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Biomedical subjects

K Weigel

Publications and source records attributed to K Weigel.

53 records · Page 3Linked to original sources
PubMed1980

Stereotactic treatment of brain lesions. Biopsy, interstitial radiotherapy (iridium-192 and iodine-125) and drainage procedures.

Integrating CT imaging techniques into stereotactic procedures makes it easy to puncture cysts, take biopsies from neoplastic and nonneoplastic lesions, and place radioactive material in tumors at exact and reproducible sites. A stereotactic program of interstitial radiotherapy in deep-seated brain tumors has been applied in 326 cases as of December 31, 1979 (270 cases using iridium-192 and 56 cases using iodine-125). The use of iodine-125 is now favored since it requires less radiation protection due to its soft 28-35 keV radiation; at the same time, however, it possesses a comparable half life of 60 days. In 126 cases, stereotactic biopsy was used exclusively for diagnostic purposes followed by open craniotomy or conventional radiation. Cystic brain tumors (i.e., craniopharyngiomas and cystic low grade gliomas) were permanently drained by insertion of Rickham reservoir catheters in 61 cases. Stereotactic ventriculocisternostomies were carried out in cases of hydrocephalus and drainage of suprasellar arachnoid cysts was performed in 15 cases. A simple method of projecting CT images onto stereotactic X-ray pictures provides an exact mapping of lesions within the actual stereotactic brain space. The results of this series of patients strongly suggest that exploratory craniotomies and free-hand punctures can no longer be advocated. No radiation treatment should be considered without histological confirmation. The more clearly the volume of a tumor can be defined, the more favorable the results of interstitial irradiation in otherwise unresectable tumors.

Biopsy↗
PubMed1978

[Cytology, lactate dehydrogenase, and creatine kinase in CSF in mild head injuries (author's transl)].

Cytology, lactate dehydrogenase, and creatine kinase in cerebrospinal fluid were investigated 6-72h after mild head injuries in 59 patients aged 16-49 years. Significant differences were not found in creatine kinase. Lactate dehydrogenase, however, was significantly more elevated in mild cerebral contusions compared with concussions 24h after head injury. Monocytoid reaction in cerebrospinal fluid was significantly more distinct in mild contusions compared with concussions 24h after impact. Large phagocytes were rarely found in concussions and were not traceable 48h after impact. Large phagocytes, however, were found in 50-55% of the mild contusions 48-72h after head injury. Siderophages were found only in contusions (16.5-35%), 48-72h after impact). The optimal time for lumbar punction is 24h after head injury.

Adolescent↗
PubMed1978

[Electric response audiometry (brain stem potentials and late potential N1) in patients with acoustic neurinoma or space-occupying lesion in the region of the brain stem].

In patients with acoustic neuronoma or space-occupying lesion in the region of the brainstem we recorded preoperatively the brainstem potentials as well as the late potential N1. With one exception all patients investigated showed changes in the brainstem potential pattern. When stimulating monaurally there exists a clear side difference, that means the changes in the potential pattern are more distinct on the side of the tumour than on the opposite side and then only if an obstructive hydrocephalus exists. Moreover we could demonstrate in patients with tumours in the region of the brainstem that the brainstem potential IV is no longer suitable for measuring the hearing threshold. On the other hand in these patients an exact determination of the hearing threshold is possible with the late potential N1. Altogether the findings show, that the recording of the brainstem potentials when stimulating monaurally is an important additional diagnostic tool to recognize impairment of the acoustic pathways within the brainstem and probably affords the possibility of perceiving pathological pressure within the brain.

Adult↗
PubMed1978

[Influence of duration and depth of ether of brevinarcon narcosis on the cerebral acetylcholine content of rat].

For decapitation of rats in order to determine brain acetylcholine (Ach) content the animals may be anaesthesized slightly by ether no longer than for 2 min, since forebrain Ach content increases quickly up to about 170% throughout the following 3 min. The progress of brain Ach content up to its maximum level is decided both by duration and degree of cns depression: In the moment of most distinctly marked Brevinarcon -narcosis -- evident 2,5 min after i. v. injection (40 mg/kg) -- the forebrain Ach content merely is increased by about 15%, but when anaesthesia is reduced considerably again -- 2,5 min later -- the Ach content only reaches its maximum level.

Acetylcholine↗
PubMed1978

[Florid oral papillomatosis. A contribution to cytostatic therapy].

Based on the recent clinical experience in treating florid oral papillomatosis (FOP), the only successful therapy appears to be the use of cytostatic agents. The case report of a patient with clinically and histologically confirmed FOP is described to emphasize the advantages of administering Bleomycin intra-arterially (external carotid artery) by means of a Holter catheter. This catheter is used to release pressure in the treatment of internal hydrocephalus and is designed to remain in place for a number of years. The successful treatment of FOP points out the possibility of employing a Holter catheter for administering cytostatic agents in the treatment of malignant neoplasms in the facial area. Cytophotometric examinations of the prickle cells within the FOP mass showed a diploid pattern of DNA distribution similar to that of benigh tumors. However, it is not possible to definitely establish the malignant or benign nature of FOP in this manner.

Alopecia↗
PubMed1976

[The effect of L-tryptophan on L-dopa absorption (author's transl)].

Dopa blood levels were measured in healthy subjects after oral intake of 0.5 g L-dopa (seven subjects) as well as of 0.5 g L-dopa and 1.0 g L-tryptophan (six subjects). Combined L-dopa and L-tryptophan administration produced significantly less of a rise in dopa blood levels than L-dopa alone.

Dihydroxyphenylalanine↗
PubMedDate not supplied

Intra-ponto-mesencephalic recording of binaural interaction in human brain-stem auditory evoked potentials.

Brain-stem auditory evoked potentials (BAEPs) were recorded at intraparenchymatous sites along a ponto-mesencephalic stereotactic penetration path in a patient with the rare condition of a ponto-medullary lesion which required biopsy but did not grossly alter scalp BAEPs. Click stimuli were applied either monaurally (with contralateral masking noise against acoustic cross-talk; conditions 'R,' 'L') or binaurally (condition 'RL'). A binaural interaction trace ('BI') was derived by subtracting the sum of the monaural from the binaural responses: BI = (RL)-(R + L). Despite failure to obtain significant BI components above noise level for scalp BAEPs, at the lower pons clearly discernible, multiphasic BI activity could be recorded beginning at the peak latency of scalp wave III and extending over approximately the next 4 msec. Its amplitude rapidly fell off with distance toward more rostral, mesencephalic recording sites. In relation to this positive finding, the equivocality among some of the previous studies on the detection of BI components in human scalp BAEPs is tentatively rephrased in terms mainly of a low signal-to-noise ratio and of functional peculiarities introduced by the respective stimulation protocols.

Adult↗