Frequency of brain tissue donation for research after suicide.

PubMed

Longaray, Vanessa K; Padoan, Carolina S; Goi, Pedro D; da Fonseca, Rodrigo C; Vieira, Daniel C; Oliveira, Francine H de; Kapczinski, Flávio; Magalhães, Pedro V

2017-01-01

To describe the frequency of brain tissue donation for research purposes by families of individuals that committed suicide. All requests for brain tissue donation to a brain biorepository made to the families of individuals aged 18-60 years who had committed suicide between March 2014 and February 2016 were included. Cases presenting with brain damage due to acute trauma were excluded. Fifty-six cases of suicide were reported. Of these, 24 fulfilled the exclusion criteria, and 11 others were excluded because no next of kin was found to provide informed consent. Of the 21 remaining cases, brain tissue donation was authorized in nine (tissue fragments in seven and the entire organ in two). Donation of brain tissue from suicide cases for research purposes is feasible. The acceptance rate of 42.8% in our sample is in accordance with international data on such donations, and similar to rates reported for neurodegenerative diseases.

Impact of Neurodegenerative Diseases on Drug Binding to Brain Tissues: From Animal Models to Human Samples.

PubMed

Ugarte, Ana; Corbacho, David; Aymerich, María S; García-Osta, Ana; Cuadrado-Tejedor, Mar; Oyarzabal, Julen

2018-04-19

Drug efficacy in the central nervous system (CNS) requires an additional step after crossing the blood-brain barrier. Therapeutic agents must reach their targets in the brain to modulate them; thus, the free drug concentration hypothesis is a key parameter for in vivo pharmacology. Here, we report the impact of neurodegeneration (Alzheimer's disease (AD) and Parkinson's disease (PD) compared with healthy controls) on the binding of 10 known drugs to postmortem brain tissues from animal models and humans. Unbound drug fractions, for some drugs, are significantly different between healthy and injured brain tissues (AD or PD). In addition, drugs binding to brain tissues from AD and PD animal models do not always recapitulate their binding to the corresponding human injured brain tissues. These results reveal potentially relevant implications for CNS drug discovery.

A family of hyperelastic models for human brain tissue

NASA Astrophysics Data System (ADS)

Mihai, L. Angela; Budday, Silvia; Holzapfel, Gerhard A.; Kuhl, Ellen; Goriely, Alain

2017-09-01

Experiments on brain samples under multiaxial loading have shown that human brain tissue is both extremely soft when compared to other biological tissues and characterized by a peculiar elastic response under combined shear and compression/tension: there is a significant increase in shear stress with increasing axial compression compared to a moderate increase with increasing axial tension. Recent studies have revealed that many widely used constitutive models for soft biological tissues fail to capture this characteristic response. Here, guided by experiments of human brain tissue, we develop a family of modeling approaches that capture the elasticity of brain tissue under varying simple shear superposed on varying axial stretch by exploiting key observations about the behavior of the nonlinear shear modulus, which can be obtained directly from the experimental data.

Novel strategies of Raman imaging for brain tumor research.

PubMed

Anna, Imiela; Bartosz, Polis; Lech, Polis; Halina, Abramczyk

2017-10-17

Raman diagnostics and imaging have been shown to be an effective tool for the analysis and discrimination of human brain tumors from normal structures. Raman spectroscopic methods have potential to be applied in clinical practice as they allow for identification of tumor margins during surgery. In this study, we investigate medulloblastoma (grade IV WHO) (n= 5), low-grade astrocytoma (grades I-II WHO) (n =4), ependymoma (n=3) and metastatic brain tumors (n= 1) and the tissue from the negative margins used as normal controls. We compare a high grade medulloblastoma, low grade astrocytoma and non-tumor samples from human central nervous system (CNS) tissue. Based on the properties of the Raman vibrational features and Raman images we provide a real-time feedback method that is label-free to monitor tumor metabolism that reveals reprogramming of biosynthesis of lipids, proteins, DNA and RNA. Our results indicate marked metabolic differences between low and high grade brain tumors. We discuss molecular mechanisms causing these metabolic changes, particularly lipid alterations in malignant medulloblastoma and low grade gliomas that may shed light on the mechanisms driving tumor recurrence thereby revealing new approaches for the treatment of malignant glioma. We have found that the high-grade tumors of central nervous system (medulloblastoma) exhibit enhanced level of β-sheet conformation and down-regulated level of α-helix conformation when comparing against normal tissue. We have found that almost all tumors studied in the paper have increased Raman signals of nucleic acids. This increase can be interpreted as increased DNA/RNA turnover in brain tumors. We have shown that the ratio of Raman intensities I 2930 /I 2845 at 2930 and 2845 cm -1 is a good source of information on the ratio of lipid and protein contents. We have found that the ratio reflects the different lipid and protein contents of cancerous brain tissue compared to the non-tumor tissue. We found that levels of the saturated fatty acids were significantly reduced in the high grade medulloblastoma samples compared with non-tumor brain samples and low grade astrocytoma. Differences were also noted in the n-6/n-3 polyunsaturated fatty acids (PUFA) content between medulloblastoma and non-tumor brain samples. The content of the oleic acid (OA) was significantly smaller in almost all brain high grade brain tumors than that observed in the control samples. It indicates that the fatty acid composition of human brain tumors differs from that found in non-tumor brain tissue. The iodine number N I for the normal brain tissue is 60. For comparison OA has 87, docosahexaenoic acid (DHA) 464, α-linolenic acid (ALA) 274. The high grade tumors have the iodine numbers between that for palmitic acid, stearic acid, arachidic acid (N I =0) and oleic acid (N I =87). Most low grade tumors have N I similar to that of OA. The iodine number for arachidonic acid (AA) (N I =334) is much higher than those observed for all studied samples.

Novel strategies of Raman imaging for brain tumor research

PubMed Central

Anna, Imiela; Bartosz, Polis; Lech, Polis; Halina, Abramczyk

2017-01-01

Raman diagnostics and imaging have been shown to be an effective tool for the analysis and discrimination of human brain tumors from normal structures. Raman spectroscopic methods have potential to be applied in clinical practice as they allow for identification of tumor margins during surgery. In this study, we investigate medulloblastoma (grade IV WHO) (n= 5), low-grade astrocytoma (grades I-II WHO) (n =4), ependymoma (n=3) and metastatic brain tumors (n= 1) and the tissue from the negative margins used as normal controls. We compare a high grade medulloblastoma, low grade astrocytoma and non-tumor samples from human central nervous system (CNS) tissue. Based on the properties of the Raman vibrational features and Raman images we provide a real–time feedback method that is label-free to monitor tumor metabolism that reveals reprogramming of biosynthesis of lipids, proteins, DNA and RNA. Our results indicate marked metabolic differences between low and high grade brain tumors. We discuss molecular mechanisms causing these metabolic changes, particularly lipid alterations in malignant medulloblastoma and low grade gliomas that may shed light on the mechanisms driving tumor recurrence thereby revealing new approaches for the treatment of malignant glioma. We have found that the high-grade tumors of central nervous system (medulloblastoma) exhibit enhanced level of β-sheet conformation and down-regulated level of α-helix conformation when comparing against normal tissue. We have found that almost all tumors studied in the paper have increased Raman signals of nucleic acids. This increase can be interpreted as increased DNA/RNA turnover in brain tumors. We have shown that the ratio of Raman intensities I2930/I2845 at 2930 and 2845 cm-1 is a good source of information on the ratio of lipid and protein contents. We have found that the ratio reflects the different lipid and protein contents of cancerous brain tissue compared to the non-tumor tissue. We found that levels of the saturated fatty acids were significantly reduced in the high grade medulloblastoma samples compared with non-tumor brain samples and low grade astrocytoma. Differences were also noted in the n-6/n-3 polyunsaturated fatty acids (PUFA) content between medulloblastoma and non-tumor brain samples. The content of the oleic acid (OA) was significantly smaller in almost all brain high grade brain tumors than that observed in the control samples. It indicates that the fatty acid composition of human brain tumors differs from that found in non-tumor brain tissue. The iodine number NI for the normal brain tissue is 60. For comparison OA has 87, docosahexaenoic acid (DHA) 464, α-linolenic acid (ALA) 274. The high grade tumors have the iodine numbers between that for palmitic acid, stearic acid, arachidic acid (NI=0) and oleic acid (NI=87). Most low grade tumors have NI similar to that of OA. The iodine number for arachidonic acid (AA) (NI=334) is much higher than those observed for all studied samples. PMID:29156720

The national DBS brain tissue network pilot study: need for more tissue and more standardization.

PubMed

Vedam-Mai, V; Krock, N; Ullman, M; Foote, K D; Shain, W; Smith, K; Yachnis, A T; Steindler, D; Reynolds, B; Merritt, S; Pagan, F; Marjama-Lyons, J; Hogarth, P; Resnick, A S; Zeilman, P; Okun, M S

2011-08-01

Over 70,000 DBS devices have been implanted worldwide; however, there remains a paucity of well-characterized post-mortem DBS brains available to researchers. We propose that the overall understanding of DBS can be improved through the establishment of a Deep Brain Stimulation-Brain Tissue Network (DBS-BTN), which will further our understanding of DBS and brain function. The objectives of the tissue bank are twofold: (a) to provide a complete (clinical, imaging and pathological) database for DBS brain tissue samples, and (b) to make available DBS tissue samples to researchers, which will help our understanding of disease and underlying brain circuitry. Standard operating procedures for processing DBS brains were developed as part of the pilot project. Complete data files were created for individual patients and included demographic information, clinical information, imaging data, pathology, and DBS lead locations/settings. 19 DBS brains were collected from 11 geographically dispersed centers from across the U.S. The average age at the time of death was 69.3 years (51-92, with a standard deviation or SD of 10.13). The male:female ratio was almost 3:1. Average post-mortem interval from death to brain collection was 10.6 h (SD of 7.17). The DBS targets included: subthalamic nucleus, globus pallidus interna, and ventralis intermedius nucleus of the thalamus. In 16.7% of cases the clinical diagnosis failed to match the pathological diagnosis. We provide neuropathological findings from the cohort, and perilead responses to DBS. One of the most important observations made in this pilot study was the missing data, which was approximately 25% of all available data fields. Preliminary results demonstrated the feasibility and utility of creating a National DBS-BTN resource for the scientific community. We plan to improve our techniques to remedy omitted clinical/research data, and expand the Network to include a larger donor pool. We will enhance sample preparation to facilitate advanced molecular studies and progenitor cell retrieval.

Tissue and organ donation for research in forensic pathology: the MRC Sudden Death Brain and Tissue Bank.

PubMed

Millar, T; Walker, R; Arango, J-C; Ironside, J W; Harrison, D J; MacIntyre, D J; Blackwood, D; Smith, C; Bell, J E

2007-12-01

Novel methodological approaches to the investigation of brain and non-central nervous system disorders have led to increased demand for well-characterized, high quality human tissue samples, particularly from control cases. In the setting of the new Human Tissue legislation, we sought to determine whether relatives who have been suddenly bereaved are willing to grant authorization for research use of post mortem tissue samples and organs in sufficient numbers to support the establishment of a brain and tissue bank based in the forensic service. Research authorization was sought from families on the day prior to forensic post mortem examination followed up by written confirmation. We have to date selected individuals who have died suddenly (age range 1-89 years) and who were likely to have normal brains or who had displayed symptoms of a CNS disorder of interest to researchers, including psychiatric disorders. One hundred and eleven families have been approached during the first 2 years of this project. Research use of tissue samples was authorized by 96% of families and 17% agreed to whole brain donation. Audit of families' experience does not suggest that they are further distressed by being approached. Respondents expressed a clear view that the opportunity for research donation should be open to all bereaved families. Despite the sometimes long post mortem intervals, the quality of tissue samples is good, as assessed by a range of markers including Agilent BioAnalyzer quantification of RNA integrity (mean value 6.4). We conclude that the vast majority of families are willing to support research use of post mortem tissues even in the context of sudden bereavement and despite previous adverse publicity. The potential for acquisition of normal CNS and non-CNS tissues and of various hard-to-get CNS disorders suggests that efforts to access the forensic post mortem service for research material are eminently worthwhile. (c) 2007 Pathological Society of Great Britain and Ireland

Composite technique for regional neurochemical studies: measurement of energy and neurotransmitter metabolites in single tissue sample.

PubMed

Djuricic, B M; Ueki, Y; Spatz, M

1985-06-01

A combined method is described for the determination of various metabolites from a single tissue sample of the brain. It comprises a quick inactivation of cerebral enzymes by microwave irradiation, easy separation of the desired brain regions, and perchloric acid extraction of tissue substances, which are assayed either by specific enzymatic techniques or by HPLC with electrochemical detection. The obtained values of most energy and neurotransmitter metabolites in the brain are in agreement with those reported using other methods. However, this technique, in contrast to the brain freezing in vitro or freeze-blowing, provides a more efficient procedure for rapid arrest of cerebral metabolism even in the deep brain structures and is therefore suitable for detection of early changes particularly those occurring in experimental pathological conditions such as ischemia.

Determination of pharmacological levels of harmane, harmine and harmaline in mammalian brain tissue, cerebrospinal fluid and plasma by high-performance liquid chromatography with fluorimetric detection.

PubMed

Moncrieff, J

1989-11-24

Increased blood aldehyde levels, as occur in alcohol intoxication, could lead to the formation of beta-carbolines such as harmane by condensation with indoleamines. Endogenous beta-carbolines, therefore, should occur in specific brain areas where indoleamine concentrations are high, whilst exogenous beta-carbolines should exhibit an even distribution. The author presents direct and sensitive methods for assaying the beta-carbolines harmane, harmine and harmaline in brain tissue, cerebrospinal fluid and plasma at picogram sample concentrations using reversed-phase high-performance liquid chromatography with fluorimetric detection and minimal sample preparation. Using these assay methods, it was found that the distribution of beta-carbolines from a source exogenous to the brain results in a relatively even distribution within the brain tissue.

Pathological changes in Alzheimer"s brain evaluated with fluorescence emission analysis (FEA)

NASA Astrophysics Data System (ADS)

Christov, Alexander; Ottman, Todd; Grammas, Paula

2004-07-01

Development of AD is associated with cerebrovascular deposition of amyloid beta (Aβ) as well as a progressive increase in vasular collagen content. Both AΒ and collagen are naturally fluorescent compounds when exposed to UV light. We analyzed autofluorescence emitted from brain tissue samples and isolated brain resistance vessels harvested postmortem from patients with Alzheimer's disease (AD) and age-matched controls. Fluorescence emission, excited at 355 nm with an Nd:YAG laser, was measured using a fiber-optic based fluorescence spectroscopic system for tissue analysis. Significantly higher values of fluorescence emission intensity (P<0.001) in the spectral region from 465 to 490 nm were detected in brain resistance vessel samples from AD patients compared to the normal individuals. Results from western blot analysis showed elevated levels of type I and type III collagen, and reduced levels of type IV collagen in resistance vessels from AD patients, compared to control samples. In addition, using direct scanning of the cortical suface for fluoresxcence emission by the laser-induced fluorescence spectroscopy system we detected a significantly (P<0.05) higher level of apoptosis in AD brain tissue compared to age-matched controls. Fluorescence emission analysis (FEA) appears to be a sensitive technique for detecting structural changes in AD brain tissue.

Metastasis Infiltration: An Investigation of the Postoperative Brain-Tumor Interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raore, Bethwel; Schniederjan, Matthew; Prabhu, Roshan

Purpose: This study aims to evaluate brain infiltration of metastatic tumor cells past the main tumor resection margin to assess the biological basis for the use of stereotactic radiosurgery treatment of the tumor resection cavity and visualized resection edge or clinical target volume. Methods and Materials: Resection margin tissue was obtained after gross total resection of a small group of metastatic lesions from a variety of primary sources. The tissue at the border of the tumor and brain tissue was carefully oriented and processed to evaluate the presence of tumor cells within brain tissue and their distance from the resectionmore » margin. Results: Microscopic assessment of the radially oriented tissue samples showed no tumor cells infiltrating the surrounding brain tissue. Among the positive findings were reactive astrocytosis observed on the brain tissue immediately adjacent to the tumor resection bed margin. Conclusions: The lack of evidence of metastatic tumor cell infiltration into surrounding brain suggests the need to target only a narrow depth of the resection cavity margin to minimize normal tissue injury and prevent treatment size-dependent stereotactic radiosurgery complications.« less

Brain invasion assessability in meningiomas is related to meningioma size and grade, and can be improved by extensive sampling of the surgically removed meningioma specimen.

PubMed

Pizem, Joze; Velnar, Tomaz; Prestor, Borut; Mlakar, Jernej; Popovic, Mara

2014-01-01

Despite the important prognostic value of brain invasion in meningiomas, little attention has been paid to its massessment, and the parameters associated with brain invasion assessability (identification of brain tissue in the surgical specimen) are not well characterized. The aim of our study was to determine the parameters that are associated with brain invasion assessability and brain invasion in meningiomas. By binary logistic regression analysis, we studied the association of various clinical and pathologic parameters with brain invasion assessabilitym and brain invasion in 294 meningiomas: 149 unselected consecutive meningiomas with extensive sampling, diagnosed in 2009 and 2010, collected prospectively, and 145 meningiomas diagnosed in 1999 and 2000 when little attention was paid to brain invasion assessment. Meningioma grade, size and number of tissue blocks were independent predictors of brain invasion assessability. Brain tissue was identified in 78 of 233 (33%) benign, 33 of 51 (65%) atypical, and 10 of 10 (100%) malignant meningiomas. In univariate analysis, group (prospective vs.retrospective), type (recurrent vs. primary), cleavability, meningioma grade and mitotic count were predictors of brain invasion, while only meningioma grade, and group retained predictive value in multivariate analysis. Brain invasion, when assessable, was identified in 22 of 78 (28%) benign, 21 of 33 (64%) atypical, and 10 of 10 (100%) malignant meningiomas. Brain invasion assessability is related to meningioma grade and size and can be improved by extensive sampling of meningioma surgical.

Dye-enhanced multimodal confocal imaging as a novel approach to intraoperative diagnosis of brain tumors.

PubMed

Snuderl, Matija; Wirth, Dennis; Sheth, Sameer A; Bourne, Sarah K; Kwon, Churl-Su; Ancukiewicz, Marek; Curry, William T; Frosch, Matthew P; Yaroslavsky, Anna N

2013-01-01

Intraoperative diagnosis plays an important role in accurate sampling of brain tumors, limiting the number of biopsies required and improving the distinction between brain and tumor. The goal of this study was to evaluate dye-enhanced multimodal confocal imaging for discriminating gliomas from nonglial brain tumors and from normal brain tissue for diagnostic use. We investigated a total of 37 samples including glioma (13), meningioma (7), metastatic tumors (9) and normal brain removed for nontumoral indications (8). Tissue was stained in 0.05 mg/mL aqueous solution of methylene blue (MB) for 2-5 minutes and multimodal confocal images were acquired using a custom-built microscope. After imaging, tissue was formalin fixed and paraffin embedded for standard neuropathologic evaluation. Thirteen pathologists provided diagnoses based on the multimodal confocal images. The investigated tumor types exhibited distinctive and complimentary characteristics in both the reflectance and fluorescence responses. Images showed distinct morphological features similar to standard histology. Pathologists were able to distinguish gliomas from normal brain tissue and nonglial brain tumors, and to render diagnoses from the images in a manner comparable to haematoxylin and eosin (H&E) slides. These results confirm the feasibility of multimodal confocal imaging for intravital intraoperative diagnosis. © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology.

Determination of friction coefficient in unconfined compression of brain tissue.

PubMed

Rashid, Badar; Destrade, Michel; Gilchrist, Michael D

2012-10-01

Unconfined compression tests are more convenient to perform on cylindrical samples of brain tissue than tensile tests in order to estimate mechanical properties of the brain tissue because they allow homogeneous deformations. The reliability of these tests depends significantly on the amount of friction generated at the specimen/platen interface. Thus, there is a crucial need to find an approximate value of the friction coefficient in order to predict a possible overestimation of stresses during unconfined compression tests. In this study, a combined experimental-computational approach was adopted to estimate the dynamic friction coefficient μ of porcine brain matter against metal platens in compressive tests. Cylindrical samples of porcine brain tissue were tested up to 30% strain at variable strain rates, both under bonded and lubricated conditions in the same controlled environment. It was established that μ was equal to 0.09±0.03, 0.18±0.04, 0.18±0.04 and 0.20±0.02 at strain rates of 1, 30, 60 and 90/s, respectively. Additional tests were also performed to analyze brain tissue under lubricated and bonded conditions, with and without initial contact of the top platen with the brain tissue, with different specimen aspect ratios and with different lubricants (Phosphate Buffer Saline (PBS), Polytetrafluoroethylene (PTFE) and Silicone). The test conditions (lubricant used, biological tissue, loading velocity) adopted in this study were similar to the studies conducted by other research groups. This study will help to understand the amount of friction generated during unconfined compression of brain tissue for strain rates of up to 90/s. Copyright © 2012 Elsevier Ltd. All rights reserved.

Metabolomics studies in brain tissue: A review.

PubMed

Gonzalez-Riano, Carolina; Garcia, Antonia; Barbas, Coral

2016-10-25

Brain is still an organ with a composition to be discovered but beyond that, mental disorders and especially all diseases that curse with dementia are devastating for the patient, the family and the society. Metabolomics can offer an alternative tool for unveiling new insights in the discovery of new treatments and biomarkers of mental disorders. Until now, most of metabolomic studies have been based on biofluids: serum/plasma or urine, because brain tissue accessibility is limited to animal models or post mortem studies, but even so it is crucial for understanding the pathological processes. Metabolomics studies of brain tissue imply several challenges due to sample extraction, along with brain heterogeneity, sample storage, and sample treatment for a wide coverage of metabolites with a wide range of concentrations of many lipophilic and some polar compounds. In this review, the current analytical practices for target and non-targeted metabolomics are described and discussed with emphasis on critical aspects: sample treatment (quenching, homogenization, filtration, centrifugation and extraction), analytical methods, as well as findings considering the used strategies. Besides that, the altered analytes in the different brain regions have been associated with their corresponding pathways to obtain a global overview of their dysregulation, trying to establish the link between altered biological pathways and pathophysiological conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Pharmacokinetics and brain penetration of carbapenems in mice.

PubMed

Matsumoto, Kazuaki; Kurihara, Yuji; Kuroda, Yuko; Hori, Seiji; Kizu, Junko

2016-05-01

An adverse effect associated with the administration of carbapenems is central nervous system (CNS) toxicity, with higher brain concentrations of carbapenems being linked to an increased risk of seizures. However, the pharmacokinetics and brain penetration of carbapenems have not yet been examined. Thus, the aim of this in vivo investigation was to determine the pharmacokinetics and brain penetration of carbapenems in mice. Blood samples and brain tissue samples were obtained 10, 20, 30, 60, and 120 min after the subcutaneous administration of carbapenems (91 mg/kg). We obtained the following values for the pharmacokinetic parameters of carbapenems in mice: 1.20-1.71 L/h/kg for CLtotal/F, 1.41-2.03 h(-1) for Ke, 0.34-0.51 h for T1/2, 0.66-0.95 L/kg for Vss/F, 0.49-0.73 h for MRT, 83.46-110.58 μg/mL for Cmax, plasma, and 0.28-0.83 μg/g for Cmax, brain tissue. The AUC0-∞ of the carbapenems tested in plasma were in the following order: doripenem > meropenem > biapenem > imipenem, and in brain tissue were: imipenem > doripenem > meropenem > biapenem. The degrees of brain tissue penetration, defined as the AUC0-∞, brain tissue/fAUC0-∞, plasma ratio, were 0.016 for imipenem, 0.004 for meropenem, 0.002 for biapenem, and 0.008 for doripenem. The results of the present study demonstrated that, of the carbapenems examined, imipenem penetrated brain tissue to the greatest extent. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Anomalous frequency-dependent ionic conductivity of lesion-laden human-brain tissue

NASA Astrophysics Data System (ADS)

Emin, David; Akhtari, Massoud; Fallah, Aria; Vinters, Harry V.; Mathern, Gary W.

2017-10-01

We study the effect of lesions on our four-electrode measurements of the ionic conductivity of (˜1 cm3) samples of human brain excised from patients undergoing pediatric epilepsy surgery. For most (˜94%) samples, the low-frequency ionic conductivity rises upon increasing the applied frequency. We attributed this behavior to the long-range (˜0.4 mm) diffusion of solvated sodium cations before encountering intrinsic impenetrable blockages such as cell membranes, blood vessels, and cell walls. By contrast, the low-frequency ionic conductivity of some (˜6%) brain-tissue samples falls with increasing applied frequency. We attribute this unusual frequency-dependence to the electric-field induced liberation of sodium cations from traps introduced by the unusually severe pathology observed in samples from these patients. Thus, the anomalous frequency-dependence of the ionic conductivity indicates trap-producing brain lesions.

Development of solid-phase microextraction coupled with liquid chromatography for analysis of tramadol in brain tissue using its molecularly imprinted polymer.

PubMed

Habibi-Khorasani, Monireh; Mohammadpour, Amir Hooshang; Mohajeri, Seyed Ahmad

2017-02-01

In this work, performance of a molecularly imprinted polymer (MIP) as a selective solid-phase microextraction sorbent for the extraction and enrichment of tramadol in aqueous solution and rabbit brain tissue, is described. Binding properties of MIPs were studied in comparison with their nonimprinted polymer (NIP). Ten milligrams of the optimized MIP was then evaluated as a sorbent, for preconcentration, in molecularly imprinted solid-phase microextraction (MISPME) of tramadol from aqueous solution and rabbit brain tissue. The analytical method was calibrated in the range of 0.004 ppm (4 ng mL -1 ) and 10 ppm (10 μg mL -1 ) in aqueous media and in the ranges of 0.01 and 10 ppm in rabbit brain tissue, respectively. The results indicated significantly higher binding affinity of MIPs to tramadol, in comparison with NIP. The MISPME procedure was developed and optimized with a recovery of 81.12-107.54% in aqueous solution and 76.16-91.20% in rabbit brain tissue. The inter- and intra-day variation values were <8.24 and 5.06%, respectively. Finally the calibrated method was applied for determination of tramadol in real rabbit brain tissue samples after administration of a lethal dose. Our data demonstrated the potential of MISPME for rapid, sensitive and cost-effective sample analysis. Copyright © 2016 John Wiley & Sons, Ltd.

Biochemical Fractionation and Stable Isotope Dilution Liquid Chromatography-mass Spectrometry for Targeted and Microdomain-specific Protein Quantification in Human Postmortem Brain Tissue*

PubMed Central

MacDonald, Matthew L.; Ciccimaro, Eugene; Prakash, Amol; Banerjee, Anamika; Seeholzer, Steven H.; Blair, Ian A.; Hahn, Chang-Gyu

2012-01-01

Synaptic architecture and its adaptive changes require numerous molecular events that are both highly ordered and complex. A majority of neuropsychiatric illnesses are complex trait disorders, in which multiple etiologic factors converge at the synapse via many signaling pathways. Investigating the protein composition of synaptic microdomains from human patient brain tissues will yield valuable insights into the interactions of risk genes in many disorders. These types of studies in postmortem tissues have been limited by the lack of proper study paradigms. Thus, it is necessary not only to develop strategies to quantify protein and post-translational modifications at the synapse, but also to rigorously validate them for use in postmortem human brain tissues. In this study we describe the development of a liquid chromatography-selected reaction monitoring method, using a stable isotope-labeled neuronal proteome standard prepared from the brain tissue of a stable isotope-labeled mouse, for the multiplexed quantification of target synaptic proteins in mammalian samples. Additionally, we report the use of this method to validate a biochemical approach for the preparation of synaptic microdomain enrichments from human postmortem prefrontal cortex. Our data demonstrate that a targeted mass spectrometry approach with a true neuronal proteome standard facilitates accurate and precise quantification of over 100 synaptic proteins in mammalian samples, with the potential to quantify over 1000 proteins. Using this method, we found that protein enrichments in subcellular fractions prepared from human postmortem brain tissue were strikingly similar to those prepared from fresh mouse brain tissue. These findings demonstrate that biochemical fractionation methods paired with targeted proteomic strategies can be used in human brain tissues, with important implications for the study of neuropsychiatric disease. PMID:22942359

NASA Robotic Neurosurgery Testbed

NASA Technical Reports Server (NTRS)

Mah, Robert

1997-01-01

The detection of tissue interface (e.g., normal tissue, cancer, tumor) has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations, In neurosurgery, the needle used in the standard stereotactic CT or MRI guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. In addition, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle tearing a blood vessel within the brain is the most devastating complication of stereotactic CT/MRI guided brain biopsy. A robotic neurosurgery testbed has been developed at NASA Ames Research Center as a spin-off of technologies from space, aeronautics and medical programs. The invention entitled "Robotic Neurosurgery Leading to Multimodality Devices for Tissue Identification" is nearing a state ready for commercialization. The devices will: 1) improve diagnostic accuracy and precision of general surgery, with near term emphasis on stereotactic brain biopsy, 2) automate tissue identification, with near term emphasis on stereotactic brain biopsy, to permit remote control of the procedure, and 3) reduce morbidity for stereotactic brain biopsy. The commercial impact from this work is the potential development of a whole new generation of smart surgical tools to increase the safety, accuracy and efficiency of surgical procedures. Other potential markets include smart surgical tools for tumor ablation in neurosurgery, general exploratory surgery, prostate cancer surgery, and breast cancer surgery.

NASA Robotic Neurosurgery Testbed

NASA Technical Reports Server (NTRS)

Mah, Robert

1997-01-01

The detection of tissue interface (e.g., normal tissue, cancer, tumor) has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations. In neurosurgery, the needle used in the standard stereotactic CT (Computational Tomography) or MRI (Magnetic Resonance Imaging) guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. In addition, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle tearing a blood vessel within the brain is the most devastating complication of stereotactic CT/MRI guided brain biopsy. A robotic neurosurgery testbed has been developed at NASA Ames Research Center as a spin-off of technologies from space, aeronautics and medical programs. The invention entitled 'Robotic Neurosurgery Leading to Multimodality Devices for Tissue Identification' is nearing a state ready for commercialization. The devices will: 1) improve diagnostic accuracy and precision of general surgery, with near term emphasis on stereotactic brain biopsy, 2) automate tissue identification, with near term emphasis on stereotactic brain biopsy, to permit remote control of the procedure, and 3) reduce morbidity for stereotactic brain biopsy. The commercial impact from this work is the potential development of a whole new generation of smart surgical tools to increase the safety, accuracy and efficiency of surgical procedures. Other potential markets include smart surgical tools for tumor ablation in neurosurgery, general exploratory surgery, prostate cancer surgery, and breast cancer surgery.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emin, David, E-mail: emin@unm.edu; Akhtari, Massoud; Ellingson, B. M.

We analyze the transient-dc and frequency-dependent electrical conductivities between blocking electrodes. We extend this analysis to measurements of ions’ transport in freshly excised bulk samples of human brain tissue whose complex cellular structure produces blockages. The associated ionic charge-carrier density and diffusivity are consistent with local values for sodium cations determined non-invasively in brain tissue by MRI (NMR) and diffusion-MRI (spin-echo NMR). The characteristic separation between blockages, about 450 microns, is very much shorter than that found for sodium-doped gel proxies for brain tissue, >1 cm.

Optical pathology of human brain metastasis of lung cancer using combined resonance Raman and spatial frequency spectroscopies

NASA Astrophysics Data System (ADS)

Zhou, Yan; Liu, Cheng-hui; Pu, Yang; Cheng, Gangge; Zhou, Lixin; Chen, Jun; Zhu, Ke; Alfano, Robert R.

2016-03-01

Raman spectroscopy has become widely used for diagnostic purpose of breast, lung and brain cancers. This report introduced a new approach based on spatial frequency spectra analysis of the underlying tissue structure at different stages of brain tumor. Combined spatial frequency spectroscopy (SFS), Resonance Raman (RR) spectroscopic method is used to discriminate human brain metastasis of lung cancer from normal tissues for the first time. A total number of thirty-one label-free micrographic images of normal and metastatic brain cancer tissues obtained from a confocal micro- Raman spectroscopic system synchronously with examined RR spectra of the corresponding samples were collected from the identical site of tissue. The difference of the randomness of tissue structures between the micrograph images of metastatic brain tumor tissues and normal tissues can be recognized by analyzing spatial frequency. By fitting the distribution of the spatial frequency spectra of human brain tissues as a Gaussian function, the standard deviation, σ, can be obtained, which was used to generate a criterion to differentiate human brain cancerous tissues from the normal ones using Support Vector Machine (SVM) classifier. This SFS-SVM analysis on micrograph images presents good results with sensitivity (85%), specificity (75%) in comparison with gold standard reports of pathology and immunology. The dual-modal advantages of SFS combined with RR spectroscopy method may open a new way in the neuropathology applications.

Effect of dietary docosahexaenoic acid (DHA) in phospholipids or triglycerides on brain DHA uptake and accretion.

PubMed

Kitson, Alex P; Metherel, Adam H; Chen, Chuck T; Domenichiello, Anthony F; Trépanier, Marc-Olivier; Berger, Alvin; Bazinet, Richard P

2016-07-01

Tracer studies suggest that phospholipid DHA (PL-DHA) more effectively targets the brain than triglyceride DHA (TAG-DHA), although the mechanism and whether this translates into higher brain DHA concentrations are not clear. Rats were gavaged with [U-(3)H]PL-DHA and [U-(3)H]TAG-DHA and blood sampled over 6h prior to collection of brain regions and other tissues. In another experiment, rats were supplemented for 4weeks with TAG-DHA (fish oil), PL-DHA (roe PL) or a mixture of both for comparison to a low-omega-3 diet. Brain regions and other tissues were collected, and blood was sampled weekly. DHA accretion rates were estimated using the balance method. [U-(3)H]PL-DHA rats had higher radioactivity in cerebellum, hippocampus and remainder of brain, with no differences in other tissues despite higher serum lipid radioactivity in [U-(3)H]TAG-DHA rats. TAG-DHA, PL-DHA or a mixture were equally effective at increasing brain DHA. There were no differences between DHA-supplemented groups in brain region, whole-body, or tissue DHA accretion rates except heart and serum TAG where the PL-DHA/TAG-DHA blend was higher than TAG-DHA. Apparent DHA β-oxidation was not different between DHA-supplemented groups. This indicates that more labeled DHA enters the brain when consumed as PL; however, this may not translate into higher brain DHA concentrations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Extraction efficiency and implications for absolute quantitation of propranolol in mouse brain, liver and kidney thin tissue sections using droplet-based liquid microjunction surface sampling-HPLC ESI-MS/MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kertesz, Vilmos; Weiskittel, Taylor M.; Vavek, Marissa

Currently, absolute quantitation aspects of droplet-based surface sampling for thin tissue analysis using a fully automated autosampler/HPLC-ESI-MS/MS system are not fully evaluated. Knowledge of extraction efficiency and its reproducibility is required to judge the potential of the method for absolute quantitation of analytes from thin tissue sections. Methods: Adjacent thin tissue sections of propranolol dosed mouse brain (10- μm-thick), kidney (10- μm-thick) and liver (8-, 10-, 16- and 24- μm-thick) were obtained. Absolute concentration of propranolol was determined in tissue punches from serial sections using standard bulk tissue extraction protocols and subsequent HPLC separations and tandem mass spectrometric analysis. Thesemore » values were used to determine propranolol extraction efficiency from the tissues with the droplet-based surface sampling approach. Results: Extraction efficiency of propranolol using 10- μm-thick brain, kidney and liver thin tissues using droplet-based surface sampling varied between ~45-63%. Extraction efficiency decreased from ~65% to ~36% with liver thickness increasing from 8 μm to 24 μm. Randomly selecting half of the samples as standards, precision and accuracy of propranolol concentrations obtained for the other half of samples as quality control metrics were determined. Resulting precision ( ±15%) and accuracy ( ±3%) values, respectively, were within acceptable limits. In conclusion, comparative quantitation of adjacent mouse thin tissue sections of different organs and of various thicknesses by droplet-based surface sampling and by bulk extraction of tissue punches showed that extraction efficiency was incomplete using the former method, and that it depended on the organ and tissue thickness. However, once extraction efficiency was determined and applied, the droplet-based approach provided the required quantitation accuracy and precision for assay validations. Furthermore, this means that once the extraction efficiency was calibrated for a given tissue type and drug, the droplet-based approach provides a non-labor intensive and high-throughput means to acquire spatially resolved quantitative analysis of multiple samples of the same type.« less

Extraction efficiency and implications for absolute quantitation of propranolol in mouse brain, liver and kidney thin tissue sections using droplet-based liquid microjunction surface sampling-HPLC ESI-MS/MS

DOE PAGES

Kertesz, Vilmos; Weiskittel, Taylor M.; Vavek, Marissa; ...

2016-06-22

Currently, absolute quantitation aspects of droplet-based surface sampling for thin tissue analysis using a fully automated autosampler/HPLC-ESI-MS/MS system are not fully evaluated. Knowledge of extraction efficiency and its reproducibility is required to judge the potential of the method for absolute quantitation of analytes from thin tissue sections. Methods: Adjacent thin tissue sections of propranolol dosed mouse brain (10- μm-thick), kidney (10- μm-thick) and liver (8-, 10-, 16- and 24- μm-thick) were obtained. Absolute concentration of propranolol was determined in tissue punches from serial sections using standard bulk tissue extraction protocols and subsequent HPLC separations and tandem mass spectrometric analysis. Thesemore » values were used to determine propranolol extraction efficiency from the tissues with the droplet-based surface sampling approach. Results: Extraction efficiency of propranolol using 10- μm-thick brain, kidney and liver thin tissues using droplet-based surface sampling varied between ~45-63%. Extraction efficiency decreased from ~65% to ~36% with liver thickness increasing from 8 μm to 24 μm. Randomly selecting half of the samples as standards, precision and accuracy of propranolol concentrations obtained for the other half of samples as quality control metrics were determined. Resulting precision ( ±15%) and accuracy ( ±3%) values, respectively, were within acceptable limits. In conclusion, comparative quantitation of adjacent mouse thin tissue sections of different organs and of various thicknesses by droplet-based surface sampling and by bulk extraction of tissue punches showed that extraction efficiency was incomplete using the former method, and that it depended on the organ and tissue thickness. However, once extraction efficiency was determined and applied, the droplet-based approach provided the required quantitation accuracy and precision for assay validations. Furthermore, this means that once the extraction efficiency was calibrated for a given tissue type and drug, the droplet-based approach provides a non-labor intensive and high-throughput means to acquire spatially resolved quantitative analysis of multiple samples of the same type.« less

Non-destructive optical clearing technique enhances optical coherence tomography (OCT) for real-time, 3D histomorphometry of brain tissue (Conference Presentation)

NASA Astrophysics Data System (ADS)

Paul, Akshay; Chang, Theodore H.; Chou, Li-Dek; Ramalingam, Tirunelveli S.

2016-03-01

Evaluation of neurodegenerative disease often requires examination of brain morphology. Volumetric analysis of brain regions and structures can be used to track developmental changes, progression of disease, and the presence of transgenic phenotypes. Current standards for microscopic investigation of brain morphology are limited to detection of superficial structures at a maximum depth of 300μm. While histological techniques can provide detailed cross-sections of brain structures, they require complicated tissue preparation and the ultimate destruction of the sample. A non-invasive, label-free imaging modality known as Optical Coherence Tomography (OCT) can produce 3-dimensional reconstructions through high-speed, cross-sectional scans of biological tissue. Although OCT allows for the preservation of intact samples, the highly scattering and absorbing properties of biological tissue limit imaging depth to 1-2mm. Optical clearing agents have been utilized to increase imaging depth by index matching and lipid digestion, however, these contemporary techniques are expensive and harsh on tissues, often irreversibly denaturing proteins. Here we present an ideal optical clearing agent that offers ease-of-use and reversibility. Similar to how SeeDB has been effective for microscopy, our fructose-based, reversible optical clearing technique provides improved OCT imaging and functional immunohistochemical mapping of disease. Fructose is a natural, non-toxic sugar with excellent water solubility, capable of increasing tissue transparency and reducing light scattering. We will demonstrate the improved depth-resolving performance of OCT for enhanced whole-brain imaging of normal and diseased murine brains following a fructose clearing treatment. This technique potentially enables rapid, 3-dimensional evaluation of biological tissues at axial and lateral resolutions comparable to histopathology.

Sensitive and specific detection of classical scrapie prions in the brains of goats by real-time quaking-induced conversion.

PubMed

Dassanayake, Rohana P; Orrú, Christina D; Hughson, Andrew G; Caughey, Byron; Graça, Telmo; Zhuang, Dongyue; Madsen-Bouterse, Sally A; Knowles, Donald P; Schneider, David A

2016-03-01

Real-time quaking-induced conversion (RT-QuIC) is a rapid, specific and highly sensitive prion seeding activity detection assay that uses recombinant prion protein (rPrPSen) to detect subinfectious levels of the abnormal isoforms of the prion protein (PrPSc). Although RT-QuIC has been successfully used to detect PrPSc in various tissues from humans and animals, including sheep, tissues from goats infected with classical scrapie have not yet been tested. Therefore, the aims of the present study were to (1) evaluate whether prion seeding activity could be detected in the brain tissues of goats with scrapie using RT-QuIC, (2) optimize reaction conditions to improve scrapie detection in goats, and (3) compare the performance of RT-QuIC for the detection of PrPSc with the more commonly used ELISA and Western blot assays. We further optimized RT-QuIC conditions for sensitive and specific detection of goat scrapie seeding activity in brain tissue from clinical animals. When used with 200  mM sodium chloride, both full-length sheep rPrPSen substrates (PrP genotypes A136R154Q171 and V136R154Q171) provided good discrimination between scrapie-infected and normal goat brain samples at 10(- )3 dilution within 15  h. Our findings indicate that RT-QuIC was at least 10,000-fold more sensitive than ELISA and Western blot assays for the detection of scrapie seeding activity in goat brain samples. In addition to PRNP WT samples, positive RT-QuIC reactions were also observed with three PRNP polymorphic goat brain samples (G/S127, I/M142 and H/R143) tested. Taken together, these findings demonstrate that RT-QuIC sensitively detects prion seeding activity in classical scrapie-infected goat brain samples.

Sensitive and specific detection of classical scrapie prions in the brains of goats by real-time quaking-induced conversion

PubMed Central

Dassanayake, Rohana P.; Orrú, Christina D.; Hughson, Andrew G.; Caughey, Byron; Graça, Telmo; Zhuang, Dongyue; Madsen-Bouterse, Sally A.; Knowles, Donald P.; Schneider, David A.

2016-01-01

Real-time quaking-induced conversion (RT-QuIC) is a rapid, specific and highly sensitive prion seeding activity detection assay that uses recombinant prion protein (rPrPSen) to detect subinfectious levels of the abnormal isoforms of the prion protein (PrPSc). Although RT-QuIC has been successfully used to detect PrPSc in various tissues from humans and animals, including sheep, tissues from goats infected with classical scrapie have not yet been tested. Therefore, the aims of the present study were to (1) evaluate whether prion seeding activity could be detected in the brain tissues of goats with scrapie using RT-QuIC, (2) optimize reaction conditions to improve scrapie detection in goats, and (3) compare the performance of RT-QuIC for the detection of PrPSc with the more commonly used ELISA and Western blot assays. We further optimized RT-QuIC conditions for sensitive and specific detection of goat scrapie seeding activity in brain tissue from clinical animals. When used with 200 mM sodium chloride, both full-length sheep rPrPSen substrates (PrP genotypes A136R154Q171 and V136R154Q171) provided good discrimination between scrapie-infected and normal goat brain samples at 10− 3 dilution within 15 h. Our findings indicate that RT-QuIC was at least 10 000-fold more sensitive than ELISA and Western blot assays for the detection of scrapie seeding activity in goat brain samples. In addition to PRNP WT samples, positive RT-QuIC reactions were also observed with three PRNP polymorphic goat brain samples (G/S127, I/M142 and H/R143) tested. Taken together, these findings demonstrate that RT-QuIC sensitively detects prion seeding activity in classical scrapie-infected goat brain samples. PMID:26653410

Brain tumor imaging of rat fresh tissue using terahertz spectroscopy

NASA Astrophysics Data System (ADS)

Yamaguchi, Sayuri; Fukushi, Yasuko; Kubota, Oichi; Itsuji, Takeaki; Ouchi, Toshihiko; Yamamoto, Seiji

2016-07-01

Tumor imaging by terahertz spectroscopy of fresh tissue without dye is demonstrated using samples from a rat glioma model. The complex refractive index spectrum obtained by a reflection terahertz time-domain spectroscopy system can discriminate between normal and tumor tissues. Both the refractive index and absorption coefficient of tumor tissues are higher than those of normal tissues and can be attributed to the higher cell density and water content of the tumor region. The results of this study indicate that terahertz technology is useful for detecting brain tumor tissue.

A Novel Application for the Cavalieri Principle: A Stereological and Methodological Study

PubMed Central

Altunkaynak, Berrin Zuhal; Altunkaynak, Eyup; Unal, Deniz; Unal, Bunyamin

2009-01-01

Objective The Cavalieri principle was applied to consecutive pathology sections that were photographed at the same magnification and used to estimate tissue volumes via superimposing a point counting grid on these images. The goal of this study was to perform the Cavalieri method quickly and practically. Materials and Methods In this study, 10 adult female Sprague Dawley rats were used. Brain tissue was removed and sampled both systematically and randomly. Brain volumes were estimated using two different methods. First, all brain slices were scanned with an HP ScanJet 3400C scanner, and their images were shown on a PC monitor. Brain volume was then calculated based on these images. Second, all brain slices were photographed in 10× magnification with a microscope camera, and brain volumes were estimated based on these micrographs. Results There was no statistically significant difference between the volume measurements of the two techniques (P>0.05; Paired Samples t Test). Conclusion This study demonstrates that personal computer scanning of serial tissue sections allows for easy and reliable volume determination based on the Cavalieri method. PMID:25610077

A novel application for the cavalieri principle: a stereological and methodological study.

PubMed

Altunkaynak, Berrin Zuhal; Altunkaynak, Eyup; Unal, Deniz; Unal, Bunyamin

2009-08-01

The Cavalieri principle was applied to consecutive pathology sections that were photographed at the same magnification and used to estimate tissue volumes via superimposing a point counting grid on these images. The goal of this study was to perform the Cavalieri method quickly and practically. In this study, 10 adult female Sprague Dawley rats were used. Brain tissue was removed and sampled both systematically and randomly. Brain volumes were estimated using two different methods. First, all brain slices were scanned with an HP ScanJet 3400C scanner, and their images were shown on a PC monitor. Brain volume was then calculated based on these images. Second, all brain slices were photographed in 10× magnification with a microscope camera, and brain volumes were estimated based on these micrographs. There was no statistically significant difference between the volume measurements of the two techniques (P>0.05; Paired Samples t Test). This study demonstrates that personal computer scanning of serial tissue sections allows for easy and reliable volume determination based on the Cavalieri method.

Confocal multispot microscope for fast and deep imaging in semicleared tissues

NASA Astrophysics Data System (ADS)

Adam, Marie-Pierre; Müllenbroich, Marie Caroline; Di Giovanna, Antonino Paolo; Alfieri, Domenico; Silvestri, Ludovico; Sacconi, Leonardo; Pavone, Francesco Saverio

2018-02-01

Although perfectly transparent specimens are imaged faster with light-sheet microscopy, less transparent samples are often imaged with two-photon microscopy leveraging its robustness to scattering; however, at the price of increased acquisition times. Clearing methods that are capable of rendering strongly scattering samples such as brain tissue perfectly transparent specimens are often complex, costly, and time intensive, even though for many applications a slightly lower level of tissue transparency is sufficient and easily achieved with simpler and faster methods. Here, we present a microscope type that has been geared toward the imaging of semicleared tissue by combining multispot two-photon excitation with rolling shutter wide-field detection to image deep and fast inside semicleared mouse brain. We present a theoretical and experimental evaluation of the point spread function and contrast as a function of shutter size. Finally, we demonstrate microscope performance in fixed brain slices by imaging dendritic spines up to 400-μm deep.

Post-sampling release of free fatty acids - effects of heat stabilization and methods of euthanasia.

PubMed

Jernerén, Fredrik; Söderquist, Marcus; Karlsson, Oskar

2015-01-01

The field of lipid research has made progress and it is now possible to study the lipidome of cells and organelles. A basic requirement of a successful lipid study is adequate pre-analytical sample handling, as some lipids can be unstable and postmortem changes can cause substantial accumulation of free fatty acids (FFAs). The aim of the present study was to investigate the effects of conductive heat stabilization and euthanasia methods on FFA levels in the rat brain and liver using liquid chromatography tandem mass spectrometry. The analysis of brain homogenates clearly demonstrated phospholipase activity and time-dependent post-sampling changes in the lipid pool of snap frozen non-stabilized tissue. There was a significant increase in FFAs already at 2min, which continued over time. Heat stabilization was shown to be an efficient method to reduce phospholipase activity and ex vivo lipolysis. Post-sampling effects due to tissue thawing and sample preparation induced a massive release of FFAs (up to 3700%) from non-stabilized liver and brain tissues compared to heat stabilized tissue. Furthermore, the choice of euthanasia method significantly influenced the levels of FFAs in the brain. The FFAs were decreased by 15-44% in the group of animals euthanized by pentobarbital injection compared with CO2 inhalation or decapitation. Our results highlight the importance of considering euthanasia methods and pre-analytical treatment in lipid analysis, factors which may otherwise interfere with the outcome of the experiments. Copyright © 2014 Elsevier Inc. All rights reserved.

Dielectric properties of dog brain tissue measured in vitro across the 0.3-3 GHz band.

PubMed

Mohammed, Beadaa; Bialkowski, Konstanty; Abbosh, Amin; Mills, Paul C; Bradley, Andrew P

2016-09-22

Dielectric properties of dead Greyhound female dogs' brain tissues at different ages were measured at room temperature across the frequency range of 0.3-3 GHz. Measurements were made on excised tissues, in vitro in the laboratory, to carry out dielectric tests on sample tissues. Each dataset for a brain tissue was parametrized using the Cole-Cole expression, and the relevant Cole-Cole parameters for four tissue types are provided. A comparison was made with the database available in literature for other animals and human brain tissue. Results of two types of tissues (white matter and skull) showed systematic variation in dielectric properties as a function of animal age, whereas no significant change related to age was noticed for other tissues. Results provide critical information regarding dielectric properties of animal tissues for a realistic animal head model that can be used to verify the validity and reliability of a microwave head scanner for animals prior to testing on live animals. Bioelectromagnetics. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Fluconazole penetration in cerebral parenchyma in humans at steady state.

PubMed Central

Thaler, F; Bernard, B; Tod, M; Jedynak, C P; Petitjean, O; Derome, P; Loirat, P

1995-01-01

We studied fluconazole penetration in the brain in five patients who had a deep cerebral tumor whose removal required the excision of healthy brain tissue. Plasma and brain samples were simultaneously obtained after oral ingestion of 400 mg of fluconazole daily for 4 days (90% of steady state). Fluconazole penetration in healthy cerebral parenchyma was determined. Plasma and brain samples were assayed by high-pressure liquid chromatography. Concentrations in plasma and brain tissue were 13.5 +/- 5.5 micrograms/ml and 17.6 +/- 6.6 micrograms/g, respectively. The average ratio of concentrations in the brain and plasma (four patients) was 1.33 (range, 0.70 to 2.39). Despite the lack of data concerning the penetration of fluconazole in brain abscesses, these results should permit the use of a daily dose of 400 mg of fluconazole in prospective clinical studies that evaluate the effectiveness of this drug in the treatment of brain abscesses due to susceptible species of fungi. PMID:7625804

Imaging whole mouse brains with a dual resolution serial swept-source optical coherence tomography scanner

NASA Astrophysics Data System (ADS)

Lefebvre, Joël.; Castonguay, Alexandre; Lesage, Frédéric

2018-02-01

High resolution imaging of whole rodent brains using serial OCT scanners is a promising method to investigate microstructural changes in tissue related to the evolution of neuropathologies. Although micron to sub-micron sampling resolution can be obtained by using high numerical aperture objectives and dynamic focusing, such an imaging system is not adapted to whole brain imaging. This is due to the large amount of data it generates and the significant computational resources required for reconstructing such volumes. To address this limitation, a dual resolution serial OCT scanner was developed. The optical setup consists in a swept-source OCT made of two sample and reference arms, each arm being coupled with different microscope objectives (3X / 40X). Motorized flip mirrors were used to switch between each OCT arm, thus allowing low and high resolution acquisitions within the same sample. The low resolution OCT volumes acquired with the 3X arm were stitched together, providing a 3D map of the whole mouse brain. This brain can be registered to an OCT brain template to enable neurological structures localization. The high resolution volumes acquired with the 40X arm were also stitched together to create local high resolution 3D maps of the tissue microstructure. The 40X data can be acquired at any arbitrary location in the sample, thus limiting storage-heavy high resolution data to application restricted to specific regions of interest. By providing dual-resolution OCT data, this setup can be used to validate diffusion MRI with tissue microstructure derived metrics measured at any location in ex vivo brains.

Tissue Distribution of Enrofloxacin in African Clawed Frogs (Xenopus laevis) after Intramuscular and Subcutaneous Administration

PubMed Central

Felt, Stephen; Papich, Mark G; Howard, Antwain; Long, Tyler; McKeon, Gabriel; Torreilles, Stéphanie; Green, Sherril

2013-01-01

As part of an enrofloxacin pharmacokinetic study, concentrations of enrofloxacin and ciprofloxacin (metabolite) were measured in various tissues (brain, heart, kidney, liver, lung, and spleen) collected from treated (subcutaneous delivery, n = 3; intramuscular delivery, n = 3; untreated controls, n = 2) adult female Xenopus laevis by using HPLC. Enrofloxacin was rapidly absorbed after administration by either route and readily diffused into all sampled tissues. Enrofloxacin and ciprofloxacin were present in the tissue samples collected at 8 h. The highest average tissue concentrations for enrofloxacin were found in kidney, with the lowest concentrations in liver. Ciprofloxacin tissue concentrations paralleled but were always lower than those of enrofloxacin for all time points and tissues except brain and kidney. These results, together with previously published pharmacokinetic data and known minimal inhibitory concentrations of common pathogenic bacteria, provide a strong evidence-based rationale for choosing enrofloxacin to treat infectious diseases in X. laevis. PMID:23562103

Tissue distribution of enrofloxacin in African clawed frogs (Xenopus laevis) after intramuscular and subcutaneous administration.

PubMed

Felt, Stephen; Papich, Mark G; Howard, Antwain; Long, Tyler; McKeon, Gabriel; Torreilles, Stéphanie; Green, Sherril

2013-03-01

As part of an enrofloxacin pharmacokinetic study, concentrations of enrofloxacin and ciprofloxacin (metabolite) were measured in various tissues (brain, heart, kidney, liver, lung, and spleen) collected from treated (subcutaneous delivery, n = 3; intramuscular delivery, n = 3; untreated controls, n = 2) adult female Xenopus laevis by using HPLC. Enrofloxacin was rapidly absorbed after administration by either route and readily diffused into all sampled tissues. Enrofloxacin and ciprofloxacin were present in the tissue samples collected at 8 h. The highest average tissue concentrations for enrofloxacin were found in kidney, with the lowest concentrations in liver. Ciprofloxacin tissue concentrations paralleled but were always lower than those of enrofloxacin for all time points and tissues except brain and kidney. These results, together with previously published pharmacokinetic data and known minimal inhibitory concentrations of common pathogenic bacteria, provide a strong evidence-based rationale for choosing enrofloxacin to treat infectious diseases in X. laevis.

Monitoring Dopamine ex Vivo during Electrical Stimulation Using Liquid-Microjunction Surface Sampling.

PubMed

Gill, Emily L; Marks, Megan; Yost, Richard A; Vedam-Mai, Vinata; Garrett, Timothy J

2017-12-19

Liquid-microjunction surface sampling (LMJ-SS) is an ambient ionization technique based on the continuous flow of solvent using an in situ microextraction device in which solvent moves through the probe, drawing in the analytes in preparation for ionization using an electrospray ionization source. However, unlike traditional mass spectrometry (MS) techniques, it operates under ambient pressure and requires no sample preparation, thereby making it ideal for rapid sampling of thicker tissue sections for electrophysiological and other neuroscientific research studies. Studies interrogating neural synapses, or a specific neural circuit, typically employ thick, ex vivo tissue sections maintained under near-physiological conditions to preserve tissue viability and maintain the neural networks. Deep brain stimulation (DBS) is a surgical procedure used to treat the neurological symptoms that are associated with certain neurodegenerative and neuropsychiatric diseases. Parkinson's disease (PD) is a neurological disorder which is commonly treated with DBS therapy. PD is characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta portion of the brain. Here, we demonstrate that the LMJ-SS methodology can provide a platform for ex vivo analysis of the brain during electrical stimulation, such as DBS. We employ LMJ-SS in the ex vivo analysis of mouse brain tissue for monitoring dopamine during electrical stimulation of the striatum region. The mouse brain tissue was sectioned fresh post sacrifice and maintained in artificial cerebrospinal fluid to create near-physiological conditions before direct sampling using LMJ-SS. A selection of metabolites, including time-sensitive metabolites involved in energy regulation in the brain, were identified using standards, and the mass spectral database mzCloud was used to assess the feasibility of the methodology. Thereafter, the intensity of m/z 154 corresponding to protonated dopamine was monitored before and after electrical stimulation of the striatum region, showing an increase in signal directly following a stimulation event. Dopamine is the key neurotransmitter implicated in PD, and although electrochemical detectors have shown such increases in dopamine post-DBS, this is the first study to do so using MS methodologies.

Computational deconvolution of genome wide expression data from Parkinson's and Huntington's disease brain tissues using population-specific expression analysis

PubMed Central

Capurro, Alberto; Bodea, Liviu-Gabriel; Schaefer, Patrick; Luthi-Carter, Ruth; Perreau, Victoria M.

2015-01-01

The characterization of molecular changes in diseased tissues gives insight into pathophysiological mechanisms and is important for therapeutic development. Genome-wide gene expression analysis has proven valuable for identifying biological processes in neurodegenerative diseases using post mortem human brain tissue and numerous datasets are publically available. However, many studies utilize heterogeneous tissue samples consisting of multiple cell types, all of which contribute to global gene expression values, confounding biological interpretation of the data. In particular, changes in numbers of neuronal and glial cells occurring in neurodegeneration confound transcriptomic analyses, particularly in human brain tissues where sample availability and controls are limited. To identify cell specific gene expression changes in neurodegenerative disease, we have applied our recently published computational deconvolution method, population specific expression analysis (PSEA). PSEA estimates cell-type-specific expression values using reference expression measures, which in the case of brain tissue comprises mRNAs with cell-type-specific expression in neurons, astrocytes, oligodendrocytes and microglia. As an exercise in PSEA implementation and hypothesis development regarding neurodegenerative diseases, we applied PSEA to Parkinson's and Huntington's disease (PD, HD) datasets. Genes identified as differentially expressed in substantia nigra pars compacta neurons by PSEA were validated using external laser capture microdissection data. Network analysis and Annotation Clustering (DAVID) identified molecular processes implicated by differential gene expression in specific cell types. The results of these analyses provided new insights into the implementation of PSEA in brain tissues and additional refinement of molecular signatures in human HD and PD. PMID:25620908

Uniform neural tissue models produced on synthetic hydrogels using standard culture techniques.

PubMed

Barry, Christopher; Schmitz, Matthew T; Propson, Nicholas E; Hou, Zhonggang; Zhang, Jue; Nguyen, Bao K; Bolin, Jennifer M; Jiang, Peng; McIntosh, Brian E; Probasco, Mitchell D; Swanson, Scott; Stewart, Ron; Thomson, James A; Schwartz, Michael P; Murphy, William L

2017-11-01

The aim of the present study was to test sample reproducibility for model neural tissues formed on synthetic hydrogels. Human embryonic stem (ES) cell-derived precursor cells were cultured on synthetic poly(ethylene glycol) (PEG) hydrogels to promote differentiation and self-organization into model neural tissue constructs. Neural progenitor, vascular, and microglial precursor cells were combined on PEG hydrogels to mimic developmental timing, which produced multicomponent neural constructs with 3D neuronal and glial organization, organized vascular networks, and microglia with ramified morphologies. Spearman's rank correlation analysis of global gene expression profiles and a comparison of coefficient of variation for expressed genes demonstrated that replicate neural constructs were highly uniform to at least day 21 for samples from independent experiments. We also demonstrate that model neural tissues formed on PEG hydrogels using a simplified neural differentiation protocol correlated more strongly to in vivo brain development than samples cultured on tissue culture polystyrene surfaces alone. These results provide a proof-of-concept demonstration that 3D cellular models that mimic aspects of human brain development can be produced from human pluripotent stem cells with high sample uniformity between experiments by using standard culture techniques, cryopreserved cell stocks, and a synthetic extracellular matrix. Impact statement Pluripotent stem (PS) cells have been characterized by an inherent ability to self-organize into 3D "organoids" resembling stomach, intestine, liver, kidney, and brain tissues, offering a potentially powerful tool for modeling human development and disease. However, organoid formation must be quantitatively reproducible for applications such as drug and toxicity screening. Here, we report a strategy to produce uniform neural tissue constructs with reproducible global gene expression profiles for replicate samples from multiple experiments.

75 FR 64986 - Marine Mammals; File No. 14525

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-21

... captivity, sampled while in captivity, and euthanized at the termination of study to obtain their brains. Whole brains and brain tissues will be imported to the U.S. for anatomical and immunohistochemical studies. The first aim of the project is to correlate the release of major neurotransmitters in the brain...

Real time analysis of brain tissue by direct combination of ultrasonic surgical aspiration and sonic spray mass spectrometry.

PubMed

Schäfer, Karl-Christian; Balog, Júlia; Szaniszló, Tamás; Szalay, Dániel; Mezey, Géza; Dénes, Júlia; Bognár, László; Oertel, Matthias; Takáts, Zoltán

2011-10-15

Direct combination of cavitron ultrasonic surgical aspirator (CUSA) and sonic spray ionization mass spectrometry is presented. A commercially available ultrasonic surgical device was coupled to a Venturi easy ambient sonic-spray ionization (V-EASI) source by directly introducing liquified tissue debris into the Venturi air jet pump. The Venturi air jet pump was found to efficiently nebulize the suspended tissue material for gas phase ion production. The ionization mechanism involving solely pneumatic spraying was associated with that of sonic spray ionization. Positive and negative ionization spectra were obtained from brain and liver samples reflecting the primary application areas of the surgical device. Mass spectra were found to feature predominantly complex lipid-type constituents of tissues in both ion polarity modes. Multiply charged peptide anions were also detected. The influence of instrumental settings was characterized in detail. Venturi pump geometry and flow parameters were found to be critically important in ionization efficiency. Standard solutions of phospholipids and peptides were analyzed in order to test the dynamic range, sensitivity, and suppression effects. The spectra of the intact tissue specimens were found to be highly specific to the histological tissue type. The principal component analysis (PCA) and linear discriminant analysis (LDA) based data analysis method was developed for real-time tissue identification in a surgical environment. The method has been successfully tested on post-mortem and ex vivo human samples including astrocytomas, meningeomas, metastatic brain tumors, and healthy brain tissue. © 2011 American Chemical Society

Supraorbital Postmortem Brain Sampling for Definitive Quantitative Confirmation of Cerebral Sequestration of Plasmodium falciparum Parasites

PubMed Central

Milner, Danny A.; Valim, Clarissa; Luo, Robert; Playforth, Krupa B.; Kamiza, Steve; Molyneux, Malcolm E.; Seydel, Karl B.; Taylor, Terrie E.

2012-01-01

Background The conventional clinical case definition of cerebral malaria (CM) is imprecise but specificity is improved by a definitive clinical feature such as retinopathy or confirming sequestration of parasites in a post-mortem examination of the brain. A full autopsy is often not possible, since it is costly and may encounter resistance of the deceased's family. Methods We have assessed the use of a cytological smear of brain tissue, obtained post-mortem by supraorbital sampling, for the purpose of quantifying cerebral sequestration in children with fatal malaria in Blantyre, Malawi. We have compared this method to histological quantification of parasites at autopsy. Results The number of parasites present on cytological smears correlated with the proportion of vessels parasitized as assessed by histology of fixed and stained brain tissue. Use of cytological results in addition to the standard clinical case definition increases the specificity of the clinical case definition alone from 48.3% to 100% with a minimal change in sensitivity. Conclusions Post-mortem supraorbital sampling of brain tissue improves the specificity of the diagnosis of fatal cerebral malaria and provides accurate quantitative estimates of cerebral sequestration. This tool can be of great value in clinical, pathogenetic, and epidemiological research studies on cerebral malaria. PMID:22291197

Dye-Enhanced Multimodal Confocal Imaging of Brain Cancers

NASA Astrophysics Data System (ADS)

Wirth, Dennis; Snuderl, Matija; Sheth, Sameer; Curry, William; Yaroslavsky, Anna

2011-04-01

Background and Significance: Accurate high resolution intraoperative detection of brain tumors may result in improved patient survival and better quality of life. The goal of this study was to evaluate dye enhanced multimodal confocal imaging for discriminating normal and cancerous brain tissue. Materials and Methods: Fresh thick brain specimens were obtained from the surgeries. Normal and cancer tissues were investigated. Samples were stained in methylene blue and imaged. Reflectance and fluorescence signals were excited at 658nm. Fluorescence emission and polarization were registered from 670 nm to 710 nm. The system provided lateral resolution of 0.6 μm and axial resolution of 7 μm. Normal and cancer specimens exhibited distinctively different characteristics. H&E histopathology was processed from each imaged sample. Results and Conclusions: The analysis of normal and cancerous tissues indicated clear differences in appearance in both the reflectance and fluorescence responses. These results confirm the feasibility of multimodal confocal imaging for intraoperative detection of small cancer nests and cells.

Oxidative stress induced by 1.8 GHz radio frequency electromagnetic radiation and effects of garlic extract in rats.

PubMed

Avci, Bahattin; Akar, Ayşegül; Bilgici, Birşen; Tunçel, Özgür Korhan

2012-11-01

We aimed to study the oxidative damage induced by radiofrequency electromagnetic radiation (RF-EMR) emitted by mobile telephones and the protective effect of garlic extract used as an anti-oxidant against this damage. A total of 66 albino Wistar rats were divided into three groups. The first group of rats was given 1.8 GHz, 0.4 W/kg specific absorption rate (SAR) for 1 h a day for three weeks. The second group was given 500 mg/kg garlic extract in addition to RF-EMR. The third group of rats was used as the control group. At the end of the study, blood and brain tissue samples were collected from the rats. After the RF-EMR exposed, the advanced oxidation protein product (AOPP) levels of brain tissue increased compared with the control group (p < 0.001). Garlic administration accompanying the RF-EMR, on the other hand, significantly reduced AOPP levels in brain tissue (p < 0.001). The serum nitric oxide (NO) levels significantly increased both in the first and second group (p < 0.001). However, in the group for which garlic administration accompanied that of RF-EMR, there was no difference in serum NO levels compared with the RF-EMR exposed group (p > 0.05). There was no significant difference among the groups with respect to malondialdehyde (MDA) levels in brain tissue and blood samples (p > 0.05). Similarly, no difference was detected among the groups regarding serum paroxonase (PON) levels (p > 0.05). We did not detect any PON levels in the brain tissue. The exposure of RF-EMR similar to 1.8 GHz Global system for mobile communication (GSM) leads to protein oxidation in brain tissue and an increase in serum NO. We observed that garlic administration reduced protein oxidation in brain tissue and that it did not have any effects on serum NO levels.

Oxidative stress in juvenile chinook salmon, Oncorhynchus tshawytscha (Walbaum)

USGS Publications Warehouse

Welker, T.L.; Congleton, J.L.

2004-01-01

Juvenile chinook salmon, Oncorhynchus tshawytscha (Walbaum), were held in 8-11??C freshwater, starved for 3 days and subjected to a low-water stressor to determine the relationship between the general stress response and oxidative stress. Lipid peroxidation (LPO) levels (lipid hydroperoxides) were measured in kidney, liver and brain samples taken at the beginning of the experiment (0-h unstressed controls) and at 6, 24 and 48 h after application of a continuous low-water stressor. Tissue samples were also taken at 48 h from fish that had not been exposed to the stressor (48-h unstressed controls). Exposure to the low-water stressor affected LPO in kidney and brain tissues. In kidney, LPO decreased 6 h after imposition of the stressor; similar but less pronounced decreases also occurred in the liver and brain. At 48 h, LPO increased (in comparison with 6-h stressed tissues) in the kidney and brain. In comparison with 48-h unstressed controls, LPO levels were higher in the kidney and brain of stressed fish. Although preliminary, results suggest that stress can cause oxidative tissue damage in juvenile chinook salmon. Measures of oxidative stress have shown similar responses to stress in mammals; however, further research is needed to determine the extent of the stress-oxidative stress relationship and the underlying physiological mechanisms in fish.

dbMDEGA: a database for meta-analysis of differentially expressed genes in autism spectrum disorder.

PubMed

Zhang, Shuyun; Deng, Libin; Jia, Qiyue; Huang, Shaoting; Gu, Junwang; Zhou, Fankun; Gao, Meng; Sun, Xinyi; Feng, Chang; Fan, Guangqin

2017-11-16

Autism spectrum disorders (ASD) are hereditary, heterogeneous and biologically complex neurodevelopmental disorders. Individual studies on gene expression in ASD cannot provide clear consensus conclusions. Therefore, a systematic review to synthesize the current findings from brain tissues and a search tool to share the meta-analysis results are urgently needed. Here, we conducted a meta-analysis of brain gene expression profiles in the current reported human ASD expression datasets (with 84 frozen male cortex samples, 17 female cortex samples, 32 cerebellum samples and 4 formalin fixed samples) and knock-out mouse ASD model expression datasets (with 80 collective brain samples). Then, we applied R language software and developed an interactive shared and updated database (dbMDEGA) displaying the results of meta-analysis of data from ASD studies regarding differentially expressed genes (DEGs) in the brain. This database, dbMDEGA ( https://dbmdega.shinyapps.io/dbMDEGA/ ), is a publicly available web-portal for manual annotation and visualization of DEGs in the brain from data from ASD studies. This database uniquely presents meta-analysis values and homologous forest plots of DEGs in brain tissues. Gene entries are annotated with meta-values, statistical values and forest plots of DEGs in brain samples. This database aims to provide searchable meta-analysis results based on the current reported brain gene expression datasets of ASD to help detect candidate genes underlying this disorder. This new analytical tool may provide valuable assistance in the discovery of DEGs and the elucidation of the molecular pathogenicity of ASD. This database model may be replicated to study other disorders.

