Biomedical subjects

M Ptok

Publications and source records attributed to M Ptok.

95 records · Page 6Linked to original sources

PubMed1989

[Current aspects of radiotherapy of glomus jugulare tumors].

Small glomus jugulare tumors can be operated on successfully. The intraoperative risk of bleeding may be reduced by preoperative irradiation or angiographic embolisation. Patients with advanced tumors (bone destruction, paralysis or cranial nerves and/or invasion of brain) are at high risk if they are operated on. In these cases radiotherapy is an effective alternative with a fairly low complication rate. Prerequisites for successful irradiation are assessment of treatment volume and treatment planning by CT, sophisticated stereotactic irradiation techniques, application of high energy photons and reliable immobilisation measures. Furthermore it is possible to deliver higher doses, leading to regression of the tumor and its symptoms. The technique is illustrated by two characteristic cases. Although irradiation alone can achieve tumor remission the long term prognosis remains doubtful.

Female↗

PubMed1989

[Radiotherapy of glomus jugulare and tympanicum tumors].

Glomus jugulare tumors are difficult to manage therapeutically due to their localisation. Operation may be successful in small tumors but can be hazardous in larger lesions mainly because of bleeding and palsy of cranial nerves. In these cases there should be used radiation therapy under the condition that it is planned by use of computed tomography. Moreover reproducibility of radiation treatment set-up is vital. In this way tumor regression may be achieved. Four own illustrative cases are demonstrated. According to the stage of disease a modified treatment strategy is presented which integrates surgical procedures, angiographic embolization and radiotherapy.

Adult↗

PubMed1989

[Assessment of kidney function before cisplatin administration: the need for 24-hour urine collection].

Creatinine clearance as a measure of the glomerular filtration rate is calculated from the serum creatinine, urine creatinine concentration and the 24-h urine volume (MCC). Cockroft and Gault as well as Davila and Gardener have shown that estimation of the creatinine clearance (ECC) from the serum creatinine, age, sex, and weight of the patient is at least as accurate as measurement of creatinine clearance (MCC). ECC is not influenced by inaccurate collections of urine or incorrect analyses of urine creatinine. 125 MCC was investigated in 51 patients receiving cisplatin. If ECC is less than or equal to 80, then MCC should eliminate inaccurate urine collections. If the value of ECC exceeds 80, it is not necessary to measure MCC.

Circadian Rhythm↗

PubMed1984

Role of gastrointestinal transit in the delay of absorption by viscous fibre (guar).

The influence of guar gum on gastric emptying of liquids in healthy volunteers and on mouth-to-caecum transit time in controls and partially gastrectomized patients has been studied. Together with a flattening effect on blood glucose profiles after a liquid glucose load, guar significantly delays mouth-to-caecum transit time both in healthy controls and partially gastrectomized patients. The retardation of transit is not explicable by a delay in gastric emptying, as can be shown by means of an isotope technique. Only in "quick starters' was a delay in initial gastric emptying observed. The exponential phase of gastric emptying remained unaffected. Moreover, it is shown that the prolongation of mouth-to-caecum transit time is not mediated by factors operating at the level of the pyloricantral region. Delayed small-bowel passage by guar might modulate absorption of glucose by increasing the unstirred layer resistance and, in the non-steady state, by limiting the absorptive area initially covered by a bolus.

Adult↗

PubMedDate not supplied

Classification of passive auditory event-related potentials using discriminant analysis and self-organizing feature maps.

Discriminant analysis (DA) and self-organizing feature maps (SOFM) were used to classify passively evoked auditory event-related potentials (ERP) P(1), N(1), P(2) and N(2). Responses from 16 children with severe behavioral auditory perception deficits, 16 children with marked behavioral auditory perception deficits, and 14 controls were examined. Eighteen ERP amplitude parameters were selected for examination of statistical differences between the groups. Different DA methods and SOFM configurations were trained to the values. SOFM had better classification results than DA methods. Subsequently, measures on another 37 subjects that were unknown for the trained SOFM were used to test the reliability of the system. With 10-dimensional vectors, reliable classifications were obtained that matched behavioral auditory perception deficits in 96%, implying central auditory processing disorder (CAPD). The results also support the assumption that CAPD includes a 'non-peripheral' auditory processing deficit.

Adolescent↗