Search results for "brain"
showing 10 items of 3997 documents
Central correlation of muscle sympathetic nerve activation during baroreflex unloading - a microneurography-positron emission tomography study
2013
The baroreceptor reflex controls spontaneous fluctuations in blood pressure. One major control variable of the baroreflex is the sympathetic vasoconstrictor activity to muscles [MSNA; burst frequency (BF) and burst incidence (BI)], which can be quantitatively assessed by microneurography. We aimed to investigate the central regions involved in baroreflex regulation of MSNA. Healthy men (mean age 25 years) participated in three experimental sessions. (i) Microneurography recordings of MSNA from the left peroneal nerve during rest and baroreflex unloading, induced by lower body negative pressure (LBNP; -40 mmHg). If MSNA could be reliably recorded throughout this procedure (n = 15), the subje…
Evaluation of the apparent diffusion coefficient in patients with recurrent glioblastoma under treatment with bevacizumab with radiographic pseudores…
2017
Abstract Background Response Assessment in Neuro-Oncology Criteria (RANO), are used to asses response to first-line treatment of glioblastoma (GBM). Differentiation between response and pseudoresponse under treatment with Bevacizumab (BVZ) remains challenging. This study evaluates ADC changes in patients with radiographic pseudoresponse under treatment with (BVZ). Methods Patients (n = 40) with recurrent GBM under-treatment with BVZ underwent MRI before, two and four months after treatment with BVZ. In patients with radiological pseudoresponse (n = 11), ADC analyses were performed. Areas with decreasing T1 contrast enhancement (CE) and FLAIR signal decrease were manually selected and compar…
Alteration of major vault protein in human glioblastoma and its relation with EGFR and PTEN status.
2014
Glioblastoma (GBM) is the most frequent and malignant primary brain tumor. Conventional therapy of surgical removal, radiation and chemotherapy is largely palliative. Major vault protein (MVP), the main component of the vault organelle has been associated with multidrug resistance by reducing cellular accumulation of chemotherapeutic agents. With regard to cancer, MVP has been shown to be overexpressed in drug resistance development and malignant progression. The aim of the present study was to evaluate the MVP gene dosage levels in 113 archival samples from GBM and its correlation with patients' survival and epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog (PTEN) …
Shape analysis of the cingulum, uncinate and arcuate fasciculi in patients with bipolar disorder
2016
Background: Abnormal maturation of brain connectivity is supposed to underlie the dysfunctional emotion regulation in patients with bipolar disorder (BD). To test this hypothesis, white matter integrity is usually investigated using measures of water diffusivity provided by MRI. Here we consider a more intuitive aspect of the morphometry of the white matter tracts: the shape of the fibre bundles, which is associated with neurodevelopment. We analyzed the shape of 3 tracts involved in BD: the cingulum (CG), uncinate fasciculus (UF) and arcuate fasciculus (AF). Methods: We analyzed diffusion MRI data in patients with BD and healthy controls. The fibre bundles were reconstructed using Q-ball–b…
Clinical staging and serum cytokines in bipolar patients during euthymia
2017
Aims: Changes in serum cytokines and altered neutrophin concentration have been associated with bipolar disorder (BD). Our aim here was to analyze peripheral blood biomarkers according to the clinical stages of BD. Method: Euthymic BD-I patients were grouped according to their level of functioning in early-stage (n = 25) and late-stage (n = 23), and compared to healthy siblings (n = 23) and genetically unrelated healthy controls (n = 21). Neurotrophin (neurotrophin-3 and BDNF) concentration and biomarkers of inflammation, including cytokines (IL-6, IL-10 and TNF-alpha), leukocytes count and acute phase proteins, were measured. Results: IL-10 concentration was significantly increased in earl…
Impaired regulation of emotion: Neural correlates of reappraisal and distraction in bipolar disorder and unaffected relatives
2015
Deficient emotion regulation has been proposed as a crucial pathological mechanism in bipolar disorder (BD). We therefore investigated emotion regulation impairments in BD, the related neural underpinnings and their etiological relevance for the disorder. Twenty-two euthymic patients with bipolar-I disorder and 17 unaffected first-degree relatives of BD-I patients, as well as two groups of healthy gender-, age- and education-matched controls (N=22/17, respectively) were included. Participants underwent functional magnetic resonance imaging while applying two different emotion regulation techniques, reappraisal and distraction, when presented with emotional images. BD patients and relatives …
Scalp, earlobe and nasopharyngeal recordings of the median nerve somatosensory evoked P14 potential in coma and brain death
1996
Median nerve somatosensory evoked potentials (SEPs) were recorded in a total of 181 patients in coma and brain death. Special attention was paid to derivation of P14 (the positive potential occurring approximately 14 ms after median nerve stimulation) with different electrode montages, using midfrontal scalp (Fz), linked earlobe (A1/2), median nasopharyngeal (Pgz) and non-cephalic reference (NC) electrodes. The P14 amplitude (and, to a lesser extent, latency) were invariably lower in brain death than in coma. The potential was preserved in coma in all patients, but lost in brain death in 9.8% in Fz-NC and Pgz-NC recordings, in 23.2% in Fz-A1/2, and in 100% in Fz-Pgz. Thus, Fz-Pgz was the de…
Tc-99m HMPAO Cerebral Scintigraphy A Reliable, Noninvaslve Method for Determination of Brain Death
1993
To determine the usefulness of cerebral blood flow imaging for the diagnosis of brain death, 4 female and 12 male patients, aged 19 to 69 years and suffering from various intracranial lesions, were studied. In addition to neurologic examination, electroencephalographic recording, and cerebral angiography, tomographic brain scintigraphy was performed using a SPECT system with a LEAP collimator after the intravenous administration of 555 MBq Tc-99m HMPAO. The radioisotopic scanning procedure revealed no intracranial perfusion in 14 of the 16 patients. Only minimal cerebellar blood flow was seen in one patient. In another, residual right-sided supratentorial flow was initially present but abse…
Contrast-enhanced transcranial Doppler ultrasonography in the diagnosis of brain death
2013
The diagnosis of brain death (BD) is based on clinical criteria including deep coma, brain stem areflexia and apnoea. Depending on different local guidelines, confirmatory technical tests are sometimes mandatory.1 Since the 1990s, transcranial Doppler sonography (TCD) has found its place in these circumstances and fulfils most of the criteria of an ‘ideal test’ in confirming BD. To confirm intracranial circulatory arrest (CA) with Doppler sonography, typical flow patterns must be recorded in bilateral intracranial and extracranial brain-supplying arteries.2 A completely absent intracranial flow signal is not a reliable sign to determine CA because this can be due to transmission problems. I…
ERP correlates of transposed-letter similarity effects: Are consonants processed differently from vowels?
2007
Recent research has shown that pseudowords created by transposing letters are very effective for activating the lexical representation of their base words (e.g., relovution activates REVOLUTION). Furthermore, pseudoword transpositions of consonants are more similar to their corresponding base words than the transposition of vowels. We report one experiment using pseudowords created by the transposition of two consonants, two vowels, and their corresponding control conditions (i.e., the replacement of two consonants or two vowels) in a lexical decision task while Event Related Potentials (ERPs) were recorded. The results showed a modulation of the amplitude of the N400 component as a functio…