Genetic differences between blood- and brain-derived viral sequences from human immunodeficiency virus type 1-infected patients: evidence of conserved elements in the V3 region of the envelope protein of brain-derived sequences.

PubMed Central

Korber, B T; Kunstman, K J; Patterson, B K; Furtado, M; McEvilly, M M; Levy, R; Wolinsky, S M

1994-01-01

Human immunodeficiency virus type 1 (HIV-1) sequences were generated from blood and from brain tissue obtained by stereotactic biopsy from six patients undergoing a diagnostic neurosurgical procedure. Proviral DNA was directly amplified by nested PCR, and 8 to 36 clones from each sample were sequenced. Phylogenetic analysis of intrapatient envelope V3-V5 region HIV-1 DNA sequence sets revealed that brain viral sequences were clustered relative to the blood viral sequences, suggestive of tissue-specific compartmentalization of the virus in four of the six cases. In the other two cases, the blood and brain virus sequences were intermingled in the phylogenetic analyses, suggesting trafficking of virus between the two tissues. Slide-based PCR-driven in situ hybridization of two of the patients' brain biopsy samples confirmed our interpretation of the intrapatient phylogenetic analyses. Interpatient V3 region brain-derived sequence distances were significantly less than blood-derived sequence distances. Relative to the tip of the loop, the set of brain-derived viral sequences had a tendency towards negative or neutral charge compared with the set of blood-derived viral sequences. Entropy calculations were used as a measure of the variability at each position in alignments of blood and brain viral sequences. A relatively conserved set of positions were found, with a significantly lower entropy in the brain-than in the blood-derived viral sequences. These sites constitute a brain "signature pattern," or a noncontiguous set of amino acids in the V3 region conserved in viral sequences derived from brain tissue. This brain-derived signature pattern was also well preserved among isolates previously characterized in vitro as macrophage tropic. Macrophage-monocyte tropism may be the biological constraint that results in the conservation of the viral brain signature pattern. Images PMID:7933130

Brain Slice Staining and Preparation for Three-Dimensional Super-Resolution Microscopy

PubMed Central

German, Christopher L.; Gudheti, Manasa V.; Fleckenstein, Annette E.; Jorgensen, Erik M.

2018-01-01

Localization microscopy techniques – such as photoactivation localization microscopy (PALM), fluorescent PALM (FPALM), ground state depletion (GSD), and stochastic optical reconstruction microscopy (STORM) – provide the highest precision for single molecule localization currently available. However, localization microscopy has been largely limited to cell cultures due to the difficulties that arise in imaging thicker tissue sections. Sample fixation and antibody staining, background fluorescence, fluorophore photoinstability, light scattering in thick sections, and sample movement create significant challenges for imaging intact tissue. We have developed a sample preparation and image acquisition protocol to address these challenges in rat brain slices. The sample preparation combined multiple fixation steps, saponin permeabilization, and tissue clarification. Together, these preserve intracellular structures, promote antibody penetration, reduce background fluorescence and light scattering, and allow acquisition of images deep in a 30 μm thick slice. Image acquisition challenges were resolved by overlaying samples with a permeable agarose pad and custom-built stainless steel imaging adapter, and sealing the imaging chamber. This approach kept slices flat, immobile, bathed in imaging buffer, and prevented buffer oxidation during imaging. Using this protocol, we consistently obtained single molecule localizations of synaptic vesicle and active zone proteins in three-dimensions within individual synaptic terminals of the striatum in rat brain slices. These techniques may be easily adapted to the preparation and imaging of other tissues, substantially broadening the application of super-resolution imaging. PMID:28924666

Antidepressant pharmaceuticals in two U.S. effluent-impacted streams: Occurrence and fate in water and sediment and selective uptake in fish neural tissue

USGS Publications Warehouse

Schultz, M.M.; Furlong, E.T.; Kolpin, D.W.; Werner, S.L.; Schoenfuss, H.L.; Barber, L.B.; Blazer, V.S.; Norris, D.O.; Vajda, A.M.

2010-01-01

Antidepressant pharmaceuticals are widely prescribed in the United States; release of municipal wastewater effluent is a primary route introducing them to aquatic environments, where little is known about their distribution and fate. Water, bed sediment, and brain tissue from native white suckers (Catostomus commersoni)were collected upstream and atpoints progressively downstream from outfalls discharging to two effluentimpacted streams, Boulder Creek (Colorado) and Fourmile Creek (Iowa). A liquid chromatography/tandem mass spectrometry method was used to quantify antidepressants, including fluoxetine, norfluoxetine (degradate), sertraline, norsertraline (degradate), paroxetine, Citalopram, fluvoxamine, duloxetine, venlafaxine, and bupropion in all three sample matrices. Antidepressants were not present above the limit of quantitation in water samples upstream from the effluent outfalls but were present at points downstream at ng/L concentrations, even at the farthest downstream sampling site 8.4 km downstream from the outfall. The antidepressants with the highest measured concentrations in both streams were venlafaxine, bupropion, and Citalopram and typically were observed at concentrations of at least an order of magnitude greater than the more commonly investigated antidepressants fluoxetine and sertraline. Concentrations of antidepressants in bed sediment were measured at ng/g levels; venlafaxine and fluoxetine were the predominant chemicals observed. Fluoxetine, sertraline, and their degradates were the principal antidepressants observed in fish brain tissue, typically at low ng/g concentrations. Aqualitatively different antidepressant profile was observed in brain tissue compared to streamwater samples. This study documents that wastewater effluent can be a point source of antidepressants to stream ecosystems and that the qualitative composition of antidepressants in brain tissue from exposed fish differs substantially from the compositions observed in streamwater and sediment, suggesting selective uptake. ?? 2010 American Chemical Society.

GC-MS/MS Analyses of Biological Samples in Support of Developmental Toxic Effects on Percutaneous Exposure of Rats to VX

DTIC Science & Technology

2016-07-01

of blood, tissues, and organs (heart, lung, liver, kidney , brain, eye, diaphragm, and skin) that were obtained from rats (postnatal days 42 and 70...of blood, tissues, and organs (heart, lung, liver, kidney , brain, eye, and diaphragm) that were used to quantify the amounts of free and regenerated...Biosamples (brain, diaphragm, eye, heart, lung, liver, and kidney ) were collected at time of death or 48 h post-exposure for survivors. All

Pathobiological investigation of naturally infected canine rabies cases from Sri Lanka.

PubMed

Beck, S; Gunawardena, P; Horton, D L; Hicks, D J; Marston, D A; Ortiz-Pelaez, A; Fooks, A R; Núñez, A

2017-04-12

The recommended screening of rabies in 'suspect' animal cases involves testing fresh brain tissue. The preservation of fresh tissue however can be difficult under field conditions and formalin fixation provides a simple alternative that may allow a confirmatory diagnosis. The occurrence and location of histopathological changes and immunohistochemical (IHC) labelling for rabies in formalin fixed paraffin embedded (FFPE) canine brain is described in samples from 57 rabies suspect cases from Sri-Lanka. The presence of Negri bodies and immunohistochemical detection of rabies virus antigen were evaluated in the cortex, hippocampus, cerebellum and brainstem. The effect of autolysis and artefactual degeneration of the tissue was also assessed. Rabies was confirmed in 53 of 57 (93%) cases by IHC. IHC labelling was statistically more abundant in the brainstem. Negri bodies were observed in 32 of 53 (60.4%) of the positive cases. Although tissue degradation had no effect on IHC diagnosis, it was associated with an inability to detect Negri bodies. In 13 cases, a confirmatory Polymerase chain reaction (PCR) testing for rabies virus RNA was undertaken by extracting RNA from fresh frozen tissue, and also attempted using FFPE samples. PCR detection using fresh frozen samples was in agreement with the IHC results. The PCR method from FFPE tissues was suitable for control material but unsuccessful in our field cases. Histopathological examination of the brain is essential to define the differential diagnoses of behaviour modifying conditions in rabies virus negative cases, but it is unreliable as the sole method for rabies diagnosis, particularly where artefactual change has occurred. Formalin fixation and paraffin embedding does not prevent detection of rabies virus via IHC labelling even where artefactual degeneration has occurred. This could represent a pragmatic secondary assay for rabies diagnosis in the field because formalin fixation can prevent sample degeneration. The brain stem was shown to be the site with most viral immunoreactivity; supporting recommended sampling protocols in favour of improved necropsy safety in the field. PCR testing of formalin fixed tissue may be successful in certain circumstances as an alternative test.

Sapphire implant based neuro-complex for deep-lying brain tumors phototheranostics

NASA Astrophysics Data System (ADS)

Sharova, A. S.; Maklygina, YU S.; Yusubalieva, G. M.; Shikunova, I. A.; Kurlov, V. N.; Loschenov, V. B.

2018-01-01

The neuro-complex as a combination of sapphire implant optical port and osteoplastic biomaterial "Collapan" as an Aluminum phthalocyanine nanoform photosensitizer (PS) depot was developed within the framework of this study. The main goals of such neuro-complex are to provide direct access of laser radiation to the brain tissue depth and to transfer PS directly to the pathological tissue location that will allow multiple optical phototheranostics of the deep-lying tumor region without repeated surgical intervention. The developed complex spectral-optical properties research was carried out by photodiagnostics method using the model sample: a brain tissue phantom. The optical transparency of sapphire implant allows obtaining a fluorescent signal with high accuracy, comparable to direct measurement "in contact" with the tissue.

Compression stiffening of brain and its effect on mechanosensing by glioma cells

NASA Astrophysics Data System (ADS)

Pogoda, Katarzyna; Chin, LiKang; Georges, Penelope C.; Byfield, FitzRoy J.; Bucki, Robert; Kim, Richard; Weaver, Michael; Wells, Rebecca G.; Marcinkiewicz, Cezary; Janmey, Paul A.

2014-07-01

Many cell types, including neurons, astrocytes and other cells of the central nervous system, respond to changes in the extracellular matrix or substrate viscoelasticity, and increased tissue stiffness is a hallmark of several disease states, including fibrosis and some types of cancers. Whether the malignant tissue in brain, an organ that lacks the protein-based filamentous extracellular matrix of other organs, exhibits the same macroscopic stiffening characteristic of breast, colon, pancreatic and other tumors is not known. In this study we show that glioma cells, like normal astrocytes, respond strongly in vitro to substrate stiffness in the range of 100 to 2000 Pa, but that macroscopic (mm to cm) tissue samples isolated from human glioma tumors have elastic moduli in the order of 200 Pa that are indistinguishable from those of normal brain. However, both normal brain and glioma tissues increase their shear elastic moduli under modest uniaxial compression, and glioma tissue stiffens more strongly under compression than normal brain. These findings suggest that local tissue stiffness has the potential to alter glial cell function, and that stiffness changes in brain tumors might arise not from increased deposition or crosslinking of the collagen-rich extracellular matrix, but from pressure gradients that form within the tumors in vivo.

In Vivo Investigation of the Effectiveness of a Hyper-viscoelastic Model in Simulating Brain Retraction

NASA Astrophysics Data System (ADS)

Li, Ping; Wang, Weiwei; Zhang, Chenxi; An, Yong; Song, Zhijian

2016-07-01

Intraoperative brain retraction leads to a misalignment between the intraoperative positions of the brain structures and their previous positions, as determined from preoperative images. In vitro swine brain sample uniaxial tests showed that the mechanical response of brain tissue to compression and extension could be described by the hyper-viscoelasticity theory. The brain retraction caused by the mechanical process is a combination of brain tissue compression and extension. In this paper, we first constructed a hyper-viscoelastic framework based on the extended finite element method (XFEM) to simulate intraoperative brain retraction. To explore its effectiveness, we then applied this framework to an in vivo brain retraction simulation. The simulation strictly followed the clinical scenario, in which seven swine were subjected to brain retraction. Our experimental results showed that the hyper-viscoelastic XFEM framework is capable of simulating intraoperative brain retraction and improving the navigation accuracy of an image-guided neurosurgery system (IGNS).

Predilection sites for Toxoplasma gondii in sheep tissues revealed by magnetic capture and real-time PCR detection.

PubMed

Juránková, Jana; Basso, Walter; Neumayerová, Helena; Frencová, Anita; Baláž, Vojtech; Deplazes, Peter; Koudela, Břetislav

2015-12-01

Undercooked lamb and mutton are common sources of Toxoplasma gondii infection for humans. A sequence specific magnetic capture technique in combination with quantitative real-time PCR targeting the 529 bp repeat element of T. gondii was used for estimation of the parasite burdens in various sheep tissues (n = 6) three months after peroral experimental inoculation with 10,000 T. gondii oocysts. Brain was the most frequently affected organ (positive in all 6 sheep) and showed the highest estimated parasite loads (0.5-30,913 parasites/g tissue). Lung samples were positive in three sheep, with load estimates of 36.3 to <1 parasite/g tissue. Heart tissue was positive in three sheep and kidney only in one animal with low parasite loads (<1 parasite/g tissue). Only few skeletal muscle samples in 2 animals showed positive results, with very low parasite burdens, while samples from further internal organs (i.e. liver and spleen) were negative in all animals. This study identified the brain as the most important predilection site and therefore the most appropriate tissue for T. gondii detection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Towards High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry Coupled to Shear Force Microscopy

NASA Astrophysics Data System (ADS)

Nguyen, Son N.; Sontag, Ryan L.; Carson, James P.; Corley, Richard A.; Ansong, Charles; Laskin, Julia

2018-02-01

Constant mode ambient mass spectrometry imaging (MSI) of tissue sections with high lateral resolution of better than 10 μm was performed by combining shear force microscopy with nanospray desorption electrospray ionization (nano-DESI). Shear force microscopy enabled precise control of the distance between the sample and nano-DESI probe during MSI experiments and provided information on sample topography. Proof-of-concept experiments were performed using lung and brain tissue sections representing spongy and dense tissues, respectively. Topography images obtained using shear force microscopy were comparable to the results obtained using contact profilometry over the same region of the tissue section. Variations in tissue height were found to be dependent on the tissue type and were in the range of 0-5 μm for lung tissue and 0-3 μm for brain tissue sections. Ion images of phospholipids obtained in this study are in good agreement with literature data. Normalization of nano-DESI MSI images to the signal of the internal standard added to the extraction solvent allowed us to construct high-resolution ion images free of matrix effects.

Nanopipettes: probes for local sample analysis.

PubMed

Saha-Shah, Anumita; Weber, Anna E; Karty, Jonathan A; Ray, Steven J; Hieftje, Gary M; Baker, Lane A

2015-06-01

Nanopipettes (pipettes with diameters <1 μm) were explored as pressure-driven fluid manipulation tools for sampling nanoliter volumes of fluids. The fundamental behavior of fluids confined in the narrow channels of the nanopipette shank was studied to optimize sampling volume and probe geometry. This method was utilized to collect nanoliter volumes (<10 nL) of sample from single Allium cepa cells and live Drosophila melanogaster first instar larvae. Matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was utilized to characterize the collected sample. The use of nanopipettes for surface sampling of mouse brain tissue sections was also explored. Lipid analyses were performed on mouse brain tissues with spatial resolution of sampling as small as 50 μm. Nanopipettes were shown to be a versatile tool that will find further application in studies of sample heterogeneity and population analysis for a wide range of samples.

Vibrational Profiling of Brain Tumors and Cells

PubMed Central

Nelson, Sultan L; Proctor, Dustin T; Ghasemloonia, Ahmad; Lama, Sanju; Zareinia, Kourosh; Ahn, Younghee; Al-Saiedy, Mustafa R; Green, Francis HY; Amrein, Matthias W; Sutherland, Garnette R

2017-01-01

This study reports vibration profiles of neuronal cells and tissues as well as brain tumor and neocortical specimens. A contact-free method and analysis protocol was designed to convert an atomic force microscope into an ultra-sensitive microphone with capacity to record and listen to live biological samples. A frequency of 3.4 Hz was observed for both cultured rat hippocampal neurons and tissues and vibration could be modulated pharmacologically. Malignant astrocytoma tissue samples obtained from operating room, transported in artificial cerebrospinal fluid, and tested within an hour, vibrated with a much different frequency profile and amplitude, compared to meningioma or lateral temporal cortex providing a quantifiable measurement to accurately distinguish the three tissues in real-time. Vibration signals were converted to audible sound waves by frequency modulation, thus demonstrating, acoustic patterns unique to meningioma, malignant astrocytoma and neocortex. PMID:28744324

The NSW Brain Tissue Resource Centre: Banking for Alcohol and Major Neuropsychiatric Disorders Research

PubMed Central

Sutherland, G.T.; Sheedy, D.; Stevens, J.; McCrossin, T.; Smith, C.C.; van Roijen, M.; Kril, J.J.

2016-01-01

The New South Wales Brain Tissue Resource Centre (NSWBTRC) at the University of Sydney (Australia) is an established human brain bank providing tissue to the neuroscience research community for investigations on alcohol-related brain damage and major psychiatric illnesses such as schizophrenia. The NSWBTRC relies on wide community engagement to encourage those with and without neuropsychiatric illness to consent to donation through its allied research programs. The subsequent provision of high-quality samples relies on standardized operational protocols, associated clinical data, quality control measures, integrated information systems, robust infrastructure, and governance. These processes are continually augmented to complement the changes in internal and external governance as well as the complexity and diversity of advanced investigation techniques. This report provides an overview of the dynamic process of brain banking and discusses the challenges of meeting the future needs of researchers, including synchronicity with other disease-focus collections. PMID:27139235

Investigation of the usefulness of fluorescein sodium fluorescence in stereotactic brain biopsy.

PubMed

Thien, Ady; Han, Julian Xinguang; Kumar, Krishan; Ng, Yew Poh; Rao, Jai Prashanth; Ng, Wai Hoe; King, Nicolas Kon Kam

2018-02-01

Intraoperative frozen section assessment, to confirm acquisition of pathological tissues, is used in stereotactic brain biopsy to minimise sampling errors. Limitations include the dependence on dedicated neuro-oncology pathologists and an increase in operative duration. We investigated the use of intraoperative fluorescein sodium, and compared it to frozen section assessment, for confirming pathological tissue samples in the stereotactic biopsy of gadolinium-contrast-enhancing brain lesions. This prospective observational study consisted of 18 consecutive patients (12 men; median age, 63 years) who underwent stereotactic biopsy of gadolinium-contrast-enhancing brain lesions with intravenous fluorescein sodium administration. Twenty-three specimens were obtained and examined for the presence of fluorescence using a microscope with fluorescence visualisation capability. Positive and negative predictive values were calculated based on the fluorescence status of the biopsy samples with its corresponding intraoperative frozen section and definitive histopathological diagnosis. Nineteen specimens (83%) were fluorescent and four (17%) were non-fluorescent. All 19 fluorescent specimens were confirmed to be lesional on intraoperative frozen section assessment and were suitable for histopathological diagnosis. Three of the non-fluorescent specimens were confirmed to be lesional on intraoperative frozen section assessment. One non-fluorescent specimen was non-diagnostic on frozen section and histological assessments. The positive predictive value was 100% and the negative predictive value was 25%. Fluorescein sodium fluorescence is as accurate as frozen section assessment in confirming sampling of pathological tissue in the stereotactic biopsy of gadolinium-contrast-enhancing brain lesions. Fluorescein sodium fluorescence-guided stereotactic biopsy is a useful addition to the neurosurgical armamentarium.

Far-red to near infrared emission and scattering spectroscopy for biomedical applications

NASA Astrophysics Data System (ADS)

Zhang, Gang

2001-06-01

The thesis investigates the far-red and near infrared (NIR) spectral region from biomedical tissue samples for monitoring the state of tissues. The NIR emission wing intensity is weak in comparison to the emission in the visible spectral region. The wing emission from biomedical samples has revealed meaningful information about the state of the tissues. A model is presented to explain the shape of the spectral wing based on a continuum of energy levels. The wing can be used to classify different kinds of tissues; especially it can be used to differentiate cancer part from normal human breast tissues. The research work of the far-red emission from thermal damaged tissue samples shows that the emission intensity in this spectral region is proportional to the extent of the thermal damage of the tissue. Near infrared spectral absorption method is used to investigate blood hemodynamics (perfusion and oxygenation) in brain during sleep-wake transition. The result of the research demonstrates that the continuous wave (CW) type near infrared spectroscopy (NIRS) device can be used to investigate brain blood perfusion and oxygenation with a similar precision with frequency domain (FD) type device. The human subject sleep and wake transition, has been monitored by CW type NIRS instrument with traditional electroencephalograph (EEG) method. Parallel change in oxy-Hb and deoxy-Hb is a discrete event that occurs in the transition from both sleep to wakefulness and wakefulness to sleep. These hemodynamic switches are generally about few seconds delayed from the human decided transition point between sleep and wake on the polygraph EEG recording paper. The combination of NIRS and EEG methods monitor the brain activity, gives more information about the brain activity. The sleep apnea investigation was associated with recurrent apneas, insufficient nasal continuous positive airway pressure (CPAP) and the different response of the peripheral and central compartments to breathing events. The different results with finger pulse oximetry and NIRS suggest that optical monitoring of the brain may have advantages that may help clarify the morbidity of obstructive sleep apnea (OSA) Syndrome.

The detection of brain oedema with frequency-dependent phase shift electromagnetic induction.

PubMed

González, César A; Rubinsky, Boris

2006-06-01

The spectroscopic distribution of inductive phase shift in the brain as a function of the relative volume of oedema was evaluated with theoretical and experimental methods in the frequency range 1 to 8 MHz. The theoretical study employed a simple mathematical model of electromagnetic induction in tissue and brain tissue data available from the literature to calculate the phase shift as a function of oedema in the bulk of the brain. Experimental data were generated from bulk measurements of ex vivo homogenized pig brain tissue mixed with various volumes of physiological saline in a volume sample typical of the human brain. There is good agreement between the analytical and the experimental results. Detectable changes in phase shift begin from a frequency of about 3 MHz to 4 MHz in the tested compositions and volume. The phase shift increases with frequency and fluid content. The results suggest that measuring phase shift in the bulk of the brain has the potential for becoming a robust means for non-contact detection of oedema in the brain.

Determination of nitrosourea compounds in brain tissue by gas chromatography and electron capture detection.

PubMed

Hassenbusch, S J; Colvin, O M; Anderson, J H

1995-07-01

A relatively simple, high-sensitivity gas chromatographic assay is described for nitrosourea compounds, such as BCNU [1,3-bis(2-chloroethyl)-1-nitrosourea] and MeCCNU [1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea], in small biopsy samples of brain and other tissues. After extraction with ethyl acetate, secondary amines in BCNU and MeCCNU are derivatized with trifluoroacetic anhydride. Compounds are separated and quantitated by gas chromatography using a capillary column with temperature programming and an electron capture detector. Standard curves of BCNU indicate a coefficient of variance of 0.066 +/- 0.018, a correlation coefficient of 0.929, and an extraction efficiency from whole brain of 68% with a minimum detectable amount of 20 ng in 5-10 mg samples. The assay has been facile and sensitive in over 1000 brain biopsy specimens after intravenous and intraarterial infusions of BCNU.

Correspondence of DNA Methylation Between Blood and Brain Tissue and Its Application to Schizophrenia Research.

PubMed

Walton, Esther; Hass, Johanna; Liu, Jingyu; Roffman, Joshua L; Bernardoni, Fabio; Roessner, Veit; Kirsch, Matthias; Schackert, Gabriele; Calhoun, Vince; Ehrlich, Stefan

2016-03-01

Given the difficulty of procuring human brain tissue, a key question in molecular psychiatry concerns the extent to which epigenetic signatures measured in more accessible tissues such as blood can serve as a surrogate marker for the brain. Here, we aimed (1) to investigate the blood-brain correspondence of DNA methylation using a within-subject design and (2) to identify changes in DNA methylation of brain-related biological pathways in schizophrenia.We obtained paired blood and temporal lobe biopsy samples simultaneously from 12 epilepsy patients during neurosurgical treatment. Using the Infinium 450K methylation array we calculated similarity of blood and brain DNA methylation for each individual separately. We applied our findings by performing gene set enrichment analyses (GSEA) of peripheral blood DNA methylation data (Infinium 27K) of 111 schizophrenia patients and 122 healthy controls and included only Cytosine-phosphate-Guanine (CpG) sites that were significantly correlated across tissues.Only 7.9% of CpG sites showed a statistically significant, large correlation between blood and brain tissue, a proportion that although small was significantly greater than predicted by chance. GSEA analysis of schizophrenia data revealed altered methylation profiles in pathways related to precursor metabolites and signaling peptides.Our findings indicate that most DNA methylation markers in peripheral blood do not reliably predict brain DNA methylation status. However, a subset of peripheral data may proxy methylation status of brain tissue. Restricting the analysis to these markers can identify meaningful epigenetic differences in schizophrenia and potentially other brain disorders. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Comparison of methods of preserving tissues for pesticide analysis

USGS Publications Warehouse

Stickel, W.H.; Stickel, L.F.; Dyrland, R.A.; Hughes, D.L.

1984-01-01

Formalin preservation, freezing, spoiling followed by freezing, and phenoxyethanol were compared in terms of concentrations of DDT, DDD, DDE, endrin, and hepatachlor epoxide measured in brain, liver and carcass of birds fed dietary dosages of pesticides and in spiked egg homogenate. Phenoxyethanol proved to be an unsatisfactory preservative; the amount of 'extractable lipid' was excessive, and measurements of concentrations in replicates were erratic. Concentrations of residues in formalin-preserved and frozen samples did not differ significantly in any tissue. Percentage lipid in brains and eggs, however, were significantly lower in formalin-preserved samples. Samples of muscle and liver that had been spoiled before freezing yielded less DDD, and muscle samples yielded more DDT than formalin-preserved samples. The authors conclude that formalin preservation is a satisfactory method for preservation of field samples and that the warming and spoiling of samples that may occur unavoidably in the field will not result in misleading analytical results.

Determination of the neuropharmacological drug nodakenin in rat plasma and brain tissues by liquid chromatography tandem mass spectrometry: Application to pharmacokinetic studies.

PubMed

Song, Yingshi; Yan, Huiyu; Xu, Jingbo; Ma, Hongxi

2017-09-01

A rapid and sensitive liquid chromatography tandem mass spectrometry detection using selected reaction monitoring in positive ionization mode was developed and validated for the quantification of nodakenin in rat plasma and brain. Pareruptorin A was used as internal standard. A single step liquid-liquid extraction was used for plasma and brain sample preparation. The method was validated with respect to selectivity, precision, accuracy, linearity, limit of quantification, recovery, matrix effect and stability. Lower limit of quantification of nodakenin was 2.0 ng/mL in plasma and brain tissue homogenates. Linear calibration curves were obtained over concentration ranges of 2.0-1000 ng/mL in plasma and brain tissue homogenates for nodakenin. Intra-day and inter-day precisions (relative standard deviation, RSD) were <15% in both biological media. This assay was successfully applied to plasma and brain pharmacokinetic studies of nodakenin in rats after intravenous administration. Copyright © 2017 John Wiley & Sons, Ltd.

Ectopic High Expression of E2-EPF Ubiquitin Carrier Protein Indicates a More Unfavorable Prognosis in Brain Glioma.

PubMed

Zhang, Xiaohui; Zhao, Fangbo; Zhang, Shujun; Song, Yichun

2017-04-01

Ubiquitination of proteins meant for elimination is a primary method of eukaryotic cellular protein degradation. The ubiquitin carrier protein E2-EPF is a key degradation enzyme that is highly expressed in many tumors. However, its expression and prognostic significance in brain glioma are still unclear. The aim of this study was to reveal how the level of E2-EPF relates to prognosis in brain glioma. Thirty low-grade and 30 high-grade brain glioma samples were divided into two tissue microarrays each. Levels of E2-EPF protein were examined by immunohistochemistry and immunofluorescence. Quantitative real-time polymerase chain reaction was used to analyze the level of E2-EPF in 60 glioma and 3 normal brain tissue samples. The relationship between E2-EPF levels and prognosis was analyzed by Kaplan-Meier survival curves. E2-EPF levels were low in normal brain tissue samples but high in glioma nuclei. E2-EPF levels gradually increased as glioma grade increased (p < 0.05). Ectopic E2-EPF levels in high-grade glioma were significantly higher than in low-grade glioma (p < 0.01). The 5-year survival rate of glioma patients with high E2-EPF levels was shorter than in patients with low expression (p < 0.05). Furthermore, the 5-year survival rate of patients with ectopic E2-EPF was significantly shorter than patients with only nuclear E2-EPF (p < 0.01). These results suggest that higher E2-EPF levels, especially ectopic, are associated with higher grade glioma and shorter survival. E2-EPF levels may play a key role in predicting the prognosis for patients with brain glioma.

Determination of selected neurotoxic insecticides in small amounts of animal tissue utilizing a newly constructed mini-extractor.

PubMed

Seifertová, Marta; Čechová, Eliška; Llansola, Marta; Felipo, Vicente; Vykoukalová, Martina; Kočan, Anton

2017-10-01

We developed a simple analytical method for the simultaneous determination of representatives of various groups of neurotoxic insecticides (carbaryl, chlorpyrifos, cypermethrin, and α-endosulfan and β-endosulfan and their metabolite endosulfan sulfate) in limited amounts of animal tissues containing different amounts of lipids. Selected tissues (rodent fat, liver, and brain) were extracted in a special in-house-designed mini-extractor constructed on the basis of the Soxhlet and Twisselmann extractors. A dried tissue sample placed in a small cartridge was extracted, while the nascent extract was simultaneously filtered through a layer of sodium sulfate. The extraction was followed by combined clean-up, including gel permeation chromatography (in case of high lipid content), ultrasonication, and solid-phase extraction chromatography using C 18 on silica and aluminum oxide. Gas chromatography coupled with high-resolution mass spectrometry was used for analyte separation, detection, and quantification. Average recoveries for individual insecticides ranged from 82 to 111%. Expanded measurement uncertainties were generally lower than 35%. The developed method was successfully applied to rat tissue samples obtained from an animal model dealing with insecticide exposure during brain development. This method may also be applied to the analytical treatment of small amounts of various types of animal and human tissue samples. A significant advantage achieved using this method is high sample throughput due to the simultaneous treatment of many samples. Graphical abstract Optimized workflow for the determination of selected insecticides in small amounts of animal tissue including newly developed mini-extractor.

HPLC determination of strychnine and brucine in rat tissues and the distribution study of processed semen strychni.

PubMed

Chen, Jun; Hou, Ting; Fang, Yun; Chen, Zhi-peng; Liu, Xiao; Cai, Hao; Lu, Tu-lin; Yan, Guo-jun; Cai, Bao-chang

2011-01-01

A simple and low-cost HPLC method with UV absorbance detection was developed and validated to simultaneously determine strychnine and brucine, the most abundant alkaloids in the processed Semen Strychni, in rat tissues (kidney, liver, spleen, lung, heart, stomach, small intestine, brain and plasma). The tissue samples were treated with a simple liquid-liquid extraction prior to HPLC. The LOQs were in the range of 0.039-0.050 µg/ml for different tissue or plasma samples. The extraction recoveries varied from 71.63 to 98.79%. The linear range was 0.05-2 µg/ml with correlation coefficient of over 0.991. The intra- and inter-day precision was less than 15%. Then the method was used to measure the tissue distribution of strychnine and brucine after intravenous administration of 1 mg/kg crude alkaloids fraction (CAF) extracted from the processed Semen Strychni. The results revealed that strychnine and brucine possessed similar tissue distribution characterization. The highest level was observed in kidney, while the lowest level was found in brain. It was indicated that kidney might be the primary excretion organ of prototype strychnine and brucine. It was also deduced that strychnine and brucine had difficulty in crossing the blood-brain barrier. Furthermore, no long-term accumulation of strychnine and brucine was found in rat tissues.

Deep Sequencing to Identify the Causes of Viral Encephalitis

PubMed Central

Chan, Benjamin K.; Wilson, Theodore; Fischer, Kael F.; Kriesel, John D.

2014-01-01

Deep sequencing allows for a rapid, accurate characterization of microbial DNA and RNA sequences in many types of samples. Deep sequencing (also called next generation sequencing or NGS) is being developed to assist with the diagnosis of a wide variety of infectious diseases. In this study, seven frozen brain samples from deceased subjects with recent encephalitis were investigated. RNA from each sample was extracted, randomly reverse transcribed and sequenced. The sequence analysis was performed in a blinded fashion and confirmed with pathogen-specific PCR. This analysis successfully identified measles virus sequences in two brain samples and herpes simplex virus type-1 sequences in three brain samples. No pathogen was identified in the other two brain specimens. These results were concordant with pathogen-specific PCR and partially concordant with prior neuropathological examinations, demonstrating that deep sequencing can accurately identify viral infections in frozen brain tissue. PMID:24699691

Brief Report: S6 Ribosomal Protein Phosphorylation in Autistic Frontal Cortex and Cerebellum: A Tissue Array Analysis

ERIC Educational Resources Information Center

Eberhart, Charles G.; Copeland, Joshua; Abel, Ty W.

2006-01-01

Few autistic brain samples are available for study, limiting investigations into molecular and histopathological abnormalities associated with this common disease. To facilitate distribution of samples, we have constructed a tissue array containing cerebral and cerebellar cores from 5 autistic children, 1 girl with Rett syndrome, and 5 age-matched…

Iron biomineralization of brain tissue and neurodegenerative disorders

NASA Astrophysics Data System (ADS)

Mikhaylova (Mikhailova), Albina

The brain is an organ with a high concentration of iron in specific areas, particularly in the globus pallidus, the substantia nigra, and the red nucleus. In certain pathological states, such as iron overload disease and neurodegenerative disorders, a disturbed iron metabolism can lead to increased accumulation of iron not only in these areas, but also in the brain regions that are typically low in iron content. Recent studies of the physical and magnetic properties of metalloproteins, and in particular the discovery of biogenic magnetite in human brain tissue, have raised new questions about the role of biogenic iron formations in living organisms. Further investigations revealed the presence of magnetite-like crystalline structures in human ferritin, and indicated that released ferritin iron might act as promoter of oxidative damage to tissue, therefore contributing to pathogenesis of neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases. The purpose of this work was to examine the elemental composition and structure of iron deposits in normal brain tissue as well as tissue affected by neurodegenerative disorders. Employing the methods of X-ray microfocus fluorescence mapping, X-ray Absorption Near Edge Structure (XANES), X-ray Absorption Fine Structure spectroscopy (XAFS), and light and electron microscopic examinations allows one to obtain qualitative as well as quantitative data with respect to the cellular distribution and chemical state of iron at levels not detected previously. The described tissue preparation technique allows not only satisfactory XAS iron elemental imaging in situ but also multimodal examination with light and electron microscopes of the same samples. The developed protocol has assured consistent and reproducible results on relatively large sections of flat-embedded tissue. The resulting tissue samples were adequate for XAS examination as well as sufficiently well-preserved for future microscopy studies. The continued development of this technique should lead to major advances in mapping iron anomalies and the related chemical and structural information directly to cells and tissue structures in human brain tissue. At present this is done primarily by iron staining methods and any information on the relationship between iron distribution and cellular structures obtained this way is limited. Iron staining also offers no information on the specific compounds of iron that are present. This can be vitally important as the form of iron [including its oxidation state] in the human body can determine whether it plays a detrimental or beneficial role in neurophysiological processes.

Nonlocal correlations of polarization-entangled photons through brain tissue (Conference Presentation)

NASA Astrophysics Data System (ADS)

Galvez, Enrique J.; Shi, Lingyan; Alfano, Robert R.

2017-02-01

We investigated the preservation of non-local correlations between polarization-entangled photons when one of them traveled through brain tissue slices of different thicknesses. Using down-converted photons at a wavelength of 802 nm minimized the absorption by the tissue. After the light passed through the tissue samples, we performed quantum state tomography to obtain quantitative measures of the entanglement. We found that entanglement is preserved to a surprising degree, and when it degrades, it does so following a particular path in a tangle versus linear-entropy graph. Such a trajectory reveals direct transfer of probability from entangled to mixed state.

High-resolution x-ray absorption spectroscopy studies of metal compounds in neurodegenerative brain tissue

NASA Astrophysics Data System (ADS)

Collingwood, J. F.; Mikhaylova, A.; Davidson, M. R.; Batich, C.; Streit, W. J.; Eskin, T.; Terry, J.; Barrea, R.; Underhill, R. S.; Dobson, J.

2005-01-01

Fluorescence mapping and microfocus X-ray absorption spectroscopy are used to detect, locate and identify iron biominerals and other inorganic metal accumulations in neurodegenerative brain tissue at sub-cellular resolution (<5 microns). Recent progress in developing the technique is reviewed. Synchrotron X-rays are used to map tissue sections for metals of interest, and XANES and XAFS are used to characterise anomalous concentrations of the metals in-situ so that they can be correlated with tissue structures and disease pathology. Iron anomalies associated with biogenic magnetite, ferritin and haemoglobin are located and identified in an avian tissue model with a pixel resolution ~5 microns. Subsequent studies include brain tissue sections from transgenic Huntington's mice, and the first high-resolution mapping and identification of iron biominerals in human Alzheimer's and control autopsy brain tissue. Technical developments include use of microfocus diffraction to obtain structural information about biominerals in-situ, and depositing sample location grids by lithography for the location of anomalies by conventional microscopy. The combined techniques provide a breakthrough in the study of both intra- and extra-cellular iron compounds and related metals in tissue. The information to be gained from this approach has implications for future diagnosis and treatment of neurodegeneration, and for our understanding of the mechanisms involved.

Bioimaging of metals in brain tissue by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and metallomics.

PubMed

Becker, J Sabine; Matusch, Andreas; Palm, Christoph; Salber, Dagmar; Morton, Kathryn A; Becker, J Susanne

2010-02-01

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been developed and established as an emerging technique in the generation of quantitative images of metal distributions in thin tissue sections of brain samples (such as human, rat and mouse brain), with applications in research related to neurodegenerative disorders. A new analytical protocol is described which includes sample preparation by cryo-cutting of thin tissue sections and matrix-matched laboratory standards, mass spectrometric measurements, data acquisition, and quantitative analysis. Specific examples of the bioimaging of metal distributions in normal rodent brains are provided. Differences to the normal were assessed in a Parkinson's disease and a stroke brain model. Furthermore, changes during normal aging were studied. Powerful analytical techniques are also required for the determination and characterization of metal-containing proteins within a large pool of proteins, e.g., after denaturing or non-denaturing electrophoretic separation of proteins in one-dimensional and two-dimensional gels. LA-ICP-MS can be employed to detect metalloproteins in protein bands or spots separated after gel electrophoresis. MALDI-MS can then be used to identify specific metal-containing proteins in these bands or spots. The combination of these techniques is described in the second section.

International recommendation for a comprehensive neuropathologic workup of epilepsy surgery brain tissue: A consensus Task Force report from the ILAE Commission on Diagnostic Methods.

PubMed

Blümcke, Ingmar; Aronica, Eleonora; Miyata, Hajime; Sarnat, Harvey B; Thom, Maria; Roessler, Karl; Rydenhag, Bertil; Jehi, Lara; Krsek, Pavel; Wiebe, Samuel; Spreafico, Roberto

2016-03-01

Epilepsy surgery is an effective treatment in many patients with drug-resistant focal epilepsies. An early decision for surgical therapy is facilitated by a magnetic resonance imaging (MRI)-visible brain lesion congruent with the electrophysiologically abnormal brain region. Recent advances in the pathologic diagnosis and classification of epileptogenic brain lesions are helpful for clinical correlation, outcome stratification, and patient management. However, application of international consensus classification systems to common epileptic pathologies (e.g., focal cortical dysplasia [FCD] and hippocampal sclerosis [HS]) necessitates standardized protocols for neuropathologic workup of epilepsy surgery specimens. To this end, the Task Force of Neuropathology from the International League Against Epilepsy (ILAE) Commission on Diagnostic Methods developed a consensus standard operational procedure for tissue inspection, distribution, and processing. The aims are to provide a systematic framework for histopathologic workup, meeting minimal standards and maximizing current and future opportunities for morphofunctional correlations and molecular studies for both clinical care and research. Whenever feasible, anatomically intact surgical specimens are desirable to enable systematic analysis in selective hippocampectomies, temporal lobe resections, and lesional or nonlesional neocortical samples. Correct orientation of sample and the sample's relation to neurophysiologically aberrant sites requires good communication between pathology and neurosurgical teams. Systematic tissue sampling of 5-mm slabs along a defined anatomic axis and application of a limited immunohistochemical panel will ensure a reliable differential diagnosis of main pathologies encountered in epilepsy surgery. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Spectral domain optical coherence tomography for ex vivo brain tumor analysis

NASA Astrophysics Data System (ADS)

Lenz, Marcel; Krug, Robin; Jaedicke, Volker; Stroop, Ralf; Schmieder, Kirsten; Hofmann, Martin R.

2015-07-01

Non-contact imaging methods to distinguish between healthy tissue and brain tumor tissue during surgery would be highly desirable but are not yet available. Optical Coherence Tomography (OCT) is a non-invasive imaging technology with a resolution around 1-15 μm and a penetration depth of 1-2 mm that may satisfy the demands. To analyze its potential, we measured ex vivo human brain tumor tissue samples from 10 patients with a Spectral Domain OCT system (Thorlabs Callisto: center wavelength of 930 nm) and compared the results with standard histology. In detail, three different measurements were made for each sample. First the sample was measured directly after surgery. Then it was embedded in paraffin (also H and E staining) and examined for the second time. At last, the slices of each paraffin block cut by the pathology were measured. Each time a B-scan was created and for a better comparison with the histology a 3D image was generated, in order to get the corresponding en face images. In both, histopathological diagnosis and the analysis of the OCT images, different types of brain tumor showed difference in structure. This has been affirmed by two blinded investigators. Nevertheless the difference between two images of samples taken directly after surgery is less distinct. To enhance the contrast in the images further, we employ Spectroscopic OCT and pattern recognition algorithms and compare these results to the histopathological standard.

Towards High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry Coupled to Shear Force Microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Son N.; Sontag, Ryan L.; Carson, James P.

Constant mode ambient mass spectrometry imaging (MSI) of tissue sections with high lateral resolution of better than 10 µm was performed by combining shear force microscopy with nanospray desorption electrospray ionization (nano-DESI). Shear force microscopy enabled precise control of the distance between the sample and nano-DESI probe during MSI experiments and provided information on sample topography. Proof-of-concept experiments were performed using lung and brain tissue sections representing spongy and dense tissues, respectively. Topography images obtained using shear force microscopy were comparable to the results obtained using contact profilometry over the same region of the tissue section. Variations in tissue heightmore » were found to be dependent on the tissue type and were in the range of 0-5 µm for lung tissue and 0-3 µm for brain tissue sections. Ion images of phospholipids obtained in this study are in good agreement with literature data. Normalization of nano-DESI MSI images to the signal of the internal standard added to the extraction solvent allowed us to construct high-resolution ion images free of matrix effects.« less

In Vivo Investigation of the Effectiveness of a Hyper-viscoelastic Model in Simulating Brain Retraction

PubMed Central

Li, Ping; Wang, Weiwei; Zhang, Chenxi; An, Yong; Song, Zhijian

2016-01-01

Intraoperative brain retraction leads to a misalignment between the intraoperative positions of the brain structures and their previous positions, as determined from preoperative images. In vitro swine brain sample uniaxial tests showed that the mechanical response of brain tissue to compression and extension could be described by the hyper-viscoelasticity theory. The brain retraction caused by the mechanical process is a combination of brain tissue compression and extension. In this paper, we first constructed a hyper-viscoelastic framework based on the extended finite element method (XFEM) to simulate intraoperative brain retraction. To explore its effectiveness, we then applied this framework to an in vivo brain retraction simulation. The simulation strictly followed the clinical scenario, in which seven swine were subjected to brain retraction. Our experimental results showed that the hyper-viscoelastic XFEM framework is capable of simulating intraoperative brain retraction and improving the navigation accuracy of an image-guided neurosurgery system (IGNS). PMID:27387301

Photon Entanglement Through Brain Tissue.

PubMed

Shi, Lingyan; Galvez, Enrique J; Alfano, Robert R

2016-12-20

Photon entanglement, the cornerstone of quantum correlations, provides a level of coherence that is not present in classical correlations. Harnessing it by study of its passage through organic matter may offer new possibilities for medical diagnosis technique. In this work, we study the preservation of photon entanglement in polarization, created by spontaneous parametric down-conversion, after one entangled photon propagates through multiphoton-scattering brain tissue slices with different thickness. The Tangle-Entropy (TS) plots show the strong preservation of entanglement of photons propagating in brain tissue. By spatially filtering the ballistic scattering of an entangled photon, we find that its polarization entanglement is preserved and non-locally correlated with its twin in the TS plots. The degree of entanglement correlates better with structure and water content than with sample thickness.

Photon Entanglement Through Brain Tissue

NASA Astrophysics Data System (ADS)

Shi, Lingyan; Galvez, Enrique J.; Alfano, Robert R.

2016-12-01

Photon entanglement, the cornerstone of quantum correlations, provides a level of coherence that is not present in classical correlations. Harnessing it by study of its passage through organic matter may offer new possibilities for medical diagnosis technique. In this work, we study the preservation of photon entanglement in polarization, created by spontaneous parametric down-conversion, after one entangled photon propagates through multiphoton-scattering brain tissue slices with different thickness. The Tangle-Entropy (TS) plots show the strong preservation of entanglement of photons propagating in brain tissue. By spatially filtering the ballistic scattering of an entangled photon, we find that its polarization entanglement is preserved and non-locally correlated with its twin in the TS plots. The degree of entanglement correlates better with structure and water content than with sample thickness.

Multi-spectral brain tissue segmentation using automatically trained k-Nearest-Neighbor classification.

PubMed

Vrooman, Henri A; Cocosco, Chris A; van der Lijn, Fedde; Stokking, Rik; Ikram, M Arfan; Vernooij, Meike W; Breteler, Monique M B; Niessen, Wiro J

2007-08-01

Conventional k-Nearest-Neighbor (kNN) classification, which has been successfully applied to classify brain tissue in MR data, requires training on manually labeled subjects. This manual labeling is a laborious and time-consuming procedure. In this work, a new fully automated brain tissue classification procedure is presented, in which kNN training is automated. This is achieved by non-rigidly registering the MR data with a tissue probability atlas to automatically select training samples, followed by a post-processing step to keep the most reliable samples. The accuracy of the new method was compared to rigid registration-based training and to conventional kNN-based segmentation using training on manually labeled subjects for segmenting gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF) in 12 data sets. Furthermore, for all classification methods, the performance was assessed when varying the free parameters. Finally, the robustness of the fully automated procedure was evaluated on 59 subjects. The automated training method using non-rigid registration with a tissue probability atlas was significantly more accurate than rigid registration. For both automated training using non-rigid registration and for the manually trained kNN classifier, the difference with the manual labeling by observers was not significantly larger than inter-observer variability for all tissue types. From the robustness study, it was clear that, given an appropriate brain atlas and optimal parameters, our new fully automated, non-rigid registration-based method gives accurate and robust segmentation results. A similarity index was used for comparison with manually trained kNN. The similarity indices were 0.93, 0.92 and 0.92, for CSF, GM and WM, respectively. It can be concluded that our fully automated method using non-rigid registration may replace manual segmentation, and thus that automated brain tissue segmentation without laborious manual training is feasible.

Gadolinium Deposition in Human Brain Tissues after Contrast-enhanced MR Imaging in Adult Patients without Intracranial Abnormalities.

PubMed

McDonald, Robert J; McDonald, Jennifer S; Kallmes, David F; Jentoft, Mark E; Paolini, Michael A; Murray, David L; Williamson, Eric E; Eckel, Laurence J

2017-11-01

Purpose To determine whether gadolinium deposits in neural tissues of patients with intracranial abnormalities following intravenous gadolinium-based contrast agent (GBCA) exposure might be related to blood-brain barrier integrity by studying adult patients with normal brain pathologic characteristics. Materials and Methods After obtaining antemortem consent and institutional review board approval, the authors compared postmortem neuronal tissue samples from five patients who had undergone four to 18 gadolinium-enhanced magnetic resonance (MR) examinations between 2005 and 2014 (contrast group) with samples from 10 gadolinium-naive patients who had undergone at least one MR examination during their lifetime (control group). All patients in the contrast group had received gadodiamide. Neuronal tissues from the dentate nuclei, pons, globus pallidus, and thalamus were harvested and analyzed with inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy with energy-dispersive x-ray spectroscopy, and light microscopy to quantify, localize, and assess the effects of gadolinium deposition. Results Tissues from the four neuroanatomic regions of gadodiamide-exposed patients contained 0.1-19.4 μg of gadolinium per gram of tissue in a statistically significant dose-dependent relationship (globus pallidus: ρ = 0.90, P = .04). In contradistinction, patients in the control group had undetectable levels of gadolinium with ICP-MS. All patients had normal brain pathologic characteristics at autopsy. Three patients in the contrast group had borderline renal function (estimated glomerular filtration rate <45 mL/min/1.73 m 2 ) and hepatobiliary dysfunction at MR examination. Gadolinium deposition in the contrast group was localized to the capillary endothelium and neuronal interstitium and, in two cases, within the nucleus of the cell. Conclusion Gadolinium deposition in neural tissues after GBCA administration occurs in the absence of intracranial abnormalities that might affect the permeability of the blood-brain barrier. These findings challenge current understanding of the biodistribution of these contrast agents and their safety. © RSNA, 2017.

Nanopipettes: probes for local sample analysis† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5sc00668f Click here for additional data file.

PubMed Central

Saha-Shah, Anumita; Weber, Anna E.; Karty, Jonathan A.; Ray, Steven J.; Hieftje, Gary M.

2015-01-01

Nanopipettes (pipettes with diameters <1 μm) were explored as pressure-driven fluid manipulation tools for sampling nanoliter volumes of fluids. The fundamental behavior of fluids confined in the narrow channels of the nanopipette shank was studied to optimize sampling volume and probe geometry. This method was utilized to collect nanoliter volumes (<10 nL) of sample from single Allium cepa cells and live Drosophila melanogaster first instar larvae. Matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was utilized to characterize the collected sample. The use of nanopipettes for surface sampling of mouse brain tissue sections was also explored. Lipid analyses were performed on mouse brain tissues with spatial resolution of sampling as small as 50 μm. Nanopipettes were shown to be a versatile tool that will find further application in studies of sample heterogeneity and population analysis for a wide range of samples. PMID:28706697

Effects of formalin fixation on tissue optical properties of in-vitro brain samples

NASA Astrophysics Data System (ADS)

Anand, Suresh; Cicchi, Riccardo; Martelli, Fabrizio; Giordano, Flavio; Buccoliero, Anna Maria; Guerrini, Renzo; Pavone, Francesco S.

2015-03-01

Application of light spectroscopy based techniques for the detection of cancers have emerged as a promising approach for tumor diagnostics. In-vivo or freshly excised samples are normally used for point spectroscopic studies. However, ethical issues related to in-vivo studies, rapid decay of surgically excised tissues and sample availability puts a limitation on in-vivo and in-vitro studies. There has been a few studies reported on the application of formalin fixed samples with good discrimination capability. Usually formalin fixation is performed to prevent degradation of tissues after surgical resection. Fixing tissues in formalin prevents cell death by forming cross-linkages with proteins. Previous investigations have revealed that washing tissues fixed in formalin using phosphate buffered saline is known to reduce the effects of formalin during spectroscopic measurements. But this could not be the case with reflectance measurements. Hemoglobin is a principal absorbing medium in biological tissues in the visible range. Formalin fixation causes hemoglobin to seep out from red blood cells. Also, there could be alterations in the refractive index of tissues when fixed in formalin. In this study, we propose to investigate the changes in tissue optical properties between freshly excised and formalin fixed brain tissues. The results indicate a complete change in the spectral profile in the visible range where hemoglobin has its maximum absorption peaks. The characteristic bands of oxy-hemoglobin at 540, 580 nm and deoxy-hemoglobin at 555 nm disappear in the case of samples fixed in formalin. In addition, an increased spectral intensity was observed for the wavelengths greater than 650 nm where scattering phenomena are presumed to dominate.

Ambient Molecular Analysis of Biological Tissue Using Low-Energy, Femtosecond Laser Vaporization and Nanospray Postionization Mass Spectrometry

NASA Astrophysics Data System (ADS)

Shi, Fengjian; Flanigan, Paul M.; Archer, Jieutonne J.; Levis, Robert J.

2016-03-01

Direct analysis of plant and animal tissue samples by laser electrospray mass spectrometry (LEMS) was investigated using low-energy, femtosecond duration laser vaporization at wavelengths of 800 and 1042 nm followed by nanospray postionization. Low-energy (<50 μJ), fiber-based 1042 nm LEMS (F-LEMS) allowed interrogation of the molecular species in fresh flower petal and leaf samples using 435 fs, 10 Hz bursts of 20 pulses from a Ytterbium-doped fiber laser and revealed comparable results to high energy (75-1120 μJ), 45 fs, 800 nm Ti:Sapphire-based LEMS (Ti:Sapphire-LEMS) measurements. Anthocyanins, sugars, and other metabolites were successfully detected and revealed the anticipated metabolite profile for the petal and leaf samples. Phospholipids, especially phosphatidylcholine, were identified from a fresh mouse brain section sample using Ti:Sapphire-LEMS without the application of matrix. These lipid features were suppressed in both the fiber-based and Ti:Sapphire-based LEMS measurements when the brain sample was prepared using the optimal cutting temperature compounds that are commonly used in animal tissue cryosections.

Reduction of Photo Bleaching and Long Term Archiving of Chemically Cleared GFP-Expressing Mouse Brains

PubMed Central

Becker, Klaus; Hahn, Christian Markus; Saghafi, Saiedeh; Jährling, Nina; Wanis, Martina; Dodt, Hans-Ulrich

2014-01-01

Tissue clearing allows microscopy of large specimens as whole mouse brains or embryos. However, lipophilic tissue clearing agents as dibenzyl ether limit storage time of GFP-expressing samples to several days and do not prevent them from photobleaching during microscopy. To preserve GFP fluorescence, we developed a transparent solid resin formulation, which maintains the specimens' transparency and provides a constant signal to noise ratio even after hours of continuous laser irradiation. If required, high-power illumination or long exposure times can be applied with virtually no loss in signal quality and samples can be archived for years. PMID:25463047

The direct analysis of drug distribution of rotigotine-loaded microspheres from tissue sections by LESA coupled with tandem mass spectrometry.

PubMed

Xu, Li-Xiao; Wang, Tian-Tian; Geng, Yin-Yin; Wang, Wen-Yan; Li, Yin; Duan, Xiao-Kun; Xu, Bin; Liu, Charles C; Liu, Wan-Hui

2017-09-01

The direct analysis of drug distribution of rotigotine-loaded microspheres (RoMS) from tissue sections by liquid extraction surface analysis (LESA) coupled with tandem mass spectrometry (MS/MS) was demonstrated. The RoMS distribution in rat tissues assessed by the ambient LESA-MS/MS approach without extensive or tedious sample pretreatment was compared with that obtained by a conventional liquid chromatography tandem mass spectrometry (LC-MS/MS) method in which organ excision and subsequent solvent extraction were commonly employed before analysis. Results obtained from the two were well correlated for a majority of the organs, such as muscle, liver, stomach, and hippocampus. The distribution of RoMS in the brain, however, was found to be mainly focused in the hippocampus and striatum regions as shown by the LESA-imaged profiles. The LESA approach we developed is sensitive enough, with an estimated LLOQ at 0.05 ng/mL of rotigotine in brain tissue, and information-rich with minimal sample preparation, suitable, and promising in assisting the development of new drug delivery systems for controlled drug release and protection. Graphical abstract Workflow for the LESA-MS/MS imaging of brain tissue section after intramuscular RoMS administration.

Spatially resolved proteome mapping of laser capture microdissected tissue with automated sample transfer to nanodroplets.

PubMed

Zhu, Ying; Dou, Maowei; Piehowski, Paul D; Liang, Yiran; Wang, Fangjun; Chu, Rosalie K; Chrisler, Will; Smith, Jordan N; Schwarz, Kaitlynn C; Shen, Yufeng; Shukla, Anil K; Moore, Ronald J; Smith, Richard D; Qian, Wei-Jun; Kelly, Ryan T

2018-06-24

Current mass spectrometry (MS)-based proteomics approaches are ineffective for mapping protein expression in tissue sections with high spatial resolution due to the limited overall sensitivity of conventional workflows. Here we report an integrated and automated method to advance spatially resolved proteomics by seamlessly coupling laser capture microdissection (LCM) with a recently developed nanoliter-scale sample preparation system termed nanoPOTS (Nanodroplet Processing in One pot for Trace Samples). The workflow is enabled by prepopulating nanowells with DMSO, which serves as a sacrificial capture liquid for microdissected tissues. The DMSO droplets efficiently collect laser-pressure catapulted LCM tissues as small as 20 µm in diameter with success rates >87%. We also demonstrate that tissue treatment with DMSO can significantly improve proteome coverage, likely due to its ability to dissolve lipids from tissue and enhance protein extraction efficiency. The LCM-nanoPOTS platform was able to identify 180, 695, and 1827 protein groups on average from 12-µm-thick rat brain cortex tissue sections with diameters of 50, 100, and 200 µm, respectively. We also analyzed 100-µm-diameter sections corresponding to 10-18 cells from three different regions of rat brain and comparatively quantified ~1000 proteins, demonstrating the potential utility for high-resolution spatially resolved mapping of protein expression in tissues. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Genomic characterization of brain metastases reveals branched evolution and potential therapeutic targets

PubMed Central

Santagata, Sandro; Cahill, Daniel P.; Taylor-Weiner, Amaro; Jones, Robert T.; Van Allen, Eliezer M.; Lawrence, Michael S.; Horowitz, Peleg M.; Cibulskis, Kristian; Ligon, Keith L.; Tabernero, Josep; Seoane, Joan; Martinez-Saez, Elena; Curry, William T.; Dunn, Ian F.; Paek, Sun Ha; Park, Sung-Hye; McKenna, Aaron; Chevalier, Aaron; Rosenberg, Mara; Barker, Frederick G.; Gill, Corey M.; Van Hummelen, Paul; Thorner, Aaron R.; Johnson, Bruce E.; Hoang, Mai P.; Choueiri, Toni K.; Signoretti, Sabina; Sougnez, Carrie; Rabin, Michael S.; Lin, Nancy U.; Winer, Eric P.; Stemmer-Rachamimov, Anat; Meyerson, Matthew; Garraway, Levi; Gabriel, Stacey; Lander, Eric S.; Beroukhim, Rameen; Batchelor, Tracy T.; Baselga, Jose; Louis, David N.

2016-01-01

Brain metastases are associated with a dismal prognosis. Whether brain metastases harbor distinct genetic alterations beyond those observed in primary tumors is unknown. We performed whole-exome sequencing of 86 matched brain metastases, primary tumors and normal tissue. In all clonally related cancer samples, we observed branched evolution, where all metastatic and primary sites shared a common ancestor yet continued to evolve independently. In 53% of cases, we found potentially clinically informative alterations in the brain metastases not detected in the matched primary-tumor sample. In contrast, spatially and temporally separated brain metastasis sites were genetically homogenous. Distal extracranial and regional lymph node metastases were highly divergent from brain metastases. We detected alterations associated with sensitivity to PI3K/AKT/mTOR, CDK, and HER2/EGFR inhibitors in the brain metastases. Genomic analysis of brain metastases provides an opportunity to identify potentially clinically informative alterations not detected in clinically sampled primary tumors, regional lymph nodes, or extracranial metastases. PMID:26410082

An efficient, reliable and inexpensive device for the rapid homogenization of multiple tissue samples by centrifugation.

PubMed

Ilyin, S E; Plata-Salamán, C R

2000-02-15

Homogenization of tissue samples is a common first step in the majority of current protocols for RNA, DNA, and protein isolation. This report describes a simple device for centrifugation-mediated homogenization of tissue samples. The method presented is applicable to RNA, DNA, and protein isolation, and we show examples where high quality total cell RNA, DNA, and protein were obtained from brain and other tissue samples. The advantages of the approach presented include: (1) a significant reduction in time investment relative to hand-driven or individual motorized-driven pestle homogenization; (2) easy construction of the device from inexpensive parts available in any laboratory; (3) high replicability in the processing; and (4) the capacity for the parallel processing of multiple tissue samples, thus allowing higher efficiency, reliability, and standardization.

Distribution of opiate alkaloids in brain tissue of experimental animals

PubMed Central

Pilija, Vladimir; Mimica-Dukic, Neda; Budakov, Branislav; Cvjeticanin, Stanko

2012-01-01

The present study examined regional distribution of opiate alkaloids from seized heroin in brain regions of experimental animals in order to select parts with the highest content of opiates. Their analysis should contribute to resolve causes of death due to heroin intake. The tests were performed at different time periods (5, 15, 45 and 120 min) after male and female Wistar rats were treated with seized heroin. Opiate alkaloids (codeine, morphine, acetylcodeine, 6-acetylmorphine and 3,6-diacetylmorphine) were quantitatively determined in brain regions known for their high concentration of µ-opiate receptors: cortex, brainstem, amygdala and basal ganglia, by using gas chromatography–mass spectrometry (GC–MS). The highest content of opiate alkaloids in the brain tissue of female animals was found 15 min and in male animals 45 min after treatment. The highest content of opiates was determined in the basal ganglia of the animals of both genders, indicating that this part of brain tissue presents a reliable sample for identifying and assessing contents of opiates after heroin intake. PMID:23554560

The NSW brain tissue resource centre: Banking for alcohol and major neuropsychiatric disorders research.

PubMed

Sutherland, G T; Sheedy, D; Stevens, J; McCrossin, T; Smith, C C; van Roijen, M; Kril, J J

2016-05-01

The New South Wales Brain Tissue Resource Centre (NSWBTRC) at the University of Sydney (Australia) is an established human brain bank providing tissue to the neuroscience research community for investigations on alcohol-related brain damage and major psychiatric illnesses such as schizophrenia. The NSWBTRC relies on wide community engagement to encourage those with and without neuropsychiatric illness to consent to donation through its allied research programs. The subsequent provision of high-quality samples relies on standardized operational protocols, associated clinical data, quality control measures, integrated information systems, robust infrastructure, and governance. These processes are continually augmented to complement the changes in internal and external governance as well as the complexity and diversity of advanced investigation techniques. This report provides an overview of the dynamic process of brain banking and discusses the challenges of meeting the future needs of researchers, including synchronicity with other disease-focus collections. Copyright © 2016 Elsevier Inc. All rights reserved.

Chemical Clearing and Dehydration of GFP Expressing Mouse Brains

PubMed Central

Saghafi, Saiedeh; Weiler, Reto; Dodt, Hans-Ulrich

2012-01-01

Generally, chemical tissue clearing is performed by a solution consisting of two parts benzyl benzoate and one part benzyl alcohol. However, prolonged exposure to this mixture markedly reduces the fluorescence of GFP expressing specimens, so that one has to compromise between clearing quality and fluorescence preservation. This can be a severe drawback when working with specimens exhibiting low GFP expression rates. Thus, we screened for a substitute and found that dibenzyl ether (phenylmethoxymethylbenzene, CAS 103-50-4) can be applied as a more GFP-friendly clearing medium. Clearing with dibenzyl ether provides improved tissue transparency and strikingly improved fluorescence intensity in GFP expressing mouse brains and other samples as mouse spinal cords, or embryos. Chemical clearing, staining, and embedding of biological samples mostly requires careful foregoing tissue dehydration. The commonly applied tissue dehydration medium is ethanol, which also can markedly impair GFP fluorescence. Screening for a substitute also for ethanol we found that tetrahydrofuran (CAS 109-99-9) is a more GFP-friendly dehydration medium than ethanol, providing better tissue transparency obtained by successive clearing. Combined, tetrahydrofuran and dibenzyl ether allow dehydration and chemical clearing of even delicate samples for UM, confocal microscopy, and other microscopy techniques. PMID:22479475

Chemical clearing and dehydration of GFP expressing mouse brains.

PubMed

Becker, Klaus; Jährling, Nina; Saghafi, Saiedeh; Weiler, Reto; Dodt, Hans-Ulrich

2012-01-01

Generally, chemical tissue clearing is performed by a solution consisting of two parts benzyl benzoate and one part benzyl alcohol. However, prolonged exposure to this mixture markedly reduces the fluorescence of GFP expressing specimens, so that one has to compromise between clearing quality and fluorescence preservation. This can be a severe drawback when working with specimens exhibiting low GFP expression rates. Thus, we screened for a substitute and found that dibenzyl ether (phenylmethoxymethylbenzene, CAS 103-50-4) can be applied as a more GFP-friendly clearing medium. Clearing with dibenzyl ether provides improved tissue transparency and strikingly improved fluorescence intensity in GFP expressing mouse brains and other samples as mouse spinal cords, or embryos. Chemical clearing, staining, and embedding of biological samples mostly requires careful foregoing tissue dehydration. The commonly applied tissue dehydration medium is ethanol, which also can markedly impair GFP fluorescence. Screening for a substitute also for ethanol we found that tetrahydrofuran (CAS 109-99-9) is a more GFP-friendly dehydration medium than ethanol, providing better tissue transparency obtained by successive clearing. Combined, tetrahydrofuran and dibenzyl ether allow dehydration and chemical clearing of even delicate samples for UM, confocal microscopy, and other microscopy techniques.

High-contrast differentiation resolution 3D imaging of rodent brain by X-ray computed microtomography

NASA Astrophysics Data System (ADS)

Zikmund, T.; Novotná, M.; Kavková, M.; Tesařová, M.; Kaucká, M.; Szarowská, B.; Adameyko, I.; Hrubá, E.; Buchtová, M.; Dražanová, E.; Starčuk, Z.; Kaiser, J.

2018-02-01

The biomedically focused brain research is largely performed on laboratory mice considering a high homology between the human and mouse genomes. A brain has an intricate and highly complex geometrical structure that is hard to display and analyse using only 2D methods. Applying some fast and efficient methods of brain visualization in 3D will be crucial for the neurobiology in the future. A post-mortem analysis of experimental animals' brains usually involves techniques such as magnetic resonance and computed tomography. These techniques are employed to visualize abnormalities in the brains' morphology or reparation processes. The X-ray computed microtomography (micro CT) plays an important role in the 3D imaging of internal structures of a large variety of soft and hard tissues. This non-destructive technique is applied in biological studies because the lab-based CT devices enable to obtain a several-micrometer resolution. However, this technique is always used along with some visualization methods, which are based on the tissue staining and thus differentiate soft tissues in biological samples. Here, a modified chemical contrasting protocol of tissues for a micro CT usage is introduced as the best tool for ex vivo 3D imaging of a post-mortem mouse brain. This way, the micro CT provides a high spatial resolution of the brain microscopic anatomy together with a high tissue differentiation contrast enabling to identify more anatomical details in the brain. As the micro CT allows a consequent reconstruction of the brain structures into a coherent 3D model, some small morphological changes can be given into context of their mutual spatial relationships.

Huntington's disease accelerates epigenetic aging of human brain and disrupts DNA methylation levels.

PubMed

Horvath, Steve; Langfelder, Peter; Kwak, Seung; Aaronson, Jeff; Rosinski, Jim; Vogt, Thomas F; Eszes, Marika; Faull, Richard L M; Curtis, Maurice A; Waldvogel, Henry J; Choi, Oi-Wa; Tung, Spencer; Vinters, Harry V; Coppola, Giovanni; Yang, X William

2016-07-01

Age of Huntington's disease (HD) motoric onset is strongly related to the number of CAG trinucleotide repeats in the huntingtin gene, suggesting that biological tissue age plays an important role in disease etiology. Recently, a DNA methylation based biomarker of tissue age has been advanced as an epigenetic aging clock. We sought to inquire if HD is associated with an accelerated epigenetic age. DNA methylation data was generated for 475 brain samples from various brain regions of 26 HD cases and 39 controls. Overall, brain regions from HD cases exhibit a significant epigenetic age acceleration effect (p=0.0012). A multivariate model analysis suggests that HD status increases biological age by 3.2 years. Accelerated epigenetic age can be observed in specific brain regions (frontal lobe, parietal lobe, and cingulate gyrus). After excluding controls, we observe a negative correlation (r=-0.41, p=5.5×10-8) between HD gene CAG repeat length and the epigenetic age of HD brain samples. Using correlation network analysis, we identify 11 co-methylation modules with a significant association with HD status across 3 broad cortical regions. In conclusion, HD is associated with an accelerated epigenetic age of specific brain regions and more broadly with substantial changes in brain methylation levels.

