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Biomedical subjects

J Otte

Publications and source records attributed to J Otte.

53 records · Page 3Linked to original sources
PubMed1988

Hyperthermia in cancer therapy.

Tumor hyperthermia is a rediscovered technique of oncotherapy which has confirmed value in many studies on cell cultures, rodent and mammalian tumors as well as first investigations on patients with tumors. The biological basis for using heat in the treatment of cancer is well established. Various direct and indirect mechanisms are significant for the effect of hyperthermia on tumor tissue. Whereas there are already extensive studies on the direct effects of hyperthermia on DNA, RNA, and protein synthesis, energy metabolism, and the membrane properties of tumor cells, the indirect effects have only been investigated more closely in recent years. These are likewise important for the damage to the tumor tissue and are mediated above all via alterations in the microcirculation and the environment. The recently gained increasing significance of this new technique in combination with other treatment modalities is well documented. Technical problems of heat application must be overcome, especially in deeper tumors and problems of thermometry must be solved in order to be able to apply tumor hyperthermia not only to selected advanced or recurrent tumors, but in order to use it as the fourth pillar of tumor therapy besides surgery, radiotherapy and chemotherapy. This article considers the biological basis and important aspects of hyperthermia therapy in combination with radiotherapy and chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Temporal bone pathology associated with intracranial abscess.

Histological studies were performed on the temporal bones of 17 persons who died of intracranial abscess as a complication of chronic otitis media and mastoiditis. In all cases the route of intracranial infection was via the dura mater rather than through the labyrinth. During the acute stage of intracranial abscess formation, the site of intracranial invasion showed a destructive inflammatory reaction characterized by the presence of granulations, resorption and sequestration of bone, invasive cholesteatoma, collections of purulent exudate, and necrosis of dura mater. At this stage any attempt at definitive removal of diseased tissue would necessarily result in a larger dural defect at a time when local disease and systemic illness present unsuitable conditions for reparative procedures. For this reason it would seem prudent to limit early otologic surgery to ensuring adequate drainage (e.g., postauricular open-wound drainage) and to perform corrective surgery (e.g., tympanomastoidectomy with repair of the dural defect) after the intracranial abscess has been brought under control.

Adolescent↗
PubMed1987

[Midazolam (Dormicum) for sedation of children in painful interventions].

In children painful diagnostic and therapeutic investigations require sedation and sometimes local anaesthesia. We tested Midazolam, a new benzodiazepine, for its sedative effect. Midazolam is the first derivate of imidabenzodiazepine and is remarkable for its rapid effect and a short half-life. It has good hypnotic, anxiolytic and amnesic properties. Sleep sets in immediately after intravenous application of Midazolam, and all patients reported anterograde amnesia afterwards. Over 24 months we observed 266 children who had been given Midazolam as a basic sedative before painful investigations. For sleep induction Midazolam was given in a dose of 0.3 mg/kg in children older than 6 years and 0.4 mg/kg in children younger than 6 years. The maximal dose was 15 mg. All patients fell asleep and did not remember anything about the procedure. In 30 patients pulse, blood pressure and respiration rate were measured before and after application of Midazolam. The quality of sleep was determined by the Glasgow-Coma-Scale. We did not observe any side effects.

Arousal↗
PubMed1986

Cysteine proteinase of Entamoeba histolytica. II. Identification of the major split position in bovine insulin B-chain.

The substrate specificity of a cysteine proteinase of Entamoeba histolytica was tested using the oxidized B-chain of bovine insulin. 28 proteolytic peptides were formed after different intervals of incubation and could be separated by high-performance liquid chromatography. Two dominant peptides appearing after 10 min of incubation were isolated and analyzed for amino acid composition. The results obtained indicate that these two peptides were formed by cleavage of the peptide bond between the amino acids 23 and 24. Thus as major split position the Gly-Phe bond in the insulin B-chain could be identified.

Amino Acids↗
PubMed1984

Impact of various thermal doses on the oxygenation and blood flow in malignant tumors upon localized hyperthermia.

Upon localized hyperthermia at modest thermal doses an increase in tumor blood flow can be observed in many tumors which is paralleled by an improvement of the oxygenation status of the tissue. At intermediate or high thermal doses a pronounced restriction of the tumor circulation becomes obvious leading to a deterioration of the tumor oxygenation. As a consequence, a further enhancement of the thermal response of tumors relative to normal tissues has to be expected at intermediate or high thermal doses.

Animals↗
PubMed1983

Relationship between size and oxygenation status of malignant tumors.

Analyzing the oxygenation status of tumors by means of the oxyhemoglobin saturation of single red blood cells within microvessels, there is clear evidence that tissue hypoxia and anoxia are inherent features during advanced stages of malignant growth. This is a consequence of distinct deteriorations of the convective and diffusive O2 transport with increasing tumor size leading to an O2 depletion in peripheral tissue layers around nutritive blood vessels. These alterations are combined with inhomogeneities of the oxygen distribution, both spatial and temporal. With enlarging tumor mass, the heterogeneities of the O2 supply distinctly intensify. Although in vitro experiments utilizing multicell spheroids failed to show very low oxygen tensions in necrotic regions, it is still proposed that chronic oxygen depletion is a paramount factor for the induction of necrosis in solid tumors under "physiological" in situ conditions.

Animals↗
PubMed1982

Impact of localized microwave hyperthermia on the oxygenation status of malignant tumors.

Upon heating at 40 degrees C for 30 minutes, the oxygenation of the tumor tissue significantly improved as compared with control conditions at 35 degrees C. In contradistinction to this, the tumor oxygenation significantly decreased directly after 43 degrees C- hyperthermia. A further temperature rise to 45 degrees C caused the oxygenation to drastically drop due to an almost complete cessation of nutritive blood flow. The changes in tumor oxygenation during hyperthermia seem to be predominatly mediated through changes in tumor blood flow, which showed the same directional changes.

