Database : MEDLINE
Search on : brain [Words]
References found : 1388886 [refine]
Displaying: 1 .. 10   in format [Detailed]

page 1 of 138889 go to page                         

  1 / 1388886 MEDLINE  
              next record last record
select
to print
Photocopy
Full text

[PMID]: 27797157
[Au] Autor:Golestanirad L; Angelone LM; Iacono MI; Katnani H; Wald LL; Bonmassar G
[Ad] Address:Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. lgolestanirad@mgh.harvard.edu.
[Ti] Title:Local SAR near deep brain stimulation (DBS) electrodes at 64 and 127 MHz: A simulation study of the effect of extracranial loops.
[So] Source:Magn Reson Med;, 2016 Oct 31.
[Is] ISSN:1522-2594
[Cp] Country of publication:United States
[La] Language:ENG
[Ab] Abstract:PURPOSE: MRI may cause brain tissue around deep brain stimulation (DBS) electrodes to become excessively hot, causing lesions. The presence of extracranial loops in the DBS lead trajectory has been shown to affect the specific absorption rate (SAR) of the radiofrequency energy at the electrode tip, but experimental studies have reported controversial results. The goal of this study was to perform a systematic numerical study to provide a better understanding of the effects of extracranial loops in DBS leads on the local SAR during MRI at 64 and 127 MHz. METHODS: A total of 160 numerical simulations were performed on patient-derived data, in which relevant factors including lead length and trajectory, loop location and topology, and frequency of MRI radiofrequency (RF) transmitter were assessed. RESULTS: Overall, the presence of extracranial loops reduced the local SAR in the tissue around the DBS tip compared with straight trajectories with the same length. SAR reduction was significantly larger at 127 MHz compared with 64 MHz. SAR reduction was significantly more sensitive to variable loop parameters (eg, topology and location) at 127 MHz compared with 64 MHz. CONCLUSION: Lead management strategies could exist that significantly reduce the risks of 3 Tesla (T) MRI for DBS patients. Magn Reson Med, 2016. © 2016 International Society for Magnetic Resonance in Medicine.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher
[do] DOI:10.1002/mrm.26535

  2 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 27797139
[Au] Autor:Switon K; Kotulska K; Janusz-Kaminska A; Zmorzynska J; Jaworski J
[Ad] Address:Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland.
[Ti] Title:Tuberous sclerosis complex: From molecular biology to novel therapeutic approaches.
[So] Source:IUBMB Life;, 2016 Oct 31.
[Is] ISSN:1521-6551
[Cp] Country of publication:England
[La] Language:ENG
[Ab] Abstract:Tuberous sclerosis complex (TSC) is a rare multi-system disorder, primary manifestations of which are benign tumors and lesions in various organs of the body, including the brain. TSC patients often suffer from epilepsy, mental retardation, and autism spectrum disorder (ASD). Therefore, TSC serves as a model of epilepsy, ASD, and tumorigenesis. TSC is caused by the lack of functional Tsc1-Tsc2 complex, which serves as a major cellular inhibitor of mammalian Target of Rapamycin Complex 1 (mTORC1). mTORC1 is a kinase controlling most of anabolic processes in eukaryotic cells. Consequently, mTORC1 inhibitors, such as rapamycin, serve as experimental or already approved drugs for several TSC symptoms. However, rapalogs, although quite effective, need to be administered chronically and likely for a lifetime, since therapy discontinuation results in tumor regrowth and epilepsy recurrence. Recent studies revealed that metabolism and excitability (in the case of neurons) of cells lacking Tsc1-Tsc2 complex are changed, and these features may potentially be used to treat some of TSC symptoms. In this review, we first provide basic facts about TSC and its molecular background, to next discuss the newest findings in TSC cell biology that can be used to improve existing therapies of TSC and other diseases linked to mTORC1 hyperactivation. © 2016 The Authors IUBMB Life published by Wiley Periodicals, Inc. on behalf of International Union of Biochemistry and Molecular Biology, 2016.
[Pt] Publication type:REVIEW; JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher
[do] DOI:10.1002/iub.1579