Huntington's disease accelerates epigenetic aging of human brain and disrupts DNA methylation levels

PubMed Central

Horvath, Steve; Langfelder, Peter; Kwak, Seung; Aaronson, Jeff; Rosinski, Jim; Vogt, Thomas F.; Eszes, Marika; Faull, Richard L.M.; Curtis, Maurice A.; Waldvogel, Henry J.; Choi, Oi-Wa; Tung, Spencer; Vinters, Harry V.; Coppola, Giovanni; Yang, X. William

2016-01-01

Age of Huntington's disease (HD) motoric onset is strongly related to the number of CAG trinucleotide repeats in the huntingtin gene, suggesting that biological tissue age plays an important role in disease etiology. Recently, a DNA methylation based biomarker of tissue age has been advanced as an epigenetic aging clock. We sought to inquire if HD is associated with an accelerated epigenetic age. DNA methylation data was generated for 475 brain samples from various brain regions of 26 HD cases and 39 controls. Overall, brain regions from HD cases exhibit a significant epigenetic age acceleration effect (p=0.0012). A multivariate model analysis suggests that HD status increases biological age by 3.2 years. Accelerated epigenetic age can be observed in specific brain regions (frontal lobe, parietal lobe, and cingulate gyrus). After excluding controls, we observe a negative correlation (r=−0.41, p=5.5×10−8) between HD gene CAG repeat length and the epigenetic age of HD brain samples. Using correlation network analysis, we identify 11 co-methylation modules with a significant association with HD status across 3 broad cortical regions. In conclusion, HD is associated with an accelerated epigenetic age of specific brain regions and more broadly with substantial changes in brain methylation levels. PMID:27479945

LC-MS/MS-based quantification of kynurenine metabolites, tryptophan, monoamines and neopterin in plasma, cerebrospinal fluid and brain.

PubMed

Fuertig, René; Ceci, Angelo; Camus, Sandrine M; Bezard, Erwan; Luippold, Andreas H; Hengerer, Bastian

2016-09-01

The kynurenine (KYN) pathway is implicated in diseases such as cancer, psychiatric, neurodegenerative and autoimmune disorders. Measurement of KYN metabolite levels will help elucidating the involvement of the KYN pathway in the disease pathology and inform drug development. Samples of plasma, cerebrospinal fluid or brain tissue were spiked with deuterated internal standards, processed and analyzed by LC-MS/MS; analytes were chromatographically separated by gradient elution on a C18 reversed phase analytical column without derivatization. We established an LC-MS/MS method to measure 11 molecules, namely tryptophan, KYN, 3-OH-KYN, 3-OH-anthranilic acid, quinolinic acid, picolinic acid, kynurenic acid, xanthurenic acid, serotonin, dopamine and neopterin within 5.5 min, with sufficient sensitivity to quantify these molecules in small sample volumes of plasma, cerebrospinal fluid and brain tissue.

Tissue-specific concentrations and patterns of perfluoroalkyl carboxylates and sulfonates in East Greenland polar bears.

PubMed

Greaves, Alana K; Letcher, Robert J; Sonne, Christian; Dietz, Rune; Born, Erik W

2012-11-06

Several perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) of varying chain length are bioaccumulative in biota. However, wildlife reports have focused on liver and with very little examination of other tissues, and thus there is a limited understanding of their distribution and potential effects in the mammalian body. In the present study, the comparative accumulation of C(6) to C(15) PFCAs, C(4), C(6), C(8) and C(10) PFSAs, and select precursors were examined in the liver, blood, muscle, adipose, and brain of 20 polar bears (Ursus maritimus) from Scoresby Sound, Central East Greenland. Overall, PFSA and PFCA concentrations were highest in liver followed by blood > brain > muscle ≈ adipose. Liver and blood samples contained proportionally more of the shorter/medium chain length (C(6) to C(11)) PFCAs, whereas adipose and brain samples were dominated by longer chain (C(13) to C(15)) PFCAs. PFCAs with lower lipophilicities accumulated more in the liver, whereas the brain accumulated PFCAs with higher lipophilicities. The concentration ratios (±SE) between perfluorooctane sulfonate and its precursor perfluorooctane sulfonamide varied among tissues from 9 (±1):1 (muscle) to 36 (±7):1 (liver). PFCA and PFSA patterns in polar bears indicate that the pharmacokinetics of these compounds are to some extent tissue-specific, and are the result of several factors that may include differing protein interactions throughout the body.

Solvent effects on differentiation of mouse brain tissue using laser microdissection ‘cut and drop’ sampling with direct mass spectral analysis

DOE PAGES

Cahill, John F.; Kertesz, Vilmos; Porta, Tiffany; ...

2018-02-08

Rationale: Laser microdissection-liquid vortex capture/electrospray ionization mass spectrometry (LMD-LVC/ESI-MS) has potential for on-line classification of tissue but an investigation into what analytical conditions provide best spectral differentiation has not been conducted. The effects of solvent, ionization polarity, and spectral acquisition parameters on differentiation of mouse brain tissue regions are described.Methods: Individual 40 × 40 μm microdissections from cortex, white, grey, granular, and nucleus regions of mouse brain tissue were analyzed using different capture/ESI solvents, in positive and negative ion mode ESI, using time-of-flight (TOF)-MS and sequential window acquisitions of all theoretical spectra (SWATH)-MS (a permutation of tandem-MS), and combinations thereof.more » Principal component analysis-linear discriminant analysis (PCA-LDA), applied to each mass spectral dataset, was used to determine the accuracy of differentiation of mouse brain tissue regions. Results: Mass spectral differences associated with capture/ESI solvent composition manifested as altered relative distributions of ions rather than the presence or absence of unique ions. In negative ion mode ESI, 80/20 (v/v) methanol/water yielded spectra with low signal/noise ratios relative to other solvents. PCA-LDA models acquired using 90/10 (v/v) methanol/chloroform differentiated tissue regions with 100% accuracy while data collected using methanol misclassified some samples. The combination of SWATH-MS and TOF-MS data improved differentiation accuracy.Conclusions: Combined TOF-MS and SWATH-MS data differentiated white, grey, granular, and nucleus mouse tissue regions with greater accuracy than when solely using TOF-MS data. Using 90/10 (v/v) methanol/chloroform, tissue regions were perfectly differentiated. Lastly, these results will guide future studies looking to utilize the potential of LMD-LVC/ESI-MS for tissue and disease differentiation.« less

Solvent effects on differentiation of mouse brain tissue using laser microdissection ‘cut and drop’ sampling with direct mass spectral analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cahill, John F.; Kertesz, Vilmos; Porta, Tiffany

Rationale: Laser microdissection-liquid vortex capture/electrospray ionization mass spectrometry (LMD-LVC/ESI-MS) has potential for on-line classification of tissue but an investigation into what analytical conditions provide best spectral differentiation has not been conducted. The effects of solvent, ionization polarity, and spectral acquisition parameters on differentiation of mouse brain tissue regions are described.Methods: Individual 40 × 40 μm microdissections from cortex, white, grey, granular, and nucleus regions of mouse brain tissue were analyzed using different capture/ESI solvents, in positive and negative ion mode ESI, using time-of-flight (TOF)-MS and sequential window acquisitions of all theoretical spectra (SWATH)-MS (a permutation of tandem-MS), and combinations thereof.more » Principal component analysis-linear discriminant analysis (PCA-LDA), applied to each mass spectral dataset, was used to determine the accuracy of differentiation of mouse brain tissue regions. Results: Mass spectral differences associated with capture/ESI solvent composition manifested as altered relative distributions of ions rather than the presence or absence of unique ions. In negative ion mode ESI, 80/20 (v/v) methanol/water yielded spectra with low signal/noise ratios relative to other solvents. PCA-LDA models acquired using 90/10 (v/v) methanol/chloroform differentiated tissue regions with 100% accuracy while data collected using methanol misclassified some samples. The combination of SWATH-MS and TOF-MS data improved differentiation accuracy.Conclusions: Combined TOF-MS and SWATH-MS data differentiated white, grey, granular, and nucleus mouse tissue regions with greater accuracy than when solely using TOF-MS data. Using 90/10 (v/v) methanol/chloroform, tissue regions were perfectly differentiated. Lastly, these results will guide future studies looking to utilize the potential of LMD-LVC/ESI-MS for tissue and disease differentiation.« less

P43/pro-EMAPII: A Potential Biomarker for Discriminating Traumatic Versus Ischemic Brain Injury

PubMed Central

Yao, Changping; Williams, Anthony J.; Ottens, Andrew K.; Lu, X.-C. May; Liu, Ming Cheng; Hayes, Ronald L.; Wang, Kevin K.; Tortella, Frank C.

2009-01-01

Abstract To gain additional insights into the pathogenic cellular and molecular mechanisms underlying different types of brain injury (e.g., trauma versus ischemia), recently attention has focused on the discovery and study of protein biomarkers. In previous studies, using a high-throughput immunoblotting (HTPI) technique, we reported changes in 29 out of 998 proteins following acute injuries to the rat brain (penetrating traumatic versus focal ischemic). Importantly, we discovered that one protein, endothelial monocyte-activating polypeptide II precursor (p43/pro-EMAPII), was differentially expressed between these two types of brain injury. Among other functions, p43/pro-EMAPII is a known pro-inflammatory cytokine involved in the progression of apoptotic cell death. Our current objective was to verify the changes in p43/pro-EMAPII expression, and to evaluate the potentially important implications that the differential regulation of this protein has on injury development. At multiple time points following either a penetrating ballistic-like brain injury (PBBI), or a transient middle cerebral artery occlusion (MCAo) brain injury, tissue samples (6–72 h), CSF samples (24 h), and blood samples (24 h) were collected from rats for analysis. Changes in protein expression were assessed by Western blot analysis and immunohistochemistry. Our results indicated that p43/pro-EMAPII was significantly increased in brain tissues, CSF, and plasma following PBBI, but decreased after MCAo injury compared to their respective sham control samples. This differential expression of p43/pro-EMAPII may be a useful injury-specific biomarker associated with the underlying pathologies of traumatic versus ischemic brain injury, and provide valuable information for directing injury-specific therapeutics. PMID:19317603

Imaging Nicotine in Rat Brain Tissue by Use of Nanospray Desorption Electrospray Ionization Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lanekoff, Ingela T.; Thomas, Mathew; Carson, James P.

Imaging mass spectrometry offers simultaneous detection of drugs, drug metabolites and endogenous substances in a single experiment. This is important when evaluating effects of a drug on a complex organ system such as the brain, where there is a need to understand how regional drug distribution impacts function. Nicotine is an addictive drug and its action in the brain is of high interest. Here we use nanospray desorption electrospray ionization, nano-DESI, imaging to discover the localization of nicotine in rat brain tissue after in vivo administration of nicotine. Nano-DESI is a new ambient technique that enables spatially-resolved analysis of tissuemore » samples without special sample pretreatment. We demonstrate high sensitivity of nano-DESI imaging that enables detection of only 0.7 fmole nicotine per pixel in the complex brain matrix. Furthermore, by adding deuterated nicotine to the solvent, we examined how matrix effects, ion suppression, and normalization affect the observed nicotine distribution. Finally, we provide preliminary results suggesting that nicotine localizes to the hippocampal substructure called dentate gyrus.« less

Expansion of Multipotent Stem Cells from the Adult Human Brain

PubMed Central

Murrell, Wayne; Palmero, Emily; Bianco, John; Stangeland, Biljana; Joel, Mrinal; Paulson, Linda; Thiede, Bernd; Grieg, Zanina; Ramsnes, Ingunn; Skjellegrind, Håvard K.; Nygård, Ståle; Brandal, Petter; Sandberg, Cecilie; Vik-Mo, Einar; Palmero, Sheryl; Langmoen, Iver A.

2013-01-01

The discovery of stem cells in the adult human brain has revealed new possible scenarios for treatment of the sick or injured brain. Both clinical use of and preclinical research on human adult neural stem cells have, however, been seriously hampered by the fact that it has been impossible to passage these cells more than a very few times and with little expansion of cell numbers. Having explored a number of alternative culturing conditions we here present an efficient method for the establishment and propagation of human brain stem cells from whatever brain tissue samples we have tried. We describe virtually unlimited expansion of an authentic stem cell phenotype. Pluripotency proteins Sox2 and Oct4 are expressed without artificial induction. For the first time multipotency of adult human brain-derived stem cells is demonstrated beyond tissue boundaries. We characterize these cells in detail in vitro including microarray and proteomic approaches. Whilst clarification of these cells’ behavior is ongoing, results so far portend well for the future repair of tissues by transplantation of an adult patient’s own-derived stem cells. PMID:23967194

A Simple and Reproducible Method to Prepare Membrane Samples from Freshly Isolated Rat Brain Microvessels.

PubMed

Brzica, Hrvoje; Abdullahi, Wazir; Reilly, Bianca G; Ronaldson, Patrick T

2018-05-07

The blood-brain barrier (BBB) is a dynamic barrier tissue that responds to various pathophysiological and pharmacological stimuli. Such changes resulting from these stimuli can greatly modulate drug delivery to the brain and, by extension, cause considerable challenges in the treatment of central nervous system (CNS) diseases. Many BBB changes that affect pharmacotherapy, involve proteins that are localized and expressed at the level of endothelial cells. Indeed, such knowledge on BBB physiology in health and disease has sparked considerable interest in the study of these membrane proteins. From a basic science research standpoint, this implies a requirement for a simple but robust and reproducible method for isolation of microvessels from brain tissue harvested from experimental animals. In order to prepare membrane samples from freshly isolated microvessels, it is essential that sample preparations be enriched in endothelial cells but limited in the presence of other cell types of the neurovascular unit (i.e., astrocytes, microglia, neurons, pericytes). An added benefit is the ability to prepare samples from individual animals in order to capture the true variability of protein expression in an experimental population. In this manuscript, details regarding a method that is utilized for isolation of rat brain microvessels and preparation of membrane samples are provided. Microvessel enrichment, from samples derived, is achieved by using four centrifugation steps where dextran is included in the sample buffer. This protocol can easily be adapted by other laboratories for their own specific applications. Samples generated from this protocol have been shown to yield robust experimental data from protein analysis experiments that can greatly aid the understanding of BBB responses to physiological, pathophysiological, and pharmacological stimuli.

Photon Entanglement Through Brain Tissue

PubMed Central

Shi, Lingyan; Galvez, Enrique J.; Alfano, Robert R.

2016-01-01

Photon entanglement, the cornerstone of quantum correlations, provides a level of coherence that is not present in classical correlations. Harnessing it by study of its passage through organic matter may offer new possibilities for medical diagnosis technique. In this work, we study the preservation of photon entanglement in polarization, created by spontaneous parametric down-conversion, after one entangled photon propagates through multiphoton-scattering brain tissue slices with different thickness. The Tangle-Entropy (TS) plots show the strong preservation of entanglement of photons propagating in brain tissue. By spatially filtering the ballistic scattering of an entangled photon, we find that its polarization entanglement is preserved and non-locally correlated with its twin in the TS plots. The degree of entanglement correlates better with structure and water content than with sample thickness. PMID:27995952

Brain tissue stiffness is a sensitive marker for acidosis.

PubMed

Holtzmann, Kathrin; Gautier, Hélène O B; Christ, Andreas F; Guck, Jochen; Káradóttir, Ragnhildur Thóra; Franze, Kristian

2016-09-15

Carbon dioxide overdose is frequently used to cull rodents for tissue harvesting. However, this treatment may lead to respiratory acidosis, which potentially could change the properties of the investigated tissue. Mechanical tissue properties often change in pathological conditions and may thus offer a sensitive generic readout for changes in biological tissues with clinical relevance. In this study, we performed force-indentation measurements with an atomic force microscope on acute cerebellar slices from adult rats to test if brain tissue undergoes changes following overexposure to CO2 compared to other methods of euthanasia. The pH significantly decreased in brain tissue of animals exposed to CO2. Concomitant with the drop in pH, cerebellar grey matter significantly stiffened. Tissue stiffening was reproduced by incubation of acute cerebellar slices in acidic medium. Tissue stiffness provides an early, generic indicator for pathophysiological changes in the CNS. Atomic force microscopy offers unprecedented high spatial resolution to detect such changes. Our results indicate that the stiffness particularly of grey matter strongly correlates with changes of the pH in the cerebellum. Furthermore, the method of tissue harvesting and preparation may not only change tissue stiffness but very likely also other physiologically relevant parameters, highlighting the importance of appropriate sample preparation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Kinetic Modeling of PET Data Without Blood Sampling

NASA Astrophysics Data System (ADS)

Bentourkia, M.

2005-06-01

In positron emission tomography (PET) imaging, application of kinetic modeling always requires an input curve (IC) together with the PET data. The IC can be obtained by means of external blood sampling or, in the case of cardiac studies, by means of a region-of-interest (ROI) drawn on the blood pool. It is, however, very unsuitable to withdraw and to analyze blood samples, and in small animals, these operations become difficult, while ICs determined from ROIs are generally contaminated by emissions from neighboring sites, or they are underestimated because of partial volume effect. In this paper, we report a new method to extract kinetic parameters from dynamic PET studies without a priori knowledge of the IC. The method is applied in human brain data measured with fluorodeoxyglucose (FDG) human-brain and in cardiac-rat perfusion studies with /sup 13/N-ammonia and /sup 11/C-acetate. The tissue blood volume (TBV), usually fitted together with the rate constants, is extracted simultaneously with the tissue time activity curves for cardiac studies, while for brain gray matter, TBV is known to be about 4% to 7%. The shape of IC is obtained by means of factor analysis from an ROI drawn around a cardiac tissue or a brain artery. The results show a good correlation (p<0.05) between the cerebral metabolic rate of glucose, myocardial blood flow, and oxygen consumption obtained with the new method in comparison to the usual method. In conclusion, it is possible to apply kinetic modeling without any blood sampling, which significantly simplifies PET acquisition and data analysis.

Miniature standoff Raman probe for neurosurgical applications

NASA Astrophysics Data System (ADS)

Stevens, Oliver A. C.; Hutchings, Joanne; Gray, William; Vincent, Rosa Louise; Day, John C.

2016-08-01

Removal of intrinsic brain tumors is a delicate process, where a high degree of specificity is required to remove all of the tumor tissue without damaging healthy brain. The accuracy of this process can be greatly enhanced by intraoperative guidance. Optical biopsies using Raman spectroscopy are a minimally invasive and lower-cost alternative to current guidance methods. A miniature Raman probe for performing optical biopsies of human brain tissue is presented. The probe allows sampling inside a conventional stereotactic brain biopsy system: a needle of length 200 mm and inner diameter of 1.8 mm. By employing a miniature stand-off Raman design, the probe removes the need for any additional components to be inserted into the brain. Additionally, the probe achieves a very low internal silica background while maintaining good collection of Raman signal. To illustrate this, the probe is compared with a Raman probe that uses a pair of optical fibers for collection. The miniature stand-off Raman probe is shown to collect a comparable number of Raman scattered photons, but the Raman signal to background ratio is improved by a factor of five at Raman shifts below ˜500 cm-1. The probe's suitability for use on tissue is demonstrated by discriminating between different types of healthy porcine brain tissue.

Developing 3D microscopy with CLARITY on human brain tissue: Towards a tool for informing and validating MRI-based histology.

PubMed

Morawski, Markus; Kirilina, Evgeniya; Scherf, Nico; Jäger, Carsten; Reimann, Katja; Trampel, Robert; Gavriilidis, Filippos; Geyer, Stefan; Biedermann, Bernd; Arendt, Thomas; Weiskopf, Nikolaus

2017-11-28

Recent breakthroughs in magnetic resonance imaging (MRI) enabled quantitative relaxometry and diffusion-weighted imaging with sub-millimeter resolution. Combined with biophysical models of MR contrast the emerging methods promise in vivo mapping of cyto- and myelo-architectonics, i.e., in vivo histology using MRI (hMRI) in humans. The hMRI methods require histological reference data for model building and validation. This is currently provided by MRI on post mortem human brain tissue in combination with classical histology on sections. However, this well established approach is limited to qualitative 2D information, while a systematic validation of hMRI requires quantitative 3D information on macroscopic voxels. We present a promising histological method based on optical 3D imaging combined with a tissue clearing method, Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging compatible Tissue hYdrogel (CLARITY), adapted for hMRI validation. Adapting CLARITY to the needs of hMRI is challenging due to poor antibody penetration into large sample volumes and high opacity of aged post mortem human brain tissue. In a pilot experiment we achieved transparency of up to 8 mm-thick and immunohistochemical staining of up to 5 mm-thick post mortem brain tissue by a combination of active and passive clearing, prolonged clearing and staining times. We combined 3D optical imaging of the cleared samples with tailored image processing methods. We demonstrated the feasibility for quantification of neuron density, fiber orientation distribution and cell type classification within a volume with size similar to a typical MRI voxel. The presented combination of MRI, 3D optical microscopy and image processing is a promising tool for validation of MRI-based microstructure estimates. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Accurate and sensitive liquid chromatography/tandem mass spectrometry simultaneous assay of seven steroids in monkey brain.

PubMed

Bertin, Jonathan; Dury, Alain Y; Ke, Yuyong; Ouellet, Johanne; Labrie, Fernand

2015-06-01

Following its secretion mainly by the adrenal glands, dehydroepiandrosterone (DHEA) acts primarily in the cells/tissues which express the enzymes catalyzing its intracellular conversion into sex steroids by the mechanisms of intracrinology. Although reliable assays of endogenous serum steroids are now available using mass spectrometry (MS)-based technology, sample preparation from tissue matrices remains a challenge. This is especially the case with high lipid-containing tissues such as the brain. With the combination of a UPLC system with a sensitive tandem MS, it is now possible to measure endogenous unconjugated steroids in monkey brain tissue. A Shimadzu UPLC LC-30AD system coupled to a tandem MS AB Sciex Qtrap 6500 system was used. The lower limits of quantifications are achieved at 250 pg/mL for DHEA, 200 pg/mL for 5-androstenediol (5-diol), 12 pg/mL for androstenedione (4-dione), 50 pg/mL for testosterone (Testo), 10 pg/mL for dihydrotestosterone (DHT), 4 pg/mL for estrone (E1) and 1 pg/mL for estradiol (E2). The linearity and accuracy of quality controls (QCs) and endogenous quality controls (EndoQCs) are according to the guidelines of the regulatory agencies for all seven compounds. We describe a highly sensitive, specific and robust LC-MS/MS method for the simultaneous measurement of seven unconjugated steroids in monkey brain tissue. The single and small amount of sample required using a relatively simple preparation method should be useful for steroid assays in various peripheral tissues and thus help analysis of the role of locally-made sex steroids in the regulation of specific physiological functions. Copyright © 2015 Elsevier Inc. All rights reserved.

Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of tigecycline in rat brain tissues.

PubMed

Munyeza, Chiedza F; Shobo, Adeola; Baijnath, Sooraj; Bratkowska, Dominika; Naiker, Suhashni; Bester, Linda A; Singh, Sanil D; Maguire, Glenn E M; Kruger, Hendrik G; Naicker, Tricia; Govender, Thavendran

2016-06-01

Tigecycline (TIG), a derivative of minocycline, is the first in the novel class of glycylcyclines and is currently indicated for the treatment of complicated skin structure and intra-abdominal infections. A selective, accurate and reversed-phase high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the determination of TIG in rat brain tissues. Sample preparation was based on protein precipitation and solid phase extraction using Supel-Select HLB (30 mg/1 mL) cartridges. The samples were separated on a YMC Triart C18 column (150 mm x 3.0 mm. 3.0 µm) using gradient elution. Positive electrospray ionization (ESI+) was used for the detection mechanism with the multiple reaction monitoring (MRM) mode. The method was validated over the concentration range of 150-1200 ng/mL for rat brain tissue. The precision and accuracy for all brain analyses were within the acceptable limit. The mean extraction recovery in rat brain was 83.6%. This validated method was successfully applied to a pharmacokinetic study in female Sprague Dawley rats, which were given a dose of 25 mg/kg TIG intraperitoneally at various time-points. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Methylation of the TERT promoter and risk stratification of childhood brain tumours: an integrative genomic and molecular study.

PubMed

Castelo-Branco, Pedro; Choufani, Sanaa; Mack, Stephen; Gallagher, Denis; Zhang, Cindy; Lipman, Tatiana; Zhukova, Nataliya; Walker, Erin J; Martin, Dianna; Merino, Diana; Wasserman, Jonathan D; Elizabeth, Cynthia; Alon, Noa; Zhang, Libo; Hovestadt, Volker; Kool, Marcel; Jones, David T W; Zadeh, Gelareh; Croul, Sidney; Hawkins, Cynthia; Hitzler, Johann; Wang, Jean C Y; Baruchel, Sylvain; Dirks, Peter B; Malkin, David; Pfister, Stefan; Taylor, Michael D; Weksberg, Rosanna; Tabori, Uri

2013-05-01

Identification of robust biomarkers of malignancy and methods to establish disease progression is a major goal in paediatric neuro-oncology. We investigated whether methylation of the TERT promoter can be a biomarker for malignancy and patient outcome in paediatric brain tumours. For the discovery cohort, we used samples obtained from patients with paediatric brain tumours and individuals with normal brain tissues stored at the German Cancer Research Center (Heidelberg, Germany). We used methylation arrays for genome-wide assessment of DNA. For the validation cohort, we used samples obtained from several tissues for which full clinical and follow-up data were available from two hospitals in Toronto (ON, Canada). We did methylation analysis using quantitative Sequenom and pyrosequencing of an identified region of the TERT promoter. We assessed TERT expression by real-time PCR. To establish whether the biomarker could be used to assess and predict progression, we analysed methylation in paired samples of tumours that transformed from low to high grade and from localised to metastatic, and in choroid plexus tumours of different grades. Finally, we investigated overall survival in patients with posterior fossa ependymomas in which the identified region was hypermethylated or not. All individuals responsible for assays were masked to the outcome of the patients. Analysis of 280 samples in the discovery cohort identified one CpG site (cg11625005) in which 78 (99%) of 79 samples from normal brain tissues and low-grade tumours were not hypermethylated, but 145 (72%) of 201 samples from malignant tumours were hypermethylated (>15% methylated; p<0.0001). Analysis of 68 samples in the validation cohort identified a subset of five CpG sites (henceforth, upstream of the transcription start site [UTSS]) that was hypermethylated in all malignant paediatric brain tumours that expressed TERT but not in normal tissues that did not express TERT (p<0.0001). UTSS had a positive predictive value of 1.00 (95% CI 0.95-1.00) and a negative predictive value of 0.95 (0.87-0.99). In two paired samples of paediatric gliomas, UTSS methylation increased during transformation from low to high grade; it also increased in two paired samples that progressed from localised to metastatic disease. Two of eight atypical papillomas that had high UTSS methylation progressed to carcinomas, while the other six assessed did not progress or require additional treatment. 5-year overall survival was 51% (95% CI 31-71) for 25 patients with hypermethylated UTSS posterior fossa ependymomas and 95% (86-100) for 20 with non-hypermethylated tumours (p=0.0008). 5-year progression-free survival was 86% (68-100) for the 25 patients with non-hypermethylated UTSS tumours and 30% (10-50) for those with hypermethylated tumours (p=0.0008). Hypermethylation of the UTSS region in the TERT promoter is associated with TERT expression in cancers. In paediatric brain tumours, UTSS hypermethylation is associated with tumour progression and poor prognosis. This region is easy to amplify, and the assay to establish hypermethylation can be done on most tissues in most clinical laboratories. Therefore the UTSS region is a potentially accessible biomarker for various cancers. The Canadian Institute of Health Research and the Terry Fox Foundation. Copyright © 2013 Elsevier Ltd. All rights reserved.

The biochemical, nanomechanical and chemometric signatures of brain cancer

NASA Astrophysics Data System (ADS)

Abramczyk, Halina; Imiela, Anna

2018-01-01

Raman spectroscopy and imaging combined with AFM topography and mechanical indentation by AFM have been shown to be an effective tool for analysis and discrimination of human brain tumors from normal structures. Raman methods have potential to be applied in clinical practice as they allow for identification of tumor margins during surgery. In this study, we investigate medulloblastoma (grade IV WHO) (n = 5) and the tissue from the negative margins used as normal controls. We compare a high grade medulloblastoma (IV grade), and non-tumor samples from human central nervous system (CNS) tissue. Based on the properties of the Raman vibrational spectra and Raman images we provide a real-time feedback that is label-free method to monitor tumor metabolism that reveals reprogramming of biosynthesis of lipids, and proteins. We have found that the high-grade tumors of central nervous system (medulloblastoma) exhibit enhanced level of β-sheet conformation and down-regulated level of α-helix conformation when comparing against normal tissue. We have shown that the ratio of Raman intensities I2930/I2845 at 2930 and 2845 cm- 1 is a good source of information on the ratio of lipid and protein contents. We have found that the ratio reflects the lipid and protein contents of tumorous brain tissue compared to the non-tumor tissue. Almost all brain tumors have the Raman intensity ratios significantly higher (1.99 ± 0.026) than that found in non-tumor brain tissue, which is 1.456 ± 0.02, and indicates that the relative amount of lipids compared to proteins is significantly higher in the normal brain tissue. Mechanical indentation using AFM on sliced human brain tissues (medulloblastoma, grade IV) revealed that the mechanical properties of this tissue are strongly heterogeneous, between 1.8 and 75.7 kPa, and the mean of 27.16 kPa. The sensitivity and specificity obtained directly from PLSDA and cross validation gives a sensitivity and specificity of 98.5% and 96% and 96.3% and 92% for cross-validation, respectively. The high sensitivity and specificity demonstrates usefulness for a proper decision for a Raman diagnostic test on biochemical alterations monitored by Raman spectroscopy related to brain cancer development.

VIROLOGICAL AND SEROLOGICAL DIAGNOSIS OF RABIES IN BATS FROM AN URBAN AREA IN THE BRAZILIAN AMAZON.

PubMed

Oliveira, Rubens Souza de; Costa, Lanna Jamile Corrêa da; Andrade, Fernanda Atanaena Gonçalves de; Uieda, Wilson; Martorelli, Luzia Fátima Alves; Kataoka, Ana Paula de Arruda Geraldes; Rosa, Elizabeth Salbé Travassos da; Vasconcelos, Pedro Fernando da Costa; Pereira, Armando de Souza; Carmo, Antônio Ismael Barros do; Fernandes, Marcus Emanuel Barroncas

2015-12-01

The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005, in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a priority area for studies on this zoonosis. Given this, the present study provides data on this phenomenon in an urban context, in order to assess the possible circulation of the classic rabies virus (RABV) among bat species in Capanema, a town in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and dry seasons. Samples of brain tissue and blood were collected for virological and serological survey, respectively. None of the 153 brain tissue samples analyzed tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum samples analyzed were seropositive. Artibeus planirostris was the most common species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31 52.60%). Statistically, equal proportions of seropositive results were obtained in the rainy and dry seasons (c2 = 0.057, d.f. = 1, p = 0.88). Significantly higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95% CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested positive for infection, the high proportion of seropositive specimens indicates that RABV may be widespread in this urban area.

Identification of Insulin Receptor Splice Variant B in Neurons by in situ Detection in Human Brain Samples.

PubMed

Spencer, Brian; Rank, Logan; Metcalf, Jeff; Desplats, Paula

2018-03-06

Insulin and its receptor are widely expressed in a variety of tissues throughout the body including liver, adipose tissue, liver and brain. The insulin receptor is expressed as two functionally distinct isoforms, differentiated by a single 12 amino acid exon. The two receptor isoforms, designated IR/A and IR/B, are expressed in a highly tissue and cell specific manner and relative proportions of the different isoforms vary during development, aging and disease states. The high degree of similarity between the two isoforms has prevented detailed studies as differentiation of the two isoforms by traditional immunological methods cannot be achieved. We describe here a new in situ RT-PCR/ FISH assay that allows for the visualization of IR/A and IR/B in tissue along with tissue specific markers. We used this new method to show for the first time that IR/A and IR/B are both expressed in neurons in the adult human brain. Thus, we present a method that enables the investigation of IR/A and IR/B insulin receptor isoform expression in situ in various tissues.

A simple procedure for the extraction of DNA from long-term formalin-preserved brain tissues for the detection of EBV by PCR.

PubMed

Hassani, Asma; Khan, Gulfaraz

2015-12-01

Long-term formalin fixed brain tissues are potentially an important source of material for molecular studies. Ironically, very few protocols have been published describing DNA extraction from such material for use in PCR analysis. In our attempt to investigate the role of Epstein-Barr virus (EBV) in the pathogenesis of multiple sclerosis (MS), extracting PCR quality DNA from brain samples fixed in formalin for 2-22 years, proved to be very difficult and challenging. As expected, DNA extracted from these samples was not only of poor quality and quantity, but more importantly, it was frequently found to be non-amplifiable due to the presence of PCR inhibitors. Here, we describe a simple and reproducible procedure for extracting DNA using a modified proteinase K and phenol-chloroform methodology. Central to this protocol is the thorough pre-digestion washing of the tissues in PBS, extensive digestion with proteinase K in low SDS containing buffer, and using low NaCl concentration during DNA precipitation. The optimized protocol was used in extracting DNA from meninges of 26 MS and 6 non-MS cases. Although the quality of DNA from these samples was generally poor, small size amplicons (100-200 nucleotides) of the house-keeping gene, β-globin could be reliably amplified from all the cases. PCR for EBV revealed positivity in 35% (9/26) MS cases, but 0/6 non-MS cases. These findings indicate that the method described here is suitable for PCR detection of viral sequences in long-term formalin persevered brain tissues. Our findings also support a possible role for EBV in the pathogenesis of MS. Copyright © 2015 Elsevier Inc. All rights reserved.

Permeabilization of brain tissue in situ enables multiregion analysis of mitochondrial function in a single mouse brain.

PubMed

Herbst, Eric A F; Holloway, Graham P

2015-02-15

Mitochondrial function in the brain is traditionally assessed through analysing respiration in isolated mitochondria, a technique that possesses significant tissue and time requirements while also disrupting the cooperative mitochondrial reticulum. We permeabilized brain tissue in situ to permit analysis of mitochondrial respiration with the native mitochondrial morphology intact, removing the need for isolation time and minimizing tissue requirements to ∼2 mg wet weight. The permeabilized brain technique was validated against the traditional method of isolated mitochondria and was then further applied to assess regional variation in the mouse brain with ischaemia-reperfusion injuries. A transgenic mouse model overexpressing catalase within mitochondria was applied to show the contribution of mitochondrial reactive oxygen species to ischaemia-reperfusion injuries in different brain regions. This technique enhances the accessibility of addressing physiological questions in small brain regions and in applying transgenic mouse models to assess mechanisms regulating mitochondrial function in health and disease. Mitochondria function as the core energy providers in the brain and symptoms of neurodegenerative diseases are often attributed to their dysregulation. Assessing mitochondrial function is classically performed in isolated mitochondria; however, this process requires significant isolation time, demand for abundant tissue and disruption of the cooperative mitochondrial reticulum, all of which reduce reliability when attempting to assess in vivo mitochondrial bioenergetics. Here we introduce a method that advances the assessment of mitochondrial respiration in the brain by permeabilizing existing brain tissue to grant direct access to the mitochondrial reticulum in situ. The permeabilized brain preparation allows for instant analysis of mitochondrial function with unaltered mitochondrial morphology using significantly small sample sizes (∼2 mg), which permits the analysis of mitochondrial function in multiple subregions within a single mouse brain. Here this technique was applied to assess regional variation in brain mitochondrial function with acute ischaemia-reperfusion injuries and to determine the role of reactive oxygen species in exacerbating dysfunction through the application of a transgenic mouse model overexpressing catalase within mitochondria. Through creating accessibility to small regions for the investigation of mitochondrial function, the permeabilized brain preparation enhances the capacity for examining regional differences in mitochondrial regulation within the brain, as the majority of genetic models used for unique approaches exist in the mouse model. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

An Automated Platform for High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lanekoff, Ingela T.; Heath, Brandi S.; Liyu, Andrey V.

2012-10-02

An automated platform has been developed for acquisition and visualization of mass spectrometry imaging (MSI) data using nanospray desorption electrospray ionization (nano-DESI). The new system enables robust operation of the nano-DESI imaging source over many hours. This is achieved by controlling the distance between the sample and the probe by mounting the sample holder onto an automated XYZ stage and defining the tilt of the sample plane. This approach is useful for imaging of relatively flat samples such as thin tissue sections. Custom software called MSI QuickView was developed for visualization of large data sets generated in imaging experiments. MSImore » QuickView enables fast visualization of the imaging data during data acquisition and detailed processing after the entire image is acquired. The performance of the system is demonstrated by imaging rat brain tissue sections. High resolution mass analysis combined with MS/MS experiments enabled identification of lipids and metabolites in the tissue section. In addition, high dynamic range and sensitivity of the technique allowed us to generate ion images of low-abundance isobaric lipids. High-spatial resolution image acquired over a small region of the tissue section revealed the spatial distribution of an abundant brain metabolite, creatine, in the white and gray matter that is consistent with the literature data obtained using magnetic resonance spectroscopy.« less

Spectroscopic optical coherence tomography for ex vivo brain tumor analysis

NASA Astrophysics Data System (ADS)

Lenz, Marcel; Krug, Robin; Dillmann, Christopher; Gerling, Alexandra; Gerhardt, Nils C.; Welp, Hubert; Schmieder, Kirsten; Hofmann, Martin R.

2017-02-01

For neurosurgeries precise tumor resection is essential for the subsequent recovery of the patients since nearby healthy tissue that may be harmed has a huge impact on the life quality after the surgery. However, so far no satisfying methodology has been established to assist the surgeon during surgery to distinguish between healthy and tumor tissue. Optical Coherence Tomography (OCT) potentially enables non-contact in vivo image acquisition at penetration depths of 1-2 mm with a resolution of approximately 1-15 μm. To analyze the potential of OCT for distinction between brain tumors and healthy tissue, we used a commercially available Thorlabs Callisto system to measure healthy tissue and meningioma samples ex vivo. All samples were measured with the OCT system and three dimensional datasets were generated. Afterwards they were sent to the pathology for staining with hematoxylin and eosin and then investigated with a bright field microscope to verify the tissue type. This is the actual gold standard for ex vivo analysis. The images taken by the OCT system exhibit variations in the structure for different tissue types, but these variations may not be objectively evaluated from raw OCT images. Since an automated distinction between tumor and healthy tissue would be highly desirable to guide the surgeon, we applied Spectroscopic Optical Coherence Tomography to further enhance the differences between the tissue types. Pattern recognition and machine learning algorithms were applied to classify the derived spectroscopic information. Finally, the classification results are analyzed in comparison to the histological analysis of the samples.

A combined MR and CT study for precise quantitative analysis of the avian brain

NASA Astrophysics Data System (ADS)

Jirak, Daniel; Janacek, Jiri; Kear, Benjamin P.

2015-10-01

Brain size is widely used as a measure of behavioural complexity and sensory-locomotive capacity in avians but has largely relied upon laborious dissections, endoneurocranial tissue displacement, and physical measurement to derive comparative volumes. As an alternative, we present a new precise calculation method based upon coupled magnetic resonance (MR) imaging and computed tomography (CT). Our approach utilizes a novel interactive Fakir probe cross-referenced with an automated CT protocol to efficiently generate total volumes and surface areas of the brain tissue and endoneurocranial space, as well as the discrete cephalic compartments. We also complemented our procedures by using sodium polytungstate (SPT) as a contrast agent. This greatly enhanced CT applications but did not degrade MR quality and is therefore practical for virtual brain tissue reconstructions employing multiple imaging modalities. To demonstrate our technique, we visualized sex-based brain size differentiation in a sample set of Ring-necked pheasants (Phasianus colchicus). This revealed no significant variance in relative volume or surface areas of the primary brain regions. Rather, a trend towards isometric enlargement of the total brain and endoneurocranial space was evidenced in males versus females, thus advocating a non-differential sexually dimorphic pattern of brain size increase amongst these facultatively flying birds.

A Hybrid Hierarchical Approach for Brain Tissue Segmentation by Combining Brain Atlas and Least Square Support Vector Machine

PubMed Central

Kasiri, Keyvan; Kazemi, Kamran; Dehghani, Mohammad Javad; Helfroush, Mohammad Sadegh

2013-01-01

In this paper, we present a new semi-automatic brain tissue segmentation method based on a hybrid hierarchical approach that combines a brain atlas as a priori information and a least-square support vector machine (LS-SVM). The method consists of three steps. In the first two steps, the skull is removed and the cerebrospinal fluid (CSF) is extracted. These two steps are performed using the toolbox FMRIB's automated segmentation tool integrated in the FSL software (FSL-FAST) developed in Oxford Centre for functional MRI of the brain (FMRIB). Then, in the third step, the LS-SVM is used to segment grey matter (GM) and white matter (WM). The training samples for LS-SVM are selected from the registered brain atlas. The voxel intensities and spatial positions are selected as the two feature groups for training and test. SVM as a powerful discriminator is able to handle nonlinear classification problems; however, it cannot provide posterior probability. Thus, we use a sigmoid function to map the SVM output into probabilities. The proposed method is used to segment CSF, GM and WM from the simulated magnetic resonance imaging (MRI) using Brainweb MRI simulator and real data provided by Internet Brain Segmentation Repository. The semi-automatically segmented brain tissues were evaluated by comparing to the corresponding ground truth. The Dice and Jaccard similarity coefficients, sensitivity and specificity were calculated for the quantitative validation of the results. The quantitative results show that the proposed method segments brain tissues accurately with respect to corresponding ground truth. PMID:24696800

Glioma tissue obtained by modern ultrasonic aspiration with a simple sterile suction trap for primary cell culture and pathological evaluation.

PubMed

Schroeteler, Juliane; Reeker, Ralf; Suero Molina, Eric; Brokinkel, Benjamin; Holling, Markus; Grauer, Oliver M; Senner, Volker; Stummer, Walter; Ewelt, Christian

2014-01-01

Ultrasonic aspiration is widely used in the resection of brain tumors. Nevertheless, tumor tissue fragments obtained by ultrasonic aspiration are usually discarded. In this study, we demonstrate that these fragments are possible sources of material for histopathological study and tissue culture and compare their microscopic features and viability in tissue culture of cavitron ultrasonic surgical aspirator tissue fragments. Brain tumor tissue collected by ultrasonic aspiration (CUSA EXcel®; Integra Radionics Inc.) in a simple sterile suction trap during resection was processed for primary cell culture. Cell viability and immunohistological markers were measured by the WST-1 test, microscopy and immunofluorescent evaluation. Six gliomas are presented to demonstrate that these tissue fragments show good preservation of histological detail and tissue viability in culture. Utilization of this material may facilitate pathological interpretation by providing a more representative sample of tumor histology as well as an adequate and sterile biosource of material for tissue culture studies.

Ex vivo brain tumor analysis using spectroscopic optical coherence tomography

NASA Astrophysics Data System (ADS)

Lenz, Marcel; Krug, Robin; Welp, Hubert; Schmieder, Kirsten; Hofmann, Martin R.

2016-03-01

A big challenge during neurosurgeries is to distinguish between healthy tissue and cancerous tissue, but currently a suitable non-invasive real time imaging modality is not available. Optical Coherence Tomography (OCT) is a potential technique for such a modality. OCT has a penetration depth of 1-2 mm and a resolution of 1-15 μm which is sufficient to illustrate structural differences between healthy tissue and brain tumor. Therefore, we investigated gray and white matter of healthy central nervous system and meningioma samples with a Spectral Domain OCT System (Thorlabs Callisto). Additional OCT images were generated after paraffin embedding and after the samples were cut into 10 μm thin slices for histological investigation with a bright field microscope. All samples were stained with Hematoxylin and Eosin. In all cases B-scans and 3D images were made. Furthermore, a camera image of the investigated area was made by the built-in video camera of our OCT system. For orientation, the backsides of all samples were marked with blue ink. The structural differences between healthy tissue and meningioma samples were most pronounced directly after removal. After paraffin embedding these differences diminished. A correlation between OCT en face images and microscopy images can be seen. In order to increase contrast, post processing algorithms were applied. Hence we employed Spectroscopic OCT, pattern recognition algorithms and machine learning algorithms such as k-means Clustering and Principal Component Analysis.

Tissue distribution of pretomanid in rat brain via mass spectrometry imaging.

PubMed

Shobo, Adeola; Bratkowska, Dominika; Baijnath, Sooraj; Naiker, Suhashni; Somboro, Anou M; Bester, Linda A; Singh, Sanil D; Naicker, Tricia; Kruger, Hendrik G; Govender, Thavendran

2016-01-01

1. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) combines the sensitivity and selectivity of mass spectrometry with spatial analysis to provide a new dimension for histological analyses of the distribution of drugs in tissue. Pretomanid is a pro-drug belonging to a class of antibiotics known as nitroimidizoles, which have been proven to be active under hypoxic conditions and to the best of our knowledge there have been no studies investigating the distribution and localisation of this class of compounds in the brain using MALDI MSI. 2. Herein, we report on the distribution of pretomanid in the healthy rat brain after intraperitoneal administration (20 mg/kg) using MALDI MSI. Our findings showed that the drug localises in specific compartments of the rat brain viz. the corpus callosum, a dense network of neurons connecting left and right cerebral hemispheres. 3. This study proves that MALDI MSI technique has great potential for mapping the pretomanid distribution in uninfected tissue samples, without the need for molecular labelling.

A non-aggressive, highly efficient, enzymatic method for dissociation of human brain-tumors and brain-tissues to viable single-cells.

PubMed

Volovitz, Ilan; Shapira, Netanel; Ezer, Haim; Gafni, Aviv; Lustgarten, Merav; Alter, Tal; Ben-Horin, Idan; Barzilai, Ori; Shahar, Tal; Kanner, Andrew; Fried, Itzhak; Veshchev, Igor; Grossman, Rachel; Ram, Zvi

2016-06-01

Conducting research on the molecular biology, immunology, and physiology of brain tumors (BTs) and primary brain tissues requires the use of viably dissociated single cells. Inadequate methods for tissue dissociation generate considerable loss in the quantity of single cells produced and in the produced cells' viability. Improper dissociation may also demote the quality of data attained in functional and molecular assays due to the presence of large quantities cellular debris containing immune-activatory danger associated molecular patterns, and due to the increased quantities of degraded proteins and RNA. Over 40 resected BTs and non-tumorous brain tissue samples were dissociated into single cells by mechanical dissociation or by mechanical and enzymatic dissociation. The quality of dissociation was compared for all frequently used dissociation enzymes (collagenase, DNase, hyaluronidase, papain, dispase) and for neutral protease (NP) from Clostridium histolyticum. Single-cell-dissociated cell mixtures were evaluated for cellular viability and for the cell-mixture dissociation quality. Dissociation quality was graded by the quantity of subcellular debris, non-dissociated cell clumps, and DNA released from dead cells. Of all enzymes or enzyme combinations examined, NP (an enzyme previously not evaluated on brain tissues) produced dissociated cell mixtures with the highest mean cellular viability: 93 % in gliomas, 85 % in brain metastases, and 89 % in non-tumorous brain tissue. NP also produced cell mixtures with significantly less cellular debris than other enzymes tested. Dissociation using NP was non-aggressive over time-no changes in cell viability or dissociation quality were found when comparing 2-h dissociation at 37 °C to overnight dissociation at ambient temperature. The use of NP allows for the most effective dissociation of viable single cells from human BTs or brain tissue. Its non-aggressive dissociative capacity may enable ambient-temperature shipping of tumor pieces in multi-center clinical trials, meanwhile being dissociated. As clinical grade NP is commercially available it can be easily integrated into cell-therapy clinical trials in neuro-oncology. The high quality viable cells produced may enable investigators to conduct more consistent research by avoiding the experimental artifacts associated with the presence dead cells or cellular debris.

Human Traumatic Brain Injury Results in Oligodendrocyte Death and Increases the Number of Oligodendrocyte Progenitor Cells.

PubMed

Flygt, Johanna; Gumucio, Astrid; Ingelsson, Martin; Skoglund, Karin; Holm, Jonatan; Alafuzoff, Irina; Marklund, Niklas

2016-06-01

Oligodendrocyte (OL) death may contribute to white matter pathology, a common cause of network dysfunction and persistent cognitive problems in patients with traumatic brain injury (TBI). Oligodendrocyte progenitor cells (OPCs) persist throughout the adult CNS and may replace dead OLs. OL death and OPCs were analyzed by immunohistochemistry of human brain tissue samples, surgically removed due to life-threatening contusions and/or focal brain swelling at 60.6 ± 75 hours (range 4-192 hours) postinjury in 10 severe TBI patients (age 51.7 ± 18.5 years). Control brain tissue was obtained postmortem from 5 age-matched patients without CNS disorders. TUNEL and CC1 co-labeling was used to analyze apoptotic OLs, which were increased in injured brain tissue (p < 0.05), without correlation with time from injury until surgery. The OPC markers Olig2, A2B5, NG2, and PDGFR-α were used. In contrast to the number of single-labeled Olig2, A2B5, NG2, and PDGFR-α-positive cells, numbers of Olig2 and A2B5 co-labeled cells were increased in TBI samples (p < 0.05); this was inversely correlated with time from injury to surgery (r = -0.8, p < 0.05). These results indicate that severe focal human TBI results in OL death and increases in OPCs postinjury, which may influence white matter function following TBI. © 2016 American Association of Neuropathologists, Inc. All rights reserved.

Potential application of a handheld confocal endomicroscope imaging system using a variety of fluorophores in experimental gliomas and normal brain.

PubMed

Martirosyan, Nikolay L; Georges, Joseph; Eschbacher, Jennifer M; Cavalcanti, Daniel D; Elhadi, Ali M; Abdelwahab, Mohammed G; Scheck, Adrienne C; Nakaji, Peter; Spetzler, Robert F; Preul, Mark C

2014-02-01

The authors sought to assess the feasibility of a handheld visible-wavelength confocal endomicroscope imaging system (Optiscan 5.1, Optiscan Pty., Ltd.) using a variety of rapid-acting fluorophores to provide histological information on gliomas, tumor margins, and normal brain in animal models. Mice (n = 25) implanted with GL261 cells were used to image fluorescein sodium (FNa), 5-aminolevulinic acid (5-ALA), acridine orange (AO), acriflavine (AF), and cresyl violet (CV). A U251 glioma xenograft model in rats (n = 5) was used to image sulforhodamine 101 (SR101). A swine (n = 3) model with AO was used to identify confocal features of normal brain. Images of normal brain, obvious tumor, and peritumoral zones were collected using the handheld confocal endomicroscope. Histological samples were acquired through biopsies from matched imaging areas. Samples were visualized with a benchtop confocal microscope. Histopathological features in corresponding confocal images and photomicrographs of H & E-stained tissues were reviewed. Fluorescence induced by FNa, 5-ALA, AO, AF, CV, and SR101 and detected with the confocal endomicroscope allowed interpretation of histological features. Confocal endomicroscopy revealed satellite tumor cells within peritumoral tissue, a definitive tumor border, and striking fluorescent cellular and subcellular structures. Fluorescence in various tumor regions correlated with standard histology and known tissue architecture. Characteristic features of different areas of normal brain were identified as well. Confocal endomicroscopy provided rapid histological information precisely related to the site of microscopic imaging with imaging characteristics of cells related to the unique labeling features of the fluorophores. Although experimental with further clinical trial validation required, these data suggest that intraoperative confocal imaging can help to distinguish normal brain from tumor and tumor margin and may have application in improving intraoperative decisions during resection of brain tumors.

Multimodal optical analysis discriminates freshly extracted human sample of gliomas, metastases and meningiomas from their appropriate controls

NASA Astrophysics Data System (ADS)

Zanello, Marc; Poulon, Fanny; Pallud, Johan; Varlet, Pascale; Hamzeh, H.; Abi Lahoud, Georges; Andreiuolo, Felipe; Ibrahim, Ali; Pages, Mélanie; Chretien, Fabrice; di Rocco, Federico; Dezamis, Edouard; Nataf, François; Turak, Baris; Devaux, Bertrand; Abi Haidar, Darine

2017-02-01

Delineating tumor margins as accurately as possible is of primordial importance in surgical oncology: extent of resection is associated with survival but respect of healthy surrounding tissue is necessary for preserved quality of life. The real-time analysis of the endogeneous fluorescence signal of brain tissues is a promising tool for defining margins of brain tumors. The present study aims to demonstrate the feasibility of multimodal optical analysis to discriminate fresh samples of gliomas, metastases and meningiomas from their appropriate controls. Tumor samples were studied on an optical fibered endoscope using spectral and fluorescence lifetime analysis and then on a multimodal set-up for acquiring spectral, one and two-photon fluorescence images, second harmonic generation signals and two-photon fluorescence lifetime datasets. The obtained data allowed us to differentiate healthy samples from tumor samples. These results confirmed the possible clinical relevance of this real-time multimodal optical analysis. This technique can be easily applied to neurosurgical procedures for a better delineation of surgical margins.

Transcriptomic profiling of human peritumoral neocortex tissues revealed genes possibly involved in tumor-induced epilepsy.

PubMed

Niesen, Charles E; Xu, Jun; Fan, Xuemo; Li, Xiaojin; Wheeler, Christopher J; Mamelak, Adam N; Wang, Charles

2013-01-01

The molecular mechanism underlying tumor-induced epileptogenesis is poorly understood. Alterations in the peritumoral microenvironment are believed to play a significant role in inducing epileptogenesis. We hypothesize that the change of gene expression in brain peritumoral tissues may contribute to the increased neuronal excitability and epileptogenesis. To identify the genes possibly involved in tumor-induced epilepsy, a genome-wide gene expression profiling was conducted using Affymetrix HG U133 plus 2.0 arrays and RNAs derived from formalin-fixed paraffin embedded (FFPE) peritumoral cortex tissue slides from 5-seizure vs. 5-non-seizure low grade brain tumor patients. We identified many differentially expressed genes (DEGs). Seven dysregulated genes (i.e., C1QB, CALCRL, CCR1, KAL1, SLC1A2, SSTR1 and TYRO3) were validated by qRT-PCR, which showed a high concordance. Principal Component Analysis (PCA) showed that epilepsy subjects were clustered together tightly (except one sample) and were clearly separated from the non-epilepsy subjects. Molecular functional categorization showed that significant portions of the DEGs functioned as receptor activity, molecular binding including enzyme binding and transcription factor binding. Pathway analysis showed these DEGs were mainly enriched in focal adhesion, ECM-receptor interaction, and cell adhesion molecules pathways. In conclusion, our study showed that dysregulation of gene expression in the peritumoral tissues may be one of the major mechanisms of brain tumor induced-epilepsy. However, due to the small sample size of the present study, further validation study is needed. A deeper characterization on the dysregulated genes involved in brain tumor-induced epilepsy may shed some light on the management of epilepsy due to brain tumors.

Quantitative determination of selenium and mercury, and an ICP-MS semi-quantitative scan of other elements in samples of eagle tissues collected from the Pacific Northwest--Summer 2011

USGS Publications Warehouse

May, Thomas; Walther, Mike; Brumbaugh, William

2013-01-01

Eagle tissues from dead eagle carcasses were collected by U.S. Fish and Wildlife Service personnel at various locations in the Pacific Northwest as part of a study to document the occurrence of metal and metalloid contaminants. A group of 182 eagle tissue samples, consisting of liver, kidney, brain, talon, feather, femur, humerus, and stomach contents, were quantitatively analyzed for concentrations of selenium and mercury by atomic absorption techniques, and for other elements by semi-quantitative scan with an inductively coupled plasma-mass spectrometer. For the various tissue matrices analyzed by an ICP-MS semiquantitative scan, some elemental concentrations (micrograms per gram dry weight) were quite variable within a particular matrix; notable observations were as follows: lead concentrations ranged from 0.2 to 31 in femurs, 0.1 to 29 in humeri, 0.1 to 54 in talons, less than (<) 0.05 to 120 in livers, <0.05 to 34 in kidneys, and 0.05 to 8 in brains; copper concentrations ranged from 5 to 9 in feathers, 8 to 47 in livers, 7 to 43 in kidneys, and 7 to 28 in brains; cadmium concentrations ranged from 0.1 to 10 in kidneys. In stomach contents, concentrations of vanadium ranged from 0.08 to 5, chromium 2 to 34, manganese 1 to 57, copper 2 to 69, arsenic <0.05 to 6, rubidium 1 to 13, and barium <0.5 to 18. Selenium concentrations from highest to lowest based on the matrix mean were as follows: kidney, liver, feather, brain, stomach content, talon, femur, and humerus. For mercury, the highest to lowest concentrations were feather, liver, talon, brain, stomach content, femur, and humerus.

Imaging MALDI MS of Dosed Brain Tissues Utilizing an Alternative Analyte Pre-extraction Approach

NASA Astrophysics Data System (ADS)

Quiason, Cristine M.; Shahidi-Latham, Sheerin K.

2015-06-01

Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry has been adopted in the pharmaceutical industry as a useful tool to detect xenobiotic distribution within tissues. A unique sample preparation approach for MALDI imaging has been described here for the extraction and detection of cobimetinib and clozapine, which were previously undetectable in mouse and rat brain using a single matrix application step. Employing a combination of a buffer wash and a cyclohexane pre-extraction step prior to standard matrix application, the xenobiotics were successfully extracted and detected with an 8 to 20-fold gain in sensitivity. This alternative approach for sample preparation could serve as an advantageous option when encountering difficult to detect analytes.

Rapid and prodium iodide-compatible optical clearing method for brain tissue based on sugar/sugar-alcohol

NASA Astrophysics Data System (ADS)

Yu, Tingting; Qi, Yisong; Wang, Jianru; Feng, Wei; Xu, Jianyi; Zhu, Jingtan; Yao, Yingtao; Gong, Hui; Luo, Qingming; Zhu, Dan

2016-08-01

The developed optical clearing methods show great potential for imaging of large-volume tissues, but these methods present some nonnegligible limitations such as complexity of implementation and long incubation times. In this study, we tried to screen out rapid optical clearing agents by means of molecular dynamical simulation and experimental demonstration. According to the optical clearing potential of sugar and sugar-alcohol, we further evaluated the improvement in the optical clearing efficacy of mouse brain samples, imaging depth, fluorescence preservation, and linear deformation. The results showed that drops of sorbitol, sucrose, and fructose could quickly make the mouse brain sample transparent within 1 to 2 min, and induce about threefold enhancement in imaging depth. The former two could evidently enhance the fluorescence intensity of green fluorescent protein (GFP) and prodium iodide (PI) nuclear dye. Fructose could significantly increase the fluorescence intensity of PI, but slightly decrease the fluorescence intensity of GFP. Even though the three agents caused some shrinkage in samples, the contraction in horizontal and longitudinal directions are almost the same.

Intracerebral Injections and Ultrastructural Analysis of High-Pressure Frozen Brain Tissue.

PubMed

Weil, Marie-Theres; Ruhwedel, Torben; Möbius, Wiebke; Simons, Mikael

2017-01-03

Intracerebral injections are an invasive method to bypass the blood brain barrier and are widely used to study molecular and cellular mechanisms of the central nervous system. The administered substances are injected directly at the site of interest, executing their effect locally. By combining injections in the rat brain with state-of-the-art electron microscopy, subtle changes in ultrastructure of the nervous tissue can be detected prior to overt damage or disease. The protocol presented here involves stereotactic injection into the corpus callosum of Lewis rats and the cryopreparation of freshly dissected tissue for electron microscopy. The localization of the injection site in tissue sections during the sample preparation for transmission electron microscopy is explained and possible artifacts of the method are indicated. With the help of this powerful combination of injections and electron microscopy, subtle effects of the applied substances on the biology of neural cells can be identified and monitored over time. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Towards child versus adult brain mechanical properties.

PubMed

Chatelin, S; Vappou, J; Roth, S; Raul, J S; Willinger, R

2012-02-01

The characterization of brain tissue mechanical properties is of crucial importance in the development of realistic numerical models of the human head. While the mechanical behavior of the adult brain has been extensively investigated in several studies, there is a considerable paucity of data concerning the influence of age on mechanical properties of the brain. Therefore, the implementation of child and infant head models often involves restrictive assumptions like properties scaling from adult or animal data. The present study presents a step towards the investigation of the effects of age on viscoelastic properties of human brain tissue from a first set of dynamic oscillatory shear experiments. Tests were also performed on three different locations of brain (corona radiata, thalamus and brainstem) in order to investigate regional differences. Despite the limited number of child brain samples a significant increase in both storage and loss moduli occurring between the age of 5 months and the age of 22 months was found, confirmed by statistical Student's t-tests (p=0.104,0.038 and 0.054 for respectively corona radiata, thalamus and brain stem samples locations respectively). The adult brain appears to be 3-4 times stiffer than the young child one. Moreover, the brainstem was found to be approximately 2-3 times stiffer than both gray and white matter from corona radiata and thalamus. As a tentative conclusion, this study provides the first rheological data on the human brain at different ages and brain regions. This data could be implemented in numerical models of the human head, especially in models concerning pediatric population. Copyright © 2011 Elsevier Ltd. All rights reserved.

Bioavailability and nervous tissue distribution of pyrethroid insecticide cyfluthrin in rats.

PubMed

Rodríguez, José-Luis; Ares, Irma; Martínez, Marta; Martínez-Larrañaga, María-Rosa; Anadón, Arturo; Martínez, María-Aránzazu

2018-05-08

Toxicokinetics of cyfluthrin after single oral [20 mg/kg body weight (bw)] and intravenous (IV) (3 mg/kg bw) doses were studied in rats. Serial blood samples were obtained after oral and IV administration. Brain tissue samples were also collected after oral administration. Cyfluthrin concentrations in plasma and brain tissues (hypothalamus, striatum, hippocampus and frontal cortex) were quantified using liquid chromatography tandem mass spectrometry (LC/MS). Cyfluthrin disposition was best described by the use of a two-compartment open model. When given orally, plasma kinetics showed an extensive oral absorption of cyfluthrin and a slow elimination. The area under the concentration-time curve [AUC (0-24h) ] and maximal plasma concentration (Cmax) were 6.11 ± 1.06 mg h/L and 0.385 ± 0.051 μg/mL, respectively; β phase elimination half-life (T 1/2 β) was (17.15 ± 1.67 h). Oral bioavailability was found to be 71.60 ± 12.36%. After oral administration, cyfluthrin was widely distributed to brain tissues. AUC (0-24h) was significant higher in all tested brain tissues than in plasma. The largest discrepancy was found for hypothalamus. AUC (0-24h) , Cmax and T 1/2 β in hypothalamus were 19.36 ± 2.56 mg h/L, 1.21 ± 0.11 μg/g and 22.73 ± 1.60 h, respectively. Assuming the identified toxicokinetics parameters, this study serves to better understand mammalian toxicity of pyrethroid cyfluthrin and to design further studies to characterize its neurotoxicity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Genotyping and pathobiologic characterization of canine parvovirus circulating in Nanjing, China

PubMed Central

2013-01-01

Background Canine parvovirus (CPV) is an important pathogen that causes acute enteric disease in dogs. It has mutated and spread throughout the world in dog populations. We provide an update on the molecular characterization of CPV that circulated in Nanjing, a provincial capital in China between 2009 and 2012. Results Seventy rectal swab samples were collected from the dogs diagnosed with CPV infection in 8 animal hospitals of Nanjing. Sequence analysis of VP2 genes of 31 samples revealed that 29 viral strains belonged to CPV-2a subtype, while other two strains were classified into CPV-2b. To investigate the pathogenicity of the prevalent virus, we isolated CPV-2a and performed the animal experiment. Nine beagles were inoculated with 105.86 of 50% tissue culture infectious doses (TCID50) of the virus. All the experimentally infected beagles exhibited mild to moderate mucoid or watery diarrhea on day 4 post-infection (p.i.). On day 9 p.i., characteristic histopathological lesions were clearly observed in multiple organs of infected dogs, including liver, spleen, kidney, brain and all segments of the small and large intestines, while viral DNA and antigen staining could be detected in the sampled tissues. It is notable that canine parvovirus was isolated in one from two brain samples processed. Conclusion Our results indicated that CPV-2a is the predominant subtype in Nanjing of China. And this virus caused extensive lesions in a variety of tissues, including the brain. PMID:23988202

Genotyping and pathobiologic characterization of canine parvovirus circulating in Nanjing, China.

PubMed

Zhao, Yanbing; Lin, Yan; Zeng, Xujian; Lu, Chengping; Hou, Jiafa

2013-08-29

Canine parvovirus (CPV) is an important pathogen that causes acute enteric disease in dogs. It has mutated and spread throughout the world in dog populations. We provide an update on the molecular characterization of CPV that circulated in Nanjing, a provincial capital in China between 2009 and 2012. Seventy rectal swab samples were collected from the dogs diagnosed with CPV infection in 8 animal hospitals of Nanjing. Sequence analysis of VP2 genes of 31 samples revealed that 29 viral strains belonged to CPV-2a subtype, while other two strains were classified into CPV-2b. To investigate the pathogenicity of the prevalent virus, we isolated CPV-2a and performed the animal experiment. Nine beagles were inoculated with 105.86 of 50% tissue culture infectious doses (TCID50) of the virus. All the experimentally infected beagles exhibited mild to moderate mucoid or watery diarrhea on day 4 post-infection (p.i.). On day 9 p.i., characteristic histopathological lesions were clearly observed in multiple organs of infected dogs, including liver, spleen, kidney, brain and all segments of the small and large intestines, while viral DNA and antigen staining could be detected in the sampled tissues. It is notable that canine parvovirus was isolated in one from two brain samples processed. Our results indicated that CPV-2a is the predominant subtype in Nanjing of China. And this virus caused extensive lesions in a variety of tissues, including the brain.

Antigen recovery and preservation using the microwave irradiation of biological samples for transmission electron microscopy analysis.

PubMed

Aïoun, Josiane; Chat, Sophie; Bordat, Christian; Péchoux, Christine

2013-01-01

Most studies using microwave irradiation (MWI) for the preparation of tissue samples have reported an improvement in structural integrity. However, there have been few studies on the effect of microwave (MW) on antigen preservation during sample preparation prior to immunolocalization. This report documents our experience of specimen preparation using an automatic microwave apparatus to obtain antigen preservation and retrieval. We tested the effects of MW processing vs. conventional procedures on the morphology and antigenicity of two different tissues: the brain and mammary gland, whose chemical composition and anatomical organization are quite different. We chose to locate the transcription factor PPARβ/δ using immunocytochemistry on brain tissue sections from hamsters. Antigen retrieval protocols involving MWI were used to restore immunoreactivity. We also studied the efficiency of the ultrastructural immunolocalization of both PPARγ and caveolin-1 following MWI vs. conventional treatment, on mammary gland tissue from mice at 10 days of lactation. Our findings showed that the treatment of tissue samples with MWI, in the context of a process lasting just a few hours from fixation to immunolocalization, enabled similar, or even better, results than conventional protocols. The quantification of immunolabeling for cav-1 indicated an increase in density of up to three-fold in tissues processed in the microwave oven. Furthermore, MW treatment permitted the localization of PPARβ/δ in glutaraldehyde-fixed specimens, which was impossible in the absence of MWI. This study thus showed that techniques involving the use of microwaves could largely improve both ultrastructure and immunodetection. Copyright © 2013 Elsevier Ltd. All rights reserved.

Molecular detection of Toxoplasma gondii and Neospora caninum in birds from South Africa.

PubMed

Lukášová, Radka; Kobédová, Kateřina; Halajian, Ali; Bártová, Eva; Murat, Jean-Benjamin; Rampedi, Kgethedi Michael; Luus-Powell, Wilmien J

2018-02-01

There are not any records on the detection of Toxoplasma gondii and Neospora caninum in tissues of wild birds in the African continent. The aim of the study was to investigate the occurrence of DNA from these protozoan parasites in brain tissue samples collected in years 2014-2015 from 110 wild and domestic birds of 15 orders. Birds came mainly from the province of Limpopo (n=103); the other seven birds came from other five provinces of South Africa. Parasite DNAs were detected by PCR in animal brains. While all samples were negative for N. caninum, T. gondii DNA was detected in three (2.7%) birds: a Red-eyed Dove (Streptopelia semitorquata), a Laughing Dove (S. senegalensis) and a Southern-Yellow-billed Hornbill (Tockus leucomelas), all from Limpopo province. Positive samples were selected for genotyping by a 15 microsatellite markers method in a single multiplex PCR assay. Only the sample from the Red-eyed Dove was successfully genotyped and characterized as type II. This is the first detection of T. gondii in tissue of native African wild birds and the first study focusing on N. caninum in birds from South Africa. Copyright © 2017. Published by Elsevier B.V.

UV-laser microdissection and mRNA expression analysis of individual neurons from postmortem Parkinson's disease brains.

PubMed

Gründemann, Jan; Schlaudraff, Falk; Liss, Birgit

2011-01-01

Cell specificity of gene expression analysis is essential to avoid tissue sample related artifacts, in particular when the relative number of target cells present in the compared tissues varies dramatically, e.g., when comparing dopamine neurons in midbrain tissues from control subjects with those from Parkinson's disease (PD) cases. Here, we describe a detailed protocol that combines contact-free UV-laser microdissection and quantitative PCR of reverse-transcribed RNA of individual neurons from postmortem human midbrain tissue from PD patients and unaffected controls. Among expression changes in a variety of dopamine neuron marker, maintenance, and cell-metabolism genes, we found that α-synuclein mRNA levels were significantly elevated in individual neuromelanin-positive dopamine midbrain neurons from PD brains when compared to those from matched controls.