Animals↗
PubMed1982

Oxygenation of malignant tumors after localized microwave hyperthermia.

The oxyhemoglobin saturation (HbO2) of single red blood cells within tumor microvessels (diameter: 3-12 micrometers) of DS-Carcinosarcoma was studied using a cryophotometric micromethod. In untreated control tumors (mean tissue temperature approx. 35 degrees C) the measured values scattered over the whole saturation range from zero to 100 sat. %, the mean being 51 sat. %. Upon heating at 40 degrees C for 30 min, the oxygenation of the tumor tissue significantly improved as compared with control conditions. After 40 degrees C-hyperthermia a mean oxyhemoglobin saturation of 66 sat. % was obtained. In contradistinction to this, after 43 degrees C-hyperthermia the tumor oxygenation was significantly lower and reached a mean HbO2 saturation value of 47 sat. %. A further temperature rise to 45 degrees C caused the oxygenation to drop drastically (mean oxyhemoglobin saturation value: 24 sat. %). This is due to a severe restriction of nutritive blood flow. The changes in tumor oxygenation after hyperthermia seem to be predominantly mediated through changes in tumor blood flow, including tumor microcirculation, which showed a similar temperature dependence. Metabolic effects probably play a minor role in the oxyhemoglobin saturation distribution within tumor microvessels.

Animals↗
PubMed1982

[Diagnostic and therapeutic problems of botulism in infants (author's transl)].

The incidence of botulism remains high. This disease is burdened by a high lethality rate. It is of significant importance for the patient that therapy is instituted sufficiently early. Botulism is an intoxication with the toxin of Clostridium botulinum. In babies, botulism can be caused also by peroral infection with the bacteria or spores. It appears that intestinal germination to toxin-forming bacteria can occur in babies only. Since honey is very frequently contaminated with Clostridium botulinum spores, honey should be eliminated from baby food. The signs manifested in botulism in infants are similar to those in somewhat older children and adults: increasing muscular hypotonia, apathy, pareses of the cranial nerves, and, finally, respiratory insufficiency through paresis of the respiratory musculature. The authors report on their own observations in cases of botulism, and on current possibilities of treatment.

Age Factors↗
PubMed1982

Changes in tumor oxygenation after localized microwave heating.

Upon heating at 40 degrees C for 30 min, the oxygenation of the tumor tissue significantly improved compared with control conditions at 35 degrees C. In contradistinction to this, the tumor oxygenation significantly decreased directly after 43 degrees C hyperthermia. A further temperature rise to 45 degrees C caused the oxygenation to drop drastically because of a severe restriction of nutritive blood flow. The changes in tumor oxygenation during hyperthermia seem to be predominantly mediated through changes in tumor blood flow, which showed the same directional changes.

Animals↗
PubMed1980

[Radiographic evidence of small amounts of pleural effusion in infant stage individuals. Animal experiments (author's transl)].

The pleural cavity of ten young pigs was punctured and pilled with specific amounts of fluid. Subsequently chest films were obtained in ap and lateral erect and in cross-table lateral decubitus position. Only 2 cases of these pigs radiographed in the erect position (after injection of 80 and even 100 ml of fluid) gave clear evidence of pleural effusion. Indirect signs of pleural effusion (such as blunting of the costophrenic angles; unsharpness, flatting or "elevation" of the diaphragm as a sign of subpulmonic effusion), however, were already noted with only 20 ml of pleural fluid. In contrast to these exams done in the erect position, the radiographs obtained in cross table lateral decubitus position showed as little as 5 ml of fluid. Therefore, the cross table lateral decubitus position is ideal for the work up of suspected pleural effusion.

Animals↗
PubMed1978

Ganglion cell populations in normal and pathological human cochleae. Implications for cochlear implantation.

A histological study of 100 hearing ears showed that some capability for speech discrimination requires at least 10,000 spiral ganglion cells. The spiral ganglion cell populations were then estimated in another group of 62 ears which were profoundly deaf for a variety of causes and it was found that 45% of these met the criterion of having 10,000 ganglion cells. The ganglion cell populations were largest in ears deafened by sudden deafness, Meniere's Disease, and ototoxic drugs; they were somewhat less for those with vascular occlusion, temporal bone fracture, otosclerosis, and cochlear dysplasias; they were least in those with measles, bacterial labyrinthitis and congenital syphilis. The data is of relevance in the selection of patients for cochlear implantation.

Adolescent↗
PubMedDate not supplied

Clinical significance of rebound nystagmus in neuro-otological diagnosis.

The present study is concerned with a clinical analysis of 17 patients with "rebound nystagmus" examined over a period of three years. All of them have shown a short duration second degree nystagmus evoked by changes in the direction of fixation, from the lateral to straight ahead gaze. This nystagmus was a fixation nystagmus, that is to say, it was enhanced in the presence of active optic fixation and inhibited in its absence. Almost all the patients (16 out of 17) had cerebellar signs on neurological examination (in one subject rebound nystagmus was the first sign suggesting cerebellar involvement and appeared several months before any other cerebellar sign was present). Rebound nystagmus was far more common than the other neuro-otological signs suggesting cerebellar dysfunction (vestibular hyperexcitability, dysrhythmia in postcaloric nystagmus and ocular dysmetria). In three out of four patients with unilateral lesions rebound nystagmus was ipsilateral with respect to the side of the lesion. Postmortem studies were carried out upon five cases and showed either pathological changes in the cerebellum or a lesion involving the cerebellar peduncles in the brain stem.

Cerebellar Diseases↗