  3 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 27797114
[Au] Autor:Landheer K; Schulte R; Geraghty B; Hanstock C; Chen AP; Cunningham CH; Graham SJ
[Ad] Address:Department of Medical Biophysics, University of Toronto, Ontario, Canada. landheer@sri.utoronto.ca.
[Ti] Title:Diffusion-weighted J-resolved spectroscopy.
[So] Source:Magn Reson Med;, 2016 Oct 31.
[Is] ISSN:1522-2594
[Cp] Country of publication:United States
[La] Language:ENG
[Ab] Abstract:PURPOSE: To develop a novel diffusion-weighted magnetic resonance spectroscopy (DW-MRS) technique in conjunction with J-resolved spatially localized spectroscopy (JPRESS) to measure the apparent diffusion coefficients (ADCs) of brain metabolites beyond N-acetylaspartic acid (NAA), creatine (Cr), and choline (Cho) at 3T. This technique will be useful to probe tissue microstructures in vivo, as the various metabolites have different physiological characteristics. METHODS: Two JPRESS spectra were collected (high b-value and low b-value), and the ADCs of 16 different metabolites were estimated. Two analysis pipelines were developed: 1) a 2D pipeline that uses ProFit software to extract ADCs from metabolites not typically accessible at 3T and 2) a 1D pipeline that uses TARQUIN software to extract the metabolite concentrations from each line in the 2D dataset, allowing for scaling as well as validation. RESULTS: The ADCs of 16 different metabolites were estimated from within six subjects in parietal white matter. There was excellent agreement between the results obtained from the 1D and 2D pipelines for NAA, Cr, and Cho. CONCLUSION: The proposed technique provided consistent estimates for the ADCs of NAA, Cr, Cho, glutamate + glutamine, and myo-inositol in all subjects and additionally glutathione and scyllo-inositol in all but one subject. Magn Reson Med, 2016. © 2016 International Society for Magnetic Resonance in Medicine.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher
[do] DOI:10.1002/mrm.26514

  4 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 27797111
[Au] Autor:Ilicak E; Senel LK; Biyik E; Çukur T
[Ad] Address:Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.
[Ti] Title:Profile-encoding reconstruction for multiple-acquisition balanced steady-state free precession imaging.
[So] Source:Magn Reson Med;, 2016 Oct 31.
[Is] ISSN:1522-2594
[Cp] Country of publication:United States
[La] Language:ENG
[Ab] Abstract:PURPOSE: The scan-efficiency in multiple-acquisition balanced steady-state free precession imaging can be maintained by accelerating and reconstructing each phase-cycled acquisition individually, but this strategy ignores correlated structural information among acquisitions. Here, an improved acceleration framework is proposed that jointly processes undersampled data across N phase cycles. METHODS: Phase-cycled imaging is cast as a profile-encoding problem, modeling each image as an artifact-free image multiplied with a distinct balanced steady-state free precession profile. A profile-encoding reconstruction (PE-SSFP) is employed to recover missing data by enforcing joint sparsity and total-variation penalties across phase cycles. PE-SSFP is compared with individual compressed-sensing and parallel-imaging (ESPIRiT) reconstructions. RESULTS: In the brain and the knee, PE-SSFP yields improved image quality compared to individual compressed-sensing and other tested methods particularly for higher N values. On average, PE-SSFP improves peak SNR by 3.8 ± 3.0 dB (mean ± s.e. across N = 2-8) and structural similarity by 1.4 ± 1.2% over individual compressed-sensing, and peak SNR by 5.6 ± 0.7 dB and structural similarity by 7.1 ± 0.5% over ESPIRiT. CONCLUSION: PE-SSFP attains improved image quality and preservation of high-spatial-frequency information at high acceleration factors, compared to conventional reconstructions. PE-SSFP is a promising technique for scan-efficient balanced steady-state free precession imaging with improved reliability against field inhomogeneity. Magn Reson Med, 2016. © 2016 International Society for Magnetic Resonance in Medicine.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher
[do] DOI:10.1002/mrm.26507

