Search results for "brain"
showing 10 items of 3997 documents
Predictive chromosomal clusters of synchronous and metachronous brain metastases in clear cell renal cell carcinoma
2014
Synchronous (early) and metachronous (late) brain metastasis (BM) events of sporadic clear cell renal cell carcinoma (ccRCC) (n = 148) were retrospectively analyzed using comparative genomic hybridization (CGH). Using oncogenetic tree models and cluster analyses, chromosomal imbalances related to recurrence-free survival until BM (RFS-BM) were analyzed. Losses at 9p and 9q appeared to be hallmarks of metachronous BM events, whereas an absence of detectable chromosomal changes at 3p was often associated with synchronous BM events. Correspondingly, k-means clustering showed that cluster 1 cases generally exhibited low copy number chromosomal changes that did not involve 3p. Cluster 2 cases ha…
Extent and patterns of MGMT promoter methylation in glioblastoma- and respective glioblastoma-derived spheres.
2010
Abstract Purpose: Quantitative methylation-specific tests suggest that not all cells in a glioblastoma with detectable promoter methylation of the O6-methylguanine DNA methyltransferase (MGMT) gene carry a methylated MGMT allele. This observation may indicate cell subpopulations with distinct MGMT status, raising the question of the clinically relevant cutoff of MGMT methylation therapy. Epigenetic silencing of the MGMT gene by promoter methylation blunts repair of O6-methyl guanine and has been shown to be a predictive factor for benefit from alkylating agent therapy in glioblastoma. Experimental Design: Ten paired samples of glioblastoma and respective glioblastoma-derived spheres (GS), c…
O6-methylguanine-DNA methyltransferase activity in breast and brain tumors.
1995
The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is a main determinant of resistance of tumor cells to the cytostatic activity of chemotherapeutic alkylating agents (methylating and chloroethylating nitrosoureas) and is effective in protecting normal cells against genotoxic and carcinogenic effects resulting from DNA alkylation. Therefore, the level of expression of MGMT is significant for the response of both the tumor and the non-target tissue following application of nitrosoureas in tumor therapy. To determine the expression of MGMT in tumor tissue, we have assayed MGMT activity in 68 breast carcinomas and 38 brain tumors. There was a wide variation of MGMT expression…
Environmental risk factors for sporadic acoustic neuroma (Interphone Study Group, Germany)
2007
The only known risk factor for sporadic acoustic neuroma is high-dose ionising radiation. Environmental exposures, such as radiofrequency electromagnetic fields and noise are under discussion, as well as an association with allergic diseases. We performed a population-based case-control study in Germany investigating these risk factors in 97 cases with acoustic neuroma, aged 30 to 69 years, and in 194 matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in multiple logistic regression models. Increased risks were found for exposure to persistent noise (OR=2.31; 95% CI 1.15-4.66), and for hay fever (OR=2.20; 95% CI 1.09-4.45), but not for ionising radiation …
Occupation and risk of glioma, meningioma and acoustic neuroma: results from a German case-control study (interphone study group, Germany)
2010
Background: Several epidemiological studies have investigated the association between occupation and brain tumour risk, but results have been inconclusive. We investigated the association between six occupational categories defined a priori: chemical, metal, agricultural, construction, electrical/electronic and transport, and the risk of glioma, meningioma and acoustic neuroma. Methods: In a population-based case-control study involving a total of 844 cases and 1688 controls conducted from 2000 to 2003, detailed information on life-long job histories was collected during personal interviews and used to create job calendars for each participant. Job title, job activity, job number, and the s…
Structure, chromosomal localization, and brain expression of human Cx36 gene
1999
Rat connexin-36 (Cx36) is the first gap junction protein shown to be expressed predominantly in neuronal cells of the mammalian central nervous system. As a prerequisite for studies devoted to the investigation of the possible role of this connexin in human neurological diseases, we report the cloning and sequencing of the human Cx36 gene, its chromosomal localization, and its pattern of expression in the human brain analyzed by radioactive in situ hybridization. The determination of the human gene sequence revealed that the coding sequence of Cx36 is highly conserved (98% identity at the protein level with the mouse and rat Cx36 and 80% with the ortholog perch and skate Cx35), and that the…
Reference interval determination for N-terminal-B-type natriuretic peptide (NT-proBNP): A study in blood donors
2005
We assessed reference values in a group of apparently healthy blood donors. A total of 1980 blood donors was recruited and tested for the presence of NT-proBNP using a newly developed electrochemiluminescence immunoassay (ECLIA) method. NT-proBNP clustered in all blood donors below the age of 50 years and an upper limit of normal (ULN) was found to be 84 pg/ml for males and 146 pg/ml for females. Mean NT-proBNP values increased with increasing age which was due to an increasing number of individuals exceeding the ULN. Age- and gender-appropriate NT-proBNP levels decreased with increasing hemoglobin levels. Hemoglobin but not creatinine levels influenced the NT-proBNP concentration in this c…
Cerebral oxygen saturation and cardiac output during anaesthesia in sitting position for neurosurgical procedures: a prospective observational study.
2016
Abstract Background Neurosurgical operations in the dorsal cranium often require the patient to be positioned in a sitting position. This can be associated with decreased cardiac output and cerebral hypoperfusion, and possibly, inadequate cerebral oxygenation. In the present study, cerebral oxygen saturation was measured during neurosurgery in the sitting position and correlated with cardiac output. Methods Perioperative cerebral oxygen saturation was measured continuously with two different monitors, INVOS® and FORE-SIGHT®. Cardiac output was measured at eight predefined time points using transoesophageal echocardiography. Results Forty patients were enrolled, but only 35 (20 female) were …
Volume flow in the common carotid artery does not decrease postprandially.
2003
Background and Purpose. A commonplace explanation for postprandial fatigue is the assumption of the redistribution of perfusion from the cerebral to the mesenterial territory. However, this assumption has never been scientifically proven. Methods. Because approximately 70% of the blood flow in the common carotid artery (CCA) is directed to the internal carotid artery, this vessel can be seen as a major brain-supplying artery. Flow volume in the CCA can be measured by color M-mode duplex sonography. The authors investigated the flow volume rate in 20 healthy volunteers before and after the intake of a high-energy meal. Heart rate, blood pressure, and expiratory CO2 were also measured at both…
Frontal hypoactivation and alterations in the reward-system during humor processing in patients with schizophrenia spectrum disorders
2018
Humor is a ubiquitous human ability with important implications for both social and emotional functioning. Patients with neuropsychiatric disorders, such as schizophrenia, experience difficulties in the comprehension and appreciation of humor. However, the specific neural mechanisms underlying these deficits are unknown. In the current study, we sought to elucidate the neural correlates of humor processing in patients with schizophrenia spectrum disorders (SSD). Functional Magnetic Resonance Imaging (fMRI) was used in thirty-one patients with SSD and a control group, performing a humor processing paradigm. Both regional brain activation and parametric modulation of brain responses via subje…