Biomedical subjects
Michael Kosteljanetz
Publications and source records attributed to Michael Kosteljanetz.
Endocannabinoid metabolism in human glioblastomas and meningiomas compared to human non-tumour brain tissue.
The endogenous levels of the two cannabinoid receptor ligands 2-arachidonoyl glycerol and anandamide, and their respective congeners, monoacyl glycerols and N-acylethanolamines, as well as the phospholipid precursors of N-acylethanolamines, were measured by gas chromatography-mass spectrometry in glioblastoma (WHO grade IV) tissue and meningioma (WHO grade I) tissue and compared with human non-tumour brain tissue. Furthermore, the metabolic turnover of N-acylethanolamines was compared by measurements of the enzymatic activity of N-acyltransferase, N-acylphosphatidylethanolamine-hydrolysing phospholipase D and fatty acid amide hydrolase in the same three types of tissue. Glioblastomas were characterized by enhanced levels of N-acylethanolamines (eightfold, 128 +/- 59 pmol/micromol lipid phosphorus) including anandamide (17-fold, 4.6 +/- 3.1 pmol/micromol lipid phosphorus) and several species of N-acylphosphatidylethanolamines (three to eightfold). This was accompanied by a more than 60% reduction in the enzyme activities of N-acylphosphatidylethanolamine-hydrolysing phospholipase D and fatty acid amide hydrolase. By contrast, meningiomas were characterized by a massively enhanced level of 2-monoacyl glycerols (20-fold, 2293 +/- 361 pmol/micromol lipid phosphorus) including 2-arachidonoyl glycerol (20-fold, 1524 +/- 361 pmol/micromol lipid phosphorus). This was accompanied by an enhanced in vitro conversion of phosphatidylcholine to monoacyl glycerol (fivefold). The enhanced level of the 2-arachidonoyl glycerol, anandamide and other N-acylethanolamines detected in the two types of tumour tissue may possibly act as endogenous anti-tumour mediators by stimulation of both cannabinoid and non-cannabinoid receptor-mediated mechanisms.
Cellular telephone use and risk of acoustic neuroma.
Despite limited evidence, cellular telephones have been claimed to cause cancer, especially in the brain. In this Danish study, the authors examined the possible association between use of cellular telephones and development of acoustic neuroma. Between 2000 and 2002, they ascertained 106 incident cases and matched these persons with 212 randomly sampled, population-based controls on age and sex. The data obtained included information on use of cellular telephones from personal interviews, data from medical records, and the results of radiologic examinations. The authors obtained information on socioeconomic factors from Statistics Denmark. The overall estimated relative risk of acoustic neuroma was 0.90 (95% confidence interval: 0.51, 1.57). Use of a cell phone for 10 years or more did not increase acoustic neuroma risk over that of short-term users. Furthermore, tumors did not occur more frequently on the side of the head on which the telephone was typically used, and the size of the tumor did not correlate with the pattern of cell phone use. The results of this prospective, population-based, nationwide study, which included a large number of long-term users of cellular telephones, do not support an association between cell phone use and risk of acoustic neuroma.
[Brain death criterion--an ethical challenge].
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["Lumbar examination" and cauda equina syndrome].
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Incidences of gliomas and meningiomas in Denmark, 1943 to 1997.
OBJECTIVE: The objective of this study was to determine the nationwide, population-based incidences of intracranial gliomas and meningiomas (of all grades) during 55 years of monitoring in Denmark. METHODS: On the basis of reports in the Danish Cancer Registry, we calculated age-standardized, period-specific incidences and age- and birth cohort-specific incidences, in 5-year age and calendar intervals, for intracranial gliomas and meningiomas. RESULTS: The incidence of gliomas increased 1.7-fold from 1943 to 1947 to 1993 to 1997, whereas the incidence for meningiomas increased 3.9-fold during the same period. CONCLUSION: Based on complete notification to the Danish Cancer Registry, the overall incidences of intracranial gliomas and meningiomas increased during a 55-year period. These increases were observed for all age groups and both sexes. These increases could be explained on the basis of improved diagnoses of these tumors. For gliomas, a maximal annual incidence of approximately 4 cases/100,000 population (World Standard Population) was observed in Denmark at the end of the study period, suggesting that the effects of improved diagnostic tools have reached their maximum with respect to this tumor type. The same was not observed for the incidence of meningiomas, suggesting that perhaps underreporting is still present.
[Brain metastases].
The incidence of symptomatic brain metastases in Denmark is about 3500. In the present review, the aetiology, symptomatology, and diagnostic procedures are described. The main topic is a review of current treatments and the evidence for their efficacy. Treatment of brain metastases rarely cures the patient, the goal is rather to improve the quality of life and prolong survival. Without treatment, the median survival following diagnosis of brain metastases is about one month, with steroid treatment two months, with whole brain irradiation four to six months, and after surgery or stereotactic radiosurgery 10-12 months. A relatively simple treatment scheme based on the number of brain metastases and the overall condition of the patient is provided.
[Brain tumors. Mainly glial tumors in adults].
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Torture: a challenge to medical science.
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