  5 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 27797108
[Au] Autor:Sanaei Nezhad F; Anton A; Parkes LM; Deakin B; Williams SR
[Ad] Address:Centre for Imaging Science, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom.
[Ti] Title:Quantification of glutathione in the human brain by MR spectroscopy at 3 Tesla: Comparison of PRESS and MEGA-PRESS.
[So] Source:Magn Reson Med;, 2016 Oct 31.
[Is] ISSN:1522-2594
[Cp] Country of publication:United States
[La] Language:ENG
[Ab] Abstract:PURPOSE: Glutathione (GSH) is an important intracellular antioxidant in the brain. A number of studies report its measurement by localized (1) H spectroscopy using PRESS and STEAM. This study evaluates the reliability and accuracy of GSH measurements from PRESS at 3 Tesla (T) and compares the results to those obtained with MEGA-PRESS. METHODS: Phantoms containing brain metabolites, identical except for variable GSH concentration between 0 and 24 mM, were scanned using PRESS (echo time (TE) = 35 ms) and MEGA-PRESS (optimized TE = 130 ms) at 3 T. Spectra of the anterior cingulate cortex and occipital cortex in seven healthy volunteers were also acquired. RESULTS: Phantom GSH concentrations from 0 to 3mM were unreliably quantified using PRESS, although at 4 mM and above there was a linear relationship between measured and true concentrations (R(2) = 0.99). Using MEGA-PRESS, there was no signal detected at 0 mM GSH, plus a linear relationship (R(2) = 0.99) over the full range from 0-24 mM. In brain, concentrations calculated from MEGA-PRESS and PRESS were significantly different in occipital cortex (P < 0.001). Moreover, only MEGA-PRESS reported significant differences in GSH between the two brain regions (P = 0.003). CONCLUSION: Due to uncertainties in GSH quantification raised by the study, the authors conclude that physiological concentrations (<4 mM) of GSH cannot be reliably quantified from PRESS (TE = 35 ms) spectra at 3 T. Magn Reson Med, 2016. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher
[do] DOI:10.1002/mrm.26532

  6 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 27797107
[Au] Autor:Lee HH; Kim H
[Ad] Address:Department of Biomedical Sciences, Seoul National University, Seoul, Korea.
[Ti] Title:Parameterization of spectral baseline directly from short echo time full spectra in (1) H-MRS.
[So] Source:Magn Reson Med;, 2016 Oct 31.
[Is] ISSN:1522-2594
[Cp] Country of publication:United States
[La] Language:ENG
[Ab] Abstract:PURPOSE: To investigate the feasibility of parameterizing macromolecule (MM) resonances directly from short echo time (TE) spectra rather than pre-acquired, T1 -weighted, metabolite-nulled spectra in (1) H-MRS. METHODS: Initial line parameters for metabolites and MMs were set for rat brain spectra acquired at 9.4 Tesla upon a priori knowledge. Then, MM line parameters were optimized over several steps with fixed metabolite line parameters. The proposed method was tested by estimating metabolite T1 . The results were compared with those obtained with two existing methods. Furthermore, subject-specific, spin density-weighted, MM model spectra were generated according to the MM line parameters from the proposed method for metabolite quantification. The results were compared with those obtained with subject-specific, T1 -weighted, metabolite-nulled spectra. RESULTS: The metabolite T1 were largely in close agreement among the three methods. The spin density-weighted MM resonances from the proposed method were in good agreement with the T1 -weighted, metabolite-nulled spectra except for the MM resonance at ∼3.2 ppm. The metabolite concentrations estimated by incorporating these two different spectral baselines were also in good agreement except for several metabolites with resonances at ∼3.2 ppm. CONCLUSION: The MM parameterization directly from short-TE spectra is feasible. Further development of the method may allow for better representation of spectral baseline with negligible T1 -weighting. Magn Reson Med, 2016. © 2016 International Society for Magnetic Resonance in Medicine.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher
[do] DOI:10.1002/mrm.26502

