined 494 patients who had been operated on between 1970--1972 in the ENT Clinic of the Free University of Berlin (Klinikum Westend). Preliminary and final hearing results were recorded with the aid of sound audiograms, which were critically assessed by two different types of evaluations. These included the results of pure-tone changes and speech reception thresholds as achieved by the tympanoplastic operations. On the basis of socially useful hearing improvements, the functional results of cases operated in our clinic are above average. The hearing gain shown from post-operative controls to the final studies is especially satisfactory, since this also includes an improvement in bone conduction.

Acoustic Impedance Tests↗
PubMed1977

[Damages of the auditory pathway at brain stem level investigated by acoustically evoked potentials (author's transl)].

In 57 patients with operated expansive tumors in the postcranial fossa auditory evoked brain stem potentials were investigated. A group of 36 with neurological evidence for the brain stem compression showed significantly prolonged latencies (Fig. 1), whereas the evoked potentials were nearly normal in the preceding state of CSF circulatory disturbances (21 cases). For one patient with a neurinoma of the right trigeminal root the post-operative reduction of the pathological latency shift is demonstrated (Fig. 2). Latency evaluation of evoked brain stem potentials are used in our clinical routine for differential diagnosis of retrocochlear hearing damages.

Acoustic Stimulation↗
PubMed1977

[The investigation of different types of vocal disorder by statistical frequency analysis (author's transl)].

Common disorders of the vocal cords were assessed by indirect and direct laryngoscopy and by stroboscopy, and they were compared over the frequency range of "a". Amplitude and frequency variations from the normal are illustrated in recurrent laryngeal nerve paralysis, intubation granuloma, chronic oedema, the hyperkeratosis of chronic laryngitis, hypokinesia and hypokinetic dysphonia. In several cases, the effects of exercise or previous surgery are demonstrated. The described technique gives a useful aid to the management of vocal cord disease.

Aged↗
PubMed1976

Formation of an 80 S methionyl-tRNA initiation complex with soluble factors from wheat germ.

Wheat germ supernatant is resolved into four fractions, C3alpha, C3beta, D and A, all of which are required in addition to elongation EF1 and EF2 for tobacco mosaic virus-RNA (TMV-RNA)-catalyzed amino acid polymerization. Fractions C3beta and D function in the binding of Met-tRNAiMet to the 40 S ribosomal subunit forming an unstable 40 S-Met-tRNA1Met complex that is detected in sucrose gradients only after fixation with glutaraldehyde. Fraction C3beta binds Met-tRNAiMet suggesting that a C3beta-Met-tRNAiMet complex may be an intermediate in the formation of the 40 S complex. GTP is required for the formation of both the C3beta-Met-tRNAiMet and the 40 S-Met-tRNAiMet complexes. In either reaction the nucleotide is partially replaceable by quanyl-5'-yl methylene diphosphonate (GMP-P (CH2) P) while ATP is inactive. When ATP, C3alpha, mRNA, and magnesium acetate (final concentration 3.6 mM) are added to an incubation reaction containing the 40 S-Met-tRNAiMet complex, a stable 80 S-Met-tRNAiMet complex is formed. Radioactive TM virus-RNA binds specifically to the 80 S-Met-tRNAi complex suggesting that mRNA is a component of this complex. C3beta and D, the fractions required in the formation of the 40 S-Met-tRNAiMet complex, are also required for formation of the 80 S-Met-tRNAiMet complex. In addition, unlabeled Met-trnaiMet does not compete significantly with preformed 40 S-Met-tRNAiMet in the 80 S complex-forming reaction. These observations suggest that the 40 S-Met-tRNAiMet complex is an intermediate in the 80 S reaction. The 80 S-Met-tRNAiMet product of the sequential reaction is reactive with puromycin and on this basis it is tentatively considered to be a functional initiation complex. The additional requirement of Fraction A for amino acid polymerization suggests, however, that the initiation process may be more complex.

Binding Sites↗
PubMed1976

Isolation and characterization of a growth-cycle-reflecting, high-molecular-weight protein associated with Escherichia coli ribosomes.

A high-molecular-weight, acidic protein, acidic protein whose amount per ribosomal particle depends on the growth cycle is shown to be associated with Escherichia coli ribosomes. The protein is associated with ribosomes from cells harvested at different phases of the growth cycle, but a large increase in its amount is seen with ribosomes from post-exponential phase cells. The protein is only slightly washed off the ribosomes by 1 M NH4CL. When ribosomes are dissociated it remains entirely with the 30-S subunits. We have purified the protein to homogeneity. It has a molecular weight of 70 000 and its amino acid composition showed some resemblance to that of ribosomal protein S1. However, the two proteins ar-shown variation in the acetylation of L12 during the growth cycle, indicated that certain proteins of (or associated with) E. coli ribosmes may carry specific biochemical roles connected with cellular adaption toward the stationary phase.

Amino Acids↗
PubMed1975

False physiological feedback and persuasion: effect of fear arousal vs. fear reduction on attitude change.

Two experiments tested the hypothesis that increases in false physiological feedback of fear arousal will enhance persuasion and that reduction in the arousal feedback is unnecessary for increased persuasion to occur. Prior research has usually found a positive relation between level of arousal and persuasion, but support for the drive reduction hypothesis is tenuous. However, Harris and Jellison (1971) claimed support for such a hypothesis. They manipulated subjects' fear arousal cognitively via false physiological feedback while the subjects listened to a persuasive communication. The present experiments used a similar procedure in an attempt to test an "arousal only" against an "arousal reduction" hypothesis. Subjects listened to a persuasive speech while receiving false feedback via a meter concerning their fear arousal. In Experiment I half of the subjects received high arousal and half received moderate arousal information. Within each of these conditions half of the subjects had their arousal reduced, and the other half did not. In Experiment II subjects received either low arousal, high arousal, or high then low arousal feedback while listening. The results of the two studies generally provided support for the "arousal only" hypothesis. An interpretation in terms of Bem's attribution theory was tentatively suggested.

Arousal↗