Search results for "nucleus"
showing 10 items of 1803 documents
Elevated [18F]FDOPA utilization in the periaqueductal gray and medial nucleus accumbens of patients with early Parkinson's disease
2010
Udgivelsesdato: 2010-Feb-15 PET studies with the DOPA decarboxylase substrate 6-[(18)F]fluoro-l-DOPA (FDOPA) reveal the storage of [(18)F]-fluorodopamine within synaptic vesicles, mainly of dopamine fibres. As such, FDOPA PET is a sensitive indicator of the integrity of the nigrostriatal dopamine innervation. Nonetheless, there have been several reports of focal elevations of FDOPA utilization in brain of patients with Parkinson's disease (PD), all based on reference tissue methods. To investigate this phenomenon further, we used voxel-wise steady-state kinetic analysis to search for regions of elevated FDOPA utilization (K; ml g(-1) min(-1)) and steady-state trapping (V(d); ml g(-1)) in a …
How many parkinsonian patients are suitable candidates for deep brain stimulation of subthalamic nucleus? Results of a questionnaire.
2008
We used a CAPSIT-based questionnaire to estimate the percentage of parkinsonian patients suitable for subthalamic nucleus (STN) deep brain stimulation (DBS) in a movement disorders clinic. We found that out of 641 consecutive PD patients only 1.6% fulfilled strict STN-DBS criteria. When we applied more flexible criteria, the percentage of eligibility increased to 4.5%. Most patients (60%) were ineligible because they did not satisfy multiple questionnaire items. Items related to disease severity were responsible for the largest number of exclusions. This knowledge will help make decisions on resource allocation in centres wishing to start DBS surgery.
Do we truly see what we think we see? The role of cognitive bias in pathological interpretation
2008
In the histomorphological grading of prostate carcinoma, pathologists have regularly assigned comparable scores for the architectural Gleason and the now-obsolete nuclear World Health Organization (WHO) grading systems. Although both systems demonstrate good correspondence between grade and survival, they are based on fundamentally different biological criteria. We tested the hypothesis that this apparent concurrence between the two grading systems originates from an interpretation bias in the minds of diagnostic pathologists, rather than reflecting a biological reality. Three pathologists graded 178 prostatectomy specimens, assigning Gleason and WHO scores on glass slides and on digital im…
Vulnerability to psychotogenic effects of ketamine is associated with elevated D2/3-receptor availability.
2012
Previous positron emission tomography (PET) studies employing competition paradigms have shown either no change or substantial declines in striatal ( 11 C)-raclopride binding after challenge with psychotogenic doses of the N-methyl-D-aspartate antagonist ketamine. We sought to probe the relationship between the severity of ketamine-induced psychotic symptoms and altered dopamine D2/3 receptor availability throughout brain using the high affinity ligand ( 18 F)-fallypride (FP). PET recordings were obtained in a group of 10 healthy, young male volunteers, in a placebo condition, and in the course of an infusion with ketamine at a psychotomimetic dose. Administration of the Positive and Negati…
Frequent blood flow restricted training not to failure and to failure induces similar gains in myonuclei and muscle mass
2021
The purpose of the present study was to compare the effects of short-term high-frequency failure vs non-failure blood flow–restricted resistance exercise (BFRRE) on changes in satellite cells (SCs), myonuclei, muscle size, and strength. Seventeen untrained men performed four sets of BFRRE to failure (Failure) with one leg and not to failure (Non-failure; 30-15-15-15 repetitions) with the other leg using knee-extensions at 20% of one repetition maximum (1RM). Fourteen sessions were distributed over two 5-day blocks, separated by a 10-day rest period. Muscle samples obtained before, at mid-training, and 10-day post-intervention (Post10) were analyzed for muscle fiber area (MFA), myonuclei, an…
Loss of the Ca2+/calmodulin-dependent protein kinase type IV in dopaminoceptive neurons enhances behavioral effects of cocaine.
2008
The persistent nature of addiction has been associated with activity-induced plasticity of neurons within the striatum and nucleus accumbens (NAc). To identify the molecular processes leading to these adaptations, we performed Cre/loxP-mediated genetic ablations of two key regulators of gene expression in response to activity, the Ca 2+ /calmodulin-dependent protein kinase IV (CaMKIV) and its postulated main target, the cAMP-responsive element binding protein (CREB). We found that acute cocaine-induced gene expression in the striatum was largely unaffected by the loss of CaMKIV. On the behavioral level, mice lacking CaMKIV in dopaminoceptive neurons displayed increased sensitivity to cocai…
Effect of changing pulse rate on profile parameters of perceptual thresholds and loudness comfort levels and relation to ECAP thresholds in recipient…
2010
Abstract: The Nucleus CI24RE Freedom device offers higher stimulation rates and lower noise levels in action potential measurements (ECAPs) than previous devices. A study including ten European implant teams showed that the effect of changes in rate from 250 to 3500 pulses per second on tilt and curvature of the T and C profiles is insignificant. When changing rate one may change the levels at all electrodes by the same amount. Using an automated procedure ECAPs could be measured quickly and reliably at a noise level of only 1 μV. However, this did not result in improved correlations between the tilt and curvature parameters of the ECAP profiles and those of the T and C profiles. Average C …
Speech perception performance as a function of stimulus pulse rate and processing strategy preference for the Cochlear™ Nucleus®CI24RE device: Relati…
2010
Current cochlear implants can operate at high pulse rates. The effect of increasing pulse rate on speech performance is not yet clear. Habituation to low rates may affect the outcome. This paper presents the results of three subsequent studies using different experimental paradigms, applying the Nucleus CI24RE device, and conducted by ten European implant teams. Pulse rate per channel varied from 500 to 3500 pulses per second with ACE and from 1200 to 3500 pps with CIS strategy. The results showed that the first rate presented had little effect on the finally preferred rate. Lower rates were preferred. The effect of pulse rate on word scores of post-linguistic implantees was small; high rat…
Epidermal growth factor receptor in human breast cancer: Correlation with cytosolic and nuclear ER receptors and with biological and histological tum…
1990
Epidermal growth factor receptor (EGFr) and cytosolic (cER) and nuclear (nER) estradiol receptors were quantified in 220 primary breast cancers. The EGFr was significantly more frequent (chi 2 = 5.9; P less than 0.025) and its concentration was significantly higher (P less than 0.001) among ER- tumors than in ER+ tumors. There was a significantly greater proportion (chi 2 = 6.4; P less than 0.05) of node involvement in EGFr+/ER+ tumors than in EFGr-/ER+. Increases in the proportion of EGFr+ in ER- tumors are parallel to Scarff-Bloom scores (chi 2 = 6.1; P less than 0.05) and there is a significant trend (Spearman rs = 0.25; P less than 0.05) towards increased EGFr concentrations with histol…
Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study.
1992
Cytogenetic, flow cytometric, cytophotometric and morphometric analyses were performed on 22 previously untreated, primary solid breast carcinomas. Although the cell nuclei as the primary object of these studies were the same in all the tumors, distinct features were evaluated in each case to determine to what degree the results obtained by these techniques are comparable. From the cytogenetic viewpoint, six tumors had a modal number in the diploid range, seven were in the triploid range, and two in the tetraploid range; seven tumors had no modal number. These data correlate with the flow cytometry and cytophotometry results obtained, with DNA values slightly higher than their respective ch…