  7 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy
Full text

[PMID]: 27797095
[Au] Autor:Madro P; Dabrowska A; Jarecki J; Garba P
[Ad] Address:Department of Anaesthesiology and Intensive Therapy, 4th Military Teaching Hospital with Outpatient Clinic in Wroclaw, Poland. pmadro@op.pl.
[Ti] Title:Anaesthesia for carotid endarterectomy. Ultrasound-guided superficial/intermediate cervical plexus block combined with carotid sheath infiltration.
[So] Source:Anaesthesiol Intensive Ther;48(4):234-238, 2016.
[Is] ISSN:1731-2515
[Cp] Country of publication:Poland
[La] Language:ENG
[Ab] Abstract:BACKGROUND: Carotid endarterectomy carries a significant risk of intraoperative brain ischaemia. Various methods for intraoperative cerebral function monitoring can be utilized, but the assessment of the patient's consciousness remains the easiest and most available method, requiring that the patient remain awake and under local/regional anaesthesia. The aim of this study was to compare infiltration anaesthesia with an ultrasound-guided superficial/combined cervical plexus block for patient safety and comfort. METHODS: Ninety-eight patients scheduled for carotid endarterectomy were randomly assigned to receive either infiltration anaesthesia performed by the surgeon or an US-guided superficial/combined cervical plexus block. The pain intensity using the numerical rating scale (NRS), the volume of local anaesthetic used and the anaesthesia-related complications were recorded. The data were analysed using selected statistical tools. RESULTS: In the US-guided group, a significantly lower volume of local anaesthetic was used (25 mL vs. 30 mL), and lower mean (1 vs. 3) and maximal (2 vs. 6) NRS scores were observed. However, hoarseness, cough and difficulty swallowing were significantly more frequent among those patients (90% vs. 27%, 30% vs. 12%, and 36% vs. 6%, respectively). CONCLUSIONS: Compared with infiltration anaesthesia, an US-guided superficial/combined cervical plexus block is an effective method for improving the comfort of the patient and the surgeon. The technique is safe, relatively simple and easy to master and requires little time to perform.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:In-Data-Review
[do] DOI:10.5603/AIT.2016.0043

  8 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy

[PMID]: 27797086
[Au] Autor:Dittrich T; Tschudin-Sutter S; Widmer AF; Rüegg S; Marsch S; Sutter R
[Ad] Address:University of Basel, Basel, Switzerland.
[Ti] Title:Risk factors for new-onset delirium in patients with bloodstream infections: independent and quantitative effect of catheters and drainages-a four-year cohort study.
[So] Source:Ann Intensive Care;6(1):104, 2016 Dec.
[Cp] Country of publication:Germany
[La] Language:ENG
[Ab] Abstract:BACKGROUND: Bloodstream infections (BSI) and delirium are frequent in critically ill patients. During systemic inflammatory response to BSI, cytokines may interact with neurotransmitters and neuronal receptors driving acute brain dysfunction. However, prospectively collected data on incidence, prediction and impact of delirium in association with BSI are lacking. This study aimed to determine the incidence and predictors of new-onset delirium and its impact on outcome in critically ill adult patients with BSI. METHODS: From 2011 to 2014, all consecutive adult patients with BSI treated in the intensive care units of an academic medical care center were identified. Pertinent clinical and microbiological data including the Intensive Care Delirium Screening Checklist (ICDSC) were assessed. Multivariable analysis was performed to identify variables independently associated with ICDSC ≥4. RESULTS: Among 240 patients, 145 (60%) had an ICDSC ≥4 (i.e., delirium). In-hospital mortality was 34%. Delirious patients had a higher mortality (40 vs. 23%; p = 0.005), a lower proportion with return to functional baseline (30 vs. 46%; p = 0.012), and a higher proportion with unfavorable outcome in survivors (74 vs. 54%; p = 0.010). Multivariable analyses revealed age (OR 1.04, 95% CI 1.02-1.06), male gender (OR 2.26, 95% CI 1.17-4.36), and the number of catheters and drainages before diagnosis of BSI (OR for every additional catheter = 1.14, 95% CI 1.04-1.25) as independent predictors for delirium (adjusted for SAPS [simplified acute physiology score] II, Riker Sedation-Agitation Scale [SAS], Sequential Organ Failure Assessment [SOFA] score, dementia and/or leukoencephalopathy, and albumin levels). CONCLUSIONS: The incidence of delirium in patients with BSI is high and associated with adverse outcome. The number of catheters and drainages may constitute a useful and readily available predictor of delirium in patients with BSI allowing to identify patients at high risk. Ultimately, reliable identification of patients at increased risk for delirium is key for allocation of specific prevention strategies.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:In-Data-Review