Optimization of Evans blue quantitation in limited rat tissue samples

PubMed Central

Wang, Hwai-Lee; Lai, Ted Weita

2014-01-01

Evans blue dye (EBD) is an inert tracer that measures plasma volume in human subjects and vascular permeability in animal models. Quantitation of EBD can be difficult when dye concentration in the sample is limited, such as when extravasated dye is measured in the blood-brain barrier (BBB) intact brain. The procedure described here used a very small volume (30 µl) per sample replicate, which enabled high-throughput measurements of the EBD concentration based on a standard 96-well plate reader. First, ethanol ensured a consistent optic path length in each well and substantially enhanced the sensitivity of EBD fluorescence spectroscopy. Second, trichloroacetic acid (TCA) removed false-positive EBD measurements as a result of biological solutes and partially extracted EBD into the supernatant. Moreover, a 1:2 volume ratio of 50% TCA ([TCA final] = 33.3%) optimally extracted EBD from the rat plasma protein-EBD complex in vitro and in vivo, and 1:2 and 1:3 weight-volume ratios of 50% TCA optimally extracted extravasated EBD from the rat brain and liver, respectively, in vivo. This procedure is particularly useful in the detection of EBD extravasation into the BBB-intact brain, but it can also be applied to detect dye extravasation into tissues where vascular permeability is less limiting. PMID:25300427

Optimization of Evans blue quantitation in limited rat tissue samples

NASA Astrophysics Data System (ADS)

Wang, Hwai-Lee; Lai, Ted Weita

2014-10-01

Evans blue dye (EBD) is an inert tracer that measures plasma volume in human subjects and vascular permeability in animal models. Quantitation of EBD can be difficult when dye concentration in the sample is limited, such as when extravasated dye is measured in the blood-brain barrier (BBB) intact brain. The procedure described here used a very small volume (30 µl) per sample replicate, which enabled high-throughput measurements of the EBD concentration based on a standard 96-well plate reader. First, ethanol ensured a consistent optic path length in each well and substantially enhanced the sensitivity of EBD fluorescence spectroscopy. Second, trichloroacetic acid (TCA) removed false-positive EBD measurements as a result of biological solutes and partially extracted EBD into the supernatant. Moreover, a 1:2 volume ratio of 50% TCA ([TCA final] = 33.3%) optimally extracted EBD from the rat plasma protein-EBD complex in vitro and in vivo, and 1:2 and 1:3 weight-volume ratios of 50% TCA optimally extracted extravasated EBD from the rat brain and liver, respectively, in vivo. This procedure is particularly useful in the detection of EBD extravasation into the BBB-intact brain, but it can also be applied to detect dye extravasation into tissues where vascular permeability is less limiting.

The biochemical, nanomechanical and chemometric signatures of brain cancer.

PubMed

Abramczyk, Halina; Imiela, Anna

2018-01-05

Raman spectroscopy and imaging combined with AFM topography and mechanical indentation by AFM have been shown to be an effective tool for analysis and discrimination of human brain tumors from normal structures. Raman methods have potential to be applied in clinical practice as they allow for identification of tumor margins during surgery. In this study, we investigate medulloblastoma (grade IV WHO) (n=5) and the tissue from the negative margins used as normal controls. We compare a high grade medulloblastoma (IV grade), and non-tumor samples from human central nervous system (CNS) tissue. Based on the properties of the Raman vibrational spectra and Raman images we provide a real-time feedback that is label-free method to monitor tumor metabolism that reveals reprogramming of biosynthesis of lipids, and proteins. We have found that the high-grade tumors of central nervous system (medulloblastoma) exhibit enhanced level of β-sheet conformation and down-regulated level of α-helix conformation when comparing against normal tissue. We have shown that the ratio of Raman intensities I2930/I2845 at 2930 and 2845cm -1 is a good source of information on the ratio of lipid and protein contents. We have found that the ratio reflects the lipid and protein contents of tumorous brain tissue compared to the non-tumor tissue. Almost all brain tumors have the Raman intensity ratios significantly higher (1.99±0.026) than that found in non-tumor brain tissue, which is 1.456±0.02, and indicates that the relative amount of lipids compared to proteins is significantly higher in the normal brain tissue. Mechanical indentation using AFM on sliced human brain tissues (medulloblastoma, grade IV) revealed that the mechanical properties of this tissue are strongly heterogeneous, between 1.8 and 75.7kPa, and the mean of 27.16kPa. The sensitivity and specificity obtained directly from PLSDA and cross validation gives a sensitivity and specificity of 98.5% and 96% and 96.3% and 92% for cross-validation, respectively. The high sensitivity and specificity demonstrates usefulness for a proper decision for a Raman diagnostic test on biochemical alterations monitored by Raman spectroscopy related to brain cancer development. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Neuroprotective effects of Quercetin on radiation-induced brain injury in rats.

PubMed

Kale, Aydemir; Piskin, Özcan; Bas, Yilmaz; Aydin, Bengü Gülhan; Can, Murat; Elmas, Özlem; Büyükuysal, Çagatay

2018-04-24

Extensive research has been focused on radiation-induced brain injury. Animal and human studies have shown that flavonoids have remarkable toxicological profiles. This study aims to investigate the neuroprotective effects of quercetin in an experimental radiation-induced brain injury. A total of 32 adult male Wistar-Albino rats were randomly divided into four groups (control, quercetin, radiation, and radiation+quercetin groups, with eight rats in each group). Doses (50 mg/kg) of quercetin were administered to the animals in the quercetin and radiation+quercetin groups; radiation and radiation+quercetin groups were exposed to a dose of 20 Gy to the cranium region. Tissue samples, and biochemical levels of tissue injury markers in the four groups were compared. In all measured parameters of oxidative stress, administration of quercetin significantly demonstrated favorable effects. Both plasma and tissue levels of malondialdehyde and total antioxidant status significantly changed in favor of antioxidant activity. Histopathological evaluation of the tissues also demonstrated a significant decrease in cellular degeneration and infiltration parameters after quercetin administration. Quercetin demonstrated significant neuroprotection after radiation-induced brain injury. Further studies of neurological outcomes under different experimental settings are required in order to achieve conclusive results.

Optical vortex beam transmission with different OAM in scattering beads and brain tissue media

NASA Astrophysics Data System (ADS)

Wang, W. B.; Shi, Lingyan; Lindwasser, Lukas; Marque, Paulo; Lavery, M. P. J.; Alfano, R. R.

2016-03-01

Light transmission of Laguerre Gaussian (LG) vortex beams with different orbital angular momentum (OAM) values (L) in scattering beads and mouse brain tissue media were experimentally investigated for the first time in comparison with Gaussian (G) beams. The LG beams with different OAM were generated using a spatial light modulator (SLM) in reflection mode. The scattering beads media consist of various sizes and concentrations of latex beads in water solutions. The transmissions of LG and G beams through scattering beads and brain tissue media were measured with different ratios of sample thicknesses (z) to scattering mean free path (ls) of the turbid media, z/ls. The results indicate that within the ballistic region where z/ls is small, the LG and G beams show no significant difference, while in the diffusive region where z/ls is higher, the vortex beams show higher transmission than G beams. In the diffusive region, the LG beams with higher L values show higher transmission than the beams with lower L values due to the eigen channels in the media. The transition points from the ballistic to diffusive regions for different scattering beads and brain tissue media were studied.

Classification of Genes and Putative Biomarker Identification Using Distribution Metrics on Expression Profiles

PubMed Central

Huang, Hung-Chung; Jupiter, Daniel; VanBuren, Vincent

2010-01-01

Background Identification of genes with switch-like properties will facilitate discovery of regulatory mechanisms that underlie these properties, and will provide knowledge for the appropriate application of Boolean networks in gene regulatory models. As switch-like behavior is likely associated with tissue-specific expression, these gene products are expected to be plausible candidates as tissue-specific biomarkers. Methodology/Principal Findings In a systematic classification of genes and search for biomarkers, gene expression profiles (GEPs) of more than 16,000 genes from 2,145 mouse array samples were analyzed. Four distribution metrics (mean, standard deviation, kurtosis and skewness) were used to classify GEPs into four categories: predominantly-off, predominantly-on, graded (rheostatic), and switch-like genes. The arrays under study were also grouped and examined by tissue type. For example, arrays were categorized as ‘brain group’ and ‘non-brain group’; the Kolmogorov-Smirnov distance and Pearson correlation coefficient were then used to compare GEPs between brain and non-brain for each gene. We were thus able to identify tissue-specific biomarker candidate genes. Conclusions/Significance The methodology employed here may be used to facilitate disease-specific biomarker discovery. PMID:20140228

Localized cortical chronic traumatic encephalopathy pathology after single, severe axonal injury in human brain.

PubMed

Shively, Sharon B; Edgerton, Sarah L; Iacono, Diego; Purohit, Dushyant P; Qu, Bao-Xi; Haroutunian, Vahram; Davis, Kenneth L; Diaz-Arrastia, Ramon; Perl, Daniel P

2017-03-01

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive mild impact traumatic brain injury from contact sports. Recently, a consensus panel defined the pathognomonic lesion for CTE as accumulations of abnormally hyperphosphorylated tau (p-tau) in neurons (neurofibrillary tangles), astrocytes and cell processes distributed around small blood vessels at sulcal depths in irregular patterns within the cortex. The pathophysiological mechanism for this lesion is unknown. Moreover, a subset of CTE cases harbors cortical β-amyloid plaques. In this study, we analyzed postmortem brain tissues from five institutionalized patients with schizophrenia and history of surgical leucotomy with subsequent survival of at least another 40 years. Because leucotomy involves severing axons bilaterally in prefrontal cortex, this surgical procedure represents a human model of single traumatic brain injury with severe axonal damage and no external impact. We examined cortical tissues at the leucotomy site and at both prefrontal cortex rostral and frontal cortex caudal to the leucotomy site. For comparison, we analyzed brain tissues at equivalent neuroanatomical sites from non-leucotomized patients with schizophrenia, matched in age and gender. All five leucotomy cases revealed severe white matter damage with dense astrogliosis at the axotomy site and also neurofibrillary tangles and p-tau immunoreactive neurites in the overlying gray matter. Four cases displayed p-tau immunoreactivity in neurons, astrocytes and cell processes encompassing blood vessels at cortical sulcal depths in irregular patterns, similar to CTE. The three cases with apolipoprotein E ε4 haplotype showed scattered β-amyloid plaques in the overlying gray matter, but not the two cases with apolipoprotein E ε3/3 genotype. Brain tissue samples from prefrontal cortex rostral and frontal cortex caudal to the leucotomy site, and all cortical samples from the non-leucotomized patients, showed minimal p-tau and β-amyloid pathology. These findings suggest that chronic axonal damage contributes to the unique pathology of CTE over time.

A fast atlas-guided high density diffuse optical tomography system for brain imaging

NASA Astrophysics Data System (ADS)

Dai, Xianjin; Zhang, Tao; Yang, Hao; Jiang, Huabei

2017-02-01

Near infrared spectroscopy (NIRS) is an emerging functional brain imaging tool capable of assessing cerebral concentrations of oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) during brain activation noninvasively. As an extension of NIRS, diffuse optical tomography (DOT) not only shares the merits of providing continuous readings of cerebral oxygenation, but also has the ability to provide spatial resolution in the millimeter scale. Based on the scattering and absorption properties of nonionizing near-infrared light in biological tissue, DOT has been successfully applied in the imaging of breast tumors, osteoarthritis and cortex activations. Here, we present a state-of-art fast high density DOT system suitable for brain imaging. It can achieve up to a 21 Hz sampling rate for a full set of two-wavelength data for 3-D DOT brain image reconstruction. The system was validated using tissue-mimicking brain-model phantom. Then, experiments on healthy subjects were conducted to demonstrate the capability of the system.

Fluorescent Pressure Response of Protein-Nanocluster Polymer Composites

DTIC Science & Technology

2016-05-01

composites as pressure sensitive indicators of brain damage. The PNC composites are made up of protein coated gold nanoclusters and a styrene- ethylene ...styrene- ethylene /butylene-styrene (SEBS):mineral oil composites that were developed as a brain tissue surrogate at ARL. Finally, we would like to...allowing us to use solid samples and create a model for brain damage. To this end, we used styrene- ethylene /butylene-styrene (SEBS) as the matrix to

Structure changes of human brain gray matter neurons and astrocytes in acute local ischemic injury.

PubMed

Sergeeva, S P; Shishkina, L V; Litvitskiy, P F; Breslavich, I D; Vinogradov, E V

2016-01-01

The purpose to identify key morphological features of the Astrocytes and Neurons in the acute local cerebral ischemia human cortex. Left middle cerebral artery ischemic stroke died persons (n = 9) brain tissue samples from 3 zones: 1st - contiguous to the tissue necrotic damage site zone, 2nd - 5-10 cm distant from the previous one, 3rd - the damage site symmetrical zone of the contralateral hemisphere. For GFAP, MAP-2, NSE, p53 detection indirect immunoperoxidase immunohistochemical staining method has been used. Also, the samples were Nissl and Hematoxylin-Eosin stained. The most pronounced changes in the quantity and morphological structure of astrocytes and neurons are found in directly adjacent to the necrotic core region of theleft middle cerebral artery ischemic stroke brain. This indicates the prevalence of the inflammation processes around the area of nerve tissueischemic destruction. Morphological changes of neurons and astrocytes, apoptosis, enhanced neuron-astrocyte interaction found in the area bordering on necrotic core (5-10 cm from it), as well as ischemic hearth symmetrical sites of the contralateral hemisphere. This interaction is essential for the neuroplasticityrealization in the local ischemic brain injury. The results obtained were shown the nerve tissue morphological characteristics changes occur in local cerebral cortex ischemic injury not only in the lesion, but also in the contralateral hemisphere. These changes are probably related to the implementation of neuroplasticity.

Influence of peptide transporter 2 (PEPT2) on the distribution of cefadroxil in mouse brain: A microdialysis study.

PubMed

Chen, Xiaomei; Keep, Richard F; Liang, Yan; Zhu, Hao-Jie; Hammarlund-Udenaes, Margareta; Hu, Yongjun; Smith, David E

2017-05-01

Peptide transporter 2 (PEPT2) is a high-affinity low-capacity transporter belonging to the proton-coupled oligopeptide transporter family. Although many aspects of PEPT2 structure-function are known, including its localization in choroid plexus and neurons, its regional activity in brain, especially extracellular fluid (ECF), is uncertain. In this study, the pharmacokinetics and regional brain distribution of cefadroxil, a β-lactam antibiotic and PEPT2 substrate, were investigated in wildtype and Pept2 null mice using in vivo intracerebral microdialysis. Cefadroxil was infused intravenously over 4h at 0.15mg/min/kg, and samples obtained from plasma, brain ECF, cerebrospinal fluid (CSF) and brain tissue. A permeability-surface area experiment was also performed in which 0.15mg/min/kg cefadroxil was infused intravenously for 10min, and samples obtained from plasma and brain tissues. Our results showed that PEPT2 ablation significantly increased the brain ECF and CSF levels of cefadroxil (2- to 2.5-fold). In contrast, there were no significant differences between wildtype and Pept2 null mice in the amount of cefadroxil in brain cells. The unbound volume of distribution of cefadroxil in brain was 60% lower in Pept2 null mice indicating an uptake function for PEPT2 in brain cells. Finally, PEPT2 did not affect the influx clearance of cefadroxil, thereby, ruling out differences between the two genotypes in drug entry across the blood-brain barriers. These findings demonstrate, for the first time, the impact of PEPT2 on brain ECF as well as the known role of PEPT2 in removing peptide-like drugs, such as cefadroxil, from the CSF to blood. Copyright © 2017 Elsevier Inc. All rights reserved.

Advances in Raman spectroscopy for the diagnosis of Alzheimer's disease

NASA Astrophysics Data System (ADS)

Sudworth, Caroline D.; Archer, John K. J.; Black, Richard A.; Mann, David

2006-02-01

Within the next 50 years Alzheimer's disease is expected to affect 100 million people worldwide. The progressive decline in the mental health of the patient is caused by severe brain atrophy generated by the breakdown and aggregation of proteins, resulting in β-amyloid plaques and neurofibrillary tangles. The greatest challenge to Alzheimer's disease lies in the pursuit of an early and definitive diagnosis, in order that suitable treatment can be administered. At the present time, definitive diagnosis is restricted to post-mortem examination. Alzheimer's disease also remains without a long-term cure. This research demonstrates the potential role of Raman spectroscopy, combined with principle components analysis (PCA), as a diagnostic method. Analyses of ethically approved ex vivo post-mortem brain tissues (originating from frontal and occipital lobes) from control (3 normal elderly subjects and 3 Huntingdon's disease subjects) and Alzheimer's disease (12 subjects) brain sections, and a further set of 12 blinded samples are presented. Spectra originating from these tissues are highly reproducible, and initial results indicate a vital difference in protein content and conformation, relating to the abnormally high levels of aggregated proteins in the diseased tissues. Further examination of these spectra using PCA allows for the separation of control from diseased tissues. The validation of the PCA models using blinded samples also displays promise for the identification of Alzheimer's disease, in conjunction with secondary information regarding other brain diseases and dementias. These results provide a route for Raman spectroscopy as a possible non-invasive, non-destructive tool for the early diagnosis of Alzheimer's disease.

Automatic recognition and analysis of synapses. [in brain tissue

NASA Technical Reports Server (NTRS)

Ungerleider, J. A.; Ledley, R. S.; Bloom, F. E.

1976-01-01

An automatic system for recognizing synaptic junctions would allow analysis of large samples of tissue for the possible classification of specific well-defined sets of synapses based upon structural morphometric indices. In this paper the three steps of our system are described: (1) cytochemical tissue preparation to allow easy recognition of the synaptic junctions; (2) transmitting the tissue information to a computer; and (3) analyzing each field to recognize the synapses and make measurements on them.

Effect of Carotenoid Supplemented Formula on Carotenoid Bioaccumulation in Tissues of Infant Rhesus Macaques: A Pilot Study Focused on Lutein

PubMed Central

Jeon, Sookyoung; Neuringer, Martha; Johnson, Emily E.; Kuchan, Matthew J.; Pereira, Suzette L.; Johnson, Elizabeth J.; Erdman, John W.

2017-01-01

Lutein is the predominant carotenoid in the developing primate brain and retina, and may have important functional roles. However, its bioaccumulation pattern during early development is not understood. In this pilot study, we investigated whether carotenoid supplementation of infant formula enhanced lutein tissue deposition in infant rhesus macaques. Monkeys were initially breastfed; from 1 to 3 months of age they were fed either a formula supplemented with lutein, zeaxanthin, β-carotene and lycopene, or a control formula with low levels of these carotenoids, for 4 months (n = 2/group). All samples were analyzed by high pressure liquid chromatography (HPLC). Final serum lutein in the supplemented group was 5 times higher than in the unsupplemented group. All brain regions examined showed a selective increase in lutein deposition in the supplemented infants. Lutein differentially accumulated across brain regions, with highest amounts in occipital cortex in both groups. β-carotene accumulated, but zeaxanthin and lycopene were undetectable in any brain region. Supplemented infants had higher lutein concentrations in peripheral retina but not in macular retina. Among adipose sites, abdominal subcutaneous adipose tissue exhibited the highest lutein level and was 3-fold higher in the supplemented infants. The supplemented formula enhanced carotenoid deposition in several other tissues. In rhesus infants, increased intake of carotenoids from formula enhanced their deposition in serum and numerous tissues and selectively increased lutein in multiple brain regions. PMID:28075370

Stability of Bovine viral diarrhea virus 1 nucleic acid in fetal bovine samples stored under different conditions.

PubMed

Ridpath, Julia F; Neill, John D; Chiang, Yu-Wei; Waldbillig, Jill

2014-01-01

Infection of pregnant cattle with both species of Bovine viral diarrhea virus (BVDV) can result in reproductive disease that includes fetal reabsorption, mummification, abortion, stillbirths, congenital defects affecting structural, neural, reproductive, and immune systems, and the birth of calves persistently infected with BVDV. Accurate diagnosis of BVDV-associated reproductive disease is important to control BVDV at the production unit level and assessment of the cost of BVDV infections in support of BVDV control programs. The purpose of the current study was to examine the stability of viral nucleic acid in fetal tissues exposed to different conditions, as measured by detection by polymerase chain reaction. Five different types of fetal tissue, including brain, skin and muscle, ear, and 2 different pooled organ samples, were subjected to conditions that mimicked those that might exist for samples collected after abortions in production settings or possible storage conditions after collection and prior to testing. In addition, tissues were archived for 36 months at -20°C and then retested, to mimic conditions that might occur in the case of retrospective surveillance studies. Brain tissue showed the highest stability under the conditions tested. The impact of fecal contamination was increased following archiving in all tissue types suggesting that, for long-term storage, effort should be made to reduce environmental contaminants before archiving.

Application of Real-Time Fluorescent PCR for Quantitative Assessment of Neospora caninum Infections in Organotypic Slice Cultures of Rat Central Nervous System Tissue

PubMed Central

Müller, Norbert; Vonlaufen, Nathalie; Gianinazzi, Christian; Leib, Stephen L.; Hemphill, Andrew

2002-01-01

The previously described Nc5-specific PCR test for the diagnosis of Neospora caninum infections was used to develop a quantitative PCR assay which allows the determination of infection intensities within different experimental and diagnostic sample groups. The quantitative PCR was performed by using a dual fluorescent hybridization probe system and the LightCycler Instrument for online detection of amplified DNA. This assay was successfully applied for demonstrating the parasite proliferation kinetics in organotypic slice cultures of rat brain which were infected in vitro with N. caninum tachyzoites. This PCR-based method of parasite quantitation with organotypic brain tissue samples can be regarded as a novel ex vivo approach for exploring different aspects of cerebral N. caninum infection. PMID:11773124

Quantitative assessment of cerebral glucose metabolic rates after blood-brain barrier disruption induced by focused ultrasound using FDG-MicroPET.

PubMed

Yang, Feng-Yi; Chang, Wen-Yuan; Chen, Jyh-Cheng; Lee, Lin-Chien; Hung, Yi-Shun

2014-04-15

The goal of this study was to evaluate the pharmacokinetics of (18)F-2-fluoro-2-deoxy-d-glucose ((18)F-FDG) and the expression of glucose transporter 1 (GLUT1) protein after blood-brain barrier (BBB) disruption of normal rat brains by focused ultrasound (FUS). After delivery of an intravenous bolus of ~37 MBq (1 mCi) (18)F-FDG, dynamic positron emission tomography scans were performed on rats with normal brains and those whose BBBs had been disrupted by FUS. Arterial blood sampling was collected throughout the scanning procedure. A 2-tissue compartmental model was used to estimate (18)F-FDG kinetic parameters in brain tissues. The rate constants Ki, K1, and k3 were assumed to characterize the uptake, transport, and hexokinase activity, respectively, of (18)F-FDG. The uptake of (18)F-FDG in brains significantly decreased immediately after the blood-brain barrier was disrupted. At the same time, the derived values of Ki, K1, and k3 for the sonicated brains were significantly lower than those for the control brains. In agreement with the reduction in glucose, Western blot analyses confirmed that focused ultrasound exposure significantly reduced the expression of GLUT1 protein in the brains. Furthermore, the effect of focused ultrasound on glucose uptake was transient and reversible 24h after sonication. Our results indicate that focused ultrasound may inhibit GLUT1 expression to decrease the glucose uptake in brain tissue during the period of BBB disruption. Copyright © 2013 Elsevier Inc. All rights reserved.

Spectromicroscopy of boron in human glioblastomas following administration of Na2B12H11SH.

PubMed

Gilbert, B; Perfetti, L; Fauchoux, O; Redondo, J; Baudat, P A; Andres, R; Neumann, M; Steen, S; Gabel, D; Mercanti, D; Ciotti, M T; Perfetti, P; Margaritondo, G; De Stasio, G

2000-07-01

Boron neutron capture therapy (BNCT) is an experimental, binary treatment for brain cancer which requires as the first step that tumor tissue is targeted with a boron-10 containing compound. Subsequent exposure to a thermal neutron flux results in destructive, short range nuclear reaction within 10 microm of the boron compound. The success of the therapy requires than the BNCT agents be well localized in tumor, rather than healthy tissue. The MEPHISTO spectromicroscope, which performs microchemical analysis by x-ray absorption near edge structure (XANES) spectroscopy from microscopic areas, has been used to study the distribution of trace quantities of boron in human brain cancer tissues surgically removed from patients first administered with the compound Na2B12H11SH (BSH). The interpretation of XANES spectra is complicated by interference from physiologically present sulfur and phosphorus, which contribute structure in the same energy range as boron. We addressed this problem with the present extensive set of spectra from S, B, and P in relevant compounds. We demonstrate that a linear combination of sulfate, phosphate and BSH XANES can be used to reproduce the spectra acquired on boron-treated human brain tumor tissues. We analyzed human glioblastoma tissue from two patients administered and one not administered with BSH. As well as weak signals attributed to BSH, x-ray absorption spectra acquired from tissue samples detected boron in a reduced chemical state with respect to boron in BSH. This chemical state was characterized by a sharp absorption peak at 188.3 eV. Complementary studies on BSH reference samples were not able to reproduce this chemical state of boron, indicating that it is not an artifact produced during sample preparation or x-ray exposure. These data demonstrate that the chemical state of BSH may be altered by in vivo metabolism.

High-throughput isotropic mapping of whole mouse brain using multi-view light-sheet microscopy

NASA Astrophysics Data System (ADS)

Nie, Jun; Li, Yusha; Zhao, Fang; Ping, Junyu; Liu, Sa; Yu, Tingting; Zhu, Dan; Fei, Peng

2018-02-01

Light-sheet fluorescence microscopy (LSFM) uses an additional laser-sheet to illuminate selective planes of the sample, thereby enabling three-dimensional imaging at high spatial-temporal resolution. These advantages make LSFM a promising tool for high-quality brain visualization. However, even by the use of LSFM, the spatial resolution remains insufficient to resolve the neural structures across a mesoscale whole mouse brain in three dimensions. At the same time, the thick-tissue scattering prevents a clear observation from the deep of brain. Here we use multi-view LSFM strategy to solve this challenge, surpassing the resolution limit of standard light-sheet microscope under a large field-of-view (FOV). As demonstrated by the imaging of optically-cleared mouse brain labelled with thy1-GFP, we achieve a brain-wide, isotropic cellular resolution of 3μm. Besides the resolution enhancement, multi-view braining imaging can also recover complete signals from deep tissue scattering and attenuation. The identification of long distance neural projections across encephalic regions can be identified and annotated as a result.

Photodynamic diagnosis and related optical techniques for the management of malignant glioma

NASA Astrophysics Data System (ADS)

Sroka, R.; Stepp, H.; Beyer, W.; Markwardt, N.; Rühm, A.

2017-04-01

Malignant gliomas are a devastating brain tumor disease with very poor prognosis. Stereotactic biopsy sampling is routinely used in larger neurosurgical centers to confirm the diagnosis of a suspected brain tumor. This procedure is associated with risk of blood vessel rupture as well as false-negative results. Recent investigations suggest a potential of light-based techniques to improve both therapy and diagnosis of GBM. Optical guidance can be utilized to improve the biopsy sampling procedure in terms of safety, reliability, and efficacy. Recording of optical signals (transmission, remission, fluorescence) can be potentially integrated into a biopsy needle for providing optical detection of tumor tissue and blood vessel recognition during the biopsy sampling. Optical signals can also be used for monitoring purposes during photodynamic therapy. Here, fluorescence signals recorded before the treatment indicate the presence and accumulation level of photosensitizer, while photobleaching of the photosensitizer fluorescence during the treatment can be used as a measure of the effectiveness of the therapy. Finally, transmitted light can reveal problematic tissue-optical conditions as well as changes of the optical properties of the treated tissue, which may be relevant with regard to treatment prognosis and strategy. Different optical concepts for interstitial PDT monitoring and optical tissue property assessment are presented.

Postmortem Brain and Blood Reference Concentrations of Alprazolam, Bromazepam, Chlordiazepoxide, Diazepam, and their Metabolites and a Review of the Literature.

PubMed

Skov, Louise; Holm, Karen Marie Dollerup; Johansen, Sys Stybe; Linnet, Kristian

2016-09-01

To interpret postmortem toxicology results, reference concentrations for non-toxic and toxic levels are needed. Usually, measurements are performed in blood, but because of postmortem redistribution phenomena this may not be optimal. Rather, measurement in the target organ of psychoactive drugs, the brain, might be considered. Here we present reference concentrations of femoral blood and brain tissue of selected benzodiazepines (BZDs). Using LC-MS/MS, we quantified alprazolam, bromazepam, chlordiazepoxide, diazepam, and the metabolites desmethyldiazepam, oxazepam and temazepam in postmortem femoral blood and brain tissue in 104 cases. BZDs were judged to be unrelated to the cause of death in 88 cases and contributing to death in 16 cases. No cases were found with cause of death solely attributed to BZD poisoning. All BZDs investigated tended to have higher concentrations in brain than in blood with median brain-blood ratios ranging from 1.1 to 2.3. A positive correlation between brain and blood concentrations was found with R(2) values from 0.51 to 0.95. Our reported femoral blood concentrations concur with literature values, but sparse information on brain concentration was available. Drug-metabolite ratios were similar in brain and blood for most compounds. Duplicate measurements of brain samples showed that the pre-analytical variation in brain (5.9%) was relatively low, supporting the notion that brain tissue is a suitable postmortem specimen. The reported concentrations in both brain and blood can be used as reference values when evaluating postmortem cases. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Large-scale Scanning Transmission Electron Microscopy (Nanotomy) of Healthy and Injured Zebrafish Brain.

PubMed

Kuipers, Jeroen; Kalicharan, Ruby D; Wolters, Anouk H G; van Ham, Tjakko J; Giepmans, Ben N G

2016-05-25

Large-scale 2D electron microscopy (EM), or nanotomy, is the tissue-wide application of nanoscale resolution electron microscopy. Others and we previously applied large scale EM to human skin pancreatic islets, tissue culture and whole zebrafish larvae(1-7). Here we describe a universally applicable method for tissue-scale scanning EM for unbiased detection of sub-cellular and molecular features. Nanotomy was applied to investigate the healthy and a neurodegenerative zebrafish brain. Our method is based on standardized EM sample preparation protocols: Fixation with glutaraldehyde and osmium, followed by epoxy-resin embedding, ultrathin sectioning and mounting of ultrathin-sections on one-hole grids, followed by post staining with uranyl and lead. Large-scale 2D EM mosaic images are acquired using a scanning EM connected to an external large area scan generator using scanning transmission EM (STEM). Large scale EM images are typically ~ 5 - 50 G pixels in size, and best viewed using zoomable HTML files, which can be opened in any web browser, similar to online geographical HTML maps. This method can be applied to (human) tissue, cross sections of whole animals as well as tissue culture(1-5). Here, zebrafish brains were analyzed in a non-invasive neuronal ablation model. We visualize within a single dataset tissue, cellular and subcellular changes which can be quantified in various cell types including neurons and microglia, the brain's macrophages. In addition, nanotomy facilitates the correlation of EM with light microscopy (CLEM)(8) on the same tissue, as large surface areas previously imaged using fluorescent microscopy, can subsequently be subjected to large area EM, resulting in the nano-anatomy (nanotomy) of tissues. In all, nanotomy allows unbiased detection of features at EM level in a tissue-wide quantifiable manner.

Large-scale Scanning Transmission Electron Microscopy (Nanotomy) of Healthy and Injured Zebrafish Brain

PubMed Central

Kuipers, Jeroen; Kalicharan, Ruby D.; Wolters, Anouk H. G.

2016-01-01

Large-scale 2D electron microscopy (EM), or nanotomy, is the tissue-wide application of nanoscale resolution electron microscopy. Others and we previously applied large scale EM to human skin pancreatic islets, tissue culture and whole zebrafish larvae1-7. Here we describe a universally applicable method for tissue-scale scanning EM for unbiased detection of sub-cellular and molecular features. Nanotomy was applied to investigate the healthy and a neurodegenerative zebrafish brain. Our method is based on standardized EM sample preparation protocols: Fixation with glutaraldehyde and osmium, followed by epoxy-resin embedding, ultrathin sectioning and mounting of ultrathin-sections on one-hole grids, followed by post staining with uranyl and lead. Large-scale 2D EM mosaic images are acquired using a scanning EM connected to an external large area scan generator using scanning transmission EM (STEM). Large scale EM images are typically ~ 5 - 50 G pixels in size, and best viewed using zoomable HTML files, which can be opened in any web browser, similar to online geographical HTML maps. This method can be applied to (human) tissue, cross sections of whole animals as well as tissue culture1-5. Here, zebrafish brains were analyzed in a non-invasive neuronal ablation model. We visualize within a single dataset tissue, cellular and subcellular changes which can be quantified in various cell types including neurons and microglia, the brain's macrophages. In addition, nanotomy facilitates the correlation of EM with light microscopy (CLEM)8 on the same tissue, as large surface areas previously imaged using fluorescent microscopy, can subsequently be subjected to large area EM, resulting in the nano-anatomy (nanotomy) of tissues. In all, nanotomy allows unbiased detection of features at EM level in a tissue-wide quantifiable manner. PMID:27285162

Advantages of infrared transflection micro spectroscopy and paraffin-embedded sample preparation for biological studies

NASA Astrophysics Data System (ADS)

Yao, Jie; Li, Qian; Zhou, Bo; Wang, Dan; Wu, Rie

2018-04-01

Fourier-Transform Infrared micro-spectroscopy is an excellent method for biological analyses. In this paper, series metal coating films on ITO glass were prepared by the electrochemical method and the different thicknesses of paraffin embedding rat's brain tissue on the substrates were studied by IR micro-spetroscopy in attenuated total reflection (ATR) mode and transflection mode respectively. The Co-Ni-Cu alloy coating film with low cost is good reflection substrates for the IR analysis. The infrared microscopic transflection mode needs not to touch the sample at all and can get the IR spectra with higher signal to noise ratios. The Paraffin-embedding method allows tissues to be stored for a long time for re-analysis to ensure the traceability of the sample. Also it isolates the sample from the metal and avoids the interaction of biological tissue with the metals. The best thickness of the tissues is 4 μm.

Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue.

PubMed

Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Lenhard, Diana Constanze; Naganawa, Shinji; Pietsch, Hubertus

2017-07-01

Signal hyperintensity on unenhanced MRI in certain brain regions has been reported after multiple administrations of some, but not all, gadolinium-based contrast agents (GBCAs). One potential initial pathway of GBCA entry into the brain, infiltration from blood into the cerebrospinal fluid (CSF), was systematically evaluated in this preclinical study. GBCA infiltration and distribution in the CSF were investigated in healthy rats using repeated fluid-attenuated MRI up to 4 h after high-dose (1.8 mmol/kg) administration of six marketed and one experimental GBCA. Additionally, gadolinium measurements in CSF, blood and brain tissue samples (after 24 h) were performed using inductively coupled plasma mass spectrometry. Enhanced MRI signals in the CSF spaces with similar distribution kinetics were observed for all GBCAs. No substantial differences in the gadolinium concentrations among the marketed GBCAs were found in the CSF, blood or brain tissue. After 4.5 h, the concentration in the CSF was clearly higher than in blood but was almost completely cleared and lower than the brain tissue concentration after 24 h. In contrast to the brain signal hyperintensities, no differences in penetration and distribution into the CSF of healthy rats exist among the marketed GBCAs. • Gadolinium-based contrast agents can cross the blood-CSF barrier. • Fluid-attenuated MRI shows GBCA distribution with CSF flow. • GBCA structure and physicochemical properties do not impact CSF penetration and distribution. • GBCA clearance from CSF was almost complete within 24 h in rats. • CSF is a potential pathway of GBCA entry into the brain.

Detecting brain tumor in pathological slides using hyperspectral imaging

PubMed Central

Ortega, Samuel; Fabelo, Himar; Camacho, Rafael; de la Luz Plaza, María; Callicó, Gustavo M.; Sarmiento, Roberto

2018-01-01

Hyperspectral imaging (HSI) is an emerging technology for medical diagnosis. This research work presents a proof-of-concept on the use of HSI data to automatically detect human brain tumor tissue in pathological slides. The samples, consisting of hyperspectral cubes collected from 400 nm to 1000 nm, were acquired from ten different patients diagnosed with high-grade glioma. Based on the diagnosis provided by pathologists, a spectral library of normal and tumor tissues was created and processed using three different supervised classification algorithms. Results prove that HSI is a suitable technique to automatically detect high-grade tumors from pathological slides. PMID:29552415

Detecting brain tumor in pathological slides using hyperspectral imaging.

PubMed

Ortega, Samuel; Fabelo, Himar; Camacho, Rafael; de la Luz Plaza, María; Callicó, Gustavo M; Sarmiento, Roberto

2018-02-01

Hyperspectral imaging (HSI) is an emerging technology for medical diagnosis. This research work presents a proof-of-concept on the use of HSI data to automatically detect human brain tumor tissue in pathological slides. The samples, consisting of hyperspectral cubes collected from 400 nm to 1000 nm, were acquired from ten different patients diagnosed with high-grade glioma. Based on the diagnosis provided by pathologists, a spectral library of normal and tumor tissues was created and processed using three different supervised classification algorithms. Results prove that HSI is a suitable technique to automatically detect high-grade tumors from pathological slides.

White matter segmentation by estimating tissue optical attenuation from volumetric OCT massive histology of whole rodent brains

NASA Astrophysics Data System (ADS)

Lefebvre, Joël.; Castonguay, Alexandre; Lesage, Frédéric

2017-02-01

A whole rodent brain was imaged using an automated massive histology setup and an Optical Coherence Tomography (OCT) microscope. Thousands of OCT volumetric tiles were acquired, each covering a size of about 2.5x2.5x0.8 mm3 with a sampling resolution of 4.9x4.9x6.5 microns. This paper shows the techniques for reconstruction, attenuation compensation and segmentation of the sliced brains. The tile positions within the mosaic were evaluated using a displacement model of the motorized stage and pairwise coregistration. Volume blending was then performed by solving the 3D Laplace equation, and consecutive slices were assembled using the cross-correlation of their 2D image gradient. This reconstruction algorithm resulted in a 3D map of optical reflectivity for the whole brain at micrometric resolution. OCT tissue slices were then used to estimate the local attenuation coefficient based on a single scattering photon model. The attenuation map obtained exhibits a high contrast for all white matter fibres, regardless of their orientation. The tissue optical attenuation from the intrinsic OCT reflectivity contributes to better white matter tissue segmentation. The combined 3D maps of reflectivity and attenuation is a step toward the study of white matter at a microscopic scale for the whole brain in small animals.

Evaluation of biomolecular distributions in rat brain tissues by means of ToF-SIMS using a continuous beam of Ar clusters.

PubMed

Nakano, Shusuke; Yokoyama, Yuta; Aoyagi, Satoka; Himi, Naoyuki; Fletcher, John S; Lockyer, Nicholas P; Henderson, Alex; Vickerman, John C

2016-06-08

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides detailed chemical structure information and high spatial resolution images. Therefore, ToF-SIMS is useful for studying biological phenomena such as ischemia. In this study, in order to evaluate cerebral microinfarction, the distribution of biomolecules generated by ischemia was measured with ToF-SIMS. ToF-SIMS data sets were analyzed by means of multivariate analysis for interpreting complex samples containing unknown information and to obtain biomolecular mapping indicated by fragment ions from the target biomolecules. Using conventional ToF-SIMS (primary ion source: Bi cluster ion), it is difficult to detect secondary ions beyond approximately 1000 u. Moreover, the intensity of secondary ions related to biomolecules is not always high enough for imaging because of low concentration even if the masses are lower than 1000 u. However, for the observation of biomolecular distributions in tissues, it is important to detect low amounts of biological molecules from a particular area of tissue. Rat brain tissue samples were measured with ToF-SIMS (J105, Ionoptika, Ltd., Chandlers Ford, UK), using a continuous beam of Ar clusters as a primary ion source. ToF-SIMS with Ar clusters efficiently detects secondary ions related to biomolecules and larger molecules. Molecules detected by ToF-SIMS were examined by analyzing ToF-SIMS data using multivariate analysis. Microspheres (45 μm diameter) were injected into the rat unilateral internal carotid artery (MS rat) to cause cerebral microinfarction. The rat brain was sliced and then measured with ToF-SIMS. The brain samples of a normal rat and the MS rat were examined to find specific secondary ions related to important biomolecules, and then the difference between them was investigated. Finally, specific secondary ions were found around vessels incorporating microspheres in the MS rat. The results suggest that important biomolecules related to cerebral microinfarction can be detected by ToF-SIMS.

Comparison of seven optical clearing methods for mouse brain

NASA Astrophysics Data System (ADS)

Wan, Peng; Zhu, Jingtan; Yu, Tingting; Zhu, Dan

2018-02-01

Recently, a variety of tissue optical clearing techniques have been developed to reduce light scattering for imaging deeper and three-dimensional reconstruction of tissue structures. Combined with optical imaging techniques and diverse labeling methods, these clearing methods have significantly promoted the development of neuroscience. However, most of the protocols were proposed aiming for specific tissue type. Though there are some comparison results, the clearing methods covered are limited and the evaluation indices are lack of uniformity, which made it difficult to select a best-fit protocol for clearing in practical applications. Hence, it is necessary to systematically assess and compare these clearing methods. In this work, we evaluated the performance of seven typical clearing methods, including 3DISCO, uDISCO, SeeDB, ScaleS, ClearT2, CUBIC and PACT, on mouse brain samples. First, we compared the clearing capability on both brain slices and whole-brains by observing brain transparency. Further, we evaluated the fluorescence preservation and the increase of imaging depth. The results showed that 3DISCO, uDISCO and PACT posed excellent clearing capability on mouse brains, ScaleS and SeeDB rendered moderate transparency, while ClearT2 was the worst. Among those methods, ScaleS was the best on fluorescence preservation, and PACT achieved the highest increase of imaging depth. This study is expected to provide important reference for users in choosing most suitable brain optical clearing method.

Development of a new method for the determination of residues of the neonictinoid insecticide imidacloprid in juvenile Chinook (Oncorhynchus tyshawytscha) using ELISA detection

USGS Publications Warehouse

Frew, John A.; Grue, Christian E.

2012-01-01

The neonicotinoid insecticide imidacloprid (IMI) has been proposed as an alternative to carbaryl for controlling indigenous burrowing shrimp on commercial oyster beds in Willapa Bay and Grays Harbor, Washington. A focus of concern over the use of this insecticide in an aquatic environment is the potential for adverse effects from exposure to non-target species residing in the Bay, such as juvenile Chinook (Oncorhynchus tshawytscha) and cutthroat trout (O. clarki). Federal registration and State permiting approval for the use of IMI will require confirmation that the compound does not adversely impact these salmonids following field applications. This will necessitate an environmental monitoring program for evaluating exposure in salmonids following the treatment of beds. Quantification of IMI residues in tissue can be used for determining salmonid exposure to the insecticide. Refinement of an existing protocol using liquid-chromatography mass spectrometry (LC-MS) detection would provide the low limits of quantification, given the relatively small tissue sample sizes, necessary for determining exposure in individual fish. Such an approach would not be viable for the environmental monitoring effort in Willapa Bay and Grays Harbor due to the high costs associated with running multiple analyses, however. A new sample preparation protocol was developed for use with a commercially available enzyme-linked immunosorbent assay (ELISA) for the quantification of IMI, thereby providing a low-cost alternative to LC-MS for environmental monitoring in Willapa Bay and Grays Harbor. Extraction of the analyte from the salmonid brain tissue was achieved by Dounce homogenization in 4.0 mL of 20.0 mM Triton X-100, followed by a 6 h incubation at 50–55 °C. Centrifugal ultrafiltration and reversed phase solid phase extraction were used for sample cleanup. The limit of quantification for an average 77.0 mg whole brain sample was calculated at 18.2 μg kg-1 (ppb) with an average recovery of 79%. This relatively low limit of quantification allows for the analysis of individual fish. Using controlled laboratory studies, a curvelinear relationship was found between the measured IMI residue concentrations in brain tissue and exposure concentrations in seawater. Additonally, a range of IMI brain residue concentrations was associated with an overt effect; illustrating the utility of the IMI tissue residue quantification approach for linking exposure with defined effects.

Selection of internal reference genes for normalization of quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis in the canine brain and other organs.

PubMed

Park, Sang-Je; Huh, Jae-Won; Kim, Young-Hyun; Lee, Sang-Rae; Kim, Sang-Hyun; Kim, Sun-Uk; Kim, Heui-Soo; Kim, Min Kyu; Chang, Kyu-Tae

2013-05-01

Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is a specific and sensitive technique for quantifying gene expression. To analyze qRT-PCR data accurately, suitable reference genes that show consistent expression patterns across different tissues and experimental conditions should be selected. The objective of this study was to obtain the most stable reference genes in dogs, using samples from 13 different brain tissues and 10 other organs. 16 well-known candidate reference genes were analyzed by the geNorm, NormFinder, and BestKeeper programs. Brain tissues were derived from several different anatomical regions, including the forebrain, cerebrum, diencephalon, hindbrain, and metencephalon, and grouped accordingly. Combination of the three different analyses clearly indicated that the ideal reference genes are ribosomal protien S5 (RPS5) in whole brain, RPL8 and RPS5 in whole body tissues, RPS5 and RPS19 in the forebrain and cerebrum, RPL32 and RPS19 in the diencephalon, GAPDH and RPS19 in the hindbrain, and MRPS7 and RPL13A in the metencephalon. These genes were identified as ideal for the normalization of qRT-PCR results in the respective tissues. These findings indicate more suitable and stable reference genes for future studies of canine gene expression.

Congenital toxoplasmosis: continued parasite proliferation in the fetal brain despite maternal immunological control in other tissues.

PubMed

Ferguson, David J P; Bowker, Colene; Jeffery, Katie J M; Chamberlain, Paul; Squier, Waney

2013-01-01

Congenital toxoplasmosis is a serious condition but little is known of the natural history of parasite development and associated fetal tissue destruction. Two cases identified by ultrasound underwent induced abortion at 21 and 30 weeks' gestation. At autopsy, the placenta and fetal organs were examined by histology and immunocytochemistry employing anti-Toxoplasma stage-specific antibodies to confirm diagnosis and also provide information on the stage of parasite development. In both cases, maternal serology prior to termination showed both specific immunoglobulin M (IgM) and immunoglobulin G (IgG), whereas retrospective analysis of an earlier sample (12-14 weeks' gestation) showed only IgM reactivity consistent with infection occurring in the first trimester. The finding of a number of tissue cysts but few or no tachyzoites within the placenta and fetal adrenal and heart is characteristic of a chronic infection. However, in contrast, there were still areas of the fetal brain with large numbers of actively dividing, tissue-destructive tachyzoites. These observations show that continued parasite proliferation and tissue destruction can occur within the fetal brain even when there is a marked maternal immune response including maternal IgG. This finding strongly suggests that there may be benefits from treating cases of recently acquired congenital infection to destroy any remaining proliferating parasites located in immunologically protected sites such as the fetal brain.

Dysbindin-1 and NRG-1 gene expression in immortalized lymphocytes from patients with schizophrenia.

PubMed

Yamamori, Hidenaga; Hashimoto, Ryota; Verrall, Louise; Yasuda, Yuka; Ohi, Kazutaka; Fukumoto, Motoyuki; Umeda-Yano, Satomi; Ito, Akira; Takeda, Masatoshi

2011-07-01

The dysbindin-1 and neuregulin-1 (NRG-1) genes are related to schizophrenia. Expression studies in postmortem brains have revealed lower expression of dysbindin-1 and higher expression of NRG-1 in brain tissue from subjects with schizophrenia. In addition to the difficulty of sampling, the use of postmortem brain tissues is not ideal because these tissues are heterogeneous with respect to biochemical parameters, lifetime history of medications and physiological status at the time of death. In contrast, medication and environmental influences that could mask the genetic basis of differences in RNA expression are removed in immortalized lymphocytes by culturing. Only a few microarray analysis studies using immortalized lymphocytes in schizophrenia have been reported, and whether immortalized lymphocytes are an appropriate alternative to neuronal tissue remains controversial. In this study, we measured the mRNA expression levels of dysbindin-1, NRG-1 and two other genes (NPY1R and GNAO1) in immortalized lymphocytes from 45 patients with schizophrenia and 45 controls using real-time quantitative reverse transcriptase-PCR. No difference was observed between patients and controls with respect to the expression of dysbindin-1, NRG-1, NPY1R or GNAO1 gene. Our findings suggest that the gene expression profile of immortalized lymphocyte from schizophrenic patients is different from that in postmortem brain tissue at least with respect to the dysbindin-1 and NRG-1 genes.

Structural and molecular interrogation of intact biological systems

PubMed Central

Chung, Kwanghun; Wallace, Jenelle; Kim, Sung-Yon; Kalyanasundaram, Sandhiya; Andalman, Aaron S.; Davidson, Thomas J.; Mirzabekov, Julie J.; Zalocusky, Kelly A.; Mattis, Joanna; Denisin, Aleksandra K.; Pak, Sally; Bernstein, Hannah; Ramakrishnan, Charu; Grosenick, Logan; Gradinaru, Viviana; Deisseroth, Karl

2014-01-01

Obtaining high-resolution information from a complex system, while maintaining the global perspective needed to understand system function, represents a key challenge in biology. Here we address this challenge with a method (termed CLARITY) for the transformation of intact tissue into a nanoporous hydrogel-hybridized form (crosslinked to a three-dimensional network of hydrophilic polymers) that is fully assembled but optically transparent and macromolecule-permeable. Using mouse brains, we show intact-tissue imaging of long-range projections, local circuit wiring, cellular relationships, subcellular structures, protein complexes, nucleic acids and neurotransmitters. CLARITY also enables intact-tissue in situ hybridization, immunohistochemistry with multiple rounds of staining and de-staining in non-sectioned tissue, and antibody labelling throughout the intact adult mouse brain. Finally, we show that CLARITY enables fine structural analysis of clinical samples, including non-sectioned human tissue from a neuropsychiatric-disease setting, establishing a path for the transmutation of human tissue into a stable, intact and accessible form suitable for probing structural and molecular underpinnings of physiological function and disease. PMID:23575631

MR-guided transcranial brain HIFU in small animal models

PubMed Central

Larrat, Benoît; Pernot, Mathieu; Aubry, Jean-François; Dervishi, Elvis; Sinkus, Ralph; Seilhean, Danielle; Marie, Yannick; Boch, Anne-Laure; Fink, Mathias; Tanter, Mickaël

2010-01-01

Recent studies have demonstrated the feasibility of transcranial High Intensity Focused Ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes to provide an accurate targeting, monitoring and control of this emerging therapeutic modality in order to ensure the safety of the treatment and avoid potential damaging effects of ultrasound on healthy tissues. For these purposes, a complete workflow and setup for HIFU treatment under Magnetic Resonance (MR) guidance is proposed and implemented in rats. For the first time, tissue displacements induced by the acoustic radiation force are detected in vivo in brain tissues and measured quantitatively using motion-sensitive MR sequences. Such a valuable target control prior to treatment assesses the quality of the focusing pattern in situ and enables to estimate the acoustic intensity at focus. This MR-Acoustic radiation force imaging is then correlated with conventional MR-Thermometry sequences which are used to follow the temperature changes during the HIFU therapeutic session. Last, pre and post treatment Magnetic Resonance Elastography (MRE) datasets are acquired and evaluated as a new potential way to non invasively control the stiffness changes due to the presence of thermal necrosis. As a proof of concept, MRguided HIFU is performed in vitro in turkey breast samples and in vivo in transcranial rat brain experiments. The experiments are conducted using a dedicated MR compatible HIFU setup in a high field MRI scanner (7T). Results obtained on rats confirmed that both the MR localization of the US focal point and the pre and post HIFU measurement of the tissue stiffness, together with temperature control during HIFU are feasible and valuable techniques for an efficient monitoring of HIFU in the brain. Brain elasticity appears to be more sensitive to the presence of oedema than to tissue necrosis. PMID:20019400

Macro- and microelements in the rat liver, kidneys, and brain tissues; sex differences and effect of blood removal by perfusion in vivo.

PubMed

Orct, Tatjana; Jurasović, Jasna; Micek, Vedran; Karaica, Dean; Sabolić, Ivan

2017-03-01

Concentrations of macro- and microelements in animal organs indicate the animal health status and represent reference data for animal experiments. Their levels in blood and tissues could be different between sexes, and could be different with and without blood in tissues. To test these hypotheses, in adult female and male rats the concentrations of various elements were measured in whole blood, blood plasma, and tissues from blood-containing (nonperfused) and blood-free liver, kidneys, and brain (perfused in vivo with an elements-free buffer). In these samples, 6 macroelements (Na, Mg, P, S, K, Ca) and 14 microelements (Fe, Mn, Co, Cu, Zn, Se, I, As, Cd, Hg, Pb, Li, B, Sr) were determined by inductively coupled plasma mass spectrometry following nitric acid digestion. In blood and plasma, female- or male-dominant sex differences were observed for 6 and 5 elements, respectively. In nonperfused organs, sex differences were observed for 3 (liver, brain) or 9 (kidneys) elements, whereas in perfused organs, similar differences were detected for 9 elements in the liver, 5 in the kidneys, and none in the brain. In females, perfused organs had significantly lower concentrations of 4, 5, and 2, and higher concentrations of 10, 4, and 7 elements, respectively, in the liver, kidneys, and brain. In males, perfusion caused lower concentrations of 4, 7, and 2, and higher concentrations of 1, 1, and 7 elements, respectively, in the liver, kidneys, and brain. Therefore, the residual blood in organs can significantly influence tissue concentrations of various elements and their sex-dependency. Copyright © 2017 Elsevier GmbH. All rights reserved.

Contaminants of legacy and emerging concern in largescale suckers (Catostomus macrocheilus) and the foodweb in the lower Columbia River, Oregon and Washington, USA.

PubMed

Nilsen, Elena; Zaugg, Steven; Alvarez, David; Morace, Jennifer; Waite, Ian; Counihan, Timothy; Hardiman, Jill; Torres, Leticia; Patiño, Reynaldo; Mesa, Matthew; Grove, Robert

2014-06-15

We investigated occurrence, transport pathways, and effects of polybrominated diphenyl ether (PBDE) flame retardants and other endocrine disrupting chemicals (EDCs) in aquatic media and the foodweb in the lower Columbia River. In 2009 and 2010, foodweb sampling at three sites along a gradient of contaminant exposure near Skamania (Washington), Columbia City (Oregon) and Longview (Washington) included water (via passive samplers), bed sediment, invertebrate biomass residing in sediment, a resident fish species (largescale suckers [Catostomus macrocheilus]), and eggs from osprey (Pandion haliaetus). This paper primarily reports fish tissue concentrations. In 2009, composites of fish brain, fillet, liver, stomach, and gonad tissues revealed that overall contaminant concentrations were highest in livers, followed by brain, stomach, gonad, and fillet. Concentrations of halogenated compounds in tissue samples from all three sites ranged from <1 to 400nanograms per gram of wet tissue. Several chemical classes, including PBDEs, organochlorine pesticides, and polychlorinated biphenyls (PCBs), were detected at all sites and in nearly all fish tissues sampled. In 2010, only fish livers were sampled and inter-site concentration differences were not as pronounced as in 2009. Chemical concentrations in sediments, fish tissues, and osprey eggs increased moving downstream from Skamania to the urbanized sites near Columbia City and Longview. Numerous organochlorine (OC) pesticides, both banned and currently used, and PBDEs, were present at each site in multiple media and concentrations exceeded environmental quality benchmarks in some cases. Frequently detected OC compounds included hexachlorobenzene, pentachloroanisole, dichlorodiphenyltrichloroethane (DDT) and its degradates, chlorpyrifos, and oxyfluorofen. Biomagnification of BDE47, 100, 153, and 154 occurred in largescale suckers and osprey eggs. Results support the hypothesis that contaminants in the environment lead to bioaccumulation and potential negative effects in multiple levels of the foodweb. Published by Elsevier B.V.

Contaminants of legacy and emerging concern in largescale suckers (Catostomus macrocheilus) and the foodweb in the lower Columbia River, Oregon and Washington, USA

USGS Publications Warehouse

Nilsen, Elena B.; Zaugg, Steven D.; Alvarez, David A.; Morace, Jennifer L.; Waite, Ian R.; Counihan, Timothy D.; Hardiman, Jill M.; Torres, Leticia; Patino, Reynaldo; Mesa, Matthew G.; Grove, Robert

2014-01-01

We investigated occurrence, transport pathways, and effects of polybrominated diphenyl ether (PBDE) flame retardants and other endocrine disrupting chemicals (EDCs) in aquatic media and the foodweb in the lower Columbia River. In 2009 and 2010, foodweb sampling at three sites along a gradient of contaminant exposure near Skamania (Washington), Columbia City (Oregon) and Longview (Washington) included water (via passive samplers), bed sediment, invertebrate biomass residing in sediment, a resident fish species (largescale suckers [Catostomus macrocheilus]), and eggs from osprey (Pandion haliaetus). This paper primarily reports fish tissue concentrations. In 2009, composites of fish brain, fillet, liver, stomach, and gonad tissues revealed that overall contaminant concentrations were highest in livers, followed by brain, stomach, gonad, and fillet. Concentrations of halogenated compounds in tissue samples from all three sites ranged from < 1 to 400 nanograms per gram of wet tissue. Several chemical classes, including PBDEs, organochlorine pesticides, and polychlorinated biphenyls (PCBs), were detected at all sites and in nearly all fish tissues sampled. In 2010, only fish livers were sampled and inter-site concentration differences were not as pronounced as in 2009. Chemical concentrations in sediments, fish tissues, and osprey eggs increased moving downstream from Skamania to the urbanized sites near Columbia City and Longview. Numerous organochlorine (OC) pesticides, both banned and currently used, and PBDEs, were present at each site in multiple media and concentrations exceeded environmental quality benchmarks in some cases. Frequently detected OC compounds included hexachlorobenzene, pentachloroanisole, dichlorodiphenyltrichloroethane (DDT) and its degradates, chlorpyrifos, and oxyfluorofen. Biomagnification of BDE47, 100, 153, and 154 occurred in largescale suckers and osprey eggs. Results support the hypothesis that contaminants in the environment lead to bioaccumulation and potential negative effects in multiple levels of the foodweb.

Comparison of various primer sets for detection of Toxoplasma gondii by polymerase chain reaction in fetal tissues from naturally aborted foxes.

PubMed

Smielewska-Loś, E

2003-01-01

Tissues from 4 aborted polar foxes (3 samples of brain and 4 samples of liver) were selected for Toxoplasma gondii PCR assay. Positive results of serological tests of mothers and immunofluorescence test (IFT) of fetal organ smears were the criteria of sample selection. Five sets of primers designed from B1 gene and ITS1 sequences of T. gondii were used for detection of the parasite in fetal fox tissues. All used primer sets successfully amplified T. gondii DNA in PCR from organs which were positive by IFT. Single tube nested PCR also showed positive result from a sample negative by IFT, but this product was not confirmed. The studies showed usefullness of PCR for routine diagnosis of toxoplasmosis in carnivores.

Evaluation of ultrasound techniques for brain injury detection

NASA Astrophysics Data System (ADS)

Mobley, Joel; Kasili, Paul M.; Norton, Stephen J.; Vo-Dinh, Tuan

1998-05-01

In this work, we examine the physics underlying wave propagation in the head to evaluate various ultrasonic transducers for use in a brian injury detection device. The results of measurements of the attenuation coefficient and phase velocity for ultrasonic propagation in samples of brain tissue and skull bone from sheep are presented. The material properties are then used to investigate the propagation of ultrasonic pressure fields in the head. The ultrasound fields for three different transducers are calculated for propagation in a simulated brain/skull model. The model is constructed using speed-of-sound and mass density values of the two tissue types. The impact of the attenuation on the ultrasound fields is then examined. Finally, the relevant points drawn from these discussions are summarized. We hope to minimize the confounding effects of the skull by using sub-MHz ultrasound while maintaining the necessary temporal and spatial resolution to successfully detect injury in the brain.

The effect of piracetam on brain damage and serum nitric oxide levels in dogs submitted to hemorrhagic shock.

PubMed

Ozkan, Seda; Ikizceli, Ibrahim; Sözüer, Erdoğan Mütevelli; Avşaroğullari, Levent; Oztürk, Figen; Muhtaroğlu, Sebahattin; Akdur, Okhan; Küçük, Can; Durukan, Polat

2008-10-01

To demonstrate the effect of piracetam on changes in brain tissue and serum nitric oxide levels in dogs submitted to hemorrhagic shock. The subjects were randomized into four subgroups each consisting of 10 dogs. Hemorrhagic shock was induced in Group I for 1 hour and no treatment was given to this group. Blood and saline solutions were administered to Group II following 1 hour hemorrhagic shock. Blood and piracetam were given to Group III following 1 hour shock. No shock was induced and no treatment was applied to Group IV. Blood samples were obtained at the onset of the experiment and at 60, 120 and 180 minutes for nitric oxide analysis. For histopathological examination, brain tissue samples were obtained at the end of the experiment. The observed improvement in blood pressure and pulse rates in Group III was more than in Group II. Nitric oxide levels were increased in Group I; however, no correlation between piracetam and nitric oxide levels was determined. It was seen that recovery in brain damage in Group III was greater than in the control group. Piracetam, added to the treatment, may ecrease ischemic damage in hemorrhagic shock.

TH-CD-206-01: Expectation-Maximization Algorithm-Based Tissue Mixture Quantification for Perfusion MRI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, H; Xing, L; Liang, Z

Purpose: To investigate the feasibility of estimating the tissue mixture perfusions and quantifying cerebral blood flow change in arterial spin labeled (ASL) perfusion MR images. Methods: The proposed perfusion MR image analysis framework consists of 5 steps: (1) Inhomogeneity correction was performed on the T1- and T2-weighted images, which are available for each studied perfusion MR dataset. (2) We used the publicly available FSL toolbox to strip off the non-brain structures from the T1- and T2-weighted MR images. (3) We applied a multi-spectral tissue-mixture segmentation algorithm on both T1- and T2-structural MR images to roughly estimate the fraction of eachmore » tissue type - white matter, grey matter and cerebral spinal fluid inside each image voxel. (4) The distributions of the three tissue types or tissue mixture across the structural image array are down-sampled and mapped onto the ASL voxel array via a co-registration operation. (5) The presented 4-dimensional expectation-maximization (4D-EM) algorithm takes the down-sampled three tissue type distributions on perfusion image data to generate the perfusion mean, variance and percentage images for each tissue type of interest. Results: Experimental results on three volunteer datasets demonstrated that the multi-spectral tissue-mixture segmentation algorithm was effective to initialize tissue mixtures from T1- and T2-weighted MR images. Compared with the conventional ASL image processing toolbox, the proposed 4D-EM algorithm not only generated comparable perfusion mean images, but also produced perfusion variance and percentage images, which the ASL toolbox cannot obtain. It is observed that the perfusion contribution percentages may not be the same as the corresponding tissue mixture volume fractions estimated in the structural images. Conclusion: A specific application to brain ASL images showed that the presented perfusion image analysis method is promising for detecting subtle changes in tissue perfusions, which is valuable for the early diagnosis of certain brain diseases, e.g. multiple sclerosis.« less

The value of intraoperative ultrasonography during the resection of relapsed irradiated malignant gliomas in the brain.

PubMed

Mursch, Kay; Scholz, Martin; Brück, Wolfgang; Behnke-Mursch, Julianne

2017-01-01

The aim of this study was to investigate whether intraoperative ultrasonography (IOUS) helped the surgeon navigate towards the tumor as seen in preoperative magnetic resonance imaging and whether IOUS was able to distinguish between tumor margins and the surrounding tissue. Twenty-five patients suffering from high-grade gliomas who were previously treated by surgery and radiotherapy were included. Intraoperatively, two histopathologic samples were obtained a sample of unequivocal tumor tissue (according to anatomical landmarks and the surgeon's visual and tactile impressions) and a small tissue sample obtained using a navigated needle when the surgeon decided to stop the resection. This specimen was considered to be a boundary specimen, where no tumor tissue was apparent. The decision to take the second sample was not influenced by IOUS. The effect of IOUS was analyzed semi-quantitatively. All 25 samples of unequivocal tumor tissue were histopathologically classified as tumor tissue and were hyperechoic on IOUS. Of the boundary specimens, eight were hypoechoic. Only one harbored tumor tissue (P=0.150). Seventeen boundaries were moderately hyperechoic, and these samples contained all possible histological results (i.e., tumor, infiltration, or no tumor). During surgery performed on relapsed, irradiated, high-grade gliomas, IOUS provided a reliable method of navigating towards the core of the tumor. At borders, it did not reliably distinguish between remnants or tumor-free tissue, but hypoechoic areas seldom contained tumor tissue.

Do anesthetics and sampling strategies affect transcription analysis of fish tissues?

PubMed Central

Olsvik, Pål A; Lie, Kai K; Hevrøy, Ernst M

2007-01-01

Background The aim of the current examination was to evaluate if sedation and anesthetic treatment techniques affect the quality of RNA extracted from liver, gill, head kidney and brain tissues in Atlantic salmon Salmo salar L. Blood parameters were measured and tissue specimens sampled in six groups of fish; one control group (0 minutes), two groups kept in pure seawater in 90 liter tanks for 30 and 120 minutes, two groups treated with the anesthetic isoeugenol for 30 and 120 minutes, and one group kept in pure seawater for 105 minutes and then anaesthetized with metacaine for 15 minutes. RNA quality was assessed with the NanoDrop ND-1000 spectrophotometer (260/280 and 260/230 nm ratios) and with the Agilent Bioanalyzer (28S/18S ratio and RIN data) in samples either preserved in liquefied nitrogen (N2) or in RNAlater. In addition, the transcriptional levels of two fast-responding genes were quantified in gill and brain tissues. Results The results show that physiological stress during sampling does not affect the quality of RNA extracted from fish specimens. However, prolonged sedation (2 hours) resulted in a metabolic alkalosis that again affected the transcriptional levels of genes involved in ionoregulation and respiration. In gills, Na+-K+-ATPase α1b was significantly downregulated and hypoxia inducible factor 1 (HIF1) significantly upregulated after two hours of treatment with isoeugenol, suggesting that this commonly used sedative affects osmo-regulation and respiration in the fish. The results also suggest that for tissue preservation in general it is better to flash-freeze fish specimens in liquefied N2 than to use RNAlater. Conclusion Prolonged sedation may affect the transcription of fast-responding genes in tissues of fish. Two hours of sedation with isoeugenol resulted in downregulation of the Na+-K+-ATPase α1b gene and upregulation of the HIF1 gene in gills of Atlantic salmon. The quality of RNA extracted from tissue specimens, however, was not affected by sedation treatment. Flash-freezing of tissue specimens seems to be the preferred preservation technique, when sampling fish tissue specimens for RNA extraction. PMID:17559653

A new viewpoint: running a nonprofit brain bank as a business.

PubMed

Rademaker, Sonja H M; Huitinga, Inge

2018-01-01

It has become clear over the past decades that studying postmortem human brain tissue is one of the most effective ways to increase our knowledge of the pathogenesis and etiology of neuropathologic and psychiatric diseases. Many breakthroughs in neuroscience have depended on the availability of human brain tissue. However, the process of brain banking presents many different challenges, including the high cost that is associated with collecting the samples and with providing the diagnostics, storage, and distribution. Funding is generally from research and facility grants and donations but all are irregular, uncertain, and only cover the costs for a determined period of time. For professional brain banks with extensive prospective donor programs and that are open-access it can be very beneficial to draft a business plan to achieve long-term sustainability. Such a business plan should identify the interests of the stakeholders and address the implementation of cost efficiency and cost recovery systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of pregnancy on the solubility of halogenated volatile anaesthetics in rat blood and tissues.

PubMed

Rao, Y; Wang, Y L; Li, H; Zhang, W; Liu, J

2008-11-01

This study was designed to evaluate the effects of pregnancy on the solubility of halogenated volatile anaesthetics in rat blood and tissues. Tissue samples from 10 pregnant and 10 non-pregnant adult female Sprague Dawley rats, including the heart, liver, kidney and brain, were obtained and made into respective homogenates. Blood/gas and tissue/gas partition coefficients for halothane, sevoflurane and isoflurane were determined by the method of two-stage headspace equilibration by gas chromatography with each of the homogenates. Values were analysed by t-test or one-way analysis of variance. The solubility within blood and brain for halothane in the pregnant group (2.90 +/- 0.44, 5.55 +/- 0.73) was significantly lower than that of the non-pregnant group (3.42 +/- 023, 6.33 +/- 0.64; P < 0.05). However, there were no significant differences between the two groups for liver, kidney or heart solubility. For sevoflurane and isoflurane, there were no significant differences in solubility between the two groups. In conclusion, pregnancy decreased the solubility of halothane within the blood and brain, whereas the solubility of halothane in other tissues including the liver, kidney and heart showed no significant alteration. Pregnancy did not affect the solubility ofsevoflurane or isoflurane within blood or the other tissues studied.

Borate-aided anion exchange high-performance liquid chromatography of uridine diphosphate-sugars in brain, heart, adipose and liver tissues.

PubMed

Oikari, Sanna; Venäläinen, Tuula; Tammi, Markku

2014-01-03

In this paper we describe a method optimized for the purification of uridine diphosphate (UDP)-sugars from liver, adipose tissue, brain, and heart, with highly reproducible up to 85% recoveries. Rapid tissue homogenization in cold ethanol, lipid removal by butanol extraction, and purification with a graphitized carbon column resulted in isolation of picomolar quantities of the UDP-sugars from 10 to 30mg of tissue. The UDP-sugars were baseline separated from each other, and from all major nucleotides using a CarboPac PA1 anion exchange column eluted with a gradient of acetate and borate buffers. The extraction and purification protocol produced samples with few unidentified peaks. UDP-N-acetylglucosamine was a dominant UDP-sugar in all the rat tissues studied. However, brain and adipose tissue showed high UDP-glucose levels, equal to that of UDP-N-acetylglucosamine. The UDP-N-acetylglucosamine showed 2.3-2.7 times higher levels than UDP-N-acetylgalactosamine in all tissues, and about the same ratio was found between UDP-glucose and UDP-galactose in adipose tissue and brain (2.6 and 2.8, respectively). Interestingly, the UDP-glucose/UDP-galactose ratio was markedly lower in liver (1.1) and heart (1.7). The UDP-N-acetylglucosamine/UDP-glucuronic acid ratio was also constant, between 9.7 and 7.7, except in liver with the ratio as low as 1.8. The distinct UDP-glucose/galactose ratio, and the abundance of UDP-glucuronic acid may reflect the specific role of liver in glycogen synthesis, and metabolism of hormones and xenobiotics, respectively, using these UDP-sugars as substrates. Copyright © 2013 Elsevier B.V. All rights reserved.

HPLC/UV quantitation of retinal, retinol, and retinyl esters in serum and tissues

PubMed Central

Kane, Maureen A.; Folias, Alexandra E.; Napoli, Joseph L.

2008-01-01

We report robust HPLC/UV methods for quantifying retinyl esters (RE), retinol (ROL) and retinal (RAL) applicable to diverse biological samples, with lower limits of detection of 0.7 pmol, 0.2 pmol, and 0.2 pmol, respectively, and linear ranges >3 orders of magnitude. These assays function well with small, complex biological samples (10–20 mg tissue). Coefficients of variation range from: intra-day, 5.9–10.0%; inter-day, 5.9–11.0%. Quantification of endogenous RE, ROL, and RAL in mouse serum and tissues (liver, kidney, adipose, muscle, spleen, testis, skin, brain, and brain regions) reveals utility. Ability to discriminate spatial concentrations of ROL and RE is illustrated with C57BL/6 mouse brain loci (hippocampus, cortex, olfactory bulb, thalamus, cerebellum, and striatum.) We also developed a method to distinguish isomeric forms of ROL to investigate precursors of retinoic acid. The ROL isomer assay has limits of detection between 3.5–4.5 pmol and a similar linear range and % CV as the ROL/RE and RAL assays. The assays described here provide for sensitive and rigorous quantification of endogenous RE, ROL, and RAL to elucidate retinoid homeostasis in disease states, such as Alzheimer’s disease, type 2 diabetes, obesity, and cancer. PMID:18410739

Brain volumetric changes and cognitive ageing during the eighth decade of life

PubMed Central

Dickie, David Alexander; Cox, Simon R.; Valdes Hernandez, Maria del C.; Corley, Janie; Royle, Natalie A.; Pattie, Alison; Aribisala, Benjamin S.; Redmond, Paul; Muñoz Maniega, Susana; Taylor, Adele M.; Sibbett, Ruth; Gow, Alan J.; Starr, John M.; Bastin, Mark E.; Wardlaw, Joanna M.; Deary, Ian J.

2015-01-01

Abstract Later‐life changes in brain tissue volumes—decreases in the volume of healthy grey and white matter and increases in the volume of white matter hyperintensities (WMH)—are strong candidates to explain some of the variation in ageing‐related cognitive decline. We assessed fluid intelligence, memory, processing speed, and brain volumes (from structural MRI) at mean age 73 years, and at mean age 76 in a narrow‐age sample of older individuals (n = 657 with brain volumetric data at the initial wave, n = 465 at follow‐up). We used latent variable modeling to extract error‐free cognitive levels and slopes. Initial levels of cognitive ability were predictive of subsequent brain tissue volume changes. Initial brain volumes were not predictive of subsequent cognitive changes. Brain volume changes, especially increases in WMH, were associated with declines in each of the cognitive abilities. All statistically significant results were modest in size (absolute r‐values ranged from 0.114 to 0.334). These results build a comprehensive picture of macrostructural brain volume changes and declines in important cognitive faculties during the eighth decade of life. Hum Brain Mapp 36:4910–4925, 2015. © 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc PMID:26769551

Development of stereotactic mass spectrometry for brain tumor surgery.

PubMed

Agar, Nathalie Y R; Golby, Alexandra J; Ligon, Keith L; Norton, Isaiah; Mohan, Vandana; Wiseman, Justin M; Tannenbaum, Allen; Jolesz, Ferenc A

2011-02-01

Surgery remains the first and most important treatment modality for the majority of solid tumors. Across a range of brain tumor types and grades, postoperative residual tumor has a great impact on prognosis. The principal challenge and objective of neurosurgical intervention is therefore to maximize tumor resection while minimizing the potential for neurological deficit by preserving critical tissue. To introduce the integration of desorption electrospray ionization mass spectrometry into surgery for in vivo molecular tissue characterization and intraoperative definition of tumor boundaries without systemic injection of contrast agents. Using a frameless stereotactic sampling approach and by integrating a 3-dimensional navigation system with an ultrasonic surgical probe, we obtained image-registered surgical specimens. The samples were analyzed with ambient desorption/ionization mass spectrometry and validated against standard histopathology. This new approach will enable neurosurgeons to detect tumor infiltration of the normal brain intraoperatively with mass spectrometry and to obtain spatially resolved molecular tissue characterization without any exogenous agent and with high sensitivity and specificity. Proof of concept is presented in using mass spectrometry intraoperatively for real-time measurement of molecular structure and using that tissue characterization method to detect tumor boundaries. Multiple sampling sites within the tumor mass were defined for a patient with a recurrent left frontal oligodendroglioma, World Health Organization grade II with chromosome 1p/19q codeletion, and mass spectrometry data indicated a correlation between lipid constitution and tumor cell prevalence. The mass spectrometry measurements reflect a complex molecular structure and are integrated with frameless stereotaxy and imaging, providing 3-dimensional molecular imaging without systemic injection of any agents, which can be implemented for surgical margins delineation of any organ and with a rapidity that allows real-time analysis.

Genotyping of the Alzheimer's Disease Genome-Wide Association Study Index Single Nucleotide Polymorphisms in the Brains for Dementia Research Cohort.

PubMed

Brookes, Keeley J; McConnell, George; Williams, Kirsty; Chaudhury, Sultan; Madhan, Gaganjit; Patel, Tulsi; Turley, Christopher; Guetta-Baranes, Tamar; Bras, Jose; Guerreiro, Rita; Hardy, John; Francis, Paul T; Morgan, Kevin

2018-06-08

The Brains for Dementia Research project is a recently established longitudinal cohort which aims to provide brain tissue for research purposes from neuropathologically defined samples. Here we present the findings from our analysis on the 19 established GWAS index SNPs for Alzheimer's disease, in order to demonstrate if the BDR sample also displays association to these variants. A highly significant association of the APOEɛ4 allele was identified (p = 3.99×10-12). Association tests for the 19 GWAS SNPs found that although no SNPs survive multiple testing, nominal significant findings were detected and concordance with the Lambert et al. GWAS meta-analysis was observed.

Pilot Randomized Trial of Hydrocortisone in Ventilator-Dependent Extremely Preterm Infants: Effects on Regional Brain Volumes

PubMed Central

Parikh, Nehal A.; Kennedy, Kathleen A.; Lasky, Robert E.; McDavid, Georgia E.; Tyson, Jon E.

2012-01-01

Objective To test the hypothesis that high-risk ventilator-dependent extremely low birth weight (ELBW; BW ≤1000g) infants treated with seven days of hydrocortisone will have larger total brain tissue volumes than placebo treated infants. Study design A predetermined sample size of 64 ELBW infants, between 10 to 21 days old and ventilator-dependent with a respiratory index score ≥2, were randomized to systemic hydrocortisone (17 mg/kg cumulative dose) or saline placebo. Primary outcome was total brain tissue volume. Volumetric MRI was performed at 38 weeks postmenstrual age; brain tissue regions were segmented and quantified automatically with a high degree of accuracy and nine structures were segmented manually. All analyses of regional brain volumes were adjusted by postmenstrual age at MRI scan. Results The study groups were similar at baseline and eight infants died in each arm. Unadjusted total brain tissue volume (mean±SD) in the hydrocortisone (N=23) and placebo treated infants (N=21) was 272±40.3 cm3 and 277.8±59.1 cm3, respectively (adjusted mean difference: 6.35 cm3 (95% CI: (−20.8, 32.5); P=0.64). Three of the 31 hydrocortisone treated infants and five of the 33 placebo treated infants survived without severe BPD (RR 0.62, 95% CI: 0.13, 2.66; P=0.49). No significant differences were noted in pre-specified secondary outcomes of regional structural volumes or days on respiratory support. No adverse effects of hydrocortisone were observed. Conclusions Low dose hydrocortisone in high-risk ventilator-dependent infants after a week of age had no discernible effect on regional brain volumes or pulmonary outcomes prior to NICU discharge. PMID:23140612

Detection of somatic mutations in the mitochondrial DNA control region D-loop in brain tumors: The first report in Malaysian patients.

PubMed

Mohamed Yusoff, Abdul Aziz; Mohd Nasir, Khairol Naaim; Haris, Khalilah; Mohd Khair, Siti Zulaikha Nashwa; Abdul Ghani, Abdul Rahman Izaini; Idris, Zamzuri; Abdullah, Jafri Malin

2017-11-01

Although the role of nuclear-encoded gene alterations has been well documented in brain tumor development, the involvement of the mitochondrial genome in brain tumorigenesis has not yet been fully elucidated and remains controversial. The present study aimed to identify mutations in the mitochondrial DNA (mtDNA) control region D-loop in patients with brain tumors in Malaysia. A mutation analysis was performed in which DNA was extracted from paired tumor tissue and blood samples obtained from 49 patients with brain tumors. The D-loop region DNA was amplified using the PCR technique, and genetic data from DNA sequencing analyses were compared with the published revised Cambridge sequence to identify somatic mutations. Among the 49 brain tumor tissue samples evaluated, 25 cases (51%) had somatic mutations of the mtDNA D-loop, with a total of 48 mutations. Novel mutations that had not previously been identified in the D-loop region (176 A-deletion, 476 C>A, 566 C>A and 16405 A-deletion) were also classified. No significant associations between the D-loop mutation status and the clinicopathological parameters were observed. To the best of our knowledge, the current study presents the first evidence of alterations in the mtDNA D-loop regions in the brain tumors of Malaysian patients. These results may provide an overview and data regarding the incidence of mitochondrial genome alterations in Malaysian patients with brain tumors. In addition to nuclear genome aberrations, these specific mitochondrial genome alterations may also be considered as potential cancer biomarkers for the diagnosis and staging of brain cancers.

An evaluation of a reagentless method for the determination of total mercury in aquatic life

USGS Publications Warehouse

Haynes, Sekeenia; Gragg, Richard D.; Johnson, Elijah; Robinson, Larry; Orazio, Carl E.

2006-01-01

Multiple treatment (i.e., drying, chemical digestion, and oxidation) steps are often required during preparation of biological matrices for quantitative analysis of mercury; these multiple steps could potentially lead to systematic errors and poor recovery of the analyte. In this study, the Direct Mercury Analyzer (Milestone Inc., Monroe, CT) was utilized to measure total mercury in fish tissue by integrating steps of drying, sample combustion and gold sequestration with successive identification using atomic absorption spectrometry. We also evaluated the differences between the mercury concentrations found in samples that were homogenized and samples with no preparation. These results were confirmed with cold vapor atomic absorbance and fluorescence spectrometric methods of analysis. Finally, total mercury in wild captured largemouth bass (n = 20) were assessed using the Direct Mercury Analyzer to examine internal variability between mercury concentrations in muscle, liver and brain organs. Direct analysis of total mercury measured in muscle tissue was strongly correlated with muscle tissue that was homogenized before analysis (r = 0.81, p < 0.0001). Additionally, results using this integrated method compared favorably (p < 0.05) with conventional cold vapor spectrometry with atomic absorbance and fluorescence detection methods. Mercury concentrations in brain were significantly lower than concentrations in muscle (p < 0.001) and liver (p < 0.05) tissues. This integrated method can measure a wide range of mercury concentrations (0-500 ??g) using small sample sizes. Total mercury measurements in this study are comparative to the methods (cold vapor) commonly used for total mercury analysis and are devoid of laborious sample preparation and expensive hazardous waste. ?? Springer 2006.

Banking brain tissue for research.

PubMed

Klioueva, Natasja; Bovenberg, Jasper; Huitinga, Inge

2017-01-01

Well-characterized human brain tissue is crucial for scientific breakthroughs in research of the human brain and brain diseases. However, the collection, characterization, management, and accessibility of brain human tissue are rather complex. Well-characterized human brain tissue is often provided from private, sometimes small, brain tissue collections by (neuro)pathologic experts. However, to meet the increasing demand for human brain tissue from the scientific community, many professional brain-banking activities aiming at both neurologic and psychiatric diseases as well as healthy controls are currently being initiated worldwide. Professional biobanks are open-access and in many cases run donor programs. They are therefore costly and need effective business plans to guarantee long-term sustainability. Here we discuss the ethical, legal, managerial, and financial aspects of professional brain banks. Copyright © 2017 Elsevier B.V. All rights reserved.

Mathematical modeling of the malignancy of cancer using graph evolution.

PubMed

Gunduz-Demir, Cigdem

2007-10-01

We report a novel computational method based on graph evolution process to model the malignancy of brain cancer called glioma. In this work, we analyze the phases that a graph passes through during its evolution and demonstrate strong relation between the malignancy of cancer and the phase of its graph. From the photomicrographs of tissues, which are diagnosed as normal, low-grade cancerous and high-grade cancerous, we construct cell-graphs based on the locations of cells; we probabilistically generate an edge between every pair of cells depending on the Euclidean distance between them. For a cell-graph, we extract connectivity information including the properties of its connected components in order to analyze the phase of the cell-graph. Working with brain tissue samples surgically removed from 12 patients, we demonstrate that cell-graphs generated for different tissue types evolve differently and that they exhibit different phase properties, which distinguish a tissue type from another.

Simple Elimination of Background Fluorescence in Formalin-Fixed Human Brain Tissue for Immunofluorescence Microscopy.

PubMed

Sun, Yulong; Ip, Philbert; Chakrabartty, Avijit

2017-09-03

Immunofluorescence is a common method used to visualize subcellular compartments and to determine the localization of specific proteins within a tissue sample. A great hindrance to the acquisition of high quality immunofluorescence images is endogenous autofluorescence of the tissue caused by aging pigments such as lipofuscin or by common sample preparation processes such as aldehyde fixation. This protocol describes how background fluorescence can be greatly reduced through photobleaching using white phosphor light emitting diode (LED) arrays prior to treatment with fluorescent probes. The broad-spectrum emission of white phosphor LEDs allow for bleaching of fluorophores across a range of emission peaks. The photobleaching apparatus can be constructed from off-the-shelf components at very low cost and offers an accessible alternative to commercially available chemical quenchers. A photobleaching pre-treatment of the tissue followed by conventional immunofluorescence staining generates images free of background autofluorescence. Compared to established chemical quenchers which reduced probe as well as background signals, photobleaching treatment had no effect on probe fluorescence intensity while it effectively reduced background and lipofuscin fluorescence. Although photobleaching requires more time for pre-treatment, higher intensity LED arrays may be used to reduce photobleaching time. This simple method can potentially be applied to a variety of tissues, particularly postmitotic tissues that accumulate lipofuscin such as the brain and cardiac or skeletal muscles.

Development of a Plastic Embedding Method for Large-Volume and Fluorescent-Protein-Expressing Tissues

PubMed Central

Yang, Zhongqin; Hu, Bihe; Zhang, Yuhui; Luo, Qingming; Gong, Hui

2013-01-01

Fluorescent proteins serve as important biomarkers for visualizing both subcellular organelles in living cells and structural and functional details in large-volume tissues or organs. However, current techniques for plastic embedding are limited in their ability to preserve fluorescence while remaining suitable for micro-optical sectioning tomography of large-volume samples. In this study, we quantitatively evaluated the fluorescence preservation and penetration time of several commonly used resins in a Thy1-eYFP-H transgenic whole mouse brain, including glycol methacrylate (GMA), LR White, hydroxypropyl methacrylate (HPMA) and Unicryl. We found that HMPA embedding doubled the eYFP fluorescence intensity but required long durations of incubation for whole brain penetration. GMA, Unicryl and LR White each penetrated the brain rapidly but also led to variable quenching of eYFP fluorescence. Among the fast-penetrating resins, GMA preserved fluorescence better than LR White and Unicryl. We found that we could optimize the GMA formulation by reducing the polymerization temperature, removing 4-methoxyphenol and adjusting the pH of the resin solution to be alkaline. By optimizing the GMA formulation, we increased percentage of eYFP fluorescence preservation in GMA-embedded brains nearly two-fold. These results suggest that modified GMA is suitable for embedding large-volume tissues such as whole mouse brain and provide a novel approach for visualizing brain-wide networks. PMID:23577174

Clofibrate-induced changes in the liver, heart, brain and white adipose lipid metabolome of Swiss-Webster mice

PubMed Central

Wheelock, Craig E.; Goto, Susumu; Hammock, Bruce D.; Newman, John W.

2008-01-01

Peroxisome proliferator activated receptor alpha (PPARα) agonists are anti-hyperlipidemic drugs that influence fatty acid combustion, phospholipid biosynthesis and lipoprotein metabolism. To evaluate impacts on other aspects of lipid metabolism, we applied targeted metabolomics to liver, heart, brain and white adipose tissue samples from male Swiss-Webster mice exposed to a 5 day, 500 mg/kg/day regimen of i.p. clofibrate. Tissue concentrations of free fatty acids and the fatty acid content of sphingomyelin, cardiolipin, cholesterol esters, triglycerides and phospholipids were quantified. Responses were tissue-specific, with changes observed in the liver > heart ≫ brain > adipose. These results indicate that liver saturated fatty acid-rich triglycerides feeds clofibrate-induced monounsaturated fatty acid (MUFA) synthesis, which were incorporated into hepatic phospholipids and sphingomyelin. In addition, selective enrichment of docosahexeneoic acid in the phosphatidylserine of liver (1.7-fold), heart (1.6-fold) and brain (1.5-fold) suggests a clofibrate-dependent systemic activation of phosphatidylserine synthetase 2. Furthermore, the observed ~20% decline in cardiac sphingomyelin is consistent with activation of a sphingomeylinase with a substrate preference for polyunsaturate-containing sphingomyelin. Finally, perturbations in the liver, brain, and adipose cholesterol esters were observed, with clofibrate exposure elevating brain cholesterol arachidonyl-esters ~20-fold. Thus, while supporting previous findings, this study has identified novel impacts of PPARα agonist exposure on lipid metabolism that should be further explored. PMID:19079556

Bioorthogonal chemical imaging of metabolic activities in live mammalian hippocampal tissues with stimulated Raman scattering

NASA Astrophysics Data System (ADS)

Hu, Fanghao; Lamprecht, Michael R.; Wei, Lu; Morrison, Barclay; Min, Wei

2016-12-01

Brain is an immensely complex system displaying dynamic and heterogeneous metabolic activities. Visualizing cellular metabolism of nucleic acids, proteins, and lipids in brain with chemical specificity has been a long-standing challenge. Recent development in metabolic labeling of small biomolecules allows the study of these metabolisms at the global level. However, these techniques generally require nonphysiological sample preparation for either destructive mass spectrometry imaging or secondary labeling with relatively bulky fluorescent labels. In this study, we have demonstrated bioorthogonal chemical imaging of DNA, RNA, protein and lipid metabolism in live rat brain hippocampal tissues by coupling stimulated Raman scattering microscopy with integrated deuterium and alkyne labeling. Heterogeneous metabolic incorporations for different molecular species and neurogenesis with newly-incorporated DNA were observed in the dentate gyrus of hippocampus at the single cell level. We further applied this platform to study metabolic responses to traumatic brain injury in hippocampal slice cultures, and observed marked upregulation of protein and lipid metabolism particularly in the hilus region of the hippocampus within days of mechanical injury. Thus, our method paves the way for the study of complex metabolic profiles in live brain tissue under both physiological and pathological conditions with single-cell resolution and minimal perturbation.

A comparison of head dynamic response and brain tissue stress and strain using accident reconstructions for concussion, concussion with persistent postconcussive symptoms, and subdural hematoma.

PubMed

Oeur, R Anna; Karton, Clara; Post, Andrew; Rousseau, Philippe; Hoshizaki, T Blaine; Marshall, Shawn; Brien, Susan E; Smith, Aynsley; Cusimano, Michael D; Gilchrist, Michael D

2015-08-01

Concussions typically resolve within several days, but in a few cases the symptoms last for a month or longer and are termed persistent postconcussive symptoms (PPCS). These persisting symptoms may also be associated with more serious brain trauma similar to subdural hematoma (SDH). The objective of this study was to investigate the head dynamic and brain tissue responses of injury reconstructions resulting in concussion, PPCS, and SDH. Reconstruction cases were obtained from sports medicine clinics and hospitals. All subjects received a direct blow to the head resulting in symptoms. Those symptoms that resolved in 9 days or fewer were defined as concussions (n = 3). Those with symptoms lasting longer than 18 months were defined as PPCS (n = 3), and 3 patients presented with SDHs (n = 3). A Hybrid III headform was used in reconstruction to obtain linear and rotational accelerations of the head. These dynamic response data were then input into the University College Dublin Brain Trauma Model to calculate maximum principal strain and von Mises stress. A Kruskal-Wallis test followed by Tukey post hoc tests were used to compare head dynamic and brain tissue responses between injury groups. Statistical significance was set at p < 0.05. A significant difference was identified for peak resultant linear and rotational acceleration between injury groups. Post hoc analyses revealed the SDH group had higher linear and rotational acceleration responses (316 g and 23,181 rad/sec(2), respectively) than the concussion group (149 g and 8111 rad/sec(2), respectively; p < 0.05). No significant differences were found between groups for either brain tissue measures of maximum principal strain or von Mises stress. The reconstruction of accidents resulting in a concussion with transient symptoms (low severity) and SDHs revealed a positive relationship between an increase in head dynamic response and the risk for more serious brain injury. This type of relationship was not found for brain tissue stress and strain results derived by finite element analysis. Future research should be undertaken using a larger sample size to confirm these initial findings. Understanding the relationship between the head dynamic and brain tissue response and the nature of the injury provides important information for developing strategies for injury prevention.

Vascular Gene Expression in Nonneoplastic and Malignant Brain

PubMed Central

Madden, Stephen L.; Cook, Brian P.; Nacht, Mariana; Weber, William D.; Callahan, Michelle R.; Jiang, Yide; Dufault, Michael R.; Zhang, Xiaoming; Zhang, Wen; Walter-Yohrling, Jennifer; Rouleau, Cecile; Akmaev, Viatcheslav R.; Wang, Clarence J.; Cao, Xiaohong; St. Martin, Thia B.; Roberts, Bruce L.; Teicher, Beverly A.; Klinger, Katherine W.; Stan, Radu-Virgil; Lucey, Brenden; Carson-Walter, Eleanor B.; Laterra, John; Walter, Kevin A.

2004-01-01

Malignant gliomas are uniformly lethal tumors whose morbidity is mediated in large part by the angiogenic response of the brain to the invading tumor. This profound angiogenic response leads to aggressive tumor invasion and destruction of surrounding brain tissue as well as blood-brain barrier breakdown and life-threatening cerebral edema. To investigate the molecular mechanisms governing the proliferation of abnormal microvasculature in malignant brain tumor patients, we have undertaken a cell-specific transcriptome analysis from surgically harvested nonneoplastic and tumor-associated endothelial cells. SAGE-derived endothelial cell gene expression patterns from glioma and nonneoplastic brain tissue reveal distinct gene expression patterns and consistent up-regulation of certain glioma endothelial marker genes across patient samples. We define the G-protein-coupled receptor RDC1 as a tumor endothelial marker whose expression is distinctly induced in tumor endothelial cells of both brain and peripheral vasculature. Further, we demonstrate that the glioma-induced gene, PV1, shows expression both restricted to endothelial cells and coincident with endothelial cell tube formation. As PV1 provides a framework for endothelial cell caveolar diaphragms, this protein may serve to enhance glioma-induced disruption of the blood-brain barrier and transendothelial exchange. Additional characterization of this extensive brain endothelial cell gene expression database will provide unique molecular insights into vascular gene expression. PMID:15277233

In vivo monitoring of glial scar proliferation on chronically implanted neural electrodes by fiber optical coherence tomography

PubMed Central

Xie, Yijing; Martini, Nadja; Hassler, Christina; Kirch, Robert D.; Stieglitz, Thomas; Seifert, Andreas; Hofmann, Ulrich G.

2014-01-01

In neural prosthetics and stereotactic neurosurgery, intracortical electrodes are often utilized for delivering therapeutic electrical pulses, and recording neural electrophysiological signals. Unfortunately, neuroinflammation impairs the neuron-electrode-interface by developing a compact glial encapsulation around the implants in long term. At present, analyzing this immune reaction is only feasible with post-mortem histology; currently no means for specific in vivo monitoring exist and most applicable imaging modalities can not provide information in deep brain regions. Optical coherence tomography (OCT) is a well established imaging modality for in vivo studies, providing cellular resolution and up to 1.2 mm imaging depth in brain tissue. A fiber based spectral domain OCT was shown to be capable of minimally invasive brain imaging. In the present study, we propose to use a fiber based spectral domain OCT to monitor the progression of the tissue's immune response through scar encapsulation progress in a rat animal model. A fine fiber catheter was implanted in rat brain together with a flexible polyimide microelectrode in sight both of which acts as a foreign body and induces the brain tissue immune reaction. OCT signals were collected from animals up to 12 weeks after implantation and thus gliotic scarring in vivo monitored for that time. Preliminary data showed a significant enhancement of the OCT backscattering signal during the first 3 weeks after implantation, and increased attenuation factor of the sampled tissue due to the glial scar formation. PMID:25191264

Deep tissue optical focusing and optogenetic modulation with time-reversed ultrasonically encoded light

PubMed Central

Ruan, Haowen; Brake, Joshua; Robinson, J. Elliott; Liu, Yan; Jang, Mooseok; Xiao, Cheng; Zhou, Chunyi; Gradinaru, Viviana; Yang, Changhuei

2017-01-01

Noninvasive light focusing deep inside living biological tissue has long been a goal in biomedical optics. However, the optical scattering of biological tissue prevents conventional optical systems from tightly focusing visible light beyond several hundred micrometers. The recently developed wavefront shaping technique time-reversed ultrasonically encoded (TRUE) focusing enables noninvasive light delivery to targeted locations beyond the optical diffusion limit. However, until now, TRUE focusing has only been demonstrated inside nonliving tissue samples. We present the first example of TRUE focusing in 2-mm-thick living brain tissue and demonstrate its application for optogenetic modulation of neural activity in 800-μm-thick acute mouse brain slices at a wavelength of 532 nm. We found that TRUE focusing enabled precise control of neuron firing and increased the spatial resolution of neuronal excitation fourfold when compared to conventional lens focusing. This work is an important step in the application of TRUE focusing for practical biomedical uses. PMID:29226248

Effect of vitro preservation on mechanical properties of brain tissue

NASA Astrophysics Data System (ADS)

Zhang, Wei; Liu, Yi-fan; Liu, Li-fu; Niu, Ying; Ma, Jian-li; Wu, Cheng-wei

2017-05-01

To develop the protective devices for preventing traumatic brain injuries, it requires the accurate characterization of the mechanical properties of brain tissue. For this, it necessary to elucidate the effect of vitro preservation on the mechanical performance of brain tissue as usually the measurements are carried out in vitro. In this paper, the thermal behavior of brain tissue preserved for various period of time was first investigated and the mechanical properties were also measured. Both reveals the deterioration with prolonged preservation duration. The observations of brain tissue slices indicates the brain tissue experiences karyorrhexis and karyorrhexis in sequence, which accounts for the deterioration phenomena.

Zinc isotope ratio imaging of rat brain thin sections from stable isotope tracer studies by LA-MC-ICP-MS.

PubMed

Urgast, Dagmar S; Hill, Sarah; Kwun, In-Sook; Beattie, John H; Goenaga-Infante, Heidi; Feldmann, Jörg

2012-10-01

Zinc stable isotope tracers (⁶⁷Zn and ⁷⁰Zn) were injected into rats at two different time points to investigate the feasibility of using tracers to study zinc kinetics at the microscale within distinct tissue features. Laser ablation coupled to multi-collector ICP-MS was used to analyse average isotope ratios in liver thin sections and to generate bio-images showing zinc isotope ratio distribution in brain thin sections. Average isotope ratios of all samples from treated animals were found to be statistically different (P < 0.05) from samples from untreated control animals. Furthermore, differing isotope ratios in physiological features of the brain, namely hippocampus, amygdala, cortex and hypothalamus, were identified. This indicates that these regions differ in their zinc metabolism kinetics. While cortex and hypothalamus contain more tracer two days after injection than 14 days after injection, the opposite is true for hippocampus and amygdala. This study showed that stable isotope tracer experiments can be combined with laser ablation MC-ICP-MS to measure trace element kinetics in tissues at a microscale level.

Development and characterization of non-resonant multiphoton photoacoustic spectroscopy (NMPPAS) for brain tumor margining

NASA Astrophysics Data System (ADS)

Dahal, Sudhir

During tumor removal surgery, due to the problems associated with obtaining high-resolution, real-time chemical images of where exactly the tumor ends and healthy tissue begins (tumor margining), it is often necessary to remove a much larger volume of tissue than the tumor itself. In the case of brain tumor surgery, however, it is extremely unsafe to remove excess tissue. Therefore, without an accurate image of the tumor margins, some of the tumor's finger-like projections are inevitably left behind in the surrounding parenchyma to grow again. For this reason, the development of techniques capable of providing high-resolution real-time images of tumor margins up to centimeters below the surface of a tissue is ideal for the diagnosis and treatment of tumors, as well as surgical guidance during brain tumor excision. A novel spectroscopic technique, non-resonant multiphoton photoacoustic spectroscopy (NMPPAS), is being developed with the capabilities of obtaining high-resolution subsurface chemical-based images of underlying tumors. This novel technique combines the strengths of multiphoton tissue spectroscopy and photoacoustic spectroscopy into a diagnostic methodology that will, ultimately, provide unparalleled chemical information and images to provide the state of sub-surface tissues. The NMPPAS technique employs near-infrared light (in the diagnostic window) to excite ultraviolet and/or visible light absorbing species deep below the tissue's surface. Once a multiphoton absorption event occurs, non-radiative relaxation processes generates a localized thermal expansion and subsequent acoustic wave that can be detected using a piezoelectric transducer. Since NMPPAS employs an acoustic detection modality, much deeper diagnoses can be performed than that is possible using current state of the art high-resolution chemical imaging techniques such as multiphoton fluorescence spectroscopy. NMPPAS was employed to differentiate between excised brain tumors (astrocytoma III) and healthy tissue with over 99% accuracy. NMPPAS spectral features showed evident differences between tumor and healthy tissues, and ratiometric analysis ensured that only a few wavelengths could be used for excitation instead of using numerous wavelength excitations to create spectra. This process would significantly reduce the analysis time while maintaining the same degree of accuracy. Tissue phantoms were fabricated in order to characterize the properties of NMPPAS. Scattering particles were doped into the phantoms to simulate their light scattering properties to real tissues. This allowed for better control over shape, size, reproducibility and doping in the sample while maintaining the light-tissue interaction properties of real tissue. To make NMPPAS viable for clinical applications, the technique was characterized to determine the spatial (lateral and longitudinal) resolution, depth of penetration and its ability to image in three-dimension through layers of tissue. Both resolutions were determined to be near-cellular level resolution (50-70 microm), obtained initially with the aid of the technique of multiphoton fluorescence, and later verified using NMPPAS imaging. Additionally, the maximum depth of penetration and detection was determined to be about 1.4cm, making the technique extremely suitable to margin tumors from underlying tissues in the brain. The capability of NMPPAS to detect and image layers that lie beneath other structures and blood vessels was also investigated. Three-dimensional images were obtained for the first time using NMPPAS. The images were obtained from different depths and structures were imaged through other layers of existing structures in the sample. This verified that NMPPAS was capable of detecting and imaging structures that lie embedded within the tissues. NMPPAS images of embedded structures were also obtained with the presence of hemoglobin, which is potentially the largest source of background in blood-perfused tissues, thus showing that the technique is capable of detecting and differentiating in blood-perfused samples.

BRAF/NRAS mutation frequencies among primary tumors and metastases in patients with melanoma.

PubMed

Colombino, Maria; Capone, Mariaelena; Lissia, Amelia; Cossu, Antonio; Rubino, Corrado; De Giorgi, Vincenzo; Massi, Daniela; Fonsatti, Ester; Staibano, Stefania; Nappi, Oscar; Pagani, Elena; Casula, Milena; Manca, Antonella; Sini, Mariacristina; Franco, Renato; Botti, Gerardo; Caracò, Corrado; Mozzillo, Nicola; Ascierto, Paolo A; Palmieri, Giuseppe

2012-07-10

The prevalence of BRAF, NRAS, and p16CDKN2A mutations during melanoma progression remains inconclusive. We investigated the prevalence and distribution of mutations in these genes in different melanoma tissues. In all, 291 tumor tissues from 132 patients with melanoma were screened. Paired samples of primary melanomas (n = 102) and synchronous or asynchronous metastases from the same patients (n = 165) were included. Tissue samples underwent mutation analysis (automated DNA sequencing). Secondary lesions included lymph nodes (n = 84), and skin (n = 36), visceral (n = 25), and brain (n = 44) sites. BRAF/NRAS mutations were identified in 58% of primary melanomas (43% BRAF; 15% NRAS); 62% in lymph nodes, 61% subcutaneous, 56% visceral, and 70% in brain sites. Mutations were observed in 63% of metastases (48% BRAF; 15% NRAS), a nonsignificant increase in mutation frequency after progression from primary melanoma. Of the paired samples, lymph nodes (93% consistency) and visceral metastases (96% consistency) presented a highly similar distribution of BRAF/NRAS mutations versus primary melanomas, with a significantly less consistent pattern in brain (80%) and skin metastases (75%). This suggests that independent subclones are generated in some patients. p16CDKN2A mutations were identified in 7% and 14% of primary melanomas and metastases, with a low consistency (31%) between secondary and primary tumor samples. In the era of targeted therapies, assessment of the spectrum and distribution of alterations in molecular targets among patients with melanoma is needed. Our findings about the prevalence of BRAF/NRAS/p16CDKN2A mutations in paired tumor lesions from patients with melanoma may be useful in the management of this disease.

Novel biomarker identification using metabolomic profiling to differentiate radiation necrosis and recurrent tumor following Gamma Knife radiosurgery.

PubMed

Lu, Alex Y; Turban, Jack L; Damisah, Eyiyemisi C; Li, Jie; Alomari, Ahmed K; Eid, Tore; Vortmeyer, Alexander O; Chiang, Veronica L

2017-08-01

OBJECTIVE Following an initial response of brain metastases to Gamma Knife radiosurgery, regrowth of the enhancing lesion as detected on MRI may represent either radiation necrosis (a treatment-related inflammatory change) or recurrent tumor. Differentiation of radiation necrosis from tumor is vital for management decision making but remains difficult by imaging alone. In this study, gas chromatography with time-of-flight mass spectrometry (GC-TOF) was used to identify differential metabolite profiles of the 2 tissue types obtained by surgical biopsy to find potential targets for noninvasive imaging. METHODS Specimens of pure radiation necrosis and pure tumor obtained from patient brain biopsies were flash-frozen and validated histologically. These formalin-free tissue samples were then analyzed using GC-TOF. The metabolite profiles of radiation necrosis and tumor samples were compared using multivariate and univariate statistical analysis. Statistical significance was defined as p ≤ 0.05. RESULTS For the metabolic profiling, GC-TOF was performed on 7 samples of radiation necrosis and 7 samples of tumor. Of the 141 metabolites identified, 17 (12.1%) were found to be statistically significantly different between comparison groups. Of these metabolites, 6 were increased in tumor, and 11 were increased in radiation necrosis. An unsupervised hierarchical clustering analysis found that tumor had elevated levels of metabolites associated with energy metabolism, whereas radiation necrosis had elevated levels of metabolites that were fatty acids and antioxidants/cofactors. CONCLUSIONS To the authors' knowledge, this is the first tissue-based metabolomics study of radiation necrosis and tumor. Radiation necrosis and recurrent tumor following Gamma Knife radiosurgery for brain metastases have unique metabolite profiles that may be targeted in the future to develop noninvasive metabolic imaging techniques.

Differentiation of the seven major lyssavirus species by oligonucleotide microarray.

PubMed

Xi, Jin; Guo, Huancheng; Feng, Ye; Xu, Yunbin; Shao, Mingfu; Su, Nan; Wan, Jiayu; Li, Jiping; Tu, Changchun

2012-03-01

An oligonucleotide microarray, LyssaChip, has been developed and verified as a highly specific diagnostic tool for differentiation of the 7 major lyssavirus species. As with conventional typing microarray methods, the LyssaChip relies on sequence differences in the 371-nucleotide region coding for the nucleoprotein. This region was amplified using nested reverse transcription-PCR primers that bind to the 7 major lyssaviruses. The LyssaChip includes 57 pairs of species typing and corresponding control oligonucleotide probes (oligoprobes) immobilized on glass slides, and it can analyze 12 samples on a single slide within 8 h. Analysis of 111 clinical brain specimens (65 from animals with suspected rabies submitted to the laboratory and 46 of butchered dog brain tissues collected from restaurants) showed that the chip method was 100% sensitive and highly consistent with the "gold standard," a fluorescent antibody test (FAT). The chip method could detect rabies virus in highly decayed brain tissues, whereas the FAT did not, and therefore the chip test may be more applicable to highly decayed brain tissues than the FAT. LyssaChip may provide a convenient and inexpensive alternative for diagnosis and differentiation of rabies and rabies-related diseases.

Diagnostic, prognostic and predictive relevance of molecular markers in gliomas.

PubMed

Brandner, Sebastian; von Deimling, Andreas

2015-10-01

The advances of genome-wide 'discovery platforms' and the increasing affordability of the analysis of significant sample sizes have led to the identification of novel mutations in brain tumours that became diagnostically and prognostically relevant. The development of mutation-specific antibodies has facilitated the introduction of these convenient biomarkers into most neuropathology laboratories and has changed our approach to brain tumour diagnostics. However, tissue diagnosis will remain an essential first step for the correct stratification for subsequent molecular tests, and the combined interpretation of the molecular and tissue diagnosis ideally remains with the neuropathologist. This overview will help our understanding of the pathobiology of common intrinsic brain tumours in adults and help guiding which molecular tests can supplement and refine the tissue diagnosis of the most common adult intrinsic brain tumours. This article will discuss the relevance of 1p/19q codeletions, IDH1/2 mutations, BRAF V600E and BRAF fusion mutations, more recently discovered mutations in ATRX, H3F3A, TERT, CIC and FUBP1, for diagnosis, prognostication and predictive testing. In a tumour-specific topic, the role of mitogen-activated protein kinase pathway mutations in the pathogenesis of pilocytic astrocytomas will be covered. © 2015 British Neuropathological Society.

On high b diffusion imaging in the human brain: ruminations and experimental insights.

PubMed

Mulkern, Robert V; Haker, Steven J; Maier, Stephan E

2009-10-01

Interest in the manner in which brain tissue signal decays with b factor in diffusion imaging schemes has grown in recent years following the observation that the decay curves depart from purely monoexponential decay behavior. Regardless of the model or fitting function proposed for characterizing sufficiently sampled decay curves (vide infra), the departure from monoexponentiality spells increased tissue characterization potential. The degree to which this potential can be harnessed to improve specificity, sensitivity and spatial localization of diseases in brain, and other tissues, largely remains to be explored. Furthermore, the degree to which currently popular diffusion tensor imaging methods, including visually impressive white matter fiber "tractography" results, have almost completely ignored the nonmonoexponential nature of the basic signal decay with b factor is worthy of communal introspection. Here we limit our attention to a review of the basic experimental features associated with brain water signal diffusion decay curves as measured over extended b-factor ranges, the simple few parameter fitting functions that have been proposed to characterize these decays and the more involved models, e.g.,"ruminations," which have been proposed to account for the nonmonoexponentiality to date.

On high b diffusion imaging in the human brain: ruminations and experimental insights✩

PubMed Central

Mulkern, Robert V.; Haker, Steven J.; Maier, Stephan E.

2010-01-01

Interest in the manner in which brain tissue signal decays with b factor in diffusion imaging schemes has grown in recent years following the observation that the decay curves depart from purely monoexponential decay behavior. Regardless of the model or fitting function proposed for characterizing sufficiently sampled decay curves (vide infra), the departure from monoexponentiality spells increased tissue characterization potential. The degree to which this potential can be harnessed to improve specificity, sensitivity and spatial localization of diseases in brain, and other tissues, largely remains to be explored. Furthermore, the degree to which currently popular diffusion tensor imaging methods, including visually impressive white matter fiber “tractography” results, have almost completely ignored the nonmonoexponential nature of the basic signal decay with b factor is worthy of communal introspection. Here we limit our attention to a review of the basic experimental features associated with brain water signal diffusion decay curves as measured over extended b-factor ranges, the simple few parameter fitting functions that have been proposed to characterize these decays and the more involved models, e.g.,“ruminations,” which have been proposed to account for the nonmonoexponentiality to date. PMID:19520535

Food-induced changes of lipids in rat neuronal tissue visualized by ToF-SIMS imaging.

PubMed

Dowlatshahi Pour, Masoumeh; Jennische, Eva; Lange, Stefan; Ewing, Andrew G; Malmberg, Per

2016-09-06

Time of flight secondary ion mass spectrometry (ToF-SIMS) was used to image the lipid localization in brain tissue sections from rats fed specially processed cereals (SPC). An IonTof 5 instrument equipped with a Bi cluster ion gun was used to analyze the tissue sections. Data from 15 brain samples from control and cereal-fed rats were recorded and exported to principal components analysis (PCA). The data clearly show changes of certain lipids in the brain following cereal feeding. PCA score plots show a good separation in lipid distribution between the control and the SPC-fed group. The loadings plot reveal that the groups separated mainly due to changes in cholesterol, vitamin E and c18:2, c16:0 fatty acid distribution as well as some short chain monocarboxylic fatty acid compositions. These insights relate to the working mechanism of SPC as a dietary supplement. SPC is thought to activate antisecretory factor (AF), an endogenous protein with regulatory function for inflammation and fluid secretion. These data provide insights into lipid content in brain following SPC feeding and suggest a relation to activating AF.

Molecular identification and histopathological study of natural Streptococcus agalactiae infection in hybrid tilapia (Oreochromis niloticus).

PubMed

Laith, A A; Ambak, Mohd Azmi; Hassan, Marina; Sheriff, Shahreza Md; Nadirah, Musa; Draman, Ahmad Shuhaimi; Wahab, Wahidah; Ibrahim, Wan Nurhafizah Wan; Aznan, Alia Syafiqah; Jabar, Amina; Najiah, Musa

2017-01-01

The main objective of this study was to emphasize on histopathological examinations and molecular identification of Streptococcus agalactiae isolated from natural infections in hybrid tilapia ( Oreochromis niloticus ) in Temerloh Pahang, Malaysia, as well as to determine the susceptibility of the pathogen strains to various currently available antimicrobial agents. The diseased fishes were observed for variable clinical signs including fin hemorrhages, alterations in behavior associated with erratic swimming, exophthalmia, and mortality. Tissue samples from the eyes, brain, kidney, liver, and spleen were taken for bacterial isolation. Identification of S. agalactiae was screened by biochemical methods and confirmed by VITEK 2 and 16S rRNA gene sequencing. The antibiogram profiling of the isolate was tested against 18 standard antibiotics included nitrofurantoin, flumequine, florfenicol, amoxylin, doxycycline, oleandomycin, tetracycline, ampicillin, lincomycin, colistin sulfate, oxolinic acid, novobiocin, spiramycin, erythromycin, fosfomycin, neomycin, gentamycin, and polymyxin B. The histopathological analysis of eyes, brain, liver, kidney, and spleen was observed for abnormalities related to S. agalactiae infection. The suspected colonies of S. agalactiae identified by biochemical methods was observed as Gram-positive chained cocci, β-hemolytic, and non-motile. The isolate was confirmed as S. agalactiae by VITEK 2 (99% similarity), reconfirmed by 16S rRNA gene sequencing (99% similarity) and deposited in GenBank with accession no. KT869025. The isolate was observed to be resistance to neomycin and gentamicin. The most consistent gross findings were marked hemorrhages, erosions of caudal fin, and exophthalmos. Microscopic examination confirmed the presence of marked congestion and infiltration of inflammatory cell in the eye, brain, kidney, liver, and spleen. Eye samples showed damage of the lens capsule, hyperemic and hemorrhagic choroid tissue, and retina hyperplasia accompanied with edema. Brain samples showed perivascular and pericellular edema and hemorrhages of the meninges. Kidney samples showed hemorrhage and thrombosis in the glomeruli and tubules along with atrophy in hematopoietic tissue. Liver samples showed congestion of the sinusoids and blood vessel, thrombosis of portal blood vessel, and vacuolar (fatty) degeneration of hepatocytes. Spleen samples showed large thrombus in the splenic blood vessel, multifocal hemosiderin deposition, congestion of blood vessels, and multifocal infiltration of macrophages. Therefore, it can be concluded that pathological changes in tissues and organs of fish occur proportionally to the pathogen invasion, and because of their high resistance, neomycin and gentamicin utilization in the prophylaxis or treatment of S. agalactiae infection should be avoided.

Molecular identification and histopathological study of natural Streptococcus agalactiae infection in hybrid tilapia (Oreochromis niloticus)

PubMed Central

Laith, AA; Ambak, Mohd Azmi; Hassan, Marina; Sheriff, Shahreza Md.; Nadirah, Musa; Draman, Ahmad Shuhaimi; Wahab, Wahidah; Ibrahim, Wan Nurhafizah Wan; Aznan, Alia Syafiqah; Jabar, Amina; Najiah, Musa

2017-01-01

Aim: The main objective of this study was to emphasize on histopathological examinations and molecular identification of Streptococcus agalactiae isolated from natural infections in hybrid tilapia (Oreochromis niloticus) in Temerloh Pahang, Malaysia, as well as to determine the susceptibility of the pathogen strains to various currently available antimicrobial agents. Materials and Methods: The diseased fishes were observed for variable clinical signs including fin hemorrhages, alterations in behavior associated with erratic swimming, exophthalmia, and mortality. Tissue samples from the eyes, brain, kidney, liver, and spleen were taken for bacterial isolation. Identification of S. agalactiae was screened by biochemical methods and confirmed by VITEK 2 and 16S rRNA gene sequencing. The antibiogram profiling of the isolate was tested against 18 standard antibiotics included nitrofurantoin, flumequine, florfenicol, amoxylin, doxycycline, oleandomycin, tetracycline, ampicillin, lincomycin, colistin sulfate, oxolinic acid, novobiocin, spiramycin, erythromycin, fosfomycin, neomycin, gentamycin, and polymyxin B. The histopathological analysis of eyes, brain, liver, kidney, and spleen was observed for abnormalities related to S. agalactiae infection. Results: The suspected colonies of S. agalactiae identified by biochemical methods was observed as Gram-positive chained cocci, β-hemolytic, and non-motile. The isolate was confirmed as S. agalactiae by VITEK 2 (99% similarity), reconfirmed by 16S rRNA gene sequencing (99% similarity) and deposited in GenBank with accession no. KT869025. The isolate was observed to be resistance to neomycin and gentamicin. The most consistent gross findings were marked hemorrhages, erosions of caudal fin, and exophthalmos. Microscopic examination confirmed the presence of marked congestion and infiltration of inflammatory cell in the eye, brain, kidney, liver, and spleen. Eye samples showed damage of the lens capsule, hyperemic and hemorrhagic choroid tissue, and retina hyperplasia accompanied with edema. Brain samples showed perivascular and pericellular edema and hemorrhages of the meninges. Kidney samples showed hemorrhage and thrombosis in the glomeruli and tubules along with atrophy in hematopoietic tissue. Liver samples showed congestion of the sinusoids and blood vessel, thrombosis of portal blood vessel, and vacuolar (fatty) degeneration of hepatocytes. Spleen samples showed large thrombus in the splenic blood vessel, multifocal hemosiderin deposition, congestion of blood vessels, and multifocal infiltration of macrophages. Conclusion: Therefore, it can be concluded that pathological changes in tissues and organs of fish occur proportionally to the pathogen invasion, and because of their high resistance, neomycin and gentamicin utilization in the prophylaxis or treatment of S. agalactiae infection should be avoided. PMID:28246454

A SELDI mass spectrometry study of experimental autoimmune encephalomyelitis: sample preparation, reproducibility, and differential protein expression patterns.

PubMed

Azzam, Sausan; Broadwater, Laurie; Li, Shuo; Freeman, Ernest J; McDonough, Jennifer; Gregory, Roger B

2013-05-01

Experimental autoimmune encephalomyelitis (EAE) is an autoimmune, inflammatory disease of the central nervous system that is widely used as a model of multiple sclerosis (MS). Mitochondrial dysfunction appears to play a role in the development of neuropathology in MS and may also play a role in disease pathology in EAE. Here, surface enhanced laser desorption ionization mass spectrometry (SELDI-MS) has been employed to obtain protein expression profiles from mitochondrially enriched fractions derived from EAE and control mouse brain. To gain insight into experimental variation, the reproducibility of sub-cellular fractionation, anion exchange fractionation as well as spot-to-spot and chip-to-chip variation using pooled samples from brain tissue was examined. Variability of SELDI mass spectral peak intensities indicates a coefficient of variation (CV) of 15.6% and 17.6% between spots on a given chip and between different chips, respectively. Thinly slicing tissue prior to homogenization with a rotor homogenizer showed better reproducibility (CV = 17.0%) than homogenization of blocks of brain tissue with a Teflon® pestle (CV = 27.0%). Fractionation of proteins with anion exchange beads prior to SELDI-MS analysis gave overall CV values from 16.1% to 18.6%. SELDI mass spectra of mitochondrial fractions obtained from brain tissue from EAE mice and controls displayed 39 differentially expressed proteins (p≤ 0.05) out of a total of 241 protein peaks observed in anion exchange fractions. Hierarchical clustering analysis showed that protein fractions from EAE animals with severe disability clearly segregated from controls. Several components of electron transport chain complexes (cytochrome c oxidase subunit 6b1, subunit 6C, and subunit 4; NADH dehydrogenase flavoprotein 3, alpha subcomplex subunit 2, Fe-S protein 4, and Fe-S protein 6; and ATP synthase subunit e) were identified as possible differentially expressed proteins. Myelin Basic Protein isoform 8 (MBP8) (14.2 kDa) levels were lower in EAE samples with advanced disease relative to controls, while an MBP fragment (12. 4kDa), likely due to calpain digestion, was increased in EAE relative to controls. The appearance of MBP in mitochondrially enriched fractions is due to tissue freezing and storage, as MBP was not found associated with mitochondria obtained from fresh tissue. SELDI mass spectrometry can be employed to explore the proteome of a complex tissue (brain) and obtain protein profiles of differentially expressed proteins from protein fractions. Appropriate homogenization protocols and protein fractionation using anion exchange beads can be employed to reduce sample complexity without introducing significant additional variation into the SELDI mass spectra beyond that inherent in the SELDI- MS method itself. SELDI-MS coupled with principal component analysis and hierarchical cluster analysis provides protein patterns that can clearly distinguish the disease state from controls. However, identification of individual differentially expressed proteins requires a separate purification of the proteins of interest by polyacrylamide electrophoresis prior to trypsin digestion and peptide mass fingerprint analysis, and unambiguous identification of differentially expressed proteins can be difficult if protein bands consist of several proteins with similar molecular weights.

A SELDI mass spectrometry study of experimental autoimmune encephalomyelitis: sample preparation, reproducibility, and differential protein expression patterns

PubMed Central

2013-01-01

Background Experimental autoimmune encephalomyelitis (EAE) is an autoimmune, inflammatory disease of the central nervous system that is widely used as a model of multiple sclerosis (MS). Mitochondrial dysfunction appears to play a role in the development of neuropathology in MS and may also play a role in disease pathology in EAE. Here, surface enhanced laser desorption ionization mass spectrometry (SELDI-MS) has been employed to obtain protein expression profiles from mitochondrially enriched fractions derived from EAE and control mouse brain. To gain insight into experimental variation, the reproducibility of sub-cellular fractionation, anion exchange fractionation as well as spot-to-spot and chip-to-chip variation using pooled samples from brain tissue was examined. Results Variability of SELDI mass spectral peak intensities indicates a coefficient of variation (CV) of 15.6% and 17.6% between spots on a given chip and between different chips, respectively. Thinly slicing tissue prior to homogenization with a rotor homogenizer showed better reproducibility (CV = 17.0%) than homogenization of blocks of brain tissue with a Teflon® pestle (CV = 27.0%). Fractionation of proteins with anion exchange beads prior to SELDI-MS analysis gave overall CV values from 16.1% to 18.6%. SELDI mass spectra of mitochondrial fractions obtained from brain tissue from EAE mice and controls displayed 39 differentially expressed proteins (p≤ 0.05) out of a total of 241 protein peaks observed in anion exchange fractions. Hierarchical clustering analysis showed that protein fractions from EAE animals with severe disability clearly segregated from controls. Several components of electron transport chain complexes (cytochrome c oxidase subunit 6b1, subunit 6C, and subunit 4; NADH dehydrogenase flavoprotein 3, alpha subcomplex subunit 2, Fe-S protein 4, and Fe-S protein 6; and ATP synthase subunit e) were identified as possible differentially expressed proteins. Myelin Basic Protein isoform 8 (MBP8) (14.2 kDa) levels were lower in EAE samples with advanced disease relative to controls, while an MBP fragment (12. 4kDa), likely due to calpain digestion, was increased in EAE relative to controls. The appearance of MBP in mitochondrially enriched fractions is due to tissue freezing and storage, as MBP was not found associated with mitochondria obtained from fresh tissue. Conclusions SELDI mass spectrometry can be employed to explore the proteome of a complex tissue (brain) and obtain protein profiles of differentially expressed proteins from protein fractions. Appropriate homogenization protocols and protein fractionation using anion exchange beads can be employed to reduce sample complexity without introducing significant additional variation into the SELDI mass spectra beyond that inherent in the SELDI- MS method itself. SELDI-MS coupled with principal component analysis and hierarchical cluster analysis provides protein patterns that can clearly distinguish the disease state from controls. However, identification of individual differentially expressed proteins requires a separate purification of the proteins of interest by polyacrylamide electrophoresis prior to trypsin digestion and peptide mass fingerprint analysis, and unambiguous identification of differentially expressed proteins can be difficult if protein bands consist of several proteins with similar molecular weights. PMID:23635033

Investigating the impact of blood pressure increase to the brain using high resolution serial histology and image processing

NASA Astrophysics Data System (ADS)

Lesage, F.; Castonguay, A.; Tardif, P. L.; Lefebvre, J.; Li, B.

2015-09-01

A combined serial OCT/confocal scanner was designed to image large sections of biological tissues at microscopic resolution. Serial imaging of organs embedded in agarose blocks is performed by cutting through tissue using a vibratome which sequentially cuts slices in order to reveal new tissue to image, overcoming limited light penetration encountered in microscopy. Two linear stages allow moving the tissue with respect to the microscope objective, acquiring a 2D grid of volumes (1x1x0.3 mm) with OCT and a 2D grid of images (1x1mm) with the confocal arm. This process is repeated automatically, until the entire sample is imaged. Raw data is then post-processed to re-stitch each individual acquisition and obtain a reconstructed volume of the imaged tissue. This design is being used to investigate correlations between white matter and microvasculature changes with aging and with increase in pulse pressure following transaortic constriction in mice. The dual imaging capability of the system allowed to reveal different contrast information: OCT imaging reveals changes in refractive indices giving contrast between white and grey matter in the mouse brain, while transcardial perfusion of FITC or pre-sacrifice injection of Evans Blue shows microsvasculature properties in the brain with confocal imaging.

Outbreaks of Neuroinvasive Astrovirus Associated with Encephalomyelitis, Weakness, and Paralysis among Weaned Pigs, Hungary

PubMed Central

Boros, Ákos; Albert, Mihály; Pankovics, Péter; Bíró, Hunor; Pesavento, Patricia A.; Phan, Tung Gia; Delwart, Eric

2017-01-01

A large, highly prolific swine farm in Hungary had a 2-year history of neurologic disease among newly weaned (25- to 35-day-old) pigs, with clinical signs of posterior paraplegia and a high mortality rate. Affected pigs that were necropsied had encephalomyelitis and neural necrosis. Porcine astrovirus type 3 was identified by reverse transcription PCR and in situ hybridization in brain and spinal cord samples in 6 animals from this farm. Among tissues tested by quantitative RT-PCR, the highest viral loads were detected in brain stem and spinal cord. Similar porcine astrovirus type 3 was also detected in archived brain and spinal cord samples from another 2 geographically distant farms. Viral RNA was predominantly restricted to neurons, particularly in the brain stem, cerebellum (Purkinje cells), and cervical spinal cord. Astrovirus was generally undetectable in feces but present in respiratory samples, indicating a possible respiratory infection. Astrovirus could cause common, neuroinvasive epidemic disease. PMID:29148391

Outbreaks of Neuroinvasive Astrovirus Associated with Encephalomyelitis, Weakness, and Paralysis among Weaned Pigs, Hungary.

PubMed

Boros, Ákos; Albert, Mihály; Pankovics, Péter; Bíró, Hunor; Pesavento, Patricia A; Phan, Tung Gia; Delwart, Eric; Reuter, Gábor

2017-12-01

A large, highly prolific swine farm in Hungary had a 2-year history of neurologic disease among newly weaned (25- to 35-day-old) pigs, with clinical signs of posterior paraplegia and a high mortality rate. Affected pigs that were necropsied had encephalomyelitis and neural necrosis. Porcine astrovirus type 3 was identified by reverse transcription PCR and in situ hybridization in brain and spinal cord samples in 6 animals from this farm. Among tissues tested by quantitative RT-PCR, the highest viral loads were detected in brain stem and spinal cord. Similar porcine astrovirus type 3 was also detected in archived brain and spinal cord samples from another 2 geographically distant farms. Viral RNA was predominantly restricted to neurons, particularly in the brain stem, cerebellum (Purkinje cells), and cervical spinal cord. Astrovirus was generally undetectable in feces but present in respiratory samples, indicating a possible respiratory infection. Astrovirus could cause common, neuroinvasive epidemic disease.

Cross-Laboratory Analysis of Brain Cell Type Transcriptomes with Applications to Interpretation of Bulk Tissue Data

PubMed Central

Toker, Lilah; Rocco, Brad; Sibille, Etienne

2017-01-01

Establishing the molecular diversity of cell types is crucial for the study of the nervous system. We compiled a cross-laboratory database of mouse brain cell type-specific transcriptomes from 36 major cell types from across the mammalian brain using rigorously curated published data from pooled cell type microarray and single-cell RNA-sequencing (RNA-seq) studies. We used these data to identify cell type-specific marker genes, discovering a substantial number of novel markers, many of which we validated using computational and experimental approaches. We further demonstrate that summarized expression of marker gene sets (MGSs) in bulk tissue data can be used to estimate the relative cell type abundance across samples. To facilitate use of this expanding resource, we provide a user-friendly web interface at www.neuroexpresso.org. PMID:29204516

Enhanced Sensitivity for High Spatial Resolution Lipid Analysis by Negative Ion Mode MALDI Imaging Mass Spectrometry

PubMed Central

Angel, Peggi M.; Spraggins, Jeffrey M.; Baldwin, H. Scott; Caprioli, Richard

2012-01-01

We have achieved enhanced lipid imaging to a ~10 μm spatial resolution using negative ion mode matrix assisted laser desorption ionization (MALDI) imaging mass spectrometry, sublimation of 2,5-dihydroxybenzoic acid as the MALDI matrix and a sample preparation protocol that uses aqueous washes. We report on the effect of treating tissue sections by washing with volatile buffers at different pHs prior to negative ion mode lipid imaging. The results show that washing with ammonium formate, pH 6.4, or ammonium acetate, pH 6.7, significantly increases signal intensity and number of analytes recorded from adult mouse brain tissue sections. Major lipid species measured were glycerophosphoinositols, glycerophosphates, glycerolphosphoglycerols, glycerophosphoethanolamines, glycerophospho-serines, sulfatides, and gangliosides. Ion images from adult mouse brain sections that compare washed and unwashed sections are presented and show up to fivefold increases in ion intensity for washed tissue. The sample preparation protocol has been found to be applicable across numerous organ types and significantly expands the number of lipid species detectable by imaging mass spectrometry at high spatial resolution. PMID:22243218

An improved ATAC-seq protocol reduces background and enables interrogation of frozen tissues.

PubMed

Corces, M Ryan; Trevino, Alexandro E; Hamilton, Emily G; Greenside, Peyton G; Sinnott-Armstrong, Nicholas A; Vesuna, Sam; Satpathy, Ansuman T; Rubin, Adam J; Montine, Kathleen S; Wu, Beijing; Kathiria, Arwa; Cho, Seung Woo; Mumbach, Maxwell R; Carter, Ava C; Kasowski, Maya; Orloff, Lisa A; Risca, Viviana I; Kundaje, Anshul; Khavari, Paul A; Montine, Thomas J; Greenleaf, William J; Chang, Howard Y

2017-10-01

We present Omni-ATAC, an improved ATAC-seq protocol for chromatin accessibility profiling that works across multiple applications with substantial improvement of signal-to-background ratio and information content. The Omni-ATAC protocol generates chromatin accessibility profiles from archival frozen tissue samples and 50-μm sections, revealing the activities of disease-associated DNA elements in distinct human brain structures. The Omni-ATAC protocol enables the interrogation of personal regulomes in tissue context and translational studies.

Exploring the mechanical behavior of degrading swine neural tissue at low strain rates via the fractional Zener constitutive model.

PubMed

Bentil, Sarah A; Dupaix, Rebecca B

2014-02-01

The ability of the fractional Zener constitutive model to predict the behavior of postmortem swine brain tissue was examined in this work. Understanding tissue behavior attributed to degradation is invaluable in many fields such as the forensic sciences or cases where only cadaveric tissue is available. To understand how material properties change with postmortem age, the fractional Zener model was considered as it includes parameters to describe brain stiffness and also the parameter α, which quantifies the viscoelasticity of a material. The relationship between the viscoelasticity described by α and tissue degradation was examined by fitting the model to data collected in a previous study (Bentil, 2013). This previous study subjected swine neural tissue to in vitro unconfined compression tests using four postmortem age groups (<6h, 24h, 3 days, and 1 week). All samples were compressed to a strain level of 10% using two compressive rates: 1mm/min and 5mm/min. Statistical analysis was used as a tool to study the influence of the fractional Zener constants on factors such as tissue degradation and compressive rate. Application of the fractional Zener constitutive model to the experimental data showed that swine neural tissue becomes less stiff with increased postmortem age. The fractional Zener model was also able to capture the nonlinear viscoelastic features of the brain tissue at low strain rates. The results showed that the parameter α was better correlated with compressive rate than with postmortem age. © 2013 Published by Elsevier Ltd.

DALMATIAN: An Algorithm for Automatic Cell Detection and Counting in 3D.

PubMed

Shuvaev, Sergey A; Lazutkin, Alexander A; Kedrov, Alexander V; Anokhin, Konstantin V; Enikolopov, Grigori N; Koulakov, Alexei A

2017-01-01

Current 3D imaging methods, including optical projection tomography, light-sheet microscopy, block-face imaging, and serial two photon tomography enable visualization of large samples of biological tissue. Large volumes of data obtained at high resolution require development of automatic image processing techniques, such as algorithms for automatic cell detection or, more generally, point-like object detection. Current approaches to automated cell detection suffer from difficulties originating from detection of particular cell types, cell populations of different brightness, non-uniformly stained, and overlapping cells. In this study, we present a set of algorithms for robust automatic cell detection in 3D. Our algorithms are suitable for, but not limited to, whole brain regions and individual brain sections. We used watershed procedure to split regional maxima representing overlapping cells. We developed a bootstrap Gaussian fit procedure to evaluate the statistical significance of detected cells. We compared cell detection quality of our algorithm and other software using 42 samples, representing 6 staining and imaging techniques. The results provided by our algorithm matched manual expert quantification with signal-to-noise dependent confidence, including samples with cells of different brightness, non-uniformly stained, and overlapping cells for whole brain regions and individual tissue sections. Our algorithm provided the best cell detection quality among tested free and commercial software.

A New Antigen Retrieval Technique for Human Brain Tissue

PubMed Central

Byne, William; Haroutunian, Vahram; García-Villanueva, Mercedes; Rábano, Alberto; García-Amado, María; Prensa, Lucía; Giménez-Amaya, José Manuel

2008-01-01

Immunohistochemical staining of tissues is a powerful tool used to delineate the presence or absence of an antigen. During the last 30 years, antigen visualization in human brain tissue has been significantly limited by the masking effect of fixatives. In the present study, we have used a new method for antigen retrieval in formalin-fixed human brain tissue and examined the effectiveness of this protocol to reveal masked antigens in tissues with both short and long formalin fixation times. This new method, which is based on the use of citraconic acid, has not been previously utilized in brain tissue although it has been employed in various other tissues such as tonsil, ovary, skin, lymph node, stomach, breast, colon, lung and thymus. Thus, we reported here a novel method to carry out immunohistochemical studies in free-floating human brain sections. Since fixation of brain tissue specimens in formaldehyde is a commonly method used in brain banks, this new antigen retrieval method could facilitate immunohistochemical studies of brains with prolonged formalin fixation times. PMID:18852880

Few-mode fiber detection for tissue characterization in optical coherence tomography

NASA Astrophysics Data System (ADS)

Eugui, Pablo; Lichtenegger, Antonia; Augustin, Marco; Harper, Danielle J.; Fialová, Stanislava; Wartak, Andreas; Hitzenberger, Christoph K.; Baumann, Bernhard

2017-07-01

A few-mode fiber based detection for OCT systems is presented. The capability of few-mode fibers for delivering light through different fiber paths enables the application of these fibers for angular scattering tissue character- ization. Since the optical path lengths traveled in the fiber change between the fiber modes, the OCT image information will be reconstructed at different depth positions, separating the directly backscattered light from the light scattered at other angles. Using the proposed method, the relation between the angle of reflection from the sample and the respective modal intensity distribution was investigated. The system was demonstrated for imaging ex-vivo brain tissue samples of patients with Alzheimer's disease.

Gangliosides and Ceramides Change in a Mouse Model of Blast Induced Traumatic Brain Injury

PubMed Central

2013-01-01

Explosive detonations generate atmospheric pressure changes that produce nonpenetrating blast induced “mild” traumatic brain injury (bTBI). The structural basis for mild bTBI has been extremely controversial. The present study applies matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging to track the distribution of gangliosides in mouse brain tissue that were exposed to very low level of explosive detonations (2.5–5.5 psi peak overpressure). We observed major increases of the ganglioside GM2 in the hippocampus, thalamus, and hypothalamus after a single blast exposure. Moreover, these changes were accompanied by depletion of ceramides. No neurological or brain structural signs of injury could be inferred using standard light microscopic techniques. The first source of variability is generated by the Latency between blast and tissue sampling (peak intensity of the blast wave). These findings suggest that subtle molecular changes in intracellular membranes and plasmalemma compartments may be biomarkers for biological responses to mild bTBI. This is also the first report of a GM2 increase in the brains of mature mice from a nongenetic etiology. PMID:23590251

Tomographic brain imaging with nucleolar detail and automatic cell counting

NASA Astrophysics Data System (ADS)

Hieber, Simone E.; Bikis, Christos; Khimchenko, Anna; Schweighauser, Gabriel; Hench, Jürgen; Chicherova, Natalia; Schulz, Georg; Müller, Bert

2016-09-01

Brain tissue evaluation is essential for gaining in-depth insight into its diseases and disorders. Imaging the human brain in three dimensions has always been a challenge on the cell level. In vivo methods lack spatial resolution, and optical microscopy has a limited penetration depth. Herein, we show that hard X-ray phase tomography can visualise a volume of up to 43 mm3 of human post mortem or biopsy brain samples, by demonstrating the method on the cerebellum. We automatically identified 5,000 Purkinje cells with an error of less than 5% at their layer and determined the local surface density to 165 cells per mm2 on average. Moreover, we highlight that three-dimensional data allows for the segmentation of sub-cellular structures, including dendritic tree and Purkinje cell nucleoli, without dedicated staining. The method suggests that automatic cell feature quantification of human tissues is feasible in phase tomograms obtained with isotropic resolution in a label-free manner.

A versatile clearing agent for multi-modal brain imaging

PubMed Central

Costantini, Irene; Ghobril, Jean-Pierre; Di Giovanna, Antonino Paolo; Mascaro, Anna Letizia Allegra; Silvestri, Ludovico; Müllenbroich, Marie Caroline; Onofri, Leonardo; Conti, Valerio; Vanzi, Francesco; Sacconi, Leonardo; Guerrini, Renzo; Markram, Henry; Iannello, Giulio; Pavone, Francesco Saverio

2015-01-01

Extensive mapping of neuronal connections in the central nervous system requires high-throughput µm-scale imaging of large volumes. In recent years, different approaches have been developed to overcome the limitations due to tissue light scattering. These methods are generally developed to improve the performance of a specific imaging modality, thus limiting comprehensive neuroanatomical exploration by multi-modal optical techniques. Here, we introduce a versatile brain clearing agent (2,2′-thiodiethanol; TDE) suitable for various applications and imaging techniques. TDE is cost-efficient, water-soluble and low-viscous and, more importantly, it preserves fluorescence, is compatible with immunostaining and does not cause deformations at sub-cellular level. We demonstrate the effectiveness of this method in different applications: in fixed samples by imaging a whole mouse hippocampus with serial two-photon tomography; in combination with CLARITY by reconstructing an entire mouse brain with light sheet microscopy and in translational research by imaging immunostained human dysplastic brain tissue. PMID:25950610

Bayesian estimation of optical properties of the human head via 3D structural MRI

NASA Astrophysics Data System (ADS)

Barnett, Alexander H.; Culver, Joseph P.; Sorensen, A. Gregory; Dale, Anders M.; Boas, David A.

2003-10-01

Knowledge of the baseline optical properties of the tissues of the human head is essential for absolute cerebral oximetry, and for quantitative studies of brain activation. In this work we numerically model the utility of signals from a small 6-optode time-resolved diffuse optical tomographic apparatus for inferring baseline scattering and absorption coefficients of the scalp, skull and brain, when complete geometric information is available from magnetic resonance imaging (MRI). We use an optical model where MRI-segmented tissues are assumed homogeneous. We introduce a noise model capturing both photon shot noise and forward model numerical accuracy, and use Bayesian inference to predict errorbars and correlations on the measurments. We also sample from the full posterior distribution using Markov chain Monte Carlo. We conclude that ~ 106 detected photons are sufficient to measure the brain"s scattering and absorption to a few percent. We present preliminary results using a fast multi-layer slab model, comparing the case when layer thicknesses are known versus unknown.

Isolation and confirmation of viral nervous necrosis (VNN) disease in golden grey mullet (Liza aurata) and leaping mullet (Liza saliens) in the Iranian waters of the Caspian Sea.