  9 / 1388886 MEDLINE  
              first record previous record next record last record
select
to print
Photocopy

[PMID]: 27797015
[Au] Autor:Ottaviani C; Brosschot JF; Lonigro A; Medea B; Van Diest I; Thayer JF
[Ad] Address:Neuroimaging Laboratory, Santa Lucia Foundation, via Ardeatina 306, 00142, Rome, Italy. cristina.ottaviani@uniroma1.it.
[Ti] Title:Hemodynamic Profiles of Functional and Dysfunctional Forms of Repetitive Thinking.
[So] Source:Ann Behav Med;, 2016 Oct 28.
[Is] ISSN:1532-4796
[Cp] Country of publication:United States
[La] Language:ENG
[Ab] Abstract:BACKGROUND: The ability of the human brain to escape the here and now (mind wandering) can take functional (problem solving) and dysfunctional (perseverative cognition) routes. Although it has been proposed that only the latter may act as a mediator of the relationship between stress and cardiovascular disease, both functional and dysfunctional forms of repetitive thinking have been associated with blood pressure (BP) reactivity of the same magnitude. However, a similar BP reactivity may be caused by different physiological determinants, which may differ in their risk for cardiovascular pathology. PURPOSE: To examine the way (hemodynamic profile) and the extent (compensation deficit) to which total peripheral resistance and cardiac output compensate for each other in determining BP reactivity during functional and dysfunctional types of repetitive thinking. METHODS: Fifty-six healthy participants randomly underwent a perseverative cognition, a mind wandering, and a problem solving induction, each followed by a 5-min recovery period while their cardiovascular parameters were continuously monitored. RESULTS: Perseverative cognition and problem solving (but not mind wandering) elicited BP increases of similar magnitude. However, perseverative cognition was characterized by a more vascular (versus myocardial) profile compared to mind wandering and problem solving. As a consequence, BP recovery was impaired after perseverative cognition compared to the other two conditions. CONCLUSIONS: Given that high vascular resistance and delayed recovery are the hallmarks of hypertension the results suggest a potential mechanism through which perseverative cognition may act as a mediator in the relationship between stress and risk for developing precursors to cardiovascular disease.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher

  10 / 1388886 MEDLINE  
              first record previous record
select
to print
Photocopy

[PMID]: 27796979
[Au] Autor:Zanjani SY; Eskandari MR; Kamali K; Mohseni M
[Ad] Address:Department of Food Safety and Hygiene, School of Health, Zanjan University of Medical Science, Zanjan, Iran.
[Ti] Title:The effect of probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium lactis) on the accumulation of lead in rat brains.
[So] Source:Environ Sci Pollut Res Int;, 2016 Oct 29.
[Is] ISSN:1614-7499
[Cp] Country of publication:Germany
[La] Language:ENG
[Ab] Abstract:Lead is a toxic metal present in different concentrations in a wide variety of food products. Exposure to lead, even to low levels, causes acute and chronic toxicities. Lead can cross the blood-brain barrier and accumulate in the nervous system. Probiotics are live microorganisms that, when used in adequate amounts, confer a health benefit on the host. Although a recent study demonstrated that the studied bacteria have a protective effect against acute lead toxicity, no research has been found that shows the long-term impact of these bacteria in vivo. The current study surveyed the protective effects of two species of probiotics, Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12, that are most widely used in many functional foods against oral lead exposure (4 weeks) in rat brains. The results revealed that, at the end of the second week of chronic exposure to lead and probiotic bacteria, the lowest level of lead belonged to the Lactobacillus group. At the end of the fourth week, the lowest amount of lead was related to the group receiving both types of probiotics. With the physiological benefits of probiotic consumption, the bacterial solution in this study did not show high efficacy in reducing brain lead concentrations.
[Pt] Publication type:JOURNAL ARTICLE
[Em] Entry month:1610
[Cu] Class update date: 161031
[Lr] Last revision date:161031
[St] Status:Publisher


page 1 of 138889 go to page                         
   


Refine the search
  Database : MEDLINE Advanced form   

    Search in field  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/PAHO/WHO - Latin American and Caribbean Center on Health Sciences Information