PubMed

Zorriehzahra, M E J; Ghasemi, M; Ghiasi, M; Karsidani, S Haghighi; Bovo, G; Nazari, A; Adel, M; Arizza, V; Dhama, K

2016-07-15

The present study was conducted on 428 moribund mullet fish samples to isolate and identify the causative agent of a mysterious acute mortality which recently occurred in wild mullets in Iranian waters of Caspian Sea, suspected to be due to viral nervous necrosis (VNN) disease. Disease investigation was carried out employing various diagnostic procedures such as virology, bacteriology, parasitology, haematology, histopathology, IFAT, IHC and nested RT-PCR. Brain and eye samples of affected fishes were collected in sterile conditions and then kept at -80°C for cell culture isolation and nested RT-PCR detection of the causative agent. Other tissue samples were also collected and fixed for histopathology, IHC and EM examinations. CPE was observed in cell cultures at 6days after inoculation. Nine samples were found positive with virological assay. Nested RT-PCR, performed on suspected tissues and CPE positive samples, showed that about 21 tissue samples and all the CPE positive samples were positive for VNN virus (VNNV). IFAT was selected as a confirmatory method for detecting the presence of Betanodavirus antigen, cell culture isolation results and nested RT-PCR findings. Moreover, VNNV particles with 25-30nm in diameter were also visualized in the infected brain and retina. In pathogenicity studies, guppy fishes bathed in VNNV-infected tissue culture (10(-4) TCID50) showed clinical signs similar to naturally infected mullet after 15days post infection (dpi), with mortality rates reaching up to 100% at 30dpi. Affected organ samples as examined by cell culture isolation, IFAT, IHC and histopathology, revealed the presence of VNNV in the guppy fishes. In conclusion, it was confirmed that VNNV was the main causative agent for the disease outbreak in mullet fish in the Caspian Sea, and this is such first official report of VNN disease from Iran. Copyright © 2016 Elsevier B.V. All rights reserved.

Total and regional brain volumes in a population-based normative sample from 4 to 18 years: the NIH MRI Study of Normal Brain Development.

PubMed

2012-01-01

Using a population-based sampling strategy, the National Institutes of Health (NIH) Magnetic Resonance Imaging Study of Normal Brain Development compiled a longitudinal normative reference database of neuroimaging and correlated clinical/behavioral data from a demographically representative sample of healthy children and adolescents aged newborn through early adulthood. The present paper reports brain volume data for 325 children, ages 4.5-18 years, from the first cross-sectional time point. Measures included volumes of whole-brain gray matter (GM) and white matter (WM), left and right lateral ventricles, frontal, temporal, parietal and occipital lobe GM and WM, subcortical GM (thalamus, caudate, putamen, and globus pallidus), cerebellum, and brainstem. Associations with cross-sectional age, sex, family income, parental education, and body mass index (BMI) were evaluated. Key observations are: 1) age-related decreases in lobar GM most prominent in parietal and occipital cortex; 2) age-related increases in lobar WM, greatest in occipital, followed by the temporal lobe; 3) age-related trajectories predominantly curvilinear in females, but linear in males; and 4) small systematic associations of brain tissue volumes with BMI but not with IQ, family income, or parental education. These findings constitute a normative reference on regional brain volumes in children and adolescents.

Quantification of endogenous retinoic acid in limited biological samples by LC/MS/MS

PubMed Central

Kane, Maureen A.; Chen, Na; Sparks, Susan; Napoli, Joseph L.

2005-01-01

We report a sensitive LC (liquid chromatography)/MS/MS assay using selected reaction monitoring to quantify RA (retinoic acid), which is applicable to biological samples of limited size (10–20 mg of tissue wet weight), requires no sample derivatization, provides mass identification and resolves atRA (all-trans-RA) from its geometric isomers. The assay quantifies over a linear range of 20 fmol to 10 pmol, and has a 10 fmol limit of detection at a signal/noise ratio of 3. Coefficients of variation are: instrumental, 0.5–2.9%; intra-assay, 5.4±0.4%; inter-assay 8.9±1.0%. An internal standard (all-trans-4,4-dimethyl-RA) improves accuracy by confirming extraction efficiency and revealing handling-induced isomerization. Tissues of 2–4-month-old C57BL/6 male mice had atRA concentrations of 7–9.6 pmol/g and serum atRA of 1.9±0.6 pmol/ml (±S.E.M.). Tissue 13-cis-RA ranged from 2.9 to 4.2 pmol/g, and serum 13-cis-RA was 1.2±0.3 pmol/ml. CRBP (cellular retinol-binding protein)-null mouse liver had atRA ∼30% lower than wild-type (P<0.05), but kidney, testis, brain and serum atRA were similar to wild-type. atRA in brain areas of 12-month-old female C57BL/6 mice were (±S.E.M.): whole brain, 5.4±0.4 pmol/g; cerebellum, 10.7±0.3 pmol/g; cortex, 2.6±0.4 pmol/g; hippocampus, 8.4±1.2 pmol/g; striatum, 15.3±4.7 pmol/g. These data provide the first analytically robust quantification of atRA in animal brain and in CRBP-null mice. Direct measurements of endogenous RA should have a substantial impact on investigating target tissues of RA, mechanisms of RA action, and the relationship between RA and chronic disease. PMID:15628969

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

PubMed

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J; Kertesz, Vilmos; Gan, Jinping

2016-03-25

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites were studied. Major organs (brain, lung, liver, kidney and muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed the same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. In addition, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement. Copyright © 2015 Elsevier B.V. All rights reserved.

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

DOE PAGES

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J.; ...

2015-11-03

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites was studied. Major organs (brain, lung, liver, kidney, muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed themore » same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. Furthermore, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement.« less

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J.

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites was studied. Major organs (brain, lung, liver, kidney, muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed themore » same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. Furthermore, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement.« less

The relationship between decorrelation time and sample thickness in acute rat brain tissue slices (Conference Presentation)

NASA Astrophysics Data System (ADS)

Brake, Joshua; Jang, Mooseok; Yang, Changhuei

2016-03-01

The optical opacity of biological tissue has long been a challenge in biomedical optics due to the strong scattering nature of tissue in the optical regime. While most conventional optical techniques attempt to gate out multiply scattered light and use only unscattered light, new approaches in the field of wavefront shaping exploit the time reversible symmetry of optical scattering in order to focus light inside or through scattering media. While these approaches have been demonstrated effectively on static samples, it has proven difficult to apply them to dynamic biological samples since even small changes in the relative positions of the scatterers within will cause the time symmetry that wavefront shaping relies upon to decorrelate. In this paper we investigate the decorrelation curves of acute rat brain slices for thicknesses in the range 1-3 mm (1/e decorrelation time on the order of seconds) using multi-speckle diffusing wave spectroscopy (MSDWS) and compare the results with theoretical predictions. The results of this study demonstrate that the 1/L^2 relationship between decorrelation time and thickness predicted by diffusing wave spectroscopy provides a good rule of thumb for estimating how the decorrelation of a sample will change with increasing thickness. Understanding this relationship will provide insight to guide the future development of biophotonic wavefront shaping tools by giving an estimate of how fast wavefront shaping systems need to operate to overcome the dynamic nature of biological samples.

Relationship between position of brain activity and change in optical density for NIR imaging

NASA Astrophysics Data System (ADS)

Kashio, Yoshihiko; Ono, Muneo; Firbank, Michael; Schweiger, Martin; Arridge, Simon R.; Okada, Eiji

2000-11-01

Multi-channel NIR system can obtain the topographic image of brain activity. Since the image is reconstructed from the change in optical density measured with the source-detector pairs, it is important to reveal the volume of tissue sampled by each source-detector pair. In this study, the light propagation in three-dimensional adult head model is calculated by hybrid radiosity-diffusion method. The model is a layered slab which mimics the extra cerebral tissue (skin, skull), CSF and brain. The change in optical density caused by the absorption change in a small cylindrical region of 10 mm in diameter at various positions in the brain is calculated. The greatest change in optical density can be observed when the absorber is located in the middle of the source and detector. When the absorber is located just below the source or detector, the change in optical density is almost half of that caused by the same absorber in the midpoint. The light propagation in the brain is strongly affected by the presence of non-scattering layer and consequently sensitive region is broadly distributed on the brain surface.

Effect of naturally mouldy wheat or fungi administration on metallothioneins level in brain tissues of rats.

PubMed

Vasatkova, Anna; Krizova, Sarka; Krystofova, Olga; Adam, Vojtech; Zeman, Ladislav; Beklova, Miroslava; Kizek, Rene

2009-01-01

The aim of this study is to determine level of metallothioneins (MTs) in brain tissues of rats administered by feed mixtures with different content of mouldy wheat or fungi. Selected male laboratory rats of Wistar albino at age of 28 days were used in our experiments. The rats were administered by feed mixtures with different content of vitamins, naturally mouldy wheat or fungi for 28 days. At the very end of the experiment, the animals were put to death and brains were sampled. MT level was determined by differential pulse voltammetry Brdicka reaction. We found that MTs' level in brain tissues from rats administered by standard feed mixtures was significantly higher compared to the level of MTs in rats supplemented by vitamins. Further we studied the effect of supplementation of naturally mouldy wheat on MTs level in rats. In mouldy wheat we detected the presence of following fungi species: Mucor spp., Absidia spp., Penicillium spp., Aspergillus spp. and Fusarium spp. Moreover we also identified and quantified following mycotoxins - deoxynivalenol, zearalenone, T2-toxin and aflatoxins. Level of MTs determined in rats treated with 33 or 66% of mouldy wheat was significantly lower compared to control ones. On the other hand rats treated with 100% of mouldy wheat had less MTs but not significantly. Supplementation of vitamins to rats fed by mouldy wheat had adverse effect on MTs level compared to rats with no other supplementation by vitamins. Moreover vitamins supplementation has no effect on MTs level in brain tissues of rats treated or non-treated with Ganoderma lucidum L. Both mycotoxins and vitamins have considerable effect on level of MTs in brain tissues. It can be assumed that the administered substances markedly influence redox metabolism, which could negatively influence numerous biochemical pathways including those closely related with MTs.

Custom fit 3D-printed brain holders for comparison of histology with MRI in marmosets.

PubMed

Guy, Joseph R; Sati, Pascal; Leibovitch, Emily; Jacobson, Steven; Silva, Afonso C; Reich, Daniel S

2016-01-15

MRI has the advantage of sampling large areas of tissue and locating areas of interest in 3D space in both living and ex vivo systems, whereas histology has the ability to examine thin slices of ex vivo tissue with high detail and specificity. Although both are valuable tools, it is currently difficult to make high-precision comparisons between MRI and histology due to large differences inherent to the techniques. A method combining the advantages would be an asset to understanding the pathological correlates of MRI. 3D-printed brain holders were used to maintain marmoset brains in the same orientation during acquisition of ex vivo MRI and pathologic cutting of the tissue. The results of maintaining this same orientation show that sub-millimeter, discrete neuropathological features in marmoset brain consistently share size, shape, and location between histology and ex vivo MRI, which facilitates comparison with serial imaging acquired in vivo. Existing methods use computational approaches sensitive to data input in order to warp histologic images to match large-scale features on MRI, but the new method requires no warping of images, due to a preregistration accomplished in the technique, and is insensitive to data formatting and artifacts in both MRI and histology. The simple method of using 3D-printed brain holders to match brain orientation during pathologic sectioning and MRI acquisition enables rapid and precise comparison of small features seen on MRI to their underlying histology. Published by Elsevier B.V.

A Whole Methylome CpG-SNP Association Study of Psychosis in Blood and Brain Tissue.

PubMed

van den Oord, Edwin J C G; Clark, Shaunna L; Xie, Lin Ying; Shabalin, Andrey A; Dozmorov, Mikhail G; Kumar, Gaurav; Vladimirov, Vladimir I; Magnusson, Patrik K E; Aberg, Karolina A

2016-07-01

Mutated CpG sites (CpG-SNPs) are potential hotspots for human diseases because in addition to the sequence variation they may show individual differences in DNA methylation. We performed methylome-wide association studies (MWAS) to test whether methylation differences at those sites were associated with schizophrenia. We assayed all common CpG-SNPs with methyl-CpG binding domain protein-enriched genome sequencing (MBD-seq) using DNA extracted from 1408 blood samples and 66 postmortem brain samples (BA10) of schizophrenia cases and controls. Seven CpG-SNPs passed our FDR threshold of 0.1 in the blood MWAS. Of the CpG-SNPs methylated in brain, 94% were also methylated in blood. This significantly exceeded the 46.2% overlap expected by chance (P-value < 1.0×10(-8)) and justified replicating findings from blood in brain tissue. CpG-SNP rs3796293 in IL1RAP replicated (P-value = .003) with the same direction of effects. This site was further validated through targeted bisulfite pyrosequencing in 736 independent case-control blood samples (P-value < 9.5×10(-4)). Our top result in the brain MWAS (P-value = 8.8×10(-7)) was CpG-SNP rs16872141 located in the potential promoter of ENC1. Overall, our results suggested that CpG-SNP methylation may reflect effects of environmental insults and can provide biomarkers in blood that could potentially improve disease management. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Differentiating pediatric epileptic brain tissue from normal brain tissue by using time-dependent diffuse reflectance spectroscopy in vivo: comprehensive data analysis method in the time domain

NASA Astrophysics Data System (ADS)

Oh, Sanghoon; Fernald, Bradley; Bhatia, Sanjiv; Ragheb, John; Sandberg, David; Johnson, Mahlon; Lin, Wei-Chiang

2009-05-01

This research investigated the feasibility of using time-dependent diffuse reflectance spectroscopy to differentiate pediatric epileptic brain tissue from normal brain tissue. The optical spectroscopic technique monitored the dynamic optical properties of the cerebral cortex that are associated with its physiological, morphological, and compositional characteristics. Due to the transient irregular epileptic discharge activity within the epileptic brain tissue it was hypothesized that the lesion would express abnormal dynamic optical behavior that would alter normal dynamic behavior. Thirteen pediatric epilepsy patients and seven pediatric brain tumor patients (normal controls) were recruited for this clinical study. Dynamic optical properties were obtained from the cortical surface intraoperatively using a timedependent diffuse reflectance spectroscopy system. This system consisted of a fiber-optic probe, a tungsten-halogen light source, and a spectrophotometer. It acquired diffuse reflectance spectra with a spectral range of 204 nm to 932 nm at a rate of 33 spectra per second for approximately 12 seconds. Biopsy samples were taken from electrophysiologically abnormal cortex and evaluated by a neuropathologist, which served as a gold standard for lesion classification. For data analysis, spectral intensity changes of diffuse reflectance in the time domain at two different wavelengths from each investigated site were compared. Negative correlation segment, defined by the periods where the intensity changes at the two wavelengths were opposite in their slope polarity, were extracted. The total duration of negative correlation, referred to as the "negative correlation time index", was calculated by integrating the negative correlation segments. The negative correlation time indices from all investigated sites were sub-grouped according to the corresponding histological classifications. The difference between the mean indices of two subgroups was evaluated by standard t-test. These comparison and calculation procedures were carried out for all possible wavelength combinations between 400 nm and 800 nm with 2 nm increments. The positive group consisted of seven pathologically abnormal test sites, and the negative group consisted of 13 normal test sites from non-epileptic tumor patients. A standard t-test showed significant difference between negative correlation time indices from the two groups at the wavelength combinations of 700-760 nm versus 550-580 nm. An empirical discrimination algorithm based on the negative correlation time indices in this range produced 100% sensitivity and 85% specificity. Based on these results time-dependent diffuse reflectance spectroscopy with optimized data analysis methods differentiates epileptic brain tissue from normal brain tissue adequately, therefore can be utilized for surgical guidance, and may enhance the surgical outcome of pediatric epilepsy surgery.

Mannitol Improves Brain Tissue Oxygenation in a Model of Diffuse Traumatic Brain Injury.

PubMed

Schilte, Clotilde; Bouzat, Pierre; Millet, Anne; Boucheix, Perrine; Pernet-Gallay, Karin; Lemasson, Benjamin; Barbier, Emmanuel L; Payen, Jean-François

2015-10-01

Based on evidence supporting a potential relation between posttraumatic brain hypoxia and microcirculatory derangements with cell edema, we investigated the effects of the antiedematous agent mannitol on brain tissue oxygenation in a model of diffuse traumatic brain injury. Experimental study. Neurosciences and physiology laboratories. Adult male Wistar rats. Thirty minutes after diffuse traumatic brain injury (impact-acceleration model), rats were IV administered with either a saline solution (traumatic brain injury-saline group) or 20% mannitol (1 g/kg) (traumatic brain injury-mannitol group). Sham-saline and sham-mannitol groups received no insult. Two series of experiments were conducted 2 hours after traumatic brain injury (or equivalent) to investigate 1) the effect of mannitol on brain edema and oxygenation, using a multiparametric magnetic resonance-based approach (n = 10 rats per group) to measure the apparent diffusion coefficient, tissue oxygen saturation, mean transit time, and blood volume fraction in the cortex and caudoputamen; 2) the effect of mannitol on brain tissue PO2 and on venous oxygen saturation of the superior sagittal sinus (n = 5 rats per group); and 3) the cortical ultrastructural changes after treatment (n = 1 per group, taken from the first experiment). Compared with the sham-saline group, the traumatic brain injury-saline group had significantly lower tissue oxygen saturation, brain tissue PO2, and venous oxygen saturation of the superior sagittal sinus values concomitant with diffuse brain edema. These effects were associated with microcirculatory collapse due to astrocyte swelling. Treatment with mannitol after traumatic brain injury reversed all these effects. In the absence of traumatic brain injury, mannitol had no effect on brain oxygenation. Mean transit time and blood volume fraction were comparable between the four groups of rats. The development of posttraumatic brain edema can limit the oxygen utilization by brain tissue without evidence of brain ischemia. Our findings indicate that an antiedematous agent such as mannitol can improve brain tissue oxygenation, possibly by limiting astrocyte swelling and restoring capillary perfusion.

Detection frequency of human herpesviruses-6A, -6B, and -7 genomic sequences in central nervous system DNA samples from post-mortem individuals with unspecified encephalopathy.

PubMed

Chapenko, Svetlana; Roga, Silvija; Skuja, Sandra; Rasa, Santa; Cistjakovs, Maksims; Svirskis, Simons; Zaserska, Zane; Groma, Valerija; Murovska, Modra

2016-08-01

In this autopsy-based study, human herpesvirus-6 (HHV-6) and -7 (HHV-7) genomic sequence frequency, HHV-6 variants, HHV-6 load and the expression of HHV-6 antigens in brain samples from the individuals, with and without unspecified encephalopathy (controls), using nested and real-time polymerase chain reactions, restriction endonuclease, and immunohistochemical analysis were examined. GraphPad Prism 6.0 Mann-Whitney nonparametric and chi-square test and Fisher's exact test were used for statistical analysis. The encephalopathy diagnoses were shown by magnetic resonance imaging made during their lifetime and macro- and microscopically studied autopsy tissue materials. Widespread HHV-6 and/or HHV-7 positivity was detected in the brain tissue of various individuals with encephalopathy, as well as in controls (51/57, 89.4 % and 35/51, 68.6 %, respectively; p = 0.009). Significantly higher detection frequency of single HHV-6 and concurrent HHV-6 + HHV-7 DNA was found in pia mater meninges, frontal lobe, temporal lobe, and olfactory tract DNAs in individuals with encephalopathy compared to the control group. HHV-6 load and higher frequency of the viral load >10 copies/10(6) cells significantly differed in samples from individuals with and without encephalopathy. The expression of HHV-6 antigens was revealed in different neural cell types with strong predominance in the encephalopathy group. In all HHV-6-positive autopsy samples of individuals with and without encephalopathy, HHV-6B was revealed. Significantly higher detection frequency of beta-herpesvirus DNA, more often detected HHV-6 load >10 copies/10(6) cells, as well as the expression of HHV-6 antigens in different brain tissue samples from individuals with encephalopathy in comparison with control group indicate on potential involvement of these viruses in encephalopathy development.

Adaptive optical microscope for brain imaging in vivo

NASA Astrophysics Data System (ADS)

Wang, Kai

2017-04-01

The optical heterogeneity of biological tissue imposes a major limitation to acquire detailed structural and functional information deep in the biological specimens using conventional microscopes. To restore optimal imaging performance, we developed an adaptive optical microscope based on direct wavefront sensing technique. This microscope can reliably measure and correct biological samples induced aberration. We demonstrated its performance and application in structural and functional brain imaging in various animal models, including fruit fly, zebrafish and mouse.

Interactions between Electromagnetic Fields.

DTIC Science & Technology

1985-02-10

the cortical surface of a cat, in vivo, caused calcium release. Follow-up.nvestigatlons, using radiofrequency (RF) radiation , utilized simplfer, in...vitro brain tissue preparations from the cat and from the chicken. RF radiation was found to cause changes in the calcium flux only when the radiation ...circumvented by the finding th#’ t sub-ELF signals applied directly to the sample can also cause changes ip the calcium fluxes, although at tissue intensities on

Brain tissue analysis using texture features based on optical coherence tomography images

NASA Astrophysics Data System (ADS)

Lenz, Marcel; Krug, Robin; Dillmann, Christopher; Gerhardt, Nils C.; Welp, Hubert; Schmieder, Kirsten; Hofmann, Martin R.

2018-02-01

Brain tissue differentiation is highly demanded in neurosurgeries, i.e. tumor resection. Exact navigation during the surgery is essential in order to guarantee best life quality afterwards. So far, no suitable method has been found that perfectly covers this demands. With optical coherence tomography (OCT), fast three dimensional images can be obtained in vivo and contactless with a resolution of 1-15 μm. With these specifications OCT is a promising tool to support neurosurgeries. Here, we investigate ex vivo samples of meningioma, healthy white and healthy gray matter in a preliminary study towards in vivo brain tumor removal assistance. Raw OCT images already display structural variations for different tissue types, especially meningioma. But, in order to achieve neurosurgical guidance directly during resection, an automated differentiation approach is desired. For this reason, we employ different texture feature based algorithms, perform a Principal Component Analysis afterwards and then train a Support Vector Machine classifier. In the future we will try different combinations of texture features and perform in vivo measurements in order to validate our findings.

Infant phantom head circuit board for EEG head phantom and pediatric brain simulation

NASA Astrophysics Data System (ADS)

Almohsen, Safa

The infant's skull differs from an adult skull because of the characteristic features of the human skull during early development. The fontanels and the conductivity of the infant skull influence surface currents, generated by neurons, which underlie electroencephalography (EEG) signals. An electric circuit was built to power a set of simulated neural sources for an infant brain activity simulator. Also, in the simulator, three phantom tissues were created using saline solution plus Agarose gel to mimic the conductivity of each layer in the head [scalp, skull brain]. The conductivity measurement was accomplished by two different techniques: using the four points' measurement technique, and a conductivity meter. Test results showed that the optimized phantom tissues had appropriate conductivities to simulate each tissue layer to fabricate a physical head phantom. In this case, the best results should be achieved by testing the electrical neural circuit with the sample physical model to generate simulated EEG data and use that to solve both the forward and the inverse problems for the purpose of localizing the neural sources in the head phantom.

Study on Material Parameters Identification of Brain Tissue Considering Uncertainty of Friction Coefficient

NASA Astrophysics Data System (ADS)

Guan, Fengjiao; Zhang, Guanjun; Liu, Jie; Wang, Shujing; Luo, Xu; Zhu, Feng

2017-10-01

Accurate material parameters are critical to construct the high biofidelity finite element (FE) models. However, it is hard to obtain the brain tissue parameters accurately because of the effects of irregular geometry and uncertain boundary conditions. Considering the complexity of material test and the uncertainty of friction coefficient, a computational inverse method for viscoelastic material parameters identification of brain tissue is presented based on the interval analysis method. Firstly, the intervals are used to quantify the friction coefficient in the boundary condition. And then the inverse problem of material parameters identification under uncertain friction coefficient is transformed into two types of deterministic inverse problem. Finally the intelligent optimization algorithm is used to solve the two types of deterministic inverse problems quickly and accurately, and the range of material parameters can be easily acquired with no need of a variety of samples. The efficiency and convergence of this method are demonstrated by the material parameters identification of thalamus. The proposed method provides a potential effective tool for building high biofidelity human finite element model in the study of traffic accident injury.

Intra-operative probe for brain cancer: feasibility study

NASA Astrophysics Data System (ADS)

Vu Thi, M. H.; Charon, Y.; Duval, M. A.; Lefebvre, F.; Menard, L.; Pitre, S.; Pinot, L.; Siebert, R.

2007-07-01

The present work aims a new medical probe for surgeons devoted to brain cancers, in particular glioblastoma multiforme. Within the last years, our group has started the development of a new intra-operative beta imaging probe. More recently, we took an alternative approach for the same application: a fluorescence probe. In both cases the purpose is to differentiate normal from tumor brain tissue. In a first step, we developed set-ups capable to measure autofluorescence. They are based on a dedicated epi-fluorescence design and on specific fiber optic probes. Relative signal amplitude, spectral shape and fluorescence lifetime measurements are foreseen to distinguish normal and cancer tissue by analyzing fluorophores like NADH, lipopigments and porphyrines. The autofluorescence spectra are recorded in the 460-640 nm range with a low resolution spectrometer. For lifetime measurements a fast detector (APD) is used together with a TCSPC-carte. Intrinsic wavelength- and time-resolutions are a few nm and 200 ps, respectively. Different samples have been analyzed to validate our new detection system and to allow a first configuration of our medical fluorescence probe. First results from the tissue measurements are shown.

Evidence of Borna disease virus genome detection in French domestic animals and in foxes (Vulpes vulpes).

PubMed

Dauphin, G; Legay, V; Sailleau, C; Smondack, S; Hammoumi, S; Zientara, S

2001-09-01

Borna disease virus (BDV) is an enveloped, non-segmented negative-stranded RNA virus which belongs to the Bornaviridae family. BDV is an aetiological agent of encephalitis in horses, sheep and several other vertebrate species. In order to extend our knowledge about the presence of BDV in France, a study based on BDV RNA detection by RT-nested-PCR was done with 196 animal tissues: 171 brain samples collected from different animal species (75 horses, 59 foxes, 31 cattle, 4 dogs, 1 sheep, 1 roe deer) and 25 horse blood samples. An RNA internal standard molecule was constructed and was co-amplified with the test template. This study reports the first detection of BDV RNA in France in 10 brain samples collected from horses, foxes and cattle, and from 14 horse blood samples. Detection of the BDV genome in the brains of six red foxes is the first evidence of BDV infection in this species.

Brain metastasis detection by resonant Raman optical biopsy method

NASA Astrophysics Data System (ADS)

Zhou, Yan; Liu, Cheng-hui; Cheng, Gangge; Zhou, Lixin; Zhang, Chunyuan; Pu, Yang; Li, Zhongwu; Liu, Yulong; Li, Qingbo; Wang, Wei; Alfano, Robert R.

2014-03-01

Resonant Raman (RR) spectroscopy provides an effective way to enhance Raman signal from particular bonds associated with key molecules due to changes on a molecular level. In this study, RR is used for detection of human brain metastases of five kinds of primary organs of lung, breast, kidney, rectal and orbital in ex-vivo. The RR spectra of brain metastases cancerous tissues were measured and compared with those of normal brain tissues and the corresponding primary cancer tissues. The differences of five types of brain metastases tissues in key bio-components of carotene, tryptophan, lactate, alanine and methyl/methylene group were investigated. The SVM-KNN classifier was used to categorize a set of RR spectra data of brain metastasis of lung cancerous tissues from normal brain tissue, yielding diagnostic sensitivity and specificity at 100% and 75%, respectively. The RR spectroscopy may provide new moleculebased optical probe tools for diagnosis and classification of brain metastatic of cancers.

Increased White Matter Inflammation in Aging- and Alzheimer's Disease Brain.

PubMed

Raj, Divya; Yin, Zhuoran; Breur, Marjolein; Doorduin, Janine; Holtman, Inge R; Olah, Marta; Mantingh-Otter, Ietje J; Van Dam, Debby; De Deyn, Peter P; den Dunnen, Wilfred; Eggen, Bart J L; Amor, Sandra; Boddeke, Erik

2017-01-01

Chronic neuroinflammation, which is primarily mediated by microglia, plays an essential role in aging and neurodegeneration. It is still unclear whether this microglia-induced neuroinflammation occurs globally or is confined to distinct brain regions. In this study, we investigated microglia activity in various brain regions upon healthy aging and Alzheimer's disease (AD)-related pathology in both human and mouse samples. In purified microglia isolated from aging mouse brains, we found a profound gene expression pattern related to pro-inflammatory processes, phagocytosis, and lipid homeostasis. Particularly in white matter microglia of 24-month-old mice, abundant expression of phagocytic markers including Mac-2, Axl, CD16/32, Dectin1, CD11c, and CD36 was detected. Interestingly, in white matter of human brain tissue the first signs of inflammatory activity were already detected during middle age. Thus quantification of microglial proteins, such as CD68 (commonly associated with phagocytosis) and HLA-DR (associated with antigen presentation), in postmortem human white matter brain tissue showed an age-dependent increase in immunoreactivity already in middle-aged people (53.2 ± 2.0 years). This early inflammation was also detectable by non-invasive positron emission tomography imaging using [ 11 C]-(R)-PK11195, a ligand that binds to activated microglia. Increased microglia activity was also prominently present in the white matter of human postmortem early-onset AD (EOAD) brain tissue. Interestingly, microglia activity in the white matter of late-onset AD (LOAD) CNS was similar to that of the aged clinically silent AD cases. These data indicate that microglia-induced neuroinflammation is predominant in the white matter of aging mice and humans as well as in EOAD brains. This white matter inflammation may contribute to the progression of neurodegeneration, and have prognostic value for detecting the onset and progression of aging and neurodegeneration.

Proposals for best-quality immunohistochemical staining of paraffin-embedded brain tissue slides in forensics.

PubMed

Trautz, Florian; Dreßler, Jan; Stassart, Ruth; Müller, Wolf; Ondruschka, Benjamin

2018-01-03

Immunohistochemistry (IHC) has become an integral part in forensic histopathology over the last decades. However, the underlying methods for IHC vary greatly depending on the institution, creating a lack of comparability. The aim of this study was to assess the optimal approach for different technical aspects of IHC, in order to improve and standardize this procedure. Therefore, qualitative results from manual and automatic IHC staining of brain samples were compared, as well as potential differences in suitability of common IHC glass slides. Further, possibilities of image digitalization and connected issues were investigated. In our study, automatic staining showed more consistent staining results, compared to manual staining procedures. Digitalization and digital post-processing facilitated direct analysis and analysis for reproducibility considerably. No differences were found for different commercially available microscopic glass slides regarding suitability of IHC brain researches, but a certain rate of tissue loss should be expected during the staining process.

Preservation of mitochondrial functional integrity in mitochondria isolated from small cryopreserved mouse brain areas.

PubMed

Valenti, Daniela; de Bari, Lidia; De Filippis, Bianca; Ricceri, Laura; Vacca, Rosa Anna

2014-01-01

Studies of mitochondrial bioenergetics in brain pathophysiology are often precluded by the need to isolate mitochondria immediately after tissue dissection from a large number of brain biopsies for comparative studies. Here we present a procedure of cryopreservation of small brain areas from which mitochondrial enriched fractions (crude mitochondria) with high oxidative phosphorylation efficiency can be isolated. Small mouse brain areas were frozen and stored in a solution containing glycerol as cryoprotectant. Crude mitochondria were isolated by differential centrifugation from both cryopreserved and freshly explanted brain samples and were compared with respect to their ability to generate membrane potential and produce ATP. Intactness of outer and inner mitochondrial membranes was verified by polarographic ascorbate and cytochrome c tests and spectrophotometric assay of citrate synthase activity. Preservation of structural integrity and oxidative phosphorylation efficiency was successfully obtained in crude mitochondria isolated from different areas of cryopreserved mouse brain samples. Long-term cryopreservation of small brain areas from which intact and phosphorylating mitochondria can be isolated for the study of mitochondrial bioenergetics will significantly expand the study of mitochondrial defects in neurological pathologies, allowing large comparative studies and favoring interlaboratory and interdisciplinary analyses. Copyright © 2013 Elsevier Inc. All rights reserved.

Edema fluid accumulation within necrotic brain tissue as a cause of the mass effect of cerebral contusion in head trauma patients.

PubMed

Katayama, Y; Kawamata, T

2003-01-01

The early massive edema caused by severe cerebral contusion results in progressive intracranial pressure (ICP) elevation and clinical deterioration within 24-72 hours post-trauma. Surgical excision of the necrotic brain tissue represents the only therapy, which can provide satisfactory control of the elevated ICP and clinical deterioration. In order to elucidate the mechanisms underlying the early massive edema, we have carried out a series of detailed clinical studies. Diffusion magnetic resonance (MR) imaging and apparent diffusion co-efficient (ADC) mapping suggest that cells in the central area of contusion undergo shrinkage, disintegration and homogenization, whereas cellular swelling is predominant in the peripheral area during the period of 24-72 hours post-trauma. The ADC values in the central and peripheral areas are maximally dissociated during this period. A large amount of edema fluid accumulates within the necrotic brain tissue of the central area beginning at approximately 24 hours post-trauma. We have found that fluid-blood interface formation within the central area does not represent an uncommon finding in various neuroimaging examinations of cerebral contusions, indicating layering of red blood cells within the necrotic brain tissue accumulating voluminous edema fluid. Intravenous slow infusion of gadolinium-DTPA and delayed MR imaging revealed that the central area of contusion can be enhanced at 24-48 hours post-trauma. implying that water supply from the blood vessels is not completely interrupted. Necrotic brain tissue sampled from the central area of contusion during surgery demonstrates a very high osmolality. It appears that the capacitance for edema fluid accumulation increases in the central area, whereas cellular swelling in the peripheral area elevates the resistance for edema fluid propagation. Combination of these circumstances may facilitate edema fluid accumulation in the central area. We also suggest that the dissociation of ADC values and high osmolality within the necrotic brain tissue may generate an osmotic potential across the central and peripheral areas and contribute to the early massive edema caused by cerebral contusion.

Analysis of acute brain slices by electron microscopy: a correlative light-electron microscopy workflow based on Tokuyasu cryo-sectioning.

PubMed

Loussert Fonta, Celine; Leis, Andrew; Mathisen, Cliff; Bouvier, David S; Blanchard, Willy; Volterra, Andrea; Lich, Ben; Humbel, Bruno M

2015-01-01

Acute brain slices are slices of brain tissue that are kept vital in vitro for further recordings and analyses. This tool is of major importance in neurobiology and allows the study of brain cells such as microglia, astrocytes, neurons and their inter/intracellular communications via ion channels or transporters. In combination with light/fluorescence microscopies, acute brain slices enable the ex vivo analysis of specific cells or groups of cells inside the slice, e.g. astrocytes. To bridge ex vivo knowledge of a cell with its ultrastructure, we developed a correlative microscopy approach for acute brain slices. The workflow begins with sampling of the tissue and precise trimming of a region of interest, which contains GFP-tagged astrocytes that can be visualised by fluorescence microscopy of ultrathin sections. The astrocytes and their surroundings are then analysed by high resolution scanning transmission electron microscopy (STEM). An important aspect of this workflow is the modification of a commercial cryo-ultramicrotome to observe the fluorescent GFP signal during the trimming process. It ensured that sections contained at least one GFP astrocyte. After cryo-sectioning, a map of the GFP-expressing astrocytes is established and transferred to correlation software installed on a focused ion beam scanning electron microscope equipped with a STEM detector. Next, the areas displaying fluorescence are selected for high resolution STEM imaging. An overview area (e.g. a whole mesh of the grid) is imaged with an automated tiling and stitching process. In the final stitched image, the local organisation of the brain tissue can be surveyed or areas of interest can be magnified to observe fine details, e.g. vesicles or gold labels on specific proteins. The robustness of this workflow is contingent on the quality of sample preparation, based on Tokuyasu's protocol. This method results in a reasonable compromise between preservation of morphology and maintenance of antigenicity. Finally, an important feature of this approach is that the fluorescence of the GFP signal is preserved throughout the entire preparation process until the last step before electron microscopy. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

[Postmortem distribution of tetrodotoxin in tissues and body fluids of guinea pigs].

PubMed

Liu, Wei; Da, Qing; Shen, Min

2012-06-01

To investigate the postmortem distribution of tetrodotoxin in tissues and body fluids of guinea pig, and to provide method and evidence for forensic identification and clinical diagnosis and treatment. Guinea pigs were intragastric administrated with 100, 50, 15 microg/kg tetrodotoxin, respectively. The poisoning symptoms were observed. The samples of heart, liver, spleen, lung, kidney, brain, stomach, intestines, bile, heart blood and urine were collected. The concentrations of tetrodotoxin in tissues and body fluids were measured with liquid chromatography-tandem mass spectrometry (LC-MS/MS). After administrated with tetrodotoxin, all guinea pigs came out poisoning signs including tachypnea, weary and dead finally. Tetrodotoxin concentrations in lung, stomach, intestines and urine were higher, followed by blood, heart and brain. The concentration in bile was the lowest. Postmortem distribution of tetrodotoxin in guinea pig is uneven. The concentration in the lung, stomach, intestines, urine and heart blood are higher, those tissues could be used for diagnosis of tetrodotoxin poisoning.

Glycoblotting method allows for rapid and efficient glycome profiling of human Alzheimer's disease brain, serum and cerebrospinal fluid towards potential biomarker discovery.

PubMed

Gizaw, Solomon T; Ohashi, Tetsu; Tanaka, Masakazu; Hinou, Hiroshi; Nishimura, Shin-Ichiro

2016-08-01

Understanding of the significance of posttranslational glycosylation in Alzheimer's disease (AD) is of growing importance for the investigation of the pathogenesis of AD as well as discovery research of the disease-specific serum biomarkers. We designed a standard protocol for the glycoblotting combined with MALDI-TOFMS to perform rapid and quantitative profiling of the glycan parts of glycoproteins (N-glycans) and glycosphingolipids (GSLs) using human AD's post-mortem samples such as brain tissues (dissected cerebral cortices such as frontal, parietal, occipital, and temporal domains), serum and cerebrospinal fluid (CSF). The structural profiles of the major N-glycans released from glycoproteins and the total expression levels of the glycans were found to be mostly similar between the brain tissues of the AD patients and those of the normal control group. In contrast, the expression levels of the serum and CSF protein N-glycans such as bisect-type and multiply branched glycoforms were increased significantly in AD patient group. In addition, the levels of some gangliosides such as GM1, GM2 and GM3 appeared to alter in the AD patient brain and serum samples when compared with the normal control groups. Alteration of the expression levels of major N- and GSL-glycans in human brain tissues, serum and CSF of AD patients can be monitored quantitatively by means of the glycoblotting-based standard protocols. The changes in the expression levels of the glycans derived from the human post-mortem samples uncovered by the standardized glycoblotting method provides potential serum biomarkers in central nervous system disorders and can contribute to the insight into the molecular mechanisms in the pathogenesis of neurodegenerative diseases and future drug discovery. Most importantly, the present preliminary trials using human post-mortem samples of AD patients suggest that large-scale serum glycomics cohort by means of various-types of human AD patients as well as the normal control sera can facilitate the discovery research of highly sensitive and reliable serum biomarkers for an early diagnosis of AD. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc. Copyright © 2016 Elsevier B.V. All rights reserved.

A surrogate analyte-based liquid chromatography-tandem mass spectrometry method for the determination of endogenous cyclic nucleotides in rat brain.

PubMed

Chen, Jie; Tabatabaei, Ali; Zook, Doug; Wang, Yan; Danks, Anne; Stauber, Kathe

2017-11-30

A robust high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) assay was developed and qualified for the measurement of cyclic nucleotides (cNTs) in rat brain tissue. Stable isotopically labeled 3',5'-cyclic adenosine- 13 C 5 monophosphate ( 13 C 5 -cAMP) and 3',5'-cyclic guanosine- 13 C, 15 N 2 monophosphate ( 13 C 15 N 2 -cGMP) were used as surrogate analytes to measure endogenous 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP). Pre-weighed frozen rat brain samples were rapidly homogenized in 0.4M perchloric acid at a ratio of 1:4 (w/v). Following internal standard addition and dilution, the resulting extracts were analyzed using negative ion mode electrospray ionization LC-MS/MS. The calibration curves for both analytes ranged from 5 to 2000ng/g and showed excellent linearity (r 2 >0.996). Relative surrogate analyte-to-analyte LC-MS/MS responses were determined to correct concentrations derived from the surrogate curves. The intra-run precision (CV%) for 13 C 5 -cAMP and 13 C 15 N 2 -cGMP was below 6.6% and 7.4%, respectively, while the inter-run precision (CV%) was 8.5% and 5.8%, respectively. The intra-run accuracy (Dev%) for 13 C 5 -cAMP and 13 C 15 N 2 -cGMP was <11.9% and 10.3%, respectively, and the inter-run Dev% was <6.8% and 5.5%, respectively. Qualification experiments demonstrated high analyte recoveries, minimal matrix effects and low autosampler carryover. Acceptable frozen storage, freeze/thaw, benchtop, processed sample and autosampler stability were shown in brain sample homogenates as well as post-processed samples. The method was found to be suitable for the analysis of rat brain tissue cAMP and cGMP levels in preclinical biomarker development studies. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Compression Stiffening of Brain and its Effect on Mechanosensing by Glioma Cells

NASA Astrophysics Data System (ADS)

Pogoda, Katarzyna

The stiffness of tissues, often characterized by their time-dependent elastic properties, is tightly controlled under normal condition and central nervous system tissue is among the softest tissues. Changes in tissue and organ stiffness occur in some physiological conditions and are frequently symptoms of diseases such as fibrosis, cardiovascular disease and many forms of cancer. Primary cells isolated from various tissues often respond to changes in the mechanical properties of their substrates, and the range of stiffness over which these responses occur appear to be limited to the tissue elastic modulus from which they are derived. Our goal was to test the hypotheses that the stiffness of tumors derived from CNS tissue differs from that of normal brain, and that transformed cells derived from such tumors exhibit mechanical responses that differ from those of normal glial cells. Unlike breast and some other cancers where the stroma and the tumor itself is substantially stiffer than the surrounding normal tissue, our data suggest that gliomas can arise without a gross change in the macroscopic tissue stiffness when measured at low strains without compression. However, both normal brain and glioma samples stiffen with compression, but not in elongation and increased shear strains. On the other hand, different classes of immortalized cells derived from human glioblastoma show substantially different responses to the stiffness of substrates in vitrowhen grown on soft polyacrylamide and hyaluronic acid gels. This outcome supports the hypothesis that compression stiffening, which might occur with increased vascularization and interstitial pressure gradients that are characteristic of tumors, effectively stiffens the environment of glioma cells, and that in situ, the elastic resistance these cells sense might be sufficient to trigger the same responses that are activated in vitro by increased substrate stiffness.

International veterinary epilepsy task force recommendations for systematic sampling and processing of brains from epileptic dogs and cats.

PubMed

Matiasek, Kaspar; Pumarola I Batlle, Martí; Rosati, Marco; Fernández-Flores, Francisco; Fischer, Andrea; Wagner, Eva; Berendt, Mette; Bhatti, Sofie F M; De Risio, Luisa; Farquhar, Robyn G; Long, Sam; Muñana, Karen; Patterson, Edward E; Pakozdy, Akos; Penderis, Jacques; Platt, Simon; Podell, Michael; Potschka, Heidrun; Rusbridge, Clare; Stein, Veronika M; Tipold, Andrea; Volk, Holger A

2015-08-28

Traditionally, histological investigations of the epileptic brain are required to identify epileptogenic brain lesions, to evaluate the impact of seizure activity, to search for mechanisms of drug-resistance and to look for comorbidities. For many instances, however, neuropathological studies fail to add substantial data on patients with complete clinical work-up. This may be due to sparse training in epilepsy pathology and or due to lack of neuropathological guidelines for companion animals.The protocols introduced herein shall facilitate systematic sampling and processing of epileptic brains and therefore increase the efficacy, reliability and reproducibility of morphological studies in animals suffering from seizures.Brain dissection protocols of two neuropathological centres with research focus in epilepsy have been optimised with regards to their diagnostic yield and accuracy, their practicability and their feasibility concerning clinical research requirements.The recommended guidelines allow for easy, standardised and ubiquitous collection of brain regions, relevant for seizure generation. Tissues harvested the prescribed way will increase the diagnostic efficacy and provide reliable material for scientific investigations.

Circulatory miR-34a as an RNA-based, noninvasive biomarker for brain aging

PubMed Central

Li, Xiaoli; Khanna, Amit; Li, Na; Wang, Eugenia

2011-01-01

MicroRNAs in blood samples have been identified as an important class of biomarkers, which can reflect physiological changes from cancer to brain dysfunction. In this report we identify concordant increases in levels of expression of miR-34a in brain and two components of mouse blood samples, peripheral blood mononuclear cells (PBMCs) and plasma, from 2 day old neonates through young adulthood and mid-life to old age at 25 months. Levels of this microRNA's prime target, silent information regulator 1 (SIRT1), in brain and the two blood-derived specimens decrease with age inversely to miR-34a, starting as early as 4 months old, when appreciable tissue aging has not yet begun. Our results suggest that: 1. Increased miR-34a and the reciprocal decrease of its target, SIRT1, in blood specimens are the accessible biomarkers for age-dependent changes in brain; and 2. these changes are predictors of impending decline in brain function, as early as in young adult mice. PMID:22064828

Development of a high-throughput brain slice method for studying drug distribution in the central nervous system.

PubMed

Fridén, Markus; Ducrozet, Frederic; Middleton, Brian; Antonsson, Madeleine; Bredberg, Ulf; Hammarlund-Udenaes, Margareta

2009-06-01

New, more efficient methods of estimating unbound drug concentrations in the central nervous system (CNS) combine the amount of drug in whole brain tissue samples measured by conventional methods with in vitro estimates of the unbound brain volume of distribution (V(u,brain)). Although the brain slice method is the most reliable in vitro method for measuring V(u,brain), it has not previously been adapted for the needs of drug discovery research. The aim of this study was to increase the throughput and optimize the experimental conditions of this method. Equilibrium of drug between the buffer and the brain slice within the 4 to 5 h of incubation is a fundamental requirement. However, it is difficult to meet this requirement for many of the extensively binding, lipophilic compounds in drug discovery programs. In this study, the dimensions of the incubation vessel and mode of stirring influenced the equilibration time, as did the amount of brain tissue per unit of buffer volume. The use of cassette experiments for investigating V(u,brain) in a linear drug concentration range increased the throughput of the method. The V(u,brain) for the model compounds ranged from 4 to 3000 ml . g brain(-1), and the sources of variability are discussed. The optimized setup of the brain slice method allows precise, robust estimation of V(u,brain) for drugs with diverse properties, including highly lipophilic compounds. This is a critical step forward for the implementation of relevant measurements of CNS exposure in the drug discovery setting.

3D resolved mapping of optical aberrations in thick tissues

PubMed Central

Zeng, Jun; Mahou, Pierre; Schanne-Klein, Marie-Claire; Beaurepaire, Emmanuel; Débarre, Delphine

2012-01-01

We demonstrate a simple method for mapping optical aberrations with 3D resolution within thick samples. The method relies on the local measurement of the variation in image quality with externally applied aberrations. We discuss the accuracy of the method as a function of the signal strength and of the aberration amplitude and we derive the achievable resolution for the resulting measurements. We then report on measured 3D aberration maps in human skin biopsies and mouse brain slices. From these data, we analyse the consequences of tissue structure and refractive index distribution on aberrations and imaging depth in normal and cleared tissue samples. The aberration maps allow the estimation of the typical aplanetism region size over which aberrations can be uniformly corrected. This method and data pave the way towards efficient correction strategies for tissue imaging applications. PMID:22876353

Distribution of the anticancer drugs doxorubicin, mitoxantrone and topotecan in tumors and normal tissues.

PubMed

Patel, Krupa J; Trédan, Olivier; Tannock, Ian F

2013-07-01

Pharmacokinetic analyses estimate the mean concentration of drug within a given tissue as a function of time, but do not give information about the spatial distribution of drugs within that tissue. Here, we compare the time-dependent spatial distribution of three anticancer drugs within tumors, heart, kidney, liver and brain. Mice bearing various xenografts were treated with doxorubicin, mitoxantrone or topotecan. At various times after injection, tumors and samples of heart, kidney, liver and brain were excised. Within solid tumors, the distribution of doxorubicin, mitoxantrone and topotecan was limited to perivascular regions at 10 min after administration and the distance from blood vessels at which drug intensity fell to half was ~25-75 μm. Although drug distribution improved after 3 and 24 h, there remained a significant decrease in drug fluorescence with increasing distance from tumor blood vessels. Drug distribution was relatively uniform in the heart, kidney and liver with substantially greater perivascular drug uptake than in tumors. There was significantly higher total drug fluorescence in the liver than in tumors after 10 min, 3 and 24 h. Little to no drug fluorescence was observed in the brain. There are marked differences in the spatial distributions of three anticancer drugs within tumor tissue and normal tissues over time, with greater exposure to most normal tissues and limited drug distribution to many cells in tumors. Studies of the spatial distribution of drugs are required to complement pharmacokinetic data in order to better understand and predict drug effects and toxicities.

Conductive carbon tape used for support and mounting of both whole animal and fragile heat-treated tissue sections for MALDI MS imaging and quantitation.

PubMed

Goodwin, Richard J A; Nilsson, Anna; Borg, Daniel; Langridge-Smith, Pat R R; Harrison, David J; Mackay, C Logan; Iverson, Suzanne L; Andrén, Per E

2012-08-30

Analysis of whole animal tissue sections by MALDI MS imaging (MSI) requires effective sample collection and transfer methods to allow the highest quality of in situ analysis of small or hard to dissect tissues. We report on the use of double-sided adhesive conductive carbon tape during whole adult rat tissue sectioning of carboxymethyl cellulose (CMC) embedded animals, with samples mounted onto large format conductive glass and conductive plastic MALDI targets, enabling MSI analysis to be performed on both TOF and FT-ICR MALDI mass spectrometers. We show that mounting does not unduly affect small molecule MSI detection by analyzing tiotropium abundance and distribution in rat lung tissues, with direct on-tissue quantitation achieved. Significantly, we use the adhesive tape to provide support to embedded delicate heat-stabilized tissues, enabling sectioning and mounting to be performed that maintained tissue integrity on samples that had previously been impossible to adequately prepare section for MSI analysis. The mapping of larger peptidomic molecules was not hindered by tape mounting samples and we demonstrate this by mapping the distribution of PEP-19 in both native and heat-stabilized rat brains. Furthermore, we show that without heat stabilization PEP-19 degradation fragments can detected and identified directly by MALDI MSI analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

The Neuro-Oncology Branch (NOB), Center for Cancer Research (CCR), National Cancer Institute (NCI) of the National Institutes of Health (NIH) is seeking outstanding postdoctoral candidates interested in studying the metabolic changes in brain tumors such as glioblastoma multiforme (GBMs).  NOB’s Metabolomics program is interested in revealing the metabolic alterations of isocitrate dehydrogenase (IDH1)-mutated GBMs and in exploiting these deregulations for therapeutic applications.  A combination of methods such as molecular biology, animal models, as well as in vitro and in vivo metabolomics using Raman Imaging Microscopy, Nuclear Magnetic Resonance spectroscopy (NMR), Mass Spectrometry (MS) and Magnetic Resonance Imaging (MRI) techniques are employed.  The position will specifically focus on molecular biology and Raman Imaging Microscopy, which includes work in Western Blotting, mammalian cell culture and other common biomedical techniques used in cancer bio  logy labs such as handling tissue samples, preparing tissue slides, staining, and extracting proteins from brain tissue.

Semiautomatic Segmentation of Glioma on Mobile Devices.

PubMed

Wu, Ya-Ping; Lin, Yu-Song; Wu, Wei-Guo; Yang, Cong; Gu, Jian-Qin; Bai, Yan; Wang, Mei-Yun

2017-01-01

Brain tumor segmentation is the first and the most critical step in clinical applications of radiomics. However, segmenting brain images by radiologists is labor intense and prone to inter- and intraobserver variability. Stable and reproducible brain image segmentation algorithms are thus important for successful tumor detection in radiomics. In this paper, we propose a supervised brain image segmentation method, especially for magnetic resonance (MR) brain images with glioma. This paper uses hard edge multiplicative intrinsic component optimization to preprocess glioma medical image on the server side, and then, the doctors could supervise the segmentation process on mobile devices in their convenient time. Since the preprocessed images have the same brightness for the same tissue voxels, they have small data size (typically 1/10 of the original image size) and simple structure of 4 types of intensity value. This observation thus allows follow-up steps to be processed on mobile devices with low bandwidth and limited computing performance. Experiments conducted on 1935 brain slices from 129 patients show that more than 30% of the sample can reach 90% similarity; over 60% of the samples can reach 85% similarity, and more than 80% of the sample could reach 75% similarity. The comparisons with other segmentation methods also demonstrate both efficiency and stability of the proposed approach.

Reproducible Tissue Homogenization and Protein Extraction for Quantitative Proteomics Using MicroPestle-Assisted Pressure-Cycling Technology.

PubMed

Shao, Shiying; Guo, Tiannan; Gross, Vera; Lazarev, Alexander; Koh, Ching Chiek; Gillessen, Silke; Joerger, Markus; Jochum, Wolfram; Aebersold, Ruedi

2016-06-03

The reproducible and efficient extraction of proteins from biopsy samples for quantitative analysis is a critical step in biomarker and translational research. Recently, we described a method consisting of pressure-cycling technology (PCT) and sequential windowed acquisition of all theoretical fragment ions-mass spectrometry (SWATH-MS) for the rapid quantification of thousands of proteins from biopsy-size tissue samples. As an improvement of the method, we have incorporated the PCT-MicroPestle into the PCT-SWATH workflow. The PCT-MicroPestle is a novel, miniaturized, disposable mechanical tissue homogenizer that fits directly into the microTube sample container. We optimized the pressure-cycling conditions for tissue lysis with the PCT-MicroPestle and benchmarked the performance of the system against the conventional PCT-MicroCap method using mouse liver, heart, brain, and human kidney tissues as test samples. The data indicate that the digestion of the PCT-MicroPestle-extracted proteins yielded 20-40% more MS-ready peptide mass from all tissues tested with a comparable reproducibility when compared to the conventional PCT method. Subsequent SWATH-MS analysis identified a higher number of biologically informative proteins from a given sample. In conclusion, we have developed a new device that can be seamlessly integrated into the PCT-SWATH workflow, leading to increased sample throughput and improved reproducibility at both the protein extraction and proteomic analysis levels when applied to the quantitative proteomic analysis of biopsy-level samples.

Differential effects of common variants in SCN2A on general cognitive ability, brain physiology, and messenger RNA expression in schizophrenia cases and control individuals.

PubMed

Dickinson, Dwight; Straub, Richard E; Trampush, Joey W; Gao, Yuan; Feng, Ningping; Xie, Bin; Shin, Joo Heon; Lim, Hun Ki; Ursini, Gianluca; Bigos, Kristin L; Kolachana, Bhaskar; Hashimoto, Ryota; Takeda, Masatoshi; Baum, Graham L; Rujescu, Dan; Callicott, Joseph H; Hyde, Thomas M; Berman, Karen F; Kleinman, Joel E; Weinberger, Daniel R

2014-06-01

One approach to understanding the genetic complexity of schizophrenia is to study associated behavioral and biological phenotypes that may be more directly linked to genetic variation. To identify single-nucleotide polymorphisms associated with general cognitive ability (g) in people with schizophrenia and control individuals. Genomewide association study, followed by analyses in unaffected siblings and independent schizophrenia samples, functional magnetic resonance imaging studies of brain physiology in vivo, and RNA sequencing in postmortem brain samples. The discovery cohort and unaffected siblings were participants in the National Institute of Mental Health Clinical Brain Disorders Branch schizophrenia genetics studies. Additional schizophrenia cohorts were from psychiatric treatment settings in the United States, Japan, and Germany. The discovery cohort comprised 339 with schizophrenia and 363 community control participants. Follow-up analyses studied 147 unaffected siblings of the schizophrenia cases and independent schizophrenia samples including a total of an additional 668 participants. Imaging analyses included 87 schizophrenia cases and 397 control individuals. Brain tissue samples were available for 64 cases and 61 control individuals. We studied genomewide association with g, by group, in the discovery cohort. We used selected genotypes to test specific associations in unaffected siblings and independent schizophrenia samples. Imaging analyses focused on activation in the prefrontal cortex during working memory. Brain tissue studies yielded messenger RNA expression levels for RefSeq transcripts. The schizophrenia discovery cohort showed genomewide-significant association of g with polymorphisms in sodium channel gene SCN2A, accounting for 10.4% of g variance (rs10174400, P = 9.27 × 10(-10)). Control individuals showed a trend for g/genotype association with reversed allelic directionality. The genotype-by-group interaction was also genomewide significant (P = 1.75 × 10(-9)). Siblings showed a genotype association with g parallel to the schizophrenia group and the same interaction pattern. Parallel, but weaker, associations with cognition were found in independent schizophrenia samples. Imaging analyses showed a similar pattern of genotype associations by group and genotype-by-group interaction. Sequencing of RNA in brain revealed reduced expression in 2 of 3 SCN2A alternative transcripts in the patient group, with genotype-by-group interaction, that again paralleled the cognition effects. The findings implicate SCN2A and sodium channel biology in cognitive impairment in schizophrenia cases and unaffected relatives and may facilitate development of cognition-enhancing treatments.

Optical guidance for stereotactic brain tumor biopsy procedures: preliminary clinical evaluation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Haj-Hosseini, Neda; Richter, Johan; Milos, Peter; Hallbeck, Martin; Wârdell, Karin

2017-02-01

In the routine of stereotactic biopsy on suspected tumors located deep in the brain or patients with multiple lesions, tissue samples are harvested to determine the type of malignancy. Biopsies are taken from pre-calculated positions based on the preoperative radiologic images susceptible to brain shift. In such cases the biopsy procedure may need to be repeated leading to a longer operation time. To provide guidance for targeting diagnostic tumor tissue and to avoid vessel rupture on the insertion path of the tumor, an application specific fiber optic probe was developed. The setup incorporated spectroscopy for 5-aminolevulinic acid induced protopophyrin IX (PpIX) fluorescence in the tumor and laser Doppler for measuring microvascular blood flow which recorded backscattered light (TLI) at 780 nm and blood perfusion. The recorded signals were compared to the histopathologic diagnosis of the tissue samples (n=16) and to the preoperative radiologic images. All together 146 fluorescence and 276 laser Doppler signals were recorded along 5 trajectories in 4 patients. On all occasions strong PpIX fluorescence peaks were visible during real-time guidance. Comparing the gliotic tumor marginal zone with the tumor, the PpIX (51 vs. 528 a.u., [0-1790], p < 0.05) was higher and TLI (2.9 vs. 2.0 a.u., [0-4.1], p < 0.05) was lower in tumor. The autofluorescence (104 vs.70 a.u., [0-442], p > 0.05) and blood perfusion (8.3 vs. 17 a.u., [0-254], p > 0.05) were not significantly different. In conclusion, the optical guidance probe made real-time tumor detection and vessel tracking possible during the stereotactic biopsy procedures. Moreover, the fluorescence and blood perfusion in the tumor could be studied at controlled positions in the brain and the tumor.

A high-throughput semi-automated preparation for filtered synaptoneurosomes.

PubMed

Murphy, Kathryn M; Balsor, Justin; Beshara, Simon; Siu, Caitlin; Pinto, Joshua G A

2014-09-30

Synaptoneurosomes have become an important tool for studying synaptic proteins. The filtered synaptoneurosomes preparation originally developed by Hollingsworth et al. (1985) is widely used and is an easy method to prepare synaptoneurosomes. The hand processing steps in that preparation, however, are labor intensive and have become a bottleneck for current proteomic studies using synaptoneurosomes. For this reason, we developed new steps for tissue homogenization and filtration that transform the preparation of synaptoneurosomes to a high-throughput, semi-automated process. We implemented a standardized protocol with easy to follow steps for homogenizing multiple samples simultaneously using a FastPrep tissue homogenizer (MP Biomedicals, LLC) and then filtering all of the samples in centrifugal filter units (EMD Millipore, Corp). The new steps dramatically reduce the time to prepare synaptoneurosomes from hours to minutes, increase sample recovery, and nearly double enrichment for synaptic proteins. These steps are also compatible with biosafety requirements for working with pathogen infected brain tissue. The new high-throughput semi-automated steps to prepare synaptoneurosomes are timely technical advances for studies of low abundance synaptic proteins in valuable tissue samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Whole-brain spectroscopic MRI biomarkers identify infiltrating margins in glioblastoma patients

PubMed Central

Cordova, James S.; Shu, Hui-Kuo G.; Liang, Zhongxing; Gurbani, Saumya S.; Cooper, Lee A. D.; Holder, Chad A.; Olson, Jeffrey J.; Kairdolf, Brad; Schreibmann, Eduard; Neill, Stewart G.; Hadjipanayis, Constantinos G.; Shim, Hyunsuk

2016-01-01

Background The standard of care for glioblastoma (GBM) is maximal safe resection followed by radiation therapy with chemotherapy. Currently, contrast-enhanced MRI is used to define primary treatment volumes for surgery and radiation therapy. However, enhancement does not identify the tumor entirely, resulting in limited local control. Proton spectroscopic MRI (sMRI), a method reporting endogenous metabolism, may better define the tumor margin. Here, we develop a whole-brain sMRI pipeline and validate sMRI metrics with quantitative measures of tumor infiltration. Methods Whole-brain sMRI metabolite maps were coregistered with surgical planning MRI and imported into a neuronavigation system to guide tissue sampling in GBM patients receiving 5-aminolevulinic acid fluorescence-guided surgery. Samples were collected from regions with metabolic abnormalities in a biopsy-like fashion before bulk resection. Tissue fluorescence was measured ex vivo using a hand-held spectrometer. Tissue samples were immunostained for Sox2 and analyzed to quantify the density of staining cells using a novel digital pathology image analysis tool. Correlations among sMRI markers, Sox2 density, and ex vivo fluorescence were evaluated. Results Spectroscopic MRI biomarkers exhibit significant correlations with Sox2-positive cell density and ex vivo fluorescence. The choline to N-acetylaspartate ratio showed significant associations with each quantitative marker (Pearson's ρ = 0.82, P < .001 and ρ = 0.36, P < .0001, respectively). Clinically, sMRI metabolic abnormalities predated contrast enhancement at sites of tumor recurrence and exhibited an inverse relationship with progression-free survival. Conclusions As it identifies tumor infiltration and regions at high risk for recurrence, sMRI could complement conventional MRI to improve local control in GBM patients. PMID:26984746

NMR imaging of cell phone radiation absorption in brain tissue

PubMed Central

Gultekin, David H.; Moeller, Lothar

2013-01-01

A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry. PMID:23248293

NMR imaging of cell phone radiation absorption in brain tissue.

PubMed

Gultekin, David H; Moeller, Lothar

2013-01-02

A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry.

HIV DNA Is Frequently Present within Pathologic Tissues Evaluated at Autopsy from Combined Antiretroviral Therapy-Treated Patients with Undetectable Viral Loads

PubMed Central

Lamers, Susanna L.; Rose, Rebecca; Maidji, Ekaterina; Agsalda-Garcia, Melissa; Nolan, David J.; Fogel, Gary B.; Salemi, Marco; Garcia, Debra L.; Bracci, Paige; Yong, William; Commins, Deborah; Said, Jonathan; Khanlou, Negar; Hinkin, Charles H.; Sueiras, Miguel Valdes; Mathisen, Glenn; Donovan, Suzanne; Shiramizu, Bruce; Stoddart, Cheryl A.; Singer, Elyse J.

2016-01-01

ABSTRACT HIV infection treatment strategies have historically defined effectiveness through measuring patient plasma HIV RNA. While combined antiretroviral therapy (cART) can reduce plasma viral load (pVL) to undetectable levels, the degree that HIV is eliminated from other anatomical sites remains unclear. We investigated the HIV DNA levels in 229 varied autopsy tissues from 20 HIV-positive (HIV+) cART-treated study participants with low or undetectable plasma VL and cerebrospinal fluid (CSF) VL prior to death who were enrolled in the National Neurological AIDS Bank (NNAB) longitudinal study and autopsy cohort. Extensive medical histories were obtained for each participant. Autopsy specimens, including at least six brain and nonbrain tissues per participant, were reviewed by study pathologists. HIV DNA, measured in tissues by quantitative and droplet digital PCR, was identified in 48/87 brain tissues and 82/142 nonbrain tissues at levels >200 HIV copies/million cell equivalents. No participant was found to be completely free of tissue HIV. Parallel sequencing studies from some tissues recovered intact HIV DNA and RNA. Abnormal histological findings were identified in all participants, especially in brain, spleen, lung, lymph node, liver, aorta, and kidney. All brain tissues demonstrated some degree of pathology. Ninety-five percent of participants had some degree of atherosclerosis, and 75% of participants died with cancer. This study assists in characterizing the anatomical locations of HIV, in particular, macrophage-rich tissues, such as the central nervous system (CNS) and testis. Additional studies are needed to determine if the HIV recovered from tissues promotes the pathogenesis of inflammatory diseases, such as HIV-associated neurocognitive disorders, cancer, and atherosclerosis. IMPORTANCE It is well-known that combined antiretroviral therapy (cART) can reduce plasma HIV to undetectable levels; however, cART cannot completely clear HIV infection. An ongoing question is, “Where is HIV hiding?” A well-studied HIV reservoir is “resting” T cells, which can be isolated from blood products and succumb to cART once activated. Less-studied reservoirs are anatomical tissue samples, which have unknown cART penetration, contain a comparably diverse spectrum of potentially HIV-infected immune cells, and are important since <2% of body lymphocytes actually reside in blood. We examined 229 varied autopsy specimens from 20 HIV+ participants who died while on cART and identified that >50% of tissues were HIV infected. Additionally, we identified considerable pathology in participants' tissues, especially in brain, spleen, lung, lymph node, liver, aorta, and kidney. This study substantiates that tissue-associated HIV is present despite cART and can inform future studies into HIV persistence. PMID:27466426

HIV DNA Is Frequently Present within Pathologic Tissues Evaluated at Autopsy from Combined Antiretroviral Therapy-Treated Patients with Undetectable Viral Loads.

PubMed

Lamers, Susanna L; Rose, Rebecca; Maidji, Ekaterina; Agsalda-Garcia, Melissa; Nolan, David J; Fogel, Gary B; Salemi, Marco; Garcia, Debra L; Bracci, Paige; Yong, William; Commins, Deborah; Said, Jonathan; Khanlou, Negar; Hinkin, Charles H; Sueiras, Miguel Valdes; Mathisen, Glenn; Donovan, Suzanne; Shiramizu, Bruce; Stoddart, Cheryl A; McGrath, Michael S; Singer, Elyse J

2016-10-15

HIV infection treatment strategies have historically defined effectiveness through measuring patient plasma HIV RNA. While combined antiretroviral therapy (cART) can reduce plasma viral load (pVL) to undetectable levels, the degree that HIV is eliminated from other anatomical sites remains unclear. We investigated the HIV DNA levels in 229 varied autopsy tissues from 20 HIV-positive (HIV(+)) cART-treated study participants with low or undetectable plasma VL and cerebrospinal fluid (CSF) VL prior to death who were enrolled in the National Neurological AIDS Bank (NNAB) longitudinal study and autopsy cohort. Extensive medical histories were obtained for each participant. Autopsy specimens, including at least six brain and nonbrain tissues per participant, were reviewed by study pathologists. HIV DNA, measured in tissues by quantitative and droplet digital PCR, was identified in 48/87 brain tissues and 82/142 nonbrain tissues at levels >200 HIV copies/million cell equivalents. No participant was found to be completely free of tissue HIV. Parallel sequencing studies from some tissues recovered intact HIV DNA and RNA. Abnormal histological findings were identified in all participants, especially in brain, spleen, lung, lymph node, liver, aorta, and kidney. All brain tissues demonstrated some degree of pathology. Ninety-five percent of participants had some degree of atherosclerosis, and 75% of participants died with cancer. This study assists in characterizing the anatomical locations of HIV, in particular, macrophage-rich tissues, such as the central nervous system (CNS) and testis. Additional studies are needed to determine if the HIV recovered from tissues promotes the pathogenesis of inflammatory diseases, such as HIV-associated neurocognitive disorders, cancer, and atherosclerosis. It is well-known that combined antiretroviral therapy (cART) can reduce plasma HIV to undetectable levels; however, cART cannot completely clear HIV infection. An ongoing question is, "Where is HIV hiding?" A well-studied HIV reservoir is "resting" T cells, which can be isolated from blood products and succumb to cART once activated. Less-studied reservoirs are anatomical tissue samples, which have unknown cART penetration, contain a comparably diverse spectrum of potentially HIV-infected immune cells, and are important since <2% of body lymphocytes actually reside in blood. We examined 229 varied autopsy specimens from 20 HIV(+) participants who died while on cART and identified that >50% of tissues were HIV infected. Additionally, we identified considerable pathology in participants' tissues, especially in brain, spleen, lung, lymph node, liver, aorta, and kidney. This study substantiates that tissue-associated HIV is present despite cART and can inform future studies into HIV persistence. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

CircRNA accumulation in the aging mouse brain

PubMed Central

Gruner, Hannah; Cortés-López, Mariela; Cooper, Daphne A.; Bauer, Matthew; Miura, Pedro

2016-01-01

Circular RNAs (circRNAs) are a newly appreciated class of RNAs expressed across diverse phyla. These enigmatic transcripts are most commonly generated by back-splicing events from exons of protein-coding genes. This results in highly stable RNAs due to the lack of free 5′ and 3′ ends. CircRNAs are enriched in neural tissues, suggesting that they might have neural functions. Here, we sought to determine whether circRNA accumulation occurs during aging in mice. Total RNA-seq profiling of young (1 month old) and aged (22 month old) cortex, hippocampus and heart samples was performed. This led to the confident detection of 6,791 distinct circRNAs across these samples, including 675 novel circRNAs. Analysis uncovered a strong bias for circRNA upregulation during aging in neural tissues. These age-accumulation trends were verified for individual circRNAs by RT-qPCR and Northern analysis. In contrast, comparison of aged versus young hearts failed to reveal a global trend for circRNA upregulation. Age-accumulation of circRNAs in brain tissues was found to be largely independent from linear RNA expression of host genes. These findings suggest that circRNAs might play biological roles relevant to the aging nervous system. PMID:27958329

Bayesian Modeling of NMR Data: Quantifying Longitudinal Relaxation in Vivo, and in Vitro with a Tissue-Water-Relaxation Mimic (Crosslinked Bovine Serum Albumin).

PubMed

Meinerz, Kelsey; Beeman, Scott C; Duan, Chong; Bretthorst, G Larry; Garbow, Joel R; Ackerman, Joseph J H

2018-01-01

Recently, a number of MRI protocols have been reported that seek to exploit the effect of dissolved oxygen (O 2 , paramagnetic) on the longitudinal 1 H relaxation of tissue water, thus providing image contrast related to tissue oxygen content. However, tissue water relaxation is dependent on a number of mechanisms, and this raises the issue of how best to model the relaxation data. This problem, the model selection problem, occurs in many branches of science and is optimally addressed by Bayesian probability theory. High signal-to-noise, densely sampled, longitudinal 1 H relaxation data were acquired from rat brain in vivo and from a cross-linked bovine serum albumin (xBSA) phantom, a sample that recapitulates the relaxation characteristics of tissue water in vivo . Bayesian-based model selection was applied to a cohort of five competing relaxation models: (i) monoexponential, (ii) stretched-exponential, (iii) biexponential, (iv) Gaussian (normal) R 1 -distribution, and (v) gamma R 1 -distribution. Bayesian joint analysis of multiple replicate datasets revealed that water relaxation of both the xBSA phantom and in vivo rat brain was best described by a biexponential model, while xBSA relaxation datasets truncated to remove evidence of the fast relaxation component were best modeled as a stretched exponential. In all cases, estimated model parameters were compared to the commonly used monoexponential model. Reducing the sampling density of the relaxation data and adding Gaussian-distributed noise served to simulate cases in which the data are acquisition-time or signal-to-noise restricted, respectively. As expected, reducing either the number of data points or the signal-to-noise increases the uncertainty in estimated parameters and, ultimately, reduces support for more complex relaxation models.

Single cell gene expression profiling in Alzheimer's disease.

PubMed

Ginsberg, Stephen D; Che, Shaoli; Counts, Scott E; Mufson, Elliott J

2006-07-01

Development and implementation of microarray techniques to quantify expression levels of dozens to hundreds to thousands of transcripts simultaneously within select tissue samples from normal control subjects and neurodegenerative diseased brains has enabled scientists to create molecular fingerprints of vulnerable neuronal populations in Alzheimer's disease (AD) and related disorders. A goal is to sample gene expression from homogeneous cell types within a defined region without potential contamination by expression profiles of adjacent neuronal subpopulations and nonneuronal cells. The precise resolution afforded by single cell and population cell RNA analysis in combination with microarrays and real-time quantitative polymerase chain reaction (qPCR)-based analyses allows for relative gene expression level comparisons across cell types under different experimental conditions and disease progression. The ability to analyze single cells is an important distinction from global and regional assessments of mRNA expression and can be applied to optimally prepared tissues from animal models of neurodegeneration as well as postmortem human brain tissues. Gene expression analysis in postmortem AD brain regions including the hippocampal formation and neocortex reveals selectively vulnerable cell types share putative pathogenetic alterations in common classes of transcripts, for example, markers of glutamatergic neurotransmission, synaptic-related markers, protein phosphatases and kinases, and neurotrophins/neurotrophin receptors. Expression profiles of vulnerable regions and neurons may reveal important clues toward the understanding of the molecular pathogenesis of various neurological diseases and aid in identifying rational targets toward pharmacotherapeutic interventions for progressive, late-onset neurodegenerative disorders such as mild cognitive impairment (MCI) and AD.

How the Brain May Have Shaped Muscle Anatomy and Physiology: A Preliminary Study.

PubMed

Muchlinski, Magdalena N; Hemingway, Holden W; Pastor, Juan; Omstead, Kailey M; Burrows, Anne M

2018-03-01

Skeletal muscle fibers are often used to evaluate functional differences in locomotion. However, because there are energetic differences among muscle fiber cells, muscle fiber composition could be used to address evolutionary questions about energetics. Skeletal muscle is composed of two main types of fibers: Type I and II. The difference between the two can be reduced to how these muscle cells use oxygen and glucose. Type I fibers convert glucose to ATP using oxygen, while Type II fibers rely primarily on anaerobic metabolic processes. The expensive tissue hypothesis (ETH) proposes that the energetic demands imposed on the body by the brain result in a reduction in other expensive tissues (e.g., gastrointestinal tract). The original ETH dismisses the energetic demands of skeletal muscle, despite skeletal muscle being (1) an expensive tissue when active and (2) in direct competition for glucose with the brain. Based on these observations we hypothesize that larger brained primates will have relatively less muscle mass and a decrease in Type I fibers. As part of a larger study to test this hypothesis, we present data from 10 species of primates. We collected body mass, muscle mass, and biopsied four muscles from each specimen for histological procedures. We collected endocranial volumes from the literature. Using immunohistochemistry, a muscle fiber composition profile was created for each species sampled. Results show that larger brained primates have less muscle and fewer Type I fibers than primates with smaller brains. Results clarify the relationship between muscle mass and brain mass and illustrate how muscle mass could be used to address energetic questions. Anat Rec, 301:528-537, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Multimodality Monitoring for Cerebral Perfusion Pressure Optimization in Comatose Patients with Intracerebral Hemorrhage

PubMed Central

Ko, Sang-Bae; Choi, H. Alex; Parikh, Gunjan; Helbok, Raimund; Schmidt, J. Michael; Lee, Kiwon; Badjatia, Neeraj; Claassen, Jan; Connolly, E. Sander; Mayer, Stephan A.

2011-01-01

Background and Purpose Limited data exists to recommend specific cerebral perfusion pressure (CPP) targets in patients with intracerebral hemorrhage (ICH). We sought to determine the feasibility of brain multimodality monitoring (MMM) for optimizing CPP and potentially reducing secondary brain injury after ICH. Methods We retrospectively analyzed brain MMM data targeted at perihematomal brain tissue in 18 comatose ICH patients (median monitoring: 164 hours). Physiological measures were averaged over one-hour intervals corresponding to each microdialysis sample. Metabolic crisis (MC) was defined as a lactate/pyruvate ratio (LPR) >40 with a brain glucose concentration <0.7 mmol/L. Brain tissue hypoxia (BTH) was defined as PbtO2 <15 mm Hg. Pressure reactivity index (PRx) and oxygen reactivity index (ORx) were calculated. Results Median age was 59 years, median GCS score 6, and median ICH volume was 37.5 ml. The risk of BTH, and to a lesser extent MC, increased with lower CPP values. Multivariable analyses showed that CPP <80 mm Hg was associated with a greater risk of BTH (OR 1.5, 95% CI 1.1–2.1, P=0.01) compared to CPP >100 mm Hg as a reference range. Six patients died (33%). Survivors had significantly higher CPP and PbtO2 and lower ICP values starting on post-bleed day 4, whereas LPR and PRx values were lower, indicating preservation of aerobic metabolism and pressure autoregulation. Conclusions PbtO2 monitoring can be used to identify CPP targets for optimal brain tissue oxygenation. In patients who do not undergo MMM, maintaining CPP >80 mm Hg may reduce the risk of BTH. PMID:21852615

Human herpesvirus multiplex ddPCR detection in brain tissue from low- and high-grade astrocytoma cases and controls.

PubMed

Lin, Cheng-Te Major; Leibovitch, Emily C; Almira-Suarez, M Isabel; Jacobson, Steven

2016-01-01

Glioblastoma (GBM) is a fatal CNS malignancy, representing 50 % of all gliomas with approximately 12-18 months survival time after initial diagnosis. Recently, the human herpesvirus cytomegalovirus (CMV) has been suggested to have an oncogenic role, yet this association remains controversial. In addition, human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) have also been associated with low-grade gliomas, but few studies have examined HHV-6 and EBV in glioblastomas. Droplet digital PCR (ddPCR) is a highly precise diagnostic tool that enables the absolute quantification of target DNA. This study examines the association between multiple human herpesviruses and astrocytomas. This study analyzed 112 brain tissue specimens, including 45 glioblastoma, 12 astrocytoma grade III, 2 astrocytoma grade II, 4 astrocytoma grade I, and 49 controls. All brain tissue samples were de-identified and pathologically confirmed. Each tissue block was sectioned for DNA extraction and CMV, EBV, HHV-6A and HHV-6B, and a cellular housekeeping gene were amplified by ddPCR. Neither CMV nor HHV-6A were detected in any of the astrocytoma samples. However, HHV-6B (p = 0.147) and EBV (p = 0.049) had a higher positivity frequency in the GBM compared to the controls. The undetectable CMV DNA in the astrocytoma cohort does not support the observation of an increased prevalence of CMV DNA in GBM, as reported in other studies. EBV has a significantly higher positivity in the GBM cohort compared to the controls, while HHV-6B has a higher but not statistically significant positivity in the case cohort. Whether these viruses play an oncogenic role in GBM remains to be further investigated.

DNA and RNA profiling of excavated human remains with varying postmortem intervals.

PubMed

van den Berge, M; Wiskerke, D; Gerretsen, R R R; Tabak, J; Sijen, T

2016-11-01

When postmortem intervals (PMIs) increase such as with longer burial times, human remains suffer increasingly from the taphonomic effects of decomposition processes such as autolysis and putrefaction. In this study, various DNA analysis techniques and a messenger RNA (mRNA) profiling method were applied to examine for trends in nucleic acid degradation and the postmortem interval. The DNA analysis techniques include highly sensitive DNA quantitation (with and without degradation index), standard and low template STR profiling, insertion and null alleles (INNUL) of retrotransposable elements typing and mitochondrial DNA profiling. The used mRNA profiling system targets genes with tissue specific expression for seven human organs as reported by Lindenbergh et al. (Int J Legal Med 127:891-900, 27) and has been applied to forensic evidentiary traces but not to excavated tissues. The techniques were applied to a total of 81 brain, lung, liver, skeletal muscle, heart, kidney and skin samples obtained from 19 excavated graves with burial times ranging from 4 to 42 years. Results show that brain and heart are the organs in which both DNA and RNA remain remarkably stable, notwithstanding long PMIs. The other organ tissues either show poor overall profiling results or vary for DNA and RNA profiling success, with sometimes DNA and other times RNA profiling being more successful. No straightforward relations were observed between nucleic acid profiling results and the PMI. This study shows that not only DNA but also RNA molecules can be remarkably stable and used for profiling of long-buried human remains, which corroborate forensic applications. The insight that the brain and heart tissues tend to provide the best profiling results may change sampling policies in identification cases of degrading cadavers.

3D imaging of optically cleared tissue using a simplified CLARITY method and on-chip microscopy

PubMed Central

Zhang, Yibo; Shin, Yoonjung; Sung, Kevin; Yang, Sam; Chen, Harrison; Wang, Hongda; Teng, Da; Rivenson, Yair; Kulkarni, Rajan P.; Ozcan, Aydogan

2017-01-01

High-throughput sectioning and optical imaging of tissue samples using traditional immunohistochemical techniques can be costly and inaccessible in resource-limited areas. We demonstrate three-dimensional (3D) imaging and phenotyping in optically transparent tissue using lens-free holographic on-chip microscopy as a low-cost, simple, and high-throughput alternative to conventional approaches. The tissue sample is passively cleared using a simplified CLARITY method and stained using 3,3′-diaminobenzidine to target cells of interest, enabling bright-field optical imaging and 3D sectioning of thick samples. The lens-free computational microscope uses pixel super-resolution and multi-height phase recovery algorithms to digitally refocus throughout the cleared tissue and obtain a 3D stack of complex-valued images of the sample, containing both phase and amplitude information. We optimized the tissue-clearing and imaging system by finding the optimal illumination wavelength, tissue thickness, sample preparation parameters, and the number of heights of the lens-free image acquisition and implemented a sparsity-based denoising algorithm to maximize the imaging volume and minimize the amount of the acquired data while also preserving the contrast-to-noise ratio of the reconstructed images. As a proof of concept, we achieved 3D imaging of neurons in a 200-μm-thick cleared mouse brain tissue over a wide field of view of 20.5 mm2. The lens-free microscope also achieved more than an order-of-magnitude reduction in raw data compared to a conventional scanning optical microscope imaging the same sample volume. Being low cost, simple, high-throughput, and data-efficient, we believe that this CLARITY-enabled computational tissue imaging technique could find numerous applications in biomedical diagnosis and research in low-resource settings. PMID:28819645

Fiber-based tissue identification for electrode placement in deep brain stimulation neurosurgery (Conference Presentation)

NASA Astrophysics Data System (ADS)

DePaoli, Damon T.; Lapointe, Nicolas; Goetz, Laurent; Parent, Martin; Prudhomme, Michel; Cantin, Léo.; Galstian, Tigran; Messaddeq, Younès.; Côté, Daniel C.

2016-03-01

Deep brain stimulation's effectiveness relies on the ability of the stimulating electrode to be properly placed within a specific target area of the brain. Optical guidance techniques that can increase the accuracy of the procedure, without causing any additional harm, are therefore of great interest. We have designed a cheap optical fiber-based device that is small enough to be placed within commercially available DBS stimulating electrodes' hollow cores and that is capable of sensing biological information from the surrounding tissue, using low power white light. With this probe we have shown the ability to distinguish white and grey matter as well as blood vessels, in vitro, in human brain samples and in vivo, in rats. We have also repeated the in vitro procedure with the probe inserted in a DBS stimulating electrode and found the results were in good agreement. We are currently validating a second fiber optic device, with micro-optical components, that will result in label free, molecular level sensing capabilities, using CARS spectroscopy. The final objective will be to use this data in real time, during deep brain stimulation neurosurgery, to increase the safety and accuracy of the procedure.

Intraoperative delineation of primary brain tumors using time-resolved fluorescence spectroscopy

PubMed Central

Butte, Pramod V.; Fang, Qiyin; Jo, Javier A.; Yong, William H.; Pikul, Brian K.; Black, Keith L.; Marcu, Laura

2010-01-01

The goal of this study is to determine the potential of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) as an adjunctive tool for delineation of brain tumor from surrounding normal tissue in order to assist the neurosurgeon in near-complete tumor excision. A time-domain TR-LIFS prototype apparatus (gated photomultiplier detection, fast digitizer) was used for recording tissue autofluorescence in normal cortex (NC), normal white matter (NWM), and various grades of gliomas intraoperatively. Tissue fluorescence was induced with a pulsed nitrogen laser (337nm, 700ps), and the intensity decay profiles were recorded in the 360-to550-nm spectral range (10-nm interval). Histopathological analysis (hematoxylin & eosin) of the biopsy samples taken from the site of TR-LIFS measurements was used for validation of spectroscopic results. Preliminary results on 17 patients demonstrate that normal cortex (N=16) and normal white matter (N=3) show two peaks of fluorescence emission at 390nm(lifetime=1.8±0.3ns) and 460nm(lifetime=0.8±0.1ns). The 390-nm emission peak is absent in low-grade glioma (N=5; lifetime=1.1ns) and reduced in high-grade glioma (N=9; lifetime=1.7±0.4ns). The emission characteristics at 460nm in all tissues correlated with the nicotinamide adenine dinucleotide fluorescence (peak: 440to460nm; lifetime: 0.8to1.0ns). These findings demonstrate the potential of using TR-LIFS as a tool for enhanced delineation of brain tumors during surgery. In addition, this study evaluates similarities and differences between TR-LIFS signatures of brain tumors obtained in vivo and those previously reported in ex vivo brain tumor specimens. PMID:20459282

Intraoperative delineation of primary brain tumors using time-resolved fluorescence spectroscopy.

PubMed

Butte, Pramod V; Fang, Qiyin; Jo, Javier A; Yong, William H; Pikul, Brian K; Black, Keith L; Marcu, Laura

2010-01-01

The goal of this study is to determine the potential of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) as an adjunctive tool for delineation of brain tumor from surrounding normal tissue in order to assist the neurosurgeon in near-complete tumor excision. A time-domain TR-LIFS prototype apparatus (gated photomultiplier detection, fast digitizer) was used for recording tissue autofluorescence in normal cortex (NC), normal white matter (NWM), and various grades of gliomas intraoperatively. Tissue fluorescence was induced with a pulsed nitrogen laser (337 nm, 700 ps), and the intensity decay profiles were recorded in the 360- to 550-nm spectral range (10-nm interval). Histopathological analysis (hematoxylin & eosin) of the biopsy samples taken from the site of TR-LIFS measurements was used for validation of spectroscopic results. Preliminary results on 17 patients demonstrate that normal cortex (N=16) and normal white matter (N=3) show two peaks of fluorescence emission at 390 nm (lifetime=1.8+/-0.3 ns) and 460 nm (lifetime=0.8+/-0.1 ns). The 390-nm emission peak is absent in low-grade glioma (N=5; lifetime=1.1 ns) and reduced in high-grade glioma (N=9; lifetime=1.7+/-0.4 ns). The emission characteristics at 460 nm in all tissues correlated with the nicotinamide adenine dinucleotide fluorescence (peak: 440 to 460 nm; lifetime: 0.8 to 1.0 ns). These findings demonstrate the potential of using TR-LIFS as a tool for enhanced delineation of brain tumors during surgery. In addition, this study evaluates similarities and differences between TR-LIFS signatures of brain tumors obtained in vivo and those previously reported in ex vivo brain tumor specimens.

Intraoperative delineation of primary brain tumors using time-resolved fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Butte, Pramod V.; Fang, Qiyin; Jo, Javier A.; Yong, William H.; Pikul, Brian K.; Black, Keith L.; Marcu, Laura

2010-03-01

The goal of this study is to determine the potential of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) as an adjunctive tool for delineation of brain tumor from surrounding normal tissue in order to assist the neurosurgeon in near-complete tumor excision. A time-domain TR-LIFS prototype apparatus (gated photomultiplier detection, fast digitizer) was used for recording tissue autofluorescence in normal cortex (NC), normal white matter (NWM), and various grades of gliomas intraoperatively. Tissue fluorescence was induced with a pulsed nitrogen laser (337 nm, 700 ps), and the intensity decay profiles were recorded in the 360- to 550-nm spectral range (10-nm interval). Histopathological analysis (hematoxylin & eosin) of the biopsy samples taken from the site of TR-LIFS measurements was used for validation of spectroscopic results. Preliminary results on 17 patients demonstrate that normal cortex (N=16) and normal white matter (N=3) show two peaks of fluorescence emission at 390 nm (lifetime=1.8+/-0.3 ns) and 460 nm (lifetime=0.8+/-0.1 ns). The 390-nm emission peak is absent in low-grade glioma (N=5; lifetime=1.1 ns) and reduced in high-grade glioma (N=9; lifetime=1.7+/-0.4 ns). The emission characteristics at 460 nm in all tissues correlated with the nicotinamide adenine dinucleotide fluorescence (peak: 440 to 460 nm lifetime: 0.8 to 1.0 ns). These findings demonstrate the potential of using TR-LIFS as a tool for enhanced delineation of brain tumors during surgery. In addition, this study evaluates similarities and differences between TR-LIFS signatures of brain tumors obtained in vivo and those previously reported in ex vivo brain tumor specimens.

In vitro 3D regeneration-like growth of human patient brain tissue.

PubMed

Tang-Schomer, M D; Wu, W B; Kaplan, D L; Bookland, M J

2018-05-01

In vitro culture of primary neurons is widely adapted with embryonic but not mature brain tissue. Here, we extended a previously developed bioengineered three-dimensional (3D) embryonic brain tissue model to resected normal patient brain tissue in an attempt to regenerate human neurons in vitro. Single cells and small sized (diameter < 100 μm) spheroids from dissociated brain tissue were seeded into 3D silk fibroin-based scaffolds, with or without collagen or Matrigel, and compared with two-dimensional cultures and scaffold-free suspension cultures. Changes of cell phenotypes (neuronal, astroglial, neural progenitor, and neuroepithelial) were quantified with flow cytometry and analyzed with a new method of statistical analysis specifically designed for percentage comparison. Compared with a complete lack of viable cells in conventional neuronal cell culture condition, supplements of vascular endothelial growth factor-containing pro-endothelial cell condition led to regenerative growth of neurons and astroglial cells from "normal" human brain tissue of epilepsy surgical patients. This process involved delayed expansion of Nestin+ neural progenitor cells, emergence of TUJ1+ immature neurons, and Vimentin+ neuroepithelium-like cell sheet formation in prolonged cultures (14 weeks). Micro-tissue spheroids, but not single cells, supported the brain tissue growth, suggesting importance of preserving native cell-cell interactions. The presence of 3D scaffold, but not hydrogel, allowed for Vimentin+ cell expansion, indicating a different growth mechanism than pluripotent cell-based brain organoid formation. The slow and delayed process implied an origin of quiescent neural precursors in the neocortex tissue. Further optimization of the 3D tissue model with primary human brain cells could provide personalized brain disease models. Copyright © 2018 John Wiley & Sons, Ltd.

Laser Microdissection and Atmospheric Pressure Chemical Ionization Mass Spectrometry Coupled for Multimodal Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorenz, Matthias; Ovchinnikova, Olga S; Kertesz, Vilmos

2013-01-01

This paper describes the coupling of ambient laser ablation surface sampling, accomplished using a laser capture microdissection system, with atmospheric pressure chemical ionization mass spectrometry for high spatial resolution multimodal imaging. A commercial laser capture microdissection system was placed in close proximity to a modified ion source of a mass spectrometer designed to allow for sampling of laser ablated material via a transfer tube directly into the ionization region. Rhodamine 6G dye of red sharpie ink in a laser etched pattern as well as cholesterol and phosphatidylcholine in a cerebellum mouse brain thin tissue section were identified and imaged frommore » full scan mass spectra. A minimal spot diameter of 8 m was achieved using the 10X microscope cutting objective with a lateral oversampling pixel resolution of about 3.7 m. Distinguishing between features approximately 13 m apart in a cerebellum mouse brain thin tissue section was demonstrated in a multimodal fashion including co-registered optical and mass spectral chemical images.« less

Usability of Immunohistochemistry in Forensic Samples With Varying Decomposition.

PubMed

Lesnikova, Iana; Schreckenbach, Marc Niclas; Kristensen, Maria Pihlmann; Papanikolaou, Liv Lindegaard; Hamilton-Dutoit, Stephen

2018-05-24

Immunohistochemistry (IHC) is an important diagnostic tool in anatomic and surgical pathology but is used less frequently in forensic pathology. Degradation of tissue because of postmortem decomposition is believed to be a major limiting factor, although it is unclear what impact such degradation actually has on IHC staining validity. This study included 120 forensic autopsy samples of liver, lung, and brain tissues obtained for diagnostic purposes. The time from death to autopsy ranged between 1 and more than 14 days. Samples were prepared using the tissue microarray technique. The antibodies chosen for the study included KL1 (for staining bile duct epithelium), S100 (for staining glial cells and myelin), vimentin (for endothelial cells in cerebral blood vessels), and CD45 (for pulmonary lymphocytes). Slides were evaluated by light microscopy. Immunohistochemistry reactions were scored according to a system based on the extent and intensity of the positive stain. An overall correlation between the postmortem interval and the IHC score for all tissue samples was found. Samples from decedents with a postmortem interval of 1 to 3 days showed positive staining with all antibodies, whereas samples from decedents with a longer postmortem interval showed decreased staining rates. Our results suggest that IHC analysis can be successfully used for postmortem diagnosis in a range of autopsy samples showing lesser degrees of decomposition.

Comprehensive analysis of a microRNA expression profile in pediatric medulloblastoma.

PubMed

Dai, Junqiang; Li, Qiao; Bing, Zhitong; Zhang, Yinian; Niu, Liang; Yin, Hang; Yuan, Guoqiang; Pan, Yawen

2017-06-01

Medulloblastoma is the most common malignant brain tumor of the central nervous system among children. Medulloblastoma is an embryonal tumor, of which little is known about the pathogenesis. Several efforts have been made to understand the molecular aspects of its tumorigenic pathways; however, these are poorly understood. microRNA (miRNA), a type of non‑coding short RNA, has been proven to be associated with a number of physiological processes and pathological processes of serious diseases, including brain tumors. Differentially expressed miRNAs serve an important role in numerous types of malignancy. The present study aims to define a differentially expressed set of miRNAs in medulloblastoma tumor tissue, compared with normal samples, to improve the understanding of the tumorigenesis. It was identified that 22 miRNAs were upregulated and 26 miRNAs were downregulated in the tumor tissue compared with the normal group. However, when the medulloblastoma tissue was compared with normal cerebellum tissue, 9 miRNAs were identified to be up or downregulated in the tumor samples. The differentially expressed miRNAs in the tumor tissue were identified in order to clarify the networks and pathways of tumorigenesis using Ingenuity Pathway Analysis. Subsequently, key regulatory genes associated with the development of medulloblastoma were identified, including tumor protein p53, insulin like growth factor 1 receptor, argonaute 2, mitogen‑activated protein kinases 1 and 3, sirtuin 1 and Y box binding protein 1.

The effects of CD147 on the cell proliferation, apoptosis, invasion, and angiogenesis in glioma.

PubMed

Yin, Haoyuan; Shao, Ying; Chen, Xuan

2017-01-01

To analyze the effects of extracellular matrix metalloproteinase inducer (CD147) on glioma proliferation, apoptosis, invasion, and angiogenesis. Tissue samples were obtained from 101 glioma cases while normal brain tissues were obtained from 30 brain injury cases. Immunohistochemical assay was performed to detect the expressions of CD147, CD34, and VEGF in tissue samples. QRT-PCR was performed to detect the relative expression of CD147 mRNA in human glioma cell lines. CD147 siRNA was transfected into glioma cell line U251. Cell proliferation, apoptosis, invasion, and angiogenesis were tested by MTT, flow cytometry, Transwell assay, and vasculogenic mimicry assay, respectively. Expressions of relative proteins were analyzed with western blot. CD147 was positively expressed with the percentage of 0, 37.5, 44.8, 67.9, and 85.7 % in normal tissues and glioma tissues with WHO grades I-IV, respectively, and the scores of MVDand VEGF were associated with the expression of CD147. CD147 was significantly upregulated in the human glioma cell lines (P < 0.05). Downregulated the expression of CD147 suppressed cell proliferation, blocked cell cycle, induced apoptosis, inhibited cell invasion and angiogenesis in glioma cells in vitro. The expression of CD147 was significantly associated with WHO tumor grade and angiogenesis; silencing of CD147 contributed to inhibition of glioma proliferation, invasion, and angiogenesis. Our study provided firm evidence that CD 147 is a potential glioma target for anti-angiogenic therapies.

Chemical imaging analysis of the brain with X-ray methods

NASA Astrophysics Data System (ADS)

Collingwood, Joanna F.; Adams, Freddy

2017-04-01

Cells employ various metal and metalloid ions to augment the structure and the function of proteins and to assist with vital biological processes. In the brain they mediate biochemical processes, and disrupted metabolism of metals may be a contributing factor in neurodegenerative disorders. In this tutorial review we will discuss the particular role of X-ray methods for elemental imaging analysis of accumulated metal species and metal-containing compounds in biological materials, in the context of post-mortem brain tissue. X-rays have the advantage that they have a short wavelength and can penetrate through a thick biological sample. Many of the X-ray microscopy techniques that provide the greatest sensitivity and specificity for trace metal concentrations in biological materials are emerging at synchrotron X-ray facilities. Here, the extremely high flux available across a wide range of soft and hard X-rays, combined with state-of-the-art focusing techniques and ultra-sensitive detectors, makes it viable to undertake direct imaging of a number of elements in brain tissue. The different methods for synchrotron imaging of metals in brain tissues at regional, cellular, and sub-cellular spatial resolution are discussed. Methods covered include X-ray fluorescence for elemental imaging, X-ray absorption spectrometry for speciation imaging, X-ray diffraction for structural imaging, phase contrast for enhanced contrast imaging and scanning transmission X-ray microscopy for spectromicroscopy. Two- and three-dimensional (confocal and tomographic) imaging methods are considered as well as the correlation of X-ray microscopy with other imaging tools.

Development of acute hydrocephalus does not change brain tissue mechanical properties in adult rats, but in juvenile rats

PubMed Central

Pong, Alice C.; Jugé, Lauriane; Bilston, Lynne E.; Cheng, Shaokoon

2017-01-01

Introduction Regional changes in brain stiffness were previously demonstrated in an experimental obstructive hydrocephalus juvenile rat model. The open cranial sutures in the juvenile rats have influenced brain compression and mechanical properties during hydrocephalus development and the extent by which closed cranial sutures in adult hydrocephalic rat models affect brain stiffness in-vivo remains unclear. The aims of this study were to determine changes in brain tissue mechanical properties and brain structure size during hydrocephalus development in adult rat with fixed cranial volume and how these changes were related to brain tissue deformation. Methods Hydrocephalus was induced in 9 female ten weeks old Sprague-Dawley rats by injecting 60 μL of a kaolin suspension (25%) into the cisterna magna under anaesthesia. 6 sham-injected age-matched female SD rats were used as controls. MR imaging (9.4T, Bruker) was performed 1 day before and then at 3 days post injection. T2-weighted anatomical MR images were collected to quantify ventricle and brain tissue cross-sectional areas. MR elastography (800 Hz) was used to measure the brain stiffness (G*, shear modulus). Results Brain tissue in the adult hydrocephalic rats was more compressed than the juvenile hydrocephalic rats because the skulls of the adult hydrocephalic rats were unable to expand like the juvenile rats. In the adult hydrocephalic rats, the cortical gray matter thickness and the caudate-putamen cross-sectional area decreased (Spearman, P < 0.001 for both) but there were no significant changes in cranial cross-sectional area (Spearman, P = 0.35), cortical gray matter stiffness (Spearman, P = 0.24) and caudate-putamen (Spearman, P = 0.11) stiffness. No significant changes in the size of brain structures were observed in the controls. Conclusions This study showed that although brain tissue in the adult hydrocephalic rats was severely compressed, their brain tissue stiffness did not change significantly. These results are in contrast with our previous findings in juvenile hydrocephalic rats which had significantly less brain compression (as the brain circumference was able to stretch with the cranium due to the open skull sutures) and had a significant increase in caudate putamen stiffness. These results suggest that change in brain mechanical properties in hydrocephalus is complex and is not solely dependent on brain tissue deformation. Further studies on the interactions between brain tissue stiffness, deformation, tissue oedema and neural damage are necessary before MRE can be used as a tool to track changes in brain biomechanics in hydrocephalus. PMID:28837671

Development of acute hydrocephalus does not change brain tissue mechanical properties in adult rats, but in juvenile rats.

PubMed

Pong, Alice C; Jugé, Lauriane; Bilston, Lynne E; Cheng, Shaokoon

2017-01-01

Regional changes in brain stiffness were previously demonstrated in an experimental obstructive hydrocephalus juvenile rat model. The open cranial sutures in the juvenile rats have influenced brain compression and mechanical properties during hydrocephalus development and the extent by which closed cranial sutures in adult hydrocephalic rat models affect brain stiffness in-vivo remains unclear. The aims of this study were to determine changes in brain tissue mechanical properties and brain structure size during hydrocephalus development in adult rat with fixed cranial volume and how these changes were related to brain tissue deformation. Hydrocephalus was induced in 9 female ten weeks old Sprague-Dawley rats by injecting 60 μL of a kaolin suspension (25%) into the cisterna magna under anaesthesia. 6 sham-injected age-matched female SD rats were used as controls. MR imaging (9.4T, Bruker) was performed 1 day before and then at 3 days post injection. T2-weighted anatomical MR images were collected to quantify ventricle and brain tissue cross-sectional areas. MR elastography (800 Hz) was used to measure the brain stiffness (G*, shear modulus). Brain tissue in the adult hydrocephalic rats was more compressed than the juvenile hydrocephalic rats because the skulls of the adult hydrocephalic rats were unable to expand like the juvenile rats. In the adult hydrocephalic rats, the cortical gray matter thickness and the caudate-putamen cross-sectional area decreased (Spearman, P < 0.001 for both) but there were no significant changes in cranial cross-sectional area (Spearman, P = 0.35), cortical gray matter stiffness (Spearman, P = 0.24) and caudate-putamen (Spearman, P = 0.11) stiffness. No significant changes in the size of brain structures were observed in the controls. This study showed that although brain tissue in the adult hydrocephalic rats was severely compressed, their brain tissue stiffness did not change significantly. These results are in contrast with our previous findings in juvenile hydrocephalic rats which had significantly less brain compression (as the brain circumference was able to stretch with the cranium due to the open skull sutures) and had a significant increase in caudate putamen stiffness. These results suggest that change in brain mechanical properties in hydrocephalus is complex and is not solely dependent on brain tissue deformation. Further studies on the interactions between brain tissue stiffness, deformation, tissue oedema and neural damage are necessary before MRE can be used as a tool to track changes in brain biomechanics in hydrocephalus.

Development and characterization of a handheld hyperspectral Raman imaging probe system for molecular characterization of tissue on mesoscopic scales.

PubMed

St-Arnaud, Karl; Aubertin, Kelly; Strupler, Mathias; Madore, Wendy-Julie; Grosset, Andrée-Anne; Petrecca, Kevin; Trudel, Dominique; Leblond, Frédéric

2018-01-01

Raman spectroscopy is a promising cancer detection technique for surgical guidance applications. It can provide quantitative information relating to global tissue properties associated with structural, metabolic, immunological, and genetic biochemical phenomena in terms of molecular species including amino acids, lipids, proteins, and nucleic acid (DNA). To date in vivo Raman spectroscopy systems mostly included probes and biopsy needles typically limited to single-point tissue interrogation over a scale between 100 and 500 microns. The development of wider field handheld systems could improve tumor localization for a range of open surgery applications including brain, ovarian, and skin cancers. Here we present a novel Raman spectroscopy implementation using a coherent imaging bundle of fibers to create a probe capable of reconstructing molecular images over mesoscopic fields of view. Detection is performed using linear scanning with a rotation mirror and an imaging spectrometer. Different slits widths were tested at the entrance of the spectrometer to optimize spatial and spectral resolution while preserving sufficient signal-to-noise ratios to detect the principal Raman tissue features. The nonbiological samples, calcite and polytetrafluoroethylene (PTFE), were used to characterize the performance of the system. The new wide-field probe was tested on ex vivo samples of calf brain and swine tissue. Raman spectral content of both tissue types were validated with data from the literature and compared with data acquired with a single-point Raman spectroscopy probe. The single-point probe was used as the gold standard against which the new instrument was benchmarked as it has already been thoroughly validated for biological tissue characterization. We have developed and characterized a practical noncontact handheld Raman imager providing tissue information at a spatial resolution of 115 microns over a field of view >14 mm 2 and a spectral resolution of 6 cm -1 over the whole fingerprint region. Typical integration time to acquire an entire Raman image over swine tissue was set to approximately 100 s. Spectra acquired with both probes (single-point and wide-field) showed good agreement, with a Pearson correlation factor >0.85 over different tissue categories. Protein and lipid content of imaged tissue were manifested into the measured spectra which correlated well with previous findings in the literature. An example of quantitative molecular map is presented for swine tissue and calf brain based on the ratio of protein-to-lipid content showing clear delineations between white and gray matter as well as between adipose and muscle tissue. We presented the development of a Raman imaging probe with a field of view of a few millimeters and a spatial resolution consistent with standard surgical imaging methods using an imaging bundle. Spectra acquired with the newly developed system on swine tissue and calf brain correlated well with an establish single-point probe and observed spectral features agreed with previous finding in the literature. The imaging probe has demonstrated its ability to reconstruct molecular images of soft tissues. The approach presented here has a lot of potential for the development of surgical Raman imaging probe to guide the surgeon during cancer surgery. © 2017 American Association of Physicists in Medicine.

Novel and sensitive reversed-phase high-pressure liquid chromatography method with electrochemical detection for the simultaneous and fast determination of eight biogenic amines and metabolites in human brain tissue.

PubMed

Van Dam, Debby; Vermeiren, Yannick; Aerts, Tony; De Deyn, Peter Paul

2014-08-01

A fast and simple RP-HPLC method with electrochemical detection (ECD) and ion pair chromatography was developed, optimized and validated in order to simultaneously determine eight different biogenic amines and metabolites in post-mortem human brain tissue in a single-run analytical approach. The compounds of interest are the indolamine serotonin (5-hydroxytryptamine, 5-HT), the catecholamines dopamine (DA) and (nor)epinephrine ((N)E), as well as their respective metabolites, i.e. 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), 5-hydroxy-3-indoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (MHPG). A two-level fractional factorial experimental design was applied to study the effect of five experimental factors (i.e. the ion-pair counter concentration, the level of organic modifier, the pH of the mobile phase, the temperature of the column, and the voltage setting of the detector) on the chromatographic behaviour. The cross effect between the five quantitative factors and the capacity and separation factors of the analytes were then analysed using a Standard Least Squares model. The optimized method was fully validated according to the requirements of SFSTP (Société Française des Sciences et Techniques Pharmaceutiques). Our human brain tissue sample preparation procedure is straightforward and relatively short, which allows samples to be loaded onto the HPLC system within approximately 4h. Additionally, a high sample throughput was achieved after optimization due to a total runtime of maximally 40min per sample. The conditions and settings of the HPLC system were found to be accurate with high intra and inter-assay repeatability, recovery and accuracy rates. The robust analytical method results in very low detection limits and good separation for all of the eight biogenic amines and metabolites in this complex mixture of biological analytes. Copyright © 2014 Elsevier B.V. All rights reserved.

Time resolved dosimetry of human brain exposed to low frequency pulsed magnetic fields.

PubMed

Paffi, Alessandra; Camera, Francesca; Lucano, Elena; Apollonio, Francesca; Liberti, Micaela

2016-06-21

An accurate dosimetry is a key issue to understanding brain stimulation and related interaction mechanisms with neuronal tissues at the basis of the increasing amount of literature revealing the effects on human brain induced by low-level, low frequency pulsed magnetic fields (PMFs). Most literature on brain dosimetry estimates the maximum E field value reached inside the tissue without considering its time pattern or tissue dispersivity. Nevertheless a time-resolved dosimetry, accounting for dispersive tissues behavior, becomes necessary considering that the threshold for an effect onset may vary depending on the pulse waveform and that tissues may filter the applied stimulatory fields altering the predicted stimulatory waveform's size and shape. In this paper a time-resolved dosimetry has been applied on a realistic brain model exposed to the signal presented in Capone et al (2009 J. Neural Transm. 116 257-65), accounting for the broadband dispersivity of brain tissues up to several kHz, to accurately reconstruct electric field and current density waveforms inside different brain tissues. The results obtained by exposing the Duke's brain model to this PMF signal show that the E peak in the brain is considerably underestimated if a simple monochromatic dosimetry is carried out at the pulse repetition frequency of 75 Hz.

Time resolved dosimetry of human brain exposed to low frequency pulsed magnetic fields

NASA Astrophysics Data System (ADS)

Paffi, Alessandra; Camera, Francesca; Lucano, Elena; Apollonio, Francesca; Liberti, Micaela

2016-06-01

An accurate dosimetry is a key issue to understanding brain stimulation and related interaction mechanisms with neuronal tissues at the basis of the increasing amount of literature revealing the effects on human brain induced by low-level, low frequency pulsed magnetic fields (PMFs). Most literature on brain dosimetry estimates the maximum E field value reached inside the tissue without considering its time pattern or tissue dispersivity. Nevertheless a time-resolved dosimetry, accounting for dispersive tissues behavior, becomes necessary considering that the threshold for an effect onset may vary depending on the pulse waveform and that tissues may filter the applied stimulatory fields altering the predicted stimulatory waveform’s size and shape. In this paper a time-resolved dosimetry has been applied on a realistic brain model exposed to the signal presented in Capone et al (2009 J. Neural Transm. 116 257-65), accounting for the broadband dispersivity of brain tissues up to several kHz, to accurately reconstruct electric field and current density waveforms inside different brain tissues. The results obtained by exposing the Duke’s brain model to this PMF signal show that the E peak in the brain is considerably underestimated if a simple monochromatic dosimetry is carried out at the pulse repetition frequency of 75 Hz.

Temperature-dependent elastic properties of brain tissues measured with the shear wave elastography method.

PubMed

Liu, Yan-Lin; Li, Guo-Yang; He, Ping; Mao, Ze-Qi; Cao, Yanping

2017-01-01

Determining the mechanical properties of brain tissues is essential in such cases as the surgery planning and surgical training using virtual reality based simulators, trauma research and the diagnosis of some diseases that alter the elastic properties of brain tissues. Here, we suggest a protocol to measure the temperature-dependent elastic properties of brain tissues in physiological saline using the shear wave elastography method. Experiments have been conducted on six porcine brains. Our results show that the shear moduli of brain tissues decrease approximately linearly with a slope of -0.041±0.006kPa/°C when the temperature T increases from room temperature (~23°C) to body temperature (~37°C). A case study has been further conducted which shows that the shear moduli are insensitive to the temperature variation when T is in the range of 37 to 43°C and will increase when T is higher than 43°C. With the present experimental setup, temperature-dependent elastic properties of brain tissues can be measured in a simulated physiological environment and a non-destructive manner. Thus the method suggested here offers a unique tool for the mechanical characterization of brain tissues with potential applications in brain biomechanics research. Copyright © 2016 Elsevier Ltd. All rights reserved.

Automated MALDI Matrix Coating System for Multiple Tissue Samples for Imaging Mass Spectrometry

NASA Astrophysics Data System (ADS)

Mounfield, William P.; Garrett, Timothy J.

2012-03-01

Uniform matrix deposition on tissue samples for matrix-assisted laser desorption/ionization (MALDI) is key for reproducible analyte ion signals. Current methods often result in nonhomogenous matrix deposition, and take time and effort to produce acceptable ion signals. Here we describe a fully-automated method for matrix deposition using an enclosed spray chamber and spray nozzle for matrix solution delivery. A commercial air-atomizing spray nozzle was modified and combined with solenoid controlled valves and a Programmable Logic Controller (PLC) to control and deliver the matrix solution. A spray chamber was employed to contain the nozzle, sample, and atomized matrix solution stream, and to prevent any interference from outside conditions as well as allow complete control of the sample environment. A gravity cup was filled with MALDI matrix solutions, including DHB in chloroform/methanol (50:50) at concentrations up to 60 mg/mL. Various samples (including rat brain tissue sections) were prepared using two deposition methods (spray chamber, inkjet). A linear ion trap equipped with an intermediate-pressure MALDI source was used for analyses. Optical microscopic examination showed a uniform coating of matrix crystals across the sample. Overall, the mass spectral images gathered from tissues coated using the spray chamber system were of better quality and more reproducible than from tissue specimens prepared by the inkjet deposition method.

Automated MALDI matrix coating system for multiple tissue samples for imaging mass spectrometry.

PubMed

Mounfield, William P; Garrett, Timothy J

2012-03-01

Uniform matrix deposition on tissue samples for matrix-assisted laser desorption/ionization (MALDI) is key for reproducible analyte ion signals. Current methods often result in nonhomogenous matrix deposition, and take time and effort to produce acceptable ion signals. Here we describe a fully-automated method for matrix deposition using an enclosed spray chamber and spray nozzle for matrix solution delivery. A commercial air-atomizing spray nozzle was modified and combined with solenoid controlled valves and a Programmable Logic Controller (PLC) to control and deliver the matrix solution. A spray chamber was employed to contain the nozzle, sample, and atomized matrix solution stream, and to prevent any interference from outside conditions as well as allow complete control of the sample environment. A gravity cup was filled with MALDI matrix solutions, including DHB in chloroform/methanol (50:50) at concentrations up to 60 mg/mL. Various samples (including rat brain tissue sections) were prepared using two deposition methods (spray chamber, inkjet). A linear ion trap equipped with an intermediate-pressure MALDI source was used for analyses. Optical microscopic examination showed a uniform coating of matrix crystals across the sample. Overall, the mass spectral images gathered from tissues coated using the spray chamber system were of better quality and more reproducible than from tissue specimens prepared by the inkjet deposition method.

Brief Report: The Role of National Brain and Tissue Banks in Research on Autism and Developmental Disorders.

ERIC Educational Resources Information Center

Zielke, H. Ronald; And Others

1996-01-01

This paper describes the establishment and work of two brain and tissue banks, which collect brain and other tissues from newly deceased individuals with autism and make these tissues available to researchers. Issues in tissue collection are identified, including the importance of advance planning, religious concerns of families, and the need for…

Wild-type Measles Virus in Brain Tissue of Children with Subacute Sclerosing Panencephalitis, Argentina

PubMed Central

Barrero, Paola Roxana; Grippo, Jorge; Viegas, Mariana

2003-01-01

We studied eight children who had measles at 6 to 10 months of age during the 1998 Argentine measles outbreak and in whom subacute sclerosing panencephalitis developed 4 years later. We report the genetic characterization of brain tissue–associated measles virus samples from three patients. Phylogenetic relationships clustered these viruses with the wild-type D6 genotype isolated during the 1998 outbreak. The children received measles vaccine; however, vaccinal strains were not found. PMID:14609476

Epileptic rat brain tissue analyzed by 2D correlation Raman spectroscopy

NASA Astrophysics Data System (ADS)

Sacharz, Julia; Wesełucha-Birczyńska, Aleksandra; Zięba-Palus, Janina; Lewandowski, Marian H.; Kowalski, Rafał; Palus, Katarzyna; Chrobok, Łukasz; Moskal, Paulina; Birczyńska, Malwina; Sozańska, Agnieszka

2018-01-01

Absence epilepsy is the neurological disorder characterized by the pathological spike-and wave discharges present in the electroencephalogram, accompanying a sudden loss of consciousness. Experiments were performed on brain slices obtained from young male WAG/Rij rats (2-3 weeks old), so that they were sampled before the appearance of brain-damaging seizures symptoms. Two differing brain areas of the rats' brain tissue were studied: the somatosensory cortex (Sc) and the dorsal lateral geniculate nucleus of the thalamus (DLG). The Raman spectra of the fresh brain scraps, kept during measurements in artificial cerebrospinal fluid, were collected using as an excitation source 442 nm, 514.5 nm, 785 nm and 1064 nm laser line. The average spectra were analyzed by 2D correlation method regarding laser line as an external perturbation. In 2D synchronous spectra positive auto-peaks corresponding to the Cdbnd C stretching and amide I band vibrations show maxima at 1660 cm- 1 and 1662 cm- 1 for Sc and DLG, respectively. The prominent auto-peak at 2937 cm- 1, originated from the CH3 mode in DLG brain area, seems to indicate the importance of methylation, considered to be significant in epileptogenesis. Synchronous and asynchronous correlations peaks, glutamic acid and gamma-aminobutyric acid (GABA), appear in Sc and DLG, respectively. In the 1730-1600 cm- 1 range occur cross-peaks which appearance might be triggered by glial fibrillary acidic protein (GFAP) activation.

Select tissue mineral concentrations and chronic wasting disease status in mule deer from North-central Colorado.

PubMed

Wolfe, Lisa L; Conner, Mary M; Bedwell, Cathy L; Lukacs, Paul M; Miller, Michael W

2010-07-01

Trace mineral imbalances have been suggested as having a causative or contributory role in chronic wasting disease (CWD), a prion disease of several North American cervid species. To begin exploring relationships between tissue mineral concentrations and CWD in natural systems, we measured liver tissue concentrations of copper, manganese, and molybdenum in samples from 447 apparently healthy, adult (> or = 2 yr old) mule deer (Odocoileus hemionus) culled or vehicle killed from free-ranging populations in north-central Colorado, United States, where CWD occurs naturally; we also measured copper concentrations in brain-stem (medulla oblongata at the obex) tissue from 181 of these deer. Analyses revealed a wide range of concentrations of all three minerals among sampled deer (copper: 5.6-331 ppm in liver, 1.5-31.9 ppm in obex; manganese: 0.1-21.4 ppm in liver; molybdenum: 0.5-4.0 ppm in liver). Bayesian multiple regression analysis revealed a negative association between obex copper (-0.097; 95% credible interval -0.192 to -0.006) and the probability of sampled deer also being infected with CWD, as well as a positive association between liver manganese (0.158; 95% credible interval 0.066 to 0.253) and probability of infection. We could not discern whether the tendencies toward lower brain-stem copper concentrations or higher systemic manganese concentrations in infected deer preceded prion infection or rather were the result of infection and its subsequent effects, although the distribution of trace mineral concentrations in infected deer seemed more suggestive of the latter.

Prediction of brain deformations and risk of traumatic brain injury due to closed-head impact: quantitative analysis of the effects of boundary conditions and brain tissue constitutive model.

PubMed

Wang, Fang; Han, Yong; Wang, Bingyu; Peng, Qian; Huang, Xiaoqun; Miller, Karol; Wittek, Adam

2018-05-12

In this study, we investigate the effects of modelling choices for the brain-skull interface (layers of tissues between the brain and skull that determine boundary conditions for the brain) and the constitutive model of brain parenchyma on the brain responses under violent impact as predicted using computational biomechanics model. We used the head/brain model from Total HUman Model for Safety (THUMS)-extensively validated finite element model of the human body that has been applied in numerous injury biomechanics studies. The computations were conducted using a well-established nonlinear explicit dynamics finite element code LS-DYNA. We employed four approaches for modelling the brain-skull interface and four constitutive models for the brain tissue in the numerical simulations of the experiments on post-mortem human subjects exposed to violent impacts reported in the literature. The brain-skull interface models included direct representation of the brain meninges and cerebrospinal fluid, outer brain surface rigidly attached to the skull, frictionless sliding contact between the brain and skull, and a layer of spring-type cohesive elements between the brain and skull. We considered Ogden hyperviscoelastic, Mooney-Rivlin hyperviscoelastic, neo-Hookean hyperviscoelastic and linear viscoelastic constitutive models of the brain tissue. Our study indicates that the predicted deformations within the brain and related brain injury criteria are strongly affected by both the approach of modelling the brain-skull interface and the constitutive model of the brain parenchyma tissues. The results suggest that accurate prediction of deformations within the brain and risk of brain injury due to violent impact using computational biomechanics models may require representation of the meninges and subarachnoidal space with cerebrospinal fluid in the model and application of hyperviscoelastic (preferably Ogden-type) constitutive model for the brain tissue.

Expression of Bcl-2 and NF-κB in brain tissue after acute renal ischemia-reperfusion in rats.

PubMed

Zhang, Na; Cheng, Gen-Yang; Liu, Xian-Zhi; Zhang, Feng-Jiang

2014-05-01

To investigate the effect of acute renal ischemia reperfusion on brain tissue. Fourty eight rats were randomly divided into four groups (n=12): sham operation group, 30 min ischemia 60 min reperfusion group, 60 min ischemia 60 min reperfusion group, and 120 min ischemia 60 min reperfusion group. The brain tissues were taken after the experiment. TUNEL assay was used to detect the brain cell apoptosis, and western blot was used to detect the expression of apoptosis-related proteins and inflammatory factors. Renal ischemia-reperfusion induced apoptosis of brain tissues, and the apoptosis increased with prolongation of ischemia time. The detection at the molecular level showed decreased Bcl-2 expression, increased Bax expression, upregulated expression of NF-κB and its downstream factor COX-2/PGE2. Acute renal ischemia-reperfusion can cause brain tissue damage, manifested as induced brain tissues apoptosis and inflammation activation. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

HIV-1 Phylogenetic analysis shows HIV-1 transits through the meninges to brain and peripheral tissues

PubMed Central

Lamers, Susanna L.; Gray, Rebecca R.; Salemi, Marco; Huysentruyt, Leanne C.; McGrath, Michael

2010-01-01

Brain infection by the human immunodeficiency virus type 1 (HIV-1) has been investigated in many reports with a variety of conclusions concerning the time of entry and degree of viral compartmentalization. To address these diverse findings, we sequenced HIV-1 gp120 clones from a wide range of brain, peripheral and meningeal tissues from five patients who died from several HIV-1 associated disease pathologies. High-resolution phylogenetic analysis confirmed previous studies that showed a significant degree of compartmentalization in brain and peripheral tissue subpopulations. Some intermixing between the HIV-1 subpopulations was evident, especially in patients that died from pathologies other than HIV-associated dementia. Interestingly, the major tissue harboring virus from both the brain and peripheral tissues was the meninges. These results show that 1) HIV-1 is clearly capable of migrating out of the brain, 2) the meninges are the most likely primary transport tissues, and 3) infected brain macrophages comprise an important HIV reservoir during highly active antiretroviral therapy. PMID:21055482

Coupled Analysis of In Vitro and Histology Tissue Samples to Quantify Structure-Function Relationship

PubMed Central

Acar, Evrim; Plopper, George E.; Yener, Bülent

2012-01-01

The structure/function relationship is fundamental to our understanding of biological systems at all levels, and drives most, if not all, techniques for detecting, diagnosing, and treating disease. However, at the tissue level of biological complexity we encounter a gap in the structure/function relationship: having accumulated an extraordinary amount of detailed information about biological tissues at the cellular and subcellular level, we cannot assemble it in a way that explains the correspondingly complex biological functions these structures perform. To help close this information gap we define here several quantitative temperospatial features that link tissue structure to its corresponding biological function. Both histological images of human tissue samples and fluorescence images of three-dimensional cultures of human cells are used to compare the accuracy of in vitro culture models with their corresponding human tissues. To the best of our knowledge, there is no prior work on a quantitative comparison of histology and in vitro samples. Features are calculated from graph theoretical representations of tissue structures and the data are analyzed in the form of matrices and higher-order tensors using matrix and tensor factorization methods, with a goal of differentiating between cancerous and healthy states of brain, breast, and bone tissues. We also show that our techniques can differentiate between the structural organization of native tissues and their corresponding in vitro engineered cell culture models. PMID:22479315

Capillary electrophoresis - Mass spectrometry metabolomics analysis revealed enrichment of hypotaurine in rat glioma tissues.

PubMed

Gao, Peng; Ji, Min; Fang, Xueyan; Liu, Yingyang; Yu, Zhigang; Cao, Yunfeng; Sun, Aijun; Zhao, Liang; Zhang, Yong

2017-11-15

Glioma is one of the most lethal brain malignancies with unknown etiologies. Many metabolomics analysis aiming at diverse kinds of samples had been performed. Due to the varied adopted analytical platforms, the reported disease-related metabolites were not consistent across different studies. Comparable metabolomics results are more likely to be acquired by analyzing the same sample types with identical analytical platform. For tumor researches, tissue samples metabolomics analysis own the unique advantage that it can gain more direct insight into disease-specific pathological molecules. In this light, a previous reported capillary electrophoresis - mass spectrometry human tissues metabolomics analysis method was employed to profile the metabolome of rat C6 cell implantation gliomas and the corresponding precancerous tissues. It was found that 9 metabolites increased in the glioma tissues. Of them, hypotaurine was the only metabolite that enriched in the malignant tissues as what had been reported in the relevant human tissues metabolomics analysis. Furthermore, hypotaurine was also proved to inhibit α-ketoglutarate-dependent dioxygenases (2-KDDs) through immunocytochemistry staining and in vitro enzymatic activity assays by using C6 cell cultures. This study reinforced the previous conclusion that hypotaurine acted as a competitive inhibitor of 2-KDDs and proved the value of metabolomics in oncology studies. Copyright © 2017. Published by Elsevier Inc.

Military blast exposure, ageing and white matter integrity

PubMed Central

Trotter, Benjamin B.; Robinson, Meghan E.; Milberg, William P.; McGlinchey, Regina E.

2015-01-01

Mild traumatic brain injury, or concussion, is associated with a range of neural changes including altered white matter structure. There is emerging evidence that blast exposure—one of the most pervasive causes of casualties in the recent overseas conflicts in Iraq and Afghanistan—is accompanied by a range of neurobiological events that may result in pathological changes to brain structure and function that occur independently of overt concussion symptoms. The potential effects of brain injury due to blast exposure are of great concern as a history of mild traumatic brain injury has been identified as a risk factor for age-associated neurodegenerative disease. The present study used diffusion tensor imaging to investigate whether military-associated blast exposure influences the association between age and white matter tissue structure integrity in a large sample of veterans of the recent conflicts (n = 190 blast-exposed; 59 without exposure) between the ages of 19 and 62 years. Tract-based spatial statistics revealed a significant blast exposure × age interaction on diffusion parameters with blast-exposed individuals exhibiting a more rapid cross-sectional age trajectory towards reduced tissue integrity. Both distinct and overlapping voxel clusters demonstrating the interaction were observed among the examined diffusion contrast measures (e.g. fractional anisotropy and radial diffusivity). The regions showing the effect on fractional anisotropy included voxels both within and beyond the boundaries of the regions exhibiting a significant negative association between fractional anisotropy and age in the entire cohort. The regional effect was sensitive to the degree of blast exposure, suggesting a ‘dose-response’ relationship between the number of blast exposures and white matter integrity. Additionally, there was an age-independent negative association between fractional anisotropy and years since most severe blast exposure in a subset of the blast-exposed group, suggesting a specific influence of time since exposure on tissue structure, and this effect was also independent of post-traumatic stress symptoms. Overall, these data suggest that blast exposure may negatively affect brain-ageing trajectories at the microstructural tissue level. Additional work examining longitudinal changes in brain tissue integrity in individuals exposed to military blast forces will be an important future direction to the initial findings presented here. PMID:26033970

Robotic multimodality stereotactic brain tissue identification: work in progress

NASA Technical Reports Server (NTRS)

Andrews, R.; Mah, R.; Galvagni, A.; Guerrero, M.; Papasin, R.; Wallace, M.; Winters, J.

1997-01-01

Real-time identification of tissue would improve procedures such as stereotactic brain biopsy (SBX), functional and implantation neurosurgery, and brain tumor excision. To standard SBX equipment has been added: (1) computer-controlled stepper motors to drive the biopsy needle/probe precisely; (2) multiple microprobes to track tissue density, detect blood vessels and changes in blood flow, and distinguish the various tissues being penetrated; (3) neural net learning programs to allow real-time comparisons of current data with a normative data bank; (4) three-dimensional graphic displays to follow the probe as it traverses brain tissue. The probe can differentiate substances such as pig brain, differing consistencies of the 'brain-like' foodstuff tofu, and gels made to simulate brain, as well as detect blood vessels imbedded in these substances. Multimodality probes should improve the safety, efficacy, and diagnostic accuracy of SBX and other neurosurgical procedures.

Fiber-probe optical spectroscopy discriminates normal brain from focal cortical dysplasia in pediatric subjects

NASA Astrophysics Data System (ADS)

Anand, Suresh; Cicchi, Riccardo; Giordano, Flavio; Conti, Valerio; Buccoliero, Anna Maria; Guerrini, Renzo; Pavone, Francesco S.

2017-02-01

Focal cortical dysplasia (FCD) is an abnormality in the cerebral cortex that is caused by malformations during cortical development. Currently, magnetic resonance imaging (MRI) and electro-corticography (ECoG) are used for detecting FCD. On the downside, MRI is very much insensitive to small malformations in the brain, while ECoG is an invasive and time consuming procedure. Recently, optical techniques were widely exploited as a minimally invasive and quantitative approaches for disease diagnosis. These techniques include fluorescence and Raman spectroscopy. The aim of this investigation is to study the diagnostic performances of optical spectroscopy incorporating fluorescence (at 378 nm and 445 nm excitation wavelengths) and Raman spectroscopy (at 785 nm excitation) for the discrimination of FCD from normal brain in pediatric subjects. The study included 10 normal and 17 FCD tissue sites from 3 normal and 7 FCD samples. The emission spectra of FCD at 378 nm excitation wavelength presented a blue-shifted peak with respect to normal tissue. Prominent spectral differences between normal and FCD tissue were observed at 1298 cm-1, 1302 cm-1, 1445 cm-1 and 1660 cm-1 using Raman spectroscopy. Tissue classification models were developed using a multivariate statistical method, principal component analysis. This study demonstrates that a combined spectroscopic approach can provide a better diagnostic capability for classifying normal and FCD tissues. Further, the implementation of the technology within a fiber probe could open the way for in vivo diagnostics and intra-operative surgical guidance.

Target-specific contrast agents for magnetic resonance microscopy

PubMed Central

Blackwell, Megan L.; Farrar, Christian T.; Fischl, Bruce; Rosen, Bruce R.

2009-01-01

High-resolution ex vivo magnetic resonance (MR) imaging can be used to delineate prominent architectonic features in the human brain, but increased contrast is required to visualize more subtle distinctions. To aid MR sensitivity to cell density and myelination, we have begun the development of target-specific paramagnetic contrast agents. This work details the first application of luxol fast blue (LFB), an optical stain for myelin, as a white matter-selective MR contrast agent for human ex vivo brain tissue. Formalin-fixed human visual cortex was imaged with an isotropic resolution between 80 and 150 μm at 4.7 and 14 T before and after en bloc staining with LFB. Longitudinal (R1) and transverse (R2) relaxation rates in LFB-stained tissue increased proportionally with myelination at both field strengths. Changes in R1 resulted in larger contrast-to-noise ratios (CNR), per unit time, on T1-weighted images between more myelinated cortical layers (IV–VI) and adjacent, superficial layers (I–III) at both field strengths. Specifically, CNR for LFB-treated samples increased by 229±13% at 4.7 T and 269±25% at 14 T when compared to controls. Also, additional cortical layers (IVca, IVd, and Va) were resolvable in 14T-MR images of LFB-treated samples but not in control samples. After imaging, samples were sliced in 40-micron sections, mounted, and photographed. Both the macroscopic and microscopic distributions of LFB were found to mimic those of traditional histological preparations. Our results suggest target-specific contrast agents will enable more detailed MR images with applications in imaging pathological ex vivo samples and constructing better MR atlases from ex vivo brains. PMID:19385012

Detection of Chronic Wasting Disease Prions in Salivary, Urinary, and Intestinal Tissues of Deer: Potential Mechanisms of Prion Shedding and Transmission▿

PubMed Central

Haley, Nicholas J.; Mathiason, Candace K.; Carver, Scott; Zabel, Mark; Telling, Glenn C.; Hoover, Edward A.

2011-01-01

Efficient horizontal transmission is a signature trait of chronic wasting disease (CWD) in cervids. Infectious prions shed into excreta appear to play a key role in this facile transmission, as has been demonstrated by bioassays of cervid and transgenic species and serial protein misfolding cyclic amplification (sPMCA). However, the source(s) of infectious prions in these body fluids has yet to be identified. In the present study, we analyzed tissues proximate to saliva, urine, and fecal production by sPMCA in an attempt to elucidate this unique aspect of CWD pathogenesis. Oropharyngeal, urogenital, and gastrointestinal tissues along with blood and obex from CWD-exposed cervids (comprising 27 animals and >350 individual samples) were analyzed and scored based on the apparent relative CWD burden. PrPCWD-generating activity was detected in a range of tissues and was highest in the salivary gland, urinary bladder, and distal intestinal tract. In the same assays, blood from the same animals and unseeded normal brain homogenate controls (n = 116 of 117) remained negative. The PrP-converting activity in peripheral tissues varied from 10−11- to 100-fold of that found in brain of the same animal. Deer with highest levels of PrPCWD amplification in the brain had higher and more widely disseminated prion amplification in excretory tissues. Interestingly, PrPCWD was not demonstrable in these excretory tissues by conventional Western blotting, suggesting a low prion burden or the presence of protease-sensitive infectious prions destroyed by harsh proteolytic treatments. These findings offer unique insights into the transmission of CWD in particular and prion infection and trafficking overall. PMID:21525361

Terahertz spectroscopy of brain tissue from a mouse model of Alzheimer's disease

NASA Astrophysics Data System (ADS)

Shi, Lingyan; Shumyatsky, Pavel; Rodríguez-Contreras, Adrián; Alfano, Robert

2016-01-01

The terahertz (THz) absorption and index of refraction of brain tissues from a mouse model of Alzheimer's disease (AD) and a control wild-type (normal) mouse were compared using THz time-domain spectroscopy (THz-TDS). Three dominating absorption peaks associated to torsional-vibrational modes were observed in AD tissue, at about 1.44, 1.8, and 2.114 THz, closer to the peaks of free tryptophan molecules than in normal tissue. A possible reason is that there is more free tryptophan in AD brain tissue, while in normal brain tissue more tryptophan is attached to other molecules. Our study suggests that THz-absorption modes may be used as an AD biomarker fingerprint in brain, and that THz-TDS is a promising technique for early diagnosis of AD.

Dental Fluorosis and Catalase Immunoreactivity of the Brain Tissues in Rats Exposed to High Fluoride Pre- and Postnatally.

PubMed

Güner, Şirin; Uyar-Bozkurt, Süheyla; Haznedaroğlu, Eda; Menteş, Ali

2016-11-01

This study evaluated dental fluorosis of the incisors and immunoreactivity in the brain tissues of rats given chronic fluoride doses pre- and postnatally. Female rats were given drinking water with 0, 30 or 100 ppm fluoride ad libitum throughout gestation and the nursing period. In addition, 63 male offspring were treated with the same water regimens as the mothers after weaning and were followed for 1, 3 or 5 months. The upper and lower incisors were collected, and all teeth were examined under a stereomicroscope and scored by two blinded examiners using a modified rodent enamel fluorosis index. Cortical, hippocampal and cerebellar brain samples were evaluated morphologically and immunohistochemically. All fluoride-treated pups were born with low body weight (p = 0.001). All animals from the fluoride groups had enamel fluorosis with defects of various degrees. The increase in the dental fluorosis scores in the fluoride treatment groups was significant (p < 0.01). The catalase immunoreactivity in the 30- and 100-ppm fluoride groups was significantly higher than that in the controls after 1, 3 and 5 months (p < 0.001). In conclusion, this study showed that rats with dental fluorosis had catalase immunoreactivity in the brain tissues, which may reflect the neurobehavioral toxicity of fluoride.

Effects of Antioxidant N-acetylcysteine Against Paraquat-Induced Oxidative Stress in Vital Tissues of Mice

PubMed Central

Ortiz, Maricelly Santiago; Forti, Kevin Muñoz; Suárez Martinez, Edu B.; Muñoz, Lenin Godoy; Husain, Kazim

2016-01-01

Paraquat (PQ) is a commonly used herbicide that induces oxidative stress via reactive oxygen species (ROS) generation. This study aimed to investigate the effects of the antioxidant N-acetylcysteine (NAC) against PQ-induced oxidative stress in mice. Male Balb/C mice (24) were randomly divided into 4 groups and treated for 3 weeks: 1) control (saline), 2) NAC (0.5% in diet), 3) PQ (20 mg/kg, IP) and 4) combination (PQ + NAC). Afterwards mice were sacrificed and oxidative stress markers were analyzed. Our data showed no significant change in serum antioxidant capacity. PQ enhanced lipid peroxidation (MDA) levels in liver tissue compared to control whereas NAC decreased MDA levels (p<0.05). NAC significantly increased MDA in brain tissue (p<0.05). PQ significantly depleted glutathione (GSH) levels in liver (p=0.001) and brain tissue (p<0.05) but non-significant GSH depletion in lung tissue. NAC counteracted PQ, showing a moderate increase GSH levels in liver and brain tissues. PQ significantly increased 8-oxodeoxyguanosine (8-OH-dG) levels (p<0.05) in liver tissue compared to control without a significant change in brain tissue. NAC treatment ameliorated PQ-induced oxidative DNA damage in the liver tissue. PQ significantly decreased the relative mtDNA amplification and increased the frequency of lesions in liver and brain tissue (p<0.0001), while NAC restored the DNA polymerase activity in liver tissue but not in brain tissue. In conclusion, PQ induced lipid peroxidation, oxidative nuclear DNA and mtDNA damage in liver tissues and depleted liver and brain GSH levels. NAC supplementation ameliorated the PQ-induced oxidative stress response in liver tissue of mice. PMID:27398384

Distinction of brain tissue, low grade and high grade glioma with time-resolved fluorescence spectroscopy

PubMed Central

Yong, William H.; Butte, Pramod V.; Pikul, Brian K.; Jo, Javier A.; Fang, Qiyin; Papaioannou, Thanassis; Black, Keith L.; Marcu, Laura

2010-01-01

Neuropathology frozen section diagnoses are difficult in part because of the small tissue samples and the paucity of adjunctive rapid intraoperative stains. This study aims to explore the use of time-resolved laser-induced fluorescence spectroscopy as a rapid adjunctive tool for the diagnosis of glioma specimens and for distinction of glioma from normal tissues intraoperatively. Ten low grade gliomas, 15 high grade gliomas without necrosis, 6 high grade gliomas with necrosis and/or radiation effect, and 14 histologically uninvolved “normal” brain specimens are spectroscopicaly analyzed and contrasted. Tissue autofluorescence was induced with a pulsed Nitrogen laser (337 nm, 1.2 ns) and the transient intensity decay profiles were recorded in the 370-500 nm spectral range with a fast digitized (0.2 ns time resolution). Spectral intensities and time-dependent parameters derived from the time-resolved spectra of each site were used for tissue characterization. A linear discriminant analysis diagnostic algorithm was used for tissue classification. Both low and high grade gliomas can be distinguished from histologically uninvolved cerebral cortex and white matter with high accuracy (above 90%). In addition, the presence or absence of treatment effect and/or necrosis can be identified in high grade gliomas. Taking advantage of tissue autofluorescence, this technique facilitates a direct and rapid investigation of surgically obtained tissue. PMID:16368511

Anatomical Distribution of Lipids in Human Brain Cortex by Imaging Mass Spectrometry

NASA Astrophysics Data System (ADS)

Veloso, Antonio; Astigarraga, Egoitz; Barreda-Gómez, Gabriel; Manuel, Iván; Ferrer, Isidro; Teresa Giralt, María; Ochoa, Begoña; Fresnedo, Olatz; Rodríguez-Puertas, Rafael; Fernández, José A.

2011-02-01

Molecular mass images of tissues will be biased if differences in the physicochemical properties of the microenvironment affect the intensity of the spectra. To address this issue, we have performed—by means of MALDI-TOF mass spectrometry—imaging on slices and lipidomic analysis in extracts of frontal cortex, both from the same postmortem tissue samples of human brain. An external calibration was used to achieve a mass accuracy of 10 ppm (1 σ) in the spectra of the extracts, although the final assignment was based on a comparison with previously reported species. The spectra recorded directly from tissue slices (imaging) show excellent s/n ratios, almost comparable to those obtained from the extracts. In addition, they retain the information about the anatomical distribution of the molecular species present in autopsied frozen tissue. Further comparison between the spectra from lipid extracts devoid of proteins and those recorded directly from the tissue unambiguously show that the differences in lipid composition between gray and white matter observed in the mass images are not an artifact due to microenvironmental influences of each anatomical area on the signal intensity, but real variations in the lipid composition.

Label-free volumetric optical imaging of intact murine brains

NASA Astrophysics Data System (ADS)

Ren, Jian; Choi, Heejin; Chung, Kwanghun; Bouma, Brett E.

2017-04-01

A central effort of today’s neuroscience is to study the brain’s ’wiring diagram’. The nervous system is believed to be a network of neurons interacting with each other through synaptic connection between axons and dendrites, therefore the neuronal connectivity map not only depicts the underlying anatomy, but also has important behavioral implications. Different approaches have been utilized to decipher neuronal circuits, including electron microscopy (EM) and light microscopy (LM). However, these approaches typically demand extensive sectioning and reconstruction for a brain sample. Recently, tissue clearing methods have enabled the investigation of a fully assembled biological system with greatly improved light penetration. Yet, most of these implementations, still require either genetic or exogenous contrast labeling for light microscopy. Here we demonstrate a high-speed approach, termed as Clearing Assisted Scattering Tomography (CAST), where intact brains can be imaged at optical resolution without labeling by leveraging tissue clearing and the scattering contrast of optical frequency domain imaging (OFDI).

The landscape of genomic imprinting across diverse adult human tissues

PubMed Central

Baran, Yael; Subramaniam, Meena; Biton, Anne; Tukiainen, Taru; Tsang, Emily K.; Rivas, Manuel A.; Pirinen, Matti; Gutierrez-Arcelus, Maria; Smith, Kevin S.; Kukurba, Kim R.; Zhang, Rui; Eng, Celeste; Torgerson, Dara G.; Urbanek, Cydney; Li, Jin Billy; Rodriguez-Santana, Jose R.; Burchard, Esteban G.; Seibold, Max A.; MacArthur, Daniel G.; Montgomery, Stephen B.; Zaitlen, Noah A.; Lappalainen, Tuuli

2015-01-01

Genomic imprinting is an important regulatory mechanism that silences one of the parental copies of a gene. To systematically characterize this phenomenon, we analyze tissue specificity of imprinting from allelic expression data in 1582 primary tissue samples from 178 individuals from the Genotype-Tissue Expression (GTEx) project. We characterize imprinting in 42 genes, including both novel and previously identified genes. Tissue specificity of imprinting is widespread, and gender-specific effects are revealed in a small number of genes in muscle with stronger imprinting in males. IGF2 shows maternal expression in the brain instead of the canonical paternal expression elsewhere. Imprinting appears to have only a subtle impact on tissue-specific expression levels, with genes lacking a systematic expression difference between tissues with imprinted and biallelic expression. In summary, our systematic characterization of imprinting in adult tissues highlights variation in imprinting between genes, individuals, and tissues. PMID:25953952

Sensitivity of bhk-21 cells supplemented with diethylaminoethyl-dextran for detection of street rabies virus in saliva samples.

PubMed Central

Larghi, O P; Nebel, A E; Lazaro, L; Savy, V L

1975-01-01

A tissue culture system for detecting rabies virus from saliva samples of suspected animals was developed and compared to suckling mouse inoculation. Swab samples were obtained from the mouth of the animal heads received for rabies diagnosis; these swabs were submerged in maintenance medium. The maintenance medium was inoculated intracerebrally into suckling mice and onto BHK-21 cells with diethylaminoethyl (DEAE)-dextran (BHK/DEAE) and without (BHK). Rabies immunofluorescence was performed on the brain of the mice dying during the observation period and also on both tissue culture systems every day after infection. The BHK-DEAE system detected 28 positive samples obtained from 48 rabid animals and the BHK system detected 18. By suckling mouse inoculation only 11 of the same positive samples were detected. A total of 90 samples was studied by the three methods. Rabies virus was detected by the tissue culture methods earlier than by suckling mouse inoculation. The BHK-DEAE method was an economic and fast method for rabies virus detection in saliva samples, which could be used for ecological and pathogenesis studies, as well for rabies diagnosis before the death of the suspected animal. PMID:1100655

BRAIN NETWORKS. Correlated gene expression supports synchronous activity in brain networks.

PubMed

Richiardi, Jonas; Altmann, Andre; Milazzo, Anna-Clare; Chang, Catie; Chakravarty, M Mallar; Banaschewski, Tobias; Barker, Gareth J; Bokde, Arun L W; Bromberg, Uli; Büchel, Christian; Conrod, Patricia; Fauth-Bühler, Mira; Flor, Herta; Frouin, Vincent; Gallinat, Jürgen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Lemaître, Hervé; Mann, Karl F; Martinot, Jean-Luc; Nees, Frauke; Paus, Tomáš; Pausova, Zdenka; Rietschel, Marcella; Robbins, Trevor W; Smolka, Michael N; Spanagel, Rainer; Ströhle, Andreas; Schumann, Gunter; Hawrylycz, Mike; Poline, Jean-Baptiste; Greicius, Michael D

2015-06-12

During rest, brain activity is synchronized between different regions widely distributed throughout the brain, forming functional networks. However, the molecular mechanisms supporting functional connectivity remain undefined. We show that functional brain networks defined with resting-state functional magnetic resonance imaging can be recapitulated by using measures of correlated gene expression in a post mortem brain tissue data set. The set of 136 genes we identify is significantly enriched for ion channels. Polymorphisms in this set of genes significantly affect resting-state functional connectivity in a large sample of healthy adolescents. Expression levels of these genes are also significantly associated with axonal connectivity in the mouse. The results provide convergent, multimodal evidence that resting-state functional networks correlate with the orchestrated activity of dozens of genes linked to ion channel activity and synaptic function. Copyright © 2015, American Association for the Advancement of Science.

HPLC analysis of para-aminosalicylic acid and its metabolite in plasma, cerebrospinal fluid and brain tissues

PubMed Central

Hong, Lan; Jiang, Wendy; Zheng, Wei; Zeng, Su

2011-01-01

Para-aminosalicylic acid (PAS), an approved drug for treatment of tuberculosis, is a promising therapeutic agent for treatment of manganese (Mn)-induced parkinsonian syndromes. Lack of a quantifying method, however, has hindered the clinical evaluation of its efficacy and thereupon new drug development. This study was aimed at developing a simple and effective method to quantify PAS and its major metabolite, N-acetyl-para-aminosalicylic acid (AcPAS), in plasma, cerebrospinal fluid (CSF) and tissues. Biological samples underwent one-step protein precipitation. The supernatant was fractionated on a reversed-phase C18 column with a gradient mobile system, followed by on-line fluorescence detection. The lower limits of quantification for both PAS and AcPAS were 50 ng/ml of plasma and 17 ng/g of tissues. The intra-day and inter-day precision values did not exceed 5% and 8%, respectively, in all three matrices. The method was used to quantify PAS and AcPAS in rat plasma and brain following a single iv injection of PAS. Data showed a greater amount of PAS than AcPAS in plasma, while a greater amount of AcPAS than PAS was found in brain tissues. The method has been proven to be sensitive, reproducible, and practically useful for laboratory and clinical investigations of PAS in treatment of Mn Parkinsonism. PMID:21159459

Flow cytometry for receptor analysis from ex-vivo brain tissue in adult rat.

PubMed

Benoit, A; Guillamin, M; Aitken, P; Smith, P F; Philoxene, B; Sola, B; Poulain, L; Coquerel, A; Besnard, S

2018-07-01

Flow cytometry allows single-cell analysis of peripheral biological samples and is useful in many fields of research and clinical applications, mainly in hematology, immunology, and oncology. In the neurosciences, the flow cytometry separation method was first applied to stem cell extraction from healthy or cerebral tumour tissue and was more recently tested in order to phenotype brain cells, hippocampal neurogenesis, and to detect prion proteins. However, it remains sparsely applied in quantifying membrane receptors in relation to synaptic plasticity. We aimed to optimize a flow cytometric procedure for receptor quantification in neurons and non-neurons. A neural dissociation process, myelin separation, fixation, and membrane permeability procedures were optimized to maximize cell survival and analysis in hippocampal tissue obtained from adult rodents. We then aimed to quantify membrane muscarinic acetylcholine receptors (mAChRs) in rats with and without bilateral vestibular loss (BVL). mAChR's were quantified for neuronal and non-neuronal cells in the hippocampus and striatum following BVL. At day 30 but not at day 7 following BVL, there was a significant increase (P ≤ 0.05) in the percentage of neurons expressing M 2/4 mAChRs in both the hippocampus and the striatum. Here, we showed that flow cytometry appears to be a reliable method of membrane receptor quantification in ex-vivo brain tissue. Copyright © 2018 Elsevier B.V. All rights reserved.

Increased White Matter Inflammation in Aging- and Alzheimer’s Disease Brain

PubMed Central

Raj, Divya; Yin, Zhuoran; Breur, Marjolein; Doorduin, Janine; Holtman, Inge R.; Olah, Marta; Mantingh-Otter, Ietje J.; Van Dam, Debby; De Deyn, Peter P.; den Dunnen, Wilfred; Eggen, Bart J. L.; Amor, Sandra; Boddeke, Erik

2017-01-01

Chronic neuroinflammation, which is primarily mediated by microglia, plays an essential role in aging and neurodegeneration. It is still unclear whether this microglia-induced neuroinflammation occurs globally or is confined to distinct brain regions. In this study, we investigated microglia activity in various brain regions upon healthy aging and Alzheimer’s disease (AD)-related pathology in both human and mouse samples. In purified microglia isolated from aging mouse brains, we found a profound gene expression pattern related to pro-inflammatory processes, phagocytosis, and lipid homeostasis. Particularly in white matter microglia of 24-month-old mice, abundant expression of phagocytic markers including Mac-2, Axl, CD16/32, Dectin1, CD11c, and CD36 was detected. Interestingly, in white matter of human brain tissue the first signs of inflammatory activity were already detected during middle age. Thus quantification of microglial proteins, such as CD68 (commonly associated with phagocytosis) and HLA-DR (associated with antigen presentation), in postmortem human white matter brain tissue showed an age-dependent increase in immunoreactivity already in middle-aged people (53.2 ± 2.0 years). This early inflammation was also detectable by non-invasive positron emission tomography imaging using [11C]-(R)-PK11195, a ligand that binds to activated microglia. Increased microglia activity was also prominently present in the white matter of human postmortem early-onset AD (EOAD) brain tissue. Interestingly, microglia activity in the white matter of late-onset AD (LOAD) CNS was similar to that of the aged clinically silent AD cases. These data indicate that microglia-induced neuroinflammation is predominant in the white matter of aging mice and humans as well as in EOAD brains. This white matter inflammation may contribute to the progression of neurodegeneration, and have prognostic value for detecting the onset and progression of aging and neurodegeneration. PMID:28713239

Mechanical versus humoral determinants of brain death-induced lung injury

PubMed Central

Dewachter, Laurence; Rorive, Sandrine; Remmelink, Myriam; Weynand, Birgit; Melot, Christian; Hupkens, Emeline; Dewachter, Céline; Creteur, Jacques; Mc Entee, Kathleen; Naeije, Robert; Rondelet, Benoît

2017-01-01

Background The mechanisms of brain death (BD)-induced lung injury remain incompletely understood, as uncertainties persist about time-course and relative importance of mechanical and humoral perturbations. Methods Brain death was induced by slow intracranial blood infusion in anesthetized pigs after randomization to placebo (n = 11) or to methylprednisolone (n = 8) to inhibit the expression of pro-inflammatory mediators. Pulmonary artery pressure (PAP), wedged PAP (PAWP), pulmonary vascular resistance (PVR) and effective pulmonary capillary pressure (PCP) were measured 1 and 5 hours after Cushing reflex. Lung tissue was sampled to determine gene expressions of cytokines and oxidative stress molecules, and pathologically score lung injury. Results Intracranial hypertension caused a transient increase in blood pressure followed, after brain death was diagnosed, by persistent increases in PAP, PCP and the venous component of PVR, while PAWP did not change. Arterial PO2/fraction of inspired O2 (PaO2/FiO2) decreased. Brain death was associated with an accumulation of neutrophils and an increased apoptotic rate in lung tissue together with increased pro-inflammatory interleukin (IL)-6/IL-10 ratio and increased heme oxygenase(HO)-1 and hypoxia inducible factor(HIF)-1 alpha expression. Blood expressions of IL-6 and IL-1β were also increased. Methylprednisolone pre-treatment was associated with a blunting of increased PCP and PVR venous component, which returned to baseline 5 hours after BD, and partially corrected lung tissue biological perturbations. PaO2/FiO2 was inversely correlated to PCP and lung injury score. Conclusions Brain death-induced lung injury may be best explained by an initial excessive increase in pulmonary capillary pressure with increased pulmonary venous resistance, and was associated with lung activation of inflammatory apoptotic processes which were partially prevented by methylprednisolone. PMID:28753621

Automatic brain tissue segmentation based on graph filter.

PubMed

Kong, Youyong; Chen, Xiaopeng; Wu, Jiasong; Zhang, Pinzheng; Chen, Yang; Shu, Huazhong

2018-05-09

Accurate segmentation of brain tissues from magnetic resonance imaging (MRI) is of significant importance in clinical applications and neuroscience research. Accurate segmentation is challenging due to the tissue heterogeneity, which is caused by noise, bias filed and partial volume effects. To overcome this limitation, this paper presents a novel algorithm for brain tissue segmentation based on supervoxel and graph filter. Firstly, an effective supervoxel method is employed to generate effective supervoxels for the 3D MRI image. Secondly, the supervoxels are classified into different types of tissues based on filtering of graph signals. The performance is evaluated on the BrainWeb 18 dataset and the Internet Brain Segmentation Repository (IBSR) 18 dataset. The proposed method achieves mean dice similarity coefficient (DSC) of 0.94, 0.92 and 0.90 for the segmentation of white matter (WM), grey matter (GM) and cerebrospinal fluid (CSF) for BrainWeb 18 dataset, and mean DSC of 0.85, 0.87 and 0.57 for the segmentation of WM, GM and CSF for IBSR18 dataset. The proposed approach can well discriminate different types of brain tissues from the brain MRI image, which has high potential to be applied for clinical applications.

Attempts to identify the source of avian vacuolar myelinopathy for waterbirds

USGS Publications Warehouse

Rocke, T.E.; Thomas, N.J.; Meteyer, C.U.; Quist, C.F.; Fischer, John R.; Augspurger, T.; Ward, S.E.

2005-01-01

Attempts were made to reproduce avian vacuolar myelinopathy (AVM) in a number of test animals in order to determine the source of the causative agent for birds and to find a suitable animal model for future studies. Submerged vegetation, plankton, invertebrates, forage fish, and sediments were collected from three lakes with ongoing outbreaks of AVM and fed to American coots (Fulica americana), mallard ducks and ducklings (Anas platyrhynchos), quail (Coturnix japonica), and laboratory mice either via gavage or ad libitum. Tissues from AVM-affected coots with brain lesions were fed to ducklings, kestrels (Falco sparverius), and American crows (Corvus brachyrhynchos). Two mallards that ingested one sample of Hydrilla verticillata along with any biotic or abiotic material associated with its external surface developed brain lesions consistent with AVM, although neither of the ducks had clinical signs of disease. Ingestion of numerous other samples of Hydrilla from the AVM affected lakes and a lake with no prior history of AVM, other materials (sediments, algae, fish, invertebrates, and water from affected lakes), or tissues from AVM-affected birds did not produce either clinical signs or brain lesions in any of the other test animals in our studies. These results suggest that waterbirds are most likely exposed to the causative agent of AVM while feeding on aquatic vegetation, but we do not believe the vegetation itself is the agent. We hypothesize that the causative agent of AVM might either be accumulated by aquatic vegetation, such as Hydrilla, or associated with biotic or abiotic material on its external surfaces. In support of that hypothesis, two coots that ingested Hydrilla sampled from a lake with an ongoing AVM outbreak in wild birds developed neurologic signs within 9 days (ataxia, limb weakness, and incoordination), and one of two coots that ingested Hydrilla collected from the same site 13 days later became sick and died within 38 days. None of these three sick coots had definitive brain lesions consistent with AVM by light microscopy, but they had no gross or histologic lesions in other tissues. It is unclear if these birds died of AVM. Perhaps they did not ingest a dose sufficient to produce brain lesions or the lesions were ultrastructural. Alternatively, it is possible that a separate neurotoxic agent is responsible for the morbidity and mortality observed in these coots.

Experimental verification of stopping-power prediction from single- and dual-energy computed tomography in biological tissues

NASA Astrophysics Data System (ADS)

Möhler, Christian; Russ, Tom; Wohlfahrt, Patrick; Elter, Alina; Runz, Armin; Richter, Christian; Greilich, Steffen

2018-01-01

An experimental setup for consecutive measurement of ion and x-ray absorption in tissue or other materials is introduced. With this setup using a 3D-printed sample container, the reference stopping-power ratio (SPR) of materials can be measured with an uncertainty of below 0.1%. A total of 65 porcine and bovine tissue samples were prepared for measurement, comprising five samples each of 13 tissue types representing about 80% of the total body mass (three different muscle and fatty tissues, liver, kidney, brain, heart, blood, lung and bone). Using a standard stoichiometric calibration for single-energy CT (SECT) as well as a state-of-the-art dual-energy CT (DECT) approach, SPR was predicted for all tissues and then compared to the measured reference. With the SECT approach, the SPRs of all tissues were predicted with a mean error of (-0.84  ±  0.12)% and a mean absolute error of (1.27  ±  0.12)%. In contrast, the DECT-based SPR predictions were overall consistent with the measured reference with a mean error of (-0.02  ±  0.15)% and a mean absolute error of (0.10  ±  0.15)%. Thus, in this study, the potential of DECT to decrease range uncertainty could be confirmed in biological tissue.

Various clinical application of phase contrast X-ray

NASA Astrophysics Data System (ADS)

Oh, Chilhwan; Park, Sangyong; Ha, Seunghan; Park, Gyuman; Lee, Gunwoo; Lee, Onseok; Je, Jungho

2008-02-01

In biomedical application study using phase contrast X-ray, both sample thickness or density and absorption difference are very important factors in aspects of contrast enhancement. We present experimental evidence that synchrotron hard X-ray are suitable for radiological imaging of biological samples down to the cellular level. We investigated the potential of refractive index radiology using un-monochromatized synchrotron hard X-rays for the imaging of cell and tissue in various diseases. Material had been adopted various medical field, such as apoE knockout mouse in cardiologic field, specimen from renal and prostatic carcinoma patient in urology, basal cell epithelioma in dermatology, brain tissue from autosy sample of pakinson's disease, artificially induced artilrtis tissue from rabbits and extracted tooth from patients of crack tooth syndrome. Formalin and paraffin fixed tissue blocks were cut in 3 mm thickness for the X-ray radiographic imaging. From adjacent areas, 4 μm thickness sections were also prepared for hematoxylin-eosin staining. Radiographic images of dissected tissues were obtained using the hard X-rays from the 7B2 beamline of the Pohang Light Source (PLS). The technique used for the study was the phase contrast images were compared with the optical microscopic images of corresponding histological slides. Radiographic images of various diseased tissues showed clear histological details of organelles in normal tissues. Most of cancerous lesions were well differentiated from adjacent normal tissues and detailed histological features of each tumor were clearly identified. Also normal microstructures were identifiable by the phase contrast imaging. Tissue in cancer or other disease showed clearly different findings from those of surrounding normal tissue. For the first time we successfully demonstrated that synchrotron hard X-rays can be used for radiological imaging of relatively thick tissue samples with great histological details.

3D on-chip microscopy of optically cleared tissue

NASA Astrophysics Data System (ADS)

Zhang, Yibo; Shin, Yoonjung; Sung, Kevin; Yang, Sam; Chen, Harrison; Wang, Hongda; Teng, Da; Rivenson, Yair; Kulkarni, Rajan P.; Ozcan, Aydogan

2018-02-01

Traditional pathology relies on tissue biopsy, micro-sectioning, immunohistochemistry and microscopic imaging, which are relatively expensive and labor-intensive, and therefore are less accessible in resource-limited areas. Low-cost tissue clearing techniques, such as the simplified CLARITY method (SCM), are promising to potentially reduce the cost of disease diagnosis by providing 3D imaging and phenotyping of thicker tissue samples with simpler preparation steps. However, the mainstream imaging approach for cleared tissue, fluorescence microscopy, suffers from high-cost, photobleaching and signal fading. As an alternative approach to fluorescence, here we demonstrate 3D imaging of SCMcleared tissue using on-chip holography, which is based on pixel-super-resolution and multi-height phase recovery algorithms to digitally compute the sample's amplitude and phase images at various z-slices/depths through the sample. The tissue clearing procedures and the lens-free imaging system were jointly optimized to find the best illumination wavelength, tissue thickness, staining solution pH, and the number of hologram heights to maximize the imaged tissue volume, minimize the amount of acquired data, while maintaining a high contrast-to-noise ratio for the imaged cells. After this optimization, we achieved 3D imaging of a 200-μm thick cleared mouse brain tissue over a field-of-view of <20mm2 , and the resulting 3D z-stack agrees well with the images acquired with a scanning lens-based microscope (20× 0.75NA). Moreover, the lens-free microscope achieves an order-of-magnitude better data efficiency compared to its lens-based counterparts for volumetric imaging of samples. The presented low-cost and high-throughput lens-free tissue imaging technique enabled by CLARITY can be used in various biomedical applications in low-resource-settings.

A simple quantitative diagnostic alternative for MGMT DNA-methylation testing on RCL2 fixed paraffin embedded tumors using restriction coupled qPCR.

PubMed

Pulverer, Walter; Hofner, Manuela; Preusser, Matthias; Dirnberger, Elisabeth; Hainfellner, Johannes A; Weinhaeusel, Andreas

2014-01-01

MGMT promoter methylation is associated with favorable prognosis and chemosensitivity in glioblastoma multiforme (GBM), especially in elderly patients. We aimed to develop a simple methylation-sensitive restriction enzyme (MSRE)-based quantitative PCR (qPCR) assay, allowing the quantification of MGMT promoter methylation. DNA was extracted from non-neoplastic brain (n = 24) and GBM samples (n = 20) upon 3 different sample conservation conditions (-80 °C, formalin-fixed and paraffin-embedded (FFPE); RCL2-fixed). We evaluated the suitability of each fixation method with respect to the MSRE-coupled qPCR methylation analyses. Methylation data were validated by MALDITOF. qPCR was used for evaluation of alternative tissue conservation procedures. DNA from FFPE tissue failed reliable testing; DNA from both RCL2-fixed and fresh frozen tissues performed equally well and was further used for validation of the quantitative MGMT methylation assay (limit of detection (LOD): 19.58 pg), using individual's undigested sample DNA for calibration. MGMT methylation analysis in non-neoplastic brain identified a background methylation of 0.10 ± 11% which we used for defining a cut-off of 0.32% for patient stratification. Of GBM patients 9 were MGMT methylationpositive (range: 0.56 - 91.95%), and 11 tested negative. MALDI-TOF measurements resulted in a concordant classification of 94% of GBM samples in comparison to qPCR. The presented methodology allows quantitative MGMT promoter methylation analyses. An amount of 200 ng DNA is sufficient for triplicate analyses including control reactions and individual calibration curves, thus excluding any DNA qualityderived bias. The combination of RCL2-fixation and quantitative methylation analyses improves pathological routine examination when histological and molecular analyses on limited amounts of tumor samples are necessary for patient stratification.

Computational analysis of transcranial magnetic stimulation in the presence of deep brain stimulation probes

NASA Astrophysics Data System (ADS)

Syeda, F.; Holloway, K.; El-Gendy, A. A.; Hadimani, R. L.

2017-05-01

Transcranial Magnetic Stimulation is an emerging non-invasive treatment for depression, Parkinson's disease, and a variety of other neurological disorders. Many Parkinson's patients receive the treatment known as Deep Brain Stimulation, but often require additional therapy for speech and swallowing impairment. Transcranial Magnetic Stimulation has been explored as a possible treatment by stimulating the mouth motor area of the brain. We have calculated induced electric field, magnetic field, and temperature distributions in the brain using finite element analysis and anatomically realistic heterogeneous head models fitted with Deep Brain Stimulation leads. A Figure of 8 coil, current of 5000 A, and frequency of 2.5 kHz are used as simulation parameters. Results suggest that Deep Brain Stimulation leads cause surrounding tissues to experience slightly increased E-field (Δ Emax =30 V/m), but not exceeding the nominal values induced in brain tissue by Transcranial Magnetic Stimulation without leads (215 V/m). The maximum temperature in the brain tissues surrounding leads did not change significantly from the normal human body temperature of 37 °C. Therefore, we ascertain that Transcranial Magnetic Stimulation in the mouth motor area may stimulate brain tissue surrounding Deep Brain Stimulation leads, but will not cause tissue damage.

HIV-1 phylogenetic analysis shows HIV-1 transits through the meninges to brain and peripheral tissues.

PubMed

Lamers, Susanna L; Gray, Rebecca R; Salemi, Marco; Huysentruyt, Leanne C; McGrath, Michael S

2011-01-01

Brain infection by the human immunodeficiency virus type 1 (HIV-1) has been investigated in many reports with a variety of conclusions concerning the time of entry and degree of viral compartmentalization. To address these diverse findings, we sequenced HIV-1 gp120 clones from a wide range of brain, peripheral and meningeal tissues from five patients who died from several HIV-1 associated disease pathologies. High-resolution phylogenetic analysis confirmed previous studies that showed a significant degree of compartmentalization in brain and peripheral tissue subpopulations. Some intermixing between the HIV-1 subpopulations was evident, especially in patients that died from pathologies other than HIV-associated dementia. Interestingly, the major tissue harboring virus from both the brain and peripheral tissues was the meninges. These results show that (1) HIV-1 is clearly capable of migrating out of the brain, (2) the meninges are the most likely primary transport tissues, and (3) infected brain macrophages comprise an important HIV reservoir during highly active antiretroviral therapy. Copyright © 2010 Elsevier B.V. All rights reserved.

Effect of Ginkgo biloba extract on apoptosis of brain tissues in rats with acute cerebral infarction and related gene expression.

PubMed

Wu, C; Zhao, X; Zhang, X; Liu, S; Zhao, H; Chen, Y

2015-06-11

We investigated the effect of Ginkgo biloba extract on apoptosis of brain tissues in rats with acute cerebral infarction and apoptosis-related gene expression. Rat models of acute cerebral infarction were constructed using the suture method, and randomly divided into the control group, model, and treatment groups. In the treatment group, 4 mg/kg G. biloba extract was intravenously injected into the rat tail vein. Phosphate-buffered saline solution was injected in the model group. Seventy-two hours after treatment, rats were euthanized, and brain tissues were removed to analyze the changes in caspase-3, B-cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) mRNA and protein levels, and variation in brain tissue cells' apoptosis indices was measured. Compared with the control group, the model and treatment groups showed significantly upregulated caspase-3, Bcl-2, and Bax mRNA and protein levels in brain tissues, but remarkably downregulated Bcl-2 mRNA and protein levels (P < 0.05). After treatment, in treatment group brain tissues, caspase-3 and Bax mRNA and protein levels were significantly lower than those in the model group, while Bcl-2 mRNA and protein levels were higher than that in the model group (P < 0.05). The model and treatment groups showed increased cell apoptosis indices of brain tissues compared to the control group; after treatment, the apoptosis index in the treatment group was significantly downregulated compared with that in the model group (P < 0.05). In conclusion, G. biloba extract significantly reduced apoptosis in rat brain tissue cells with acute cerebral infarction and thus protected brain tissues.

A high-resolution optical imaging system for obtaining the serial transverse section images of biologic tissue

NASA Astrophysics Data System (ADS)

Wu, Li; Zhang, Bin; Wu, Ping; Liu, Qian; Gong, Hui

2007-05-01

A high-resolution optical imaging system was designed and developed to obtain the serial transverse section images of the biologic tissue, such as the mouse brain, in which new knife-edge imaging technology, high-speed and high-sensitive line-scan CCD and linear air bearing stages were adopted and incorporated with an OLYMPUS microscope. The section images on the tip of the knife-edge were synchronously captured by the reflection imaging in the microscope while cutting the biologic tissue. The biologic tissue can be sectioned at interval of 250 nm with the same resolution of the transverse section images obtained in x and y plane. And the cutting job can be automatically finished based on the control program wrote specially in advance, so we save the mass labor of the registration of the vast images data. In addition, by using this system a larger sample can be cut than conventional ultramicrotome so as to avoid the loss of the tissue structure information because of splitting the tissue sample to meet the size request of the ultramicrotome.

Morphology enabled dipole inversion (MEDI) from a single-angle acquisition: comparison with COSMOS in human brain imaging.

PubMed

Liu, Tian; Liu, Jing; de Rochefort, Ludovic; Spincemaille, Pascal; Khalidov, Ildar; Ledoux, James Robert; Wang, Yi

2011-09-01

Magnetic susceptibility varies among brain structures and provides insights into the chemical and molecular composition of brain tissues. However, the determination of an arbitrary susceptibility distribution from the measured MR signal phase is a challenging, ill-conditioned inverse problem. Although a previous method named calculation of susceptibility through multiple orientation sampling (COSMOS) has solved this inverse problem both theoretically and experimentally using multiple angle acquisitions, it is often impractical to carry out on human subjects. Recently, the feasibility of calculating the brain susceptibility distribution from a single-angle acquisition was demonstrated using morphology enabled dipole inversion (MEDI). In this study, we further improved the original MEDI method by sparsifying the edges in the quantitative susceptibility map that do not have a corresponding edge in the magnitude image. Quantitative susceptibility maps generated by the improved MEDI were compared qualitatively and quantitatively with those generated by calculation of susceptibility through multiple orientation sampling. The results show a high degree of agreement between MEDI and calculation of susceptibility through multiple orientation sampling, and the practicality of MEDI allows many potential clinical applications. Copyright © 2011 Wiley-Liss, Inc.

Altered transition metal homeostasis in Niemann-Pick disease, Type C1

PubMed Central

Hung, Ya Hui; Faux, Noel G.; Killilea, David W.; Yanjanin, Nicole; Firnkes, Sally; Volitakis, Irene; Ganio, George; Walterfang, Mark; Hastings, Caroline; Porter, Forbes D.; Ory, Daniel S.; Bush, Ashley I.

2014-01-01

The loss of NPC1 protein function is the predominant cause of Niemann-Pick type C1 disease (NP-C1), a systemic and neurodegenerative disorder characterized by late-endosomal/lysosomal accumulation of cholesterol and other lipids. Limited evidence from post-mortem human tissues, an Npc1−/− mouse model, and cell culture studies also suggest failure of metal homeostasis in NP-C1. To investigate these findings, we performed a comprehensive transition metal analysis of cerebrospinal fluid (CSF), plasma and tissue samples from human NP-C1 patients and an Npc1−/− mouse model. NPC1 deficiency in the Npc1−/− mouse model resulted in a perturbation of transition metal homeostasis in the plasma and key organs (brain, liver, spleen, heart, lungs, and kidneys). Analysis of human patient CSF, plasma and post-mortem brain tissues also indicated disrupted metal homeostasis. There was a disparity in the direction of metal changes between the human and the Npc1−/− mouse samples, which may reflect species-specific metal metabolism. Nevertheless, common to both species is brain zinc accumulation. Furthermore, treatment with the glucosylceramide synthase inhibitor miglustat, the only drug shown in a controlled clinical trial to have some efficacy for NP-C1, did not correct the alterations in CSF and plasma transition metal and ceruloplasmin (CP) metabolism in NP-C1 patients. These findings highlight the importance of NPC1 function in metal homeostasis, and indicate that metal-targeting therapy may be of value as a treatment for NP-C. PMID:24343124

Population transcriptomics with single-cell resolution: a new field made possible by microfluidics: a technology for high throughput transcript counting and data-driven definition of cell types.

PubMed

Plessy, Charles; Desbois, Linda; Fujii, Teruo; Carninci, Piero

2013-02-01

Tissues contain complex populations of cells. Like countries, which are comprised of mixed populations of people, tissues are not homogeneous. Gene expression studies that analyze entire populations of cells from tissues as a mixture are blind to this diversity. Thus, critical information is lost when studying samples rich in specialized but diverse cells such as tumors, iPS colonies, or brain tissue. High throughput methods are needed to address, model and understand the constitutive and stochastic differences between individual cells. Here, we describe microfluidics technologies that utilize a combination of molecular biology and miniaturized labs on chips to study gene expression at the single cell level. We discuss how the characterization of the transcriptome of each cell in a sample will open a new field in gene expression analysis, population transcriptomics, that will change the academic and biomedical analysis of complex samples by defining them as quantified populations of single cells. Copyright © 2013 WILEY Periodicals, Inc.

Molecular glycopathology by capillary electrophoresis: Analysis of the N-glycome of formalin-fixed paraffin-embedded mouse tissue samples.

PubMed

Donczo, Boglarka; Szarka, Mate; Tovari, Jozsef; Ostoros, Gyorgyi; Csanky, Eszter; Guttman, Andras

2017-06-01

Capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection was used to analyze endoglycosidase released and fluorophore-labeled N-glycans from formalin-fixed paraffin-embedded (FFPE) mouse tissue samples of lung, brain, heart, spleen, liver, kidney and intestine. The FFPE samples were first deparaffinized followed by solubilization and glycoprotein retrieval. PNGase F mediated release of the N-linked oligosaccharides was followed by labeling with aminopyrene trisulfonate. After CE-LIF glycoprofiling of the FFPE mouse tissues, the N-glycan pool of the lung specimen was subject to further investigation by exoglycosidase array based carbohydrate sequencing. Structural assignment of the oligosaccharides was accomplished by the help of the GUcal software and the associated database, based on the mobility shifts after treatments with the corresponding exoglycosidase reaction mixtures. Sixteen major N-linked carbohydrate structures were sequenced from the mouse lung FFPE tissue glycome and identified, as high mannose (3) neutral biantennary (3) sialylated monoantennary (1) and sialylated bianennary (9) oligosaccharides. Two of these latter ones also possessed alpha(1-3) linked galactose residues. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of the boundary between normal brain tissue and ischemia region using two-photon excitation fluorescence microscopy

NASA Astrophysics Data System (ADS)

Du, Huiping; Wang, Shu; Wang, Xingfu; Zhu, Xiaoqin; Zhuo, Shuangmu; Chen, Jianxin

2016-10-01

Ischemic stroke is one of the common neurological diseases, and it is becoming the leading causes of death and permanent disability around the world. Early and accurate identification of the potentially salvageable boundary region of ischemia brain tissues may enable selection of the most appropriate candidates for early stroke therapies. In this work, TPEF microscopy was used to image the microstructures of normal brain tissues, ischemia regions and the boundary region between normal and ischemia brain tissues. The ischemia brain tissues from Sprague-Dawley (SD) rats were subjected to 6 hours of middle cerebral artery occlusion (MCAO). Our study demonstrates that TPEF microscopy has the ability to not only reveal the morphological changes of the neurons but also identify the boundary between normal brain tissue and ischemia region, which correspond well to the hematoxylin and eosin (H and E) stained images. With the development of miniaturized TPEF microscope imaging devices, TPEF microscopy can be developed into an effectively diagnostic and monitoring tool for cerebral ischemia.

Online, absolute quantitation of propranolol from spatially distinct 20-μm and 40-μm dissections of brain, liver, and kidney thin tissue sections by laser microdissection – liquid vortex capture – mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kertesz, Vilmos; Vavrek, Marissa; Freddo, Carol

Here, spatial resolved quantitation of chemical species in thin tissue sections by mass spectrometric methods has been constrained by the need for matrix-matched standards or other arduous calibration protocols and procedures to mitigate matrix effects (e.g., spatially varying ionization suppression). Reported here is the use of laser cut and drop sampling with a laser microdissection-liquid vortex capture electrospray ionization tandem mass spectrometry (LMD-LVC/ESI-MS/MS) system for online and absolute quantitation of propranolol in mouse brain, kidney, and liver thin tissue sections of mice administered with the drug at a 7.5 mg/kg dose, intravenously. In this procedure either 20 μm x 20more » μm or 40 μm x 40 μm tissue microdissections were cut and dropped into the flowing solvent of the capture probe. During transport to the ESI source drug related material was completely extracted from the tissue into the solvent, which contained a known concentration of propranolol-d 7 as an internal standard. This allowed absolute quantitation to be achieved with an external calibration curve generated from standards containing the same fixed concentration of propranolold-d 7 and varied concentrations of propranolol. Average propranolol concentrations determined with the laser cut and drop sampling method closely agreed with concentration values obtained from 2.3 mm diameter tissue punches from serial sections that were extracted and quantified by HPLC/ESI-MS/MS measurements. In addition, the relative abundance of hydroxypropranolol glucuronide metabolites were recorded and found to be consistent with previous findings.« less

Online, absolute quantitation of propranolol from spatially distinct 20-μm and 40-μm dissections of brain, liver, and kidney thin tissue sections by laser microdissection – liquid vortex capture – mass spectrometry

DOE PAGES

Kertesz, Vilmos; Vavrek, Marissa; Freddo, Carol; ...

2016-05-23

Here, spatial resolved quantitation of chemical species in thin tissue sections by mass spectrometric methods has been constrained by the need for matrix-matched standards or other arduous calibration protocols and procedures to mitigate matrix effects (e.g., spatially varying ionization suppression). Reported here is the use of laser cut and drop sampling with a laser microdissection-liquid vortex capture electrospray ionization tandem mass spectrometry (LMD-LVC/ESI-MS/MS) system for online and absolute quantitation of propranolol in mouse brain, kidney, and liver thin tissue sections of mice administered with the drug at a 7.5 mg/kg dose, intravenously. In this procedure either 20 μm x 20more » μm or 40 μm x 40 μm tissue microdissections were cut and dropped into the flowing solvent of the capture probe. During transport to the ESI source drug related material was completely extracted from the tissue into the solvent, which contained a known concentration of propranolol-d 7 as an internal standard. This allowed absolute quantitation to be achieved with an external calibration curve generated from standards containing the same fixed concentration of propranolold-d 7 and varied concentrations of propranolol. Average propranolol concentrations determined with the laser cut and drop sampling method closely agreed with concentration values obtained from 2.3 mm diameter tissue punches from serial sections that were extracted and quantified by HPLC/ESI-MS/MS measurements. In addition, the relative abundance of hydroxypropranolol glucuronide metabolites were recorded and found to be consistent with previous findings.« less

Effect of irradiation on the viability of Toxoplasma gondii cysts in tissues of mice and pigs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dubey, J.P.; Brake, R.J.; Murrell, K.D.

1986-03-01

Muscles from tongue, heart, and limbs of 14 pigs inoculated orally with Toxoplasma gondii oocysts were irradiated with 10, 20, 25, and 30 krad of gamma (cesium-137 and cobalt-60) irradiation. Viability of T gondii cysts was assayed by feeding porcine muscles to T gondii-free cats and/or by inoculation of sediment from acid-pepsin digested porcine muscle into mice. Cats fed 500-g samples of muscles irradiated with up to 20 krad shed T gondii oocysts. Cats fed muscles irradiated with 25 or 30 krad did not shed oocysts. Mice were inoculated with 8 isolates of T gondii, and tissue cysts in theirmore » brains irradiated with up to 40 krad were infective to mice; however, there was a 10,000-fold reduction in the viability of organisms in tissue cysts irradiated with 40 krad, compared with that in nonirradiated cysts. At 50 krad of gamma irradiation, there were no detectable infective organisms in infected mouse brains.« less

Multi-scale spectrally resolved quantitative fluorescence imaging system: towards neurosurgical guidance in glioma resection

NASA Astrophysics Data System (ADS)

Xie, Yijing; Thom, Maria; Miserocchi, Anna; McEvoy, Andrew W.; Desjardins, Adrien; Ourselin, Sebastien; Vercauteren, Tom

2017-02-01

In glioma resection surgery, the detection of tumour is often guided by using intraoperative fluorescence imaging notably with 5-ALA-PpIX, providing fluorescent contrast between normal brain tissue and the gliomas tissue to achieve improved tumour delineation and prolonged patient survival compared with the conventional white-light guided resection. However, the commercially available fluorescence imaging system relies on surgeon's eyes to visualise and distinguish the fluorescence signals, which unfortunately makes the resection subjective. In this study, we developed a novel multi-scale spectrally-resolved fluorescence imaging system and a computational model for quantification of PpIX concentration. The system consisted of a wide-field spectrally-resolved quantitative imaging device and a fluorescence endomicroscopic imaging system enabling optical biopsy. Ex vivo animal tissue experiments as well as human tumour sample studies demonstrated that the system was capable of specifically detecting the PpIX fluorescent signal and estimate the true concentration of PpIX in brain specimen.

Observation of tissues in open aqueous solution by atmospheric scanning electron microscopy: applicability to intraoperative cancer diagnosis.

PubMed

Memtily, Nassirhadjy; Okada, Tomoko; Ebihara, Tatsuhiko; Sato, Mari; Kurabayashi, Atsushi; Furihata, Mutsuo; Suga, Mitsuo; Nishiyama, Hidetoshi; Mio, Kazuhiro; Sato, Chikara

2015-05-01

In the atmospheric scanning electron microscope (ASEM), a 2- to 3-µm layer of the sample resting on a silicon nitride-film window in the base of an open sample dish is imaged, in liquid, at atmospheric pressure, from below by an inverted SEM. Thus, the time-consuming pretreatments generally required for biological samples to withstand the vacuum of a standard electron microscope are avoided. In the present study, various mouse tissues (brain, spinal cord, muscle, heart, lung, liver, kidney, spleen and stomach) were fixed, stained with heavy metals, and visualized in radical scavenger D-glucose solution using the ASEM. While some stains made the nuclei of cells very prominent (platinum-blue, phosphotungstic acid), others also emphasized cell organelles and membranous structures (uranium acetate or the NCMIR method). Notably, symbiotic bacteria were sometimes observed on stomach mucosa. Furthermore, kidney tissue could be stained and successfully imaged in <30 min. Lung and spinal cord tissue from normal mice and mice metastasized with breast cancer cells was also examined. Cancer cells present in lung alveoli and in parts of the spine tissue clearly had larger nuclei than normal cells. The results indicate that the ASEM has the potential to accelerate intraoperative cancer diagnosis, the diagnosis of kidney diseases and pathogen detection. Importantly, in the course of the present study it was possible to increase the observable tissue area by using a new multi-windowed ASEM sample dish and sliding the tissue across its eight windows.

Analysis of Lutein, Zeaxanthin, and Meso-Zeaxanthin in the Organs of Carotenoid-Supplemented Chickens.

PubMed

Phelan, David; Prado-Cabrero, Alfonso; Nolan, John M

2018-02-03

The macular carotenoids (i.e., lutein (L), zeaxanthin (Z) and meso -zeaxanthin (MZ)) exhibit anti-inflammatory, antioxidant and optical properties that are believed to support human health and function. Studying the accumulation and distribution of these nutrients in tissues and organs, in addition to the eye, is an important step in understanding how these nutrients might support global human function and health (e.g., heart and brain). Chicken is an appropriate animal model with which to study the accumulation of these carotenoids in organs, as the relevant transport molecules and carotenoid binding proteins for L, Z and MZ are present in both humans and chickens. In this experiment, a sample of 3 chickens that were supplemented with L and MZ diacetate (active group) and a sample of 3 chickens that received a standard diet (control group) were analysed. Both groups were analysed for L, Z and MZ concentrations in the brain, eyes, heart, lung, duodenum/pancreas, jejunum/ileum, kidney and breast tissue. L, Z and MZ were identified in all the organs/tissues analysed from the active group. L and Z were identified in all of the organs/tissues analysed from the control group; while, MZ was identified in the eyes of these animals only. The discovery that MZ is accumulated in the tissues and organs of chickens supplemented with this carotenoid is important, given that it is known that a combination of L, Z and MZ exhibits superior antioxidant capacity when compared to any of these carotenoids in isolation.

Differences in Relative Levels of 88 microRNAs in Various Regions of the Normal Adult Human Brain.

PubMed

Filatova, Elena V; Alieva, Anelya; Shadrina, Maria I; Slominsky, Petr A

2017-08-16

Since the discovery of microRNAs (miRNAs) in the 1990s, our knowledge about their biology has grown considerably. The increasing number of studies addressing the role of miRNAs in development and in various diseases emphasizes the need for a comprehensive catalogue of accurate sequence, expression and conservation information regarding the large number of miRNAs proposed recently in all organs and tissues. The objective of this study was to provide data on the levels of miRNA expression in 15 tissues of the normal human brain. We conducted an analysis of the relative levels of 88 of the most abundantly expressed and best characterized miRNA derived postmortem from well-characterized samples of various regions of the brains from five normal individuals. The cluster analysis revealed some differences in the relative levels of these miRNAs among the brain regions studied. Such diversity can be explained by different functioning of these brain regions. We hope that the data from the current study are a resource that will be useful to our colleagues in this exciting field, as more hypotheses will be generated and tested with regard to small noncoding RNA in the human brain in healthy and disease states. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Imaging Metals in Brain Tissue by Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry (LA-ICP-MS)

PubMed Central

Hare, Dominic J.; Kysenius, Kai; Paul, Bence; Knauer, Beate; Hutchinson, Robert W.; O'Connor, Ciaran; Fryer, Fred; Hennessey, Tom P.; Bush, Ashley I.; Crouch, Peter J.; Doble, Philip A.

2017-01-01

Metals are found ubiquitously throughout an organism, with their biological role dictated by both their chemical reactivity and abundance within a specific anatomical region. Within the brain, metals have a highly compartmentalized distribution, depending on the primary function they play within the central nervous system. Imaging the spatial distribution of metals has provided unique insight into the biochemical architecture of the brain, allowing direct correlation between neuroanatomical regions and their known function with regard to metal-dependent processes. In addition, several age-related neurological disorders feature disrupted metal homeostasis, which is often confined to small regions of the brain that are otherwise difficult to analyze. Here, we describe a comprehensive method for quantitatively imaging metals in the mouse brain, using laser ablation - inductively coupled plasma - mass spectrometry (LA-ICP-MS) and specially designed image processing software. Focusing on iron, copper and zinc, which are three of the most abundant and disease-relevant metals within the brain, we describe the essential steps in sample preparation, analysis, quantitative measurements and image processing to produce maps of metal distribution within the low micrometer resolution range. This technique, applicable to any cut tissue section, is capable of demonstrating the highly variable distribution of metals within an organ or system, and can be used to identify changes in metal homeostasis and absolute levels within fine anatomical structures. PMID:28190025

Postmortem changes in the neuroanatomical characteristics of the primate brain: the hippocampal formation

PubMed Central

Lavenex, Pierre; Lavenex, Pamela Banta; Bennett, Jeffrey L.; Amaral, David G.

2009-01-01

Comparative studies of the structural organization of the brain are fundamental to our understanding of human brain function. However, whereas brains of experimental animals are fixed by perfusion of a fixative through the vasculature, human or ape brains are fixed by immersion after varying postmortem intervals. Although differential treatments might affect the fundamental characteristics of the tissue, this question has not been evaluated empirically in primate brains. Monkey brains were either perfused, or acquired after varying postmortem intervals before immersion-fixation in 4% paraformaldehyde. We found that the fixation method affected the neuroanatomical characteristics of the monkey hippocampal formation. Soma size was smaller in Nissl-stained, immersion-fixed tissue, although overall brain volume was larger, as compared to perfusion-fixed tissue. Non-phosphorylated high-molecular-weight neurofilament immunoreactivity was lower in CA3 pyramidal neurons, dentate mossy cells and the entorhinal cortex, whereas it was higher in the mossy fiber pathway in immersion-fixed tissue. Serotonin-immunoreactive fibers were well-stained in perfused tissue but were undetectable in immersion-fixed tissue. Although regional immunoreactivity patterns for calcium-binding proteins were not affected, intracellular staining degraded with increasing postmortem intervals. Somatostatin-immunoreactive clusters of large axonal varicosities, previously reported only in humans, were observed in immersion-fixed monkey tissue. In addition, calretinin-immunoreactive multipolar neurons, previously observed only in rodents, were found in the rostral dentate gyrus in both perfused and immersion-fixed brains. In conclusion, comparative studies of the brain must evaluate the effects of fixation on the staining pattern of each marker in every structure of interest before drawing conclusions about species differences. PMID:18972553

Postmortem changes in the neuroanatomical characteristics of the primate brain: hippocampal formation.

PubMed

Lavenex, Pierre; Lavenex, Pamela Banta; Bennett, Jeffrey L; Amaral, David G

2009-01-01

Comparative studies of the structural organization of the brain are fundamental to our understanding of human brain function. However, whereas brains of experimental animals are fixed by perfusion of a fixative through the vasculature, human or ape brains are fixed by immersion after varying postmortem intervals. Although differential treatments might affect the fundamental characteristics of the tissue, this question has not been evaluated empirically in primate brains. Monkey brains were either perfused or acquired after varying postmortem intervals before immersion-fixation in 4% paraformaldehyde. We found that the fixation method affected the neuroanatomical characteristics of the monkey hippocampal formation. Soma size was smaller in Nissl-stained, immersion-fixed tissue, although overall brain volume was larger as compared to perfusion-fixed tissue. Nonphosphorylated high-molecular-weight neurofilament immunoreactivity was lower in CA3 pyramidal neurons, dentate mossy cells, and the entorhinal cortex, whereas it was higher in the mossy fiber pathway in immersion-fixed tissue. Serotonin-immunoreactive fibers were well stained in perfused tissue but were undetectable in immersion-fixed tissue. Although regional immunoreactivity patterns for calcium-binding proteins were not affected, intracellular staining degraded with increasing postmortem intervals. Somatostatin-immunoreactive clusters of large axonal varicosities, previously reported only in humans, were observed in immersion-fixed monkey tissue. In addition, calretinin-immunoreactive multipolar neurons, previously observed only in rodents, were found in the rostral dentate gyrus in both perfused and immersion-fixed brains. In conclusion, comparative studies of the brain must evaluate the effects of fixation on the staining pattern of each marker in every structure of interest before drawing conclusions about species differences.

A Whole Brain Staining, Embedding, and Clearing Pipeline for Adult Zebrafish to Visualize Cell Proliferation and Morphology in 3-Dimensions.

PubMed

Lindsey, Benjamin W; Douek, Alon M; Loosli, Felix; Kaslin, Jan

2017-01-01

The field of macro-imaging has grown considerably with the appearance of innovative clearing methods and confocal microscopes with lasers capable of penetrating increasing tissue depths. The ability to visualize and model the growth of whole organs as they develop from birth, or with manipulation, disease or injury, provides new ways of thinking about development, tissue-wide signaling, and cell-to-cell interactions. The zebrafish ( Danio rerio ) has ascended from a predominantly developmental model to a leading adult model of tissue regeneration. The unmatched neurogenic and regenerative capacity of the mature central nervous system, in particular, has received much attention, however tools to interrogate the adult brain are sparse. At present there exists no straightforward methods of visualizing changes in the whole adult brain in 3-dimensions (3-D) to examine systemic patterns of cell proliferation or cell populations of interest under physiological, injury, or diseased conditions. The method presented here is the first of its kind to offer an efficient step-by-step pipeline from intraperitoneal injections of the proliferative marker, 5-ethynyl-2'-deoxyuridine (EdU), to whole brain labeling, to a final embedded and cleared brain sample suitable for 3-D imaging using optical projection tomography (OPT). Moreover, this method allows potential for imaging GFP-reporter lines and cell-specific antibodies in the presence or absence of EdU. The small size of the adult zebrafish brain, the highly consistent degree of EdU labeling, and the use of basic clearing agents, benzyl benzoate, and benzyl alcohol, makes this method highly tractable for most laboratories interested in understanding the vertebrate central nervous system in health and disease. Post-processing of OPT-imaged adult zebrafish brains injected with EdU illustrate that proliferative patterns in EdU can readily be observed and analyzed using IMARIS and/or FIJI/IMAGEJ software. This protocol will be a valuable tool to unlock new ways of understanding systemic patterns in cell proliferation in the healthy and injured brain, brain-wide cellular interactions, stem cell niche development, and changes in brain morphology.

A Whole Brain Staining, Embedding, and Clearing Pipeline for Adult Zebrafish to Visualize Cell Proliferation and Morphology in 3-Dimensions

PubMed Central

Lindsey, Benjamin W.; Douek, Alon M.; Loosli, Felix; Kaslin, Jan

2018-01-01

The field of macro-imaging has grown considerably with the appearance of innovative clearing methods and confocal microscopes with lasers capable of penetrating increasing tissue depths. The ability to visualize and model the growth of whole organs as they develop from birth, or with manipulation, disease or injury, provides new ways of thinking about development, tissue-wide signaling, and cell-to-cell interactions. The zebrafish (Danio rerio) has ascended from a predominantly developmental model to a leading adult model of tissue regeneration. The unmatched neurogenic and regenerative capacity of the mature central nervous system, in particular, has received much attention, however tools to interrogate the adult brain are sparse. At present there exists no straightforward methods of visualizing changes in the whole adult brain in 3-dimensions (3-D) to examine systemic patterns of cell proliferation or cell populations of interest under physiological, injury, or diseased conditions. The method presented here is the first of its kind to offer an efficient step-by-step pipeline from intraperitoneal injections of the proliferative marker, 5-ethynyl-2′-deoxyuridine (EdU), to whole brain labeling, to a final embedded and cleared brain sample suitable for 3-D imaging using optical projection tomography (OPT). Moreover, this method allows potential for imaging GFP-reporter lines and cell-specific antibodies in the presence or absence of EdU. The small size of the adult zebrafish brain, the highly consistent degree of EdU labeling, and the use of basic clearing agents, benzyl benzoate, and benzyl alcohol, makes this method highly tractable for most laboratories interested in understanding the vertebrate central nervous system in health and disease. Post-processing of OPT-imaged adult zebrafish brains injected with EdU illustrate that proliferative patterns in EdU can readily be observed and analyzed using IMARIS and/or FIJI/IMAGEJ software. This protocol will be a valuable tool to unlock new ways of understanding systemic patterns in cell proliferation in the healthy and injured brain, brain-wide cellular interactions, stem cell niche development, and changes in brain morphology. PMID:29386991

Evaluation of Nucleic Acid Preservation Cards for West Nile Virus Testing in Dead Birds

PubMed Central

Foss, Leslie; Reisen, William K.; Fang, Ying; Kramer, Vicki; Padgett, Kerry

2016-01-01

The California West Nile virus (WNV) Dead Bird Surveillance Program (DBSP) is an important component of WNV surveillance in the state. We evaluated FTA™ and RNASound™ cards as an alternative method for sampling dead birds for WNV molecular testing as these cards allow for more cost effective, rapid, and safer diagnostic sampling than the shipment of bird carcasses. To evaluate accuracy of results among avian sampling regimes, Reverse-Transcription Polymerase Chain Reaction (RT-PCR) results from FTA™ and RNASound™ cards were compared with results from kidney tissue, brain tissue, or oral swabs in lysis buffer in 2012–2013. In addition, RT-PCR results were compared with results from oral swabs tested by rapid antigen tests (RAMP™ and VecTOR™). While test results from the cards were not as sensitive as kidney tissue testing, they were more likely to provide accurate results than rapid antigen tests, and detected WNV in corvids as well as in other passerines, raptors, and waterfowl. Overall, WNV RT-PCR cycle threshold (Ct) scores from the cards were higher than those from tissue testing, but both card products displayed high sensitivity and specificity. American Crow samples provided the highest sensitivity. The cards also proved to be easier and more convenient vehicles for collecting and shipping samples, and in 2014 our program launched use of RNASound™ cards in the DBSP. Both FTA™ and RNASound™ products displayed 96% agreement with tissue results and are an adequate alternative sampling method for WNV dead bird testing. PMID:27341492

Effects of the Variation in Brain Tissue Mechanical Properties on the Intracranial Response of a 6-Year-Old Child.

PubMed

Cui, Shihai; Li, Haiyan; Li, Xiangnan; Ruan, Jesse

2015-01-01

Brain tissue mechanical properties are of importance to investigate child head injury using finite element (FE) method. However, these properties used in child head FE model normally vary in a large range in published literatures because of the insufficient child cadaver experiments. In this work, a head FE model with detailed anatomical structures is developed from the computed tomography (CT) data of a 6-year-old healthy child head. The effects of brain tissue mechanical properties on traumatic brain response are also analyzed by reconstruction of a head impact on engine hood according to Euro-NCAP testing regulation using FE method. The result showed that the variations of brain tissue mechanical parameters in linear viscoelastic constitutive model had different influences on the intracranial response. Furthermore, the opposite trend was obtained in the predicted shear stress and shear strain of brain tissues caused by the variations of mentioned parameters.

Development of a population pharmacokinetic model to predict brain distribution and dopamine D2 receptor occupancy of raclopride in non-anesthetized rat.

PubMed

Wong, Yin Cheong; Ilkova, Trayana; van Wijk, Rob C; Hartman, Robin; de Lange, Elizabeth C M

2018-01-01

Raclopride is a selective antagonist of the dopamine D2 receptor. It is one of the most frequently used in vivo D2 tracers (at low doses) for assessing drug-induced receptor occupancy (RO) in animals and humans. It is also commonly used as a pharmacological blocker (at high doses) to occupy the available D2 receptors and antagonize the action of dopamine or drugs on D2 in preclinical studies. The aims of this study were to comprehensively evaluate its pharmacokinetic (PK) profiles in different brain compartments and to establish a PK-RO model that could predict the brain distribution and RO of raclopride in the freely moving rat using a LC-MS based approach. Rats (n=24) received a 10-min IV infusion of non-radiolabeled raclopride (1.61μmol/kg, i.e. 0.56mg/kg). Plasma and the brain tissues of striatum (with high density of D2 receptors) and cerebellum (with negligible amount of D2 receptors) were collected. Additional microdialysis experiments were performed in some rats (n=7) to measure the free drug concentration in the extracellular fluid of the striatum and cerebellum. Raclopride concentrations in all samples were analyzed by LC-MS. A population PK-RO model was constructed in NONMEM to describe the concentration-time profiles in the unbound plasma, brain extracellular fluid and brain tissue compartments and to estimate the RO based on raclopride-D2 receptor binding kinetics. In plasma raclopride showed a rapid distribution phase followed by a slower elimination phase. The striatum tissue concentrations were consistently higher than that of cerebellum tissue throughout the whole experimental period (10-h) due to higher non-specific tissue binding and D2 receptor binding in the striatum. Model-based simulations accurately predicted the literature data on rat plasma PK, brain tissue PK and D2 RO at different time points after intravenous or subcutaneous administration of raclopride at tracer dose (RO <10%), sub-pharmacological dose (RO 10%-30%) and pharmacological dose (RO >30%). For the first time a predictive model that could describe the quantitative in vivo relationship between dose, PK and D2 RO of raclopride in non-anesthetized rat was established. The PK-RO model could facilitate the selection of optimal dose and dosing time when raclopride is used as tracer or as pharmacological blocker in various rat studies. The LC-MS based approach, which doses and quantifies a non-radiolabeled tracer, could be useful in evaluating the systemic disposition and brain kinetics of tracers. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Multimodality Instrument for Tissue Characterization

NASA Technical Reports Server (NTRS)

Mah, Robert W. (Inventor); Andrews, Russell J. (Inventor)

2000-01-01

A system with multimodality instrument for tissue identification includes a computer-controlled motor driven heuristic probe with a multisensory tip is discussed. For neurosurgical applications, the instrument is mounted on a stereotactic frame for the probe to penetrate the brain in a precisely controlled fashion. The resistance of the brain tissue being penetrated is continually monitored by a miniaturized strain gauge attached to the probe tip. Other modality sensors may be mounted near the probe tip to provide real-time tissue characterizations and the ability to detect the proximity of blood vessels, thus eliminating errors normally associated with registration of pre-operative scans, tissue swelling, elastic tissue deformation, human judgement, etc., and rendering surgical procedures safer, more accurate, and efficient. A neural network, program adaptively learns the information on resistance and other characteristic features of normal brain tissue during the surgery and provides near real-time modeling. A fuzzy logic interface to the neural network program incorporates expert medical knowledge in the learning process. Identification of abnormal brain tissue is determined by the detection of change and comparison with previously learned models of abnormal brain tissues. The operation of the instrument is controlled through a user friendly graphical interface. Patient data is presented in a 3D stereographics display. Acoustic feedback of selected information may optionally be provided. Upon detection of the close proximity to blood vessels or abnormal brain tissue, the computer-controlled motor immediately stops probe penetration.

The Importance of Brain Banks for Molecular Neuropathological Research: The New South Wales Tissue Resource Centre Experience

PubMed Central

Dedova, Irina; Harding, Antony; Sheedy, Donna; Garrick, Therese; Sundqvist, Nina; Hunt, Clare; Gillies, Juliette; Harper, Clive G.

2009-01-01

New developments in molecular neuropathology have evoked increased demands for postmortem human brain tissue. The New South Wales Tissue Resource Centre (TRC) at The University of Sydney has grown from a small tissue collection into one of the leading international brain banking facilities, which operates with best practice and quality control protocols. The focus of this tissue collection is on schizophrenia and allied disorders, alcohol use disorders and controls. This review highlights changes in TRC operational procedures dictated by modern neuroscience, and provides examples of applications of modern molecular techniques to study the neuropathogenesis of many different brain disorders. PMID:19333451

Lifespan mercury accumulation pattern in Liza aurata : Evidence from two southern European estuaries

NASA Astrophysics Data System (ADS)

Tavares, S.; Oliveira, H.; Coelho, J. P.; Pereira, M. E.; Duarte, A. C.; Pardal, M. A.

2011-10-01

Mercury accumulation throughout the lifespan of Liza aurata (Risso, 1810) was analysed in four tissues (muscle, gills, liver and brain) in two southern European coastal ecosystems with distinct mercury contamination. Specimens from four to five age classes were captured in two sampling sites in the Ria de Aveiro (Laranjo bay and Mira), a system historically contaminated by industrial mercury, and in one site in the Mondego estuary, assumed as a mercury-free ecosystem. Mercury concentration in all tissues was found to be significantly higher in the Ria de Aveiro (Laranjo bay) compared to the Mondego, in accordance with the environmental contamination (water, sediments and suspended particulate matter). Significant differences inside the Ria de Aveiro (between the Mira and Laranjo bay) were only detected in the liver. This tissue registered the highest levels of mercury (ranging from 0.11 to 4.2 μg g -1 ) in all sampling sites, followed by muscle, brain, and gills. In all sampling sites and tissues was denoted a mercury dilution pattern along the lifecycle (except in liver at the Mondego, the reference area where the concentrations are always very low). An exponential trend was found in the metal age variation patterns in Laranjo (the most contaminated area) and a linear trend in the Mira and the Mondego (the least contaminated areas). Organic mercury concentration in muscle generally accounted for over 95% of total mercury concentration, and followed the same accumulation pattern of total mercury. This fish species is of lesser importance in mercury transfer to adjacent coastal areas and although the consumption of fish from Laranjo may present some risk for the humans, this risk decreases with fish age/size.

Different modes of herpes simplex virus type 1 spread in brain and skin tissues.

PubMed

Tsalenchuck, Yael; Tzur, Tomer; Steiner, Israel; Panet, Amos

2014-02-01

Herpes simplex virus type 1 (HSV-1) initially infects the skin and subsequently spreads to the nervous system. To investigate and compare HSV-1 mode of propagation in the two clinically relevant tissues, we have established ex vivo infection models, using native tissues of mouse and human skin, as well as mouse brain, maintained in organ cultures. HSV-1, which is naturally restricted to the human, infects and spreads in the mouse and human skin tissues in a similar fashion, thus validating the mouse model. The spread of HSV-1 in the skin was concentric to form typical plaques of limited size, predominantly of cytopathic cells. By contrast, HSV-1 spread in the brain tissue was directed along specific neuronal networks with no apparent cytopathic effect. Two additional differences were noted following infection of the skin and brain tissues. First, only a negligible amount of extracellular progeny virus was produced of the infected brain tissues, while substantial quantity of infectious progeny virus was released to the media of the infected skin. Second, antibodies against HSV-1, added following the infection, effectively restricted viral spread in the skin but have no effect on viral spread in the brain tissue. Taken together, these results reveal that HSV-1 spread within the brain tissue mostly by direct transfer from cell to cell, while in the skin the progeny extracellular virus predominates, thus facilitating the infection to new individuals.

Rapid and sensitive liquid chromatography-tandem mass spectrometry method for determination of protein-free pro-drug treosulfan and its biologically active monoepoxy-transformer in plasma and brain tissue.

PubMed

Romański, Michał; Teżyk, Artur; Zaba, Czesław; Główka, Franciszek K

2014-09-01

For the first time a high performance liquid chromatography method with tandem mass spectrometry detection (HPLC-MS/MS) was developed for simultaneous determination of a pro-drug treosulfan (TREO) and its active monoepoxide (S,S-EBDM) in biological matrices. Small volumes of rat plasma (50 μL) and the brain homogenate supernatant (100 μL), equivalent to 0.02 g of brain tissue, were required for the analysis. Protein-free TREO, S,S-EBDM and acetaminophen, internal standard (IS), were isolated from the samples by ultrafiltration. Complete resolution of the analytes and the IS was accomplished on Zorbax Eclipse column using an isocratic elution with a mobile phase composed of ammonium formate - formic acid buffer pH 4.0 and acetonitrile. Detection was performed on a triple-quadrupole MS via multiple-reaction-monitoring following electrospray ionization. The developed method was fully validated according to the current guidelines of the European Medicines Agency. Calibration curves were linear in ranges: TREO 0.2-5720 μM and S,S-EBDM 0.9-175 μM for plasma, and TREO 0.2-29 μM and S,S-EBDM 0.4-44 μM for the brain homogenate supernatant. The limits of quantitation of TREO and S,S-EBDM in the studied matrices were much lower in comparison to the previously used bioanalytical methods. The HPLC-MS/MS method was adequately precise (coefficient of variation≤12.2%), accurate (relative error≤8.6%), and provided no carry-over, acceptable matrix effect as well as dilution integrity. The analytes were stable in acidified plasma and the brain homogenate supernatant samples for 4 h at room temperature, for 4 months at-80°C as well as within two cycles of freezing and thawing, and demonstrated 18-24h autosampler stability. The validated method enabled determination of low concentrations of TREO and S,S-EBDM in incurred brain samples of the rats treated with TREO, which constitutes a novel bioanalytical application. Copyright © 2014 Elsevier B.V. All rights reserved.

Experimental investigation of the mechanical properties of brain simulants used for cranial gunshot simulation.

PubMed

Lazarjan, Milad Soltanipour; Geoghegan, Patrick Henry; Jermy, Mark Christopher; Taylor, Michael

2014-06-01

The mechanical properties of the human brain at high strain rate were investigated to analyse the mechanisms that cause backspatter when a cranial gunshot wound occurs. Different concentrations of gelatine and a new material (M1) developed in this work were tested and compared to bovine brain samples. Kinetic energy absorption and expansion rate of the samples caused by the impact of a bullet from .22 air rifle (AR) (average velocity (uav) of 290m/s) and .22 long rifle (LR) (average velocity (uav) of 330m/s) were analysed using a high speed camera (24,000fps). The AR projectile had, in the region of interest, an average kinetic energy (Ek) of 42±1.3J. On average, the bovine brain absorbed 50±5% of Ek, and the simulants 46-58±5%. The Ek of the .22 LR was 141±3.7J. The bovine brain absorbed 27% of the .22LR Ek and the simulants 15-29%. The expansion of the sample, after penetration, was measured. The bovine brain experienced significant plastic deformation whereas the gelatine solution exhibited a principally elastic response. The permanent damage patterns in the M1 material were much closer to those in brain tissue, than were the damage patterns in the gelatine. The results provide a first step to developing a realistic experimental simulant for the human brain which can produce the same blood backspatter patterns as a human brain during a cranial gunshot. These results can also be used to improve the 3D models of human heads used in car crash and blast trauma injury research. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Lack of utility of arteriojugular venous differences of lactate as a reliable indicator of increased brain anaerobic metabolism in traumatic brain injury.

PubMed

Poca, Maria A; Sahuquillo, Juan; Vilalta, Anna; Garnacho, Angel

2007-04-01

Ischemic lesions are highly prevalent in patients with traumatic brain injuries (TBIs) and are the single most important cause of secondary brain damage. The prevention and early treatment of these lesions is the primary aim in the modem treatment of these patients. One of the most widely used monitoring techniques at the bedside is quantification of brain extracellular level of lactate by using arteriojugular venous differences of lactate (AVDL). The purpose of this study was to determine the sensitivity, specificity, and predictive value of AVDL as an indicator of increases in brain lactate production in patients with TBIs. Arteriojugular venous differences of lactate were calculated every 6 hours using samples obtained though a catheter placed in the jugular bulb in 45 patients with diffuse head injuries (57.8%) or evacuated brain lesions (42.2%). Cerebral lactate concentration obtained with a 20-kD microdialysis catheter implanted in undamaged tissue was used as the de facto gold standard. Six hundred seventy-three AVDL determinations and cerebral microdialysis samples were obtained simultaneously; 543 microdialysis samples (81%) showed lactate values greater than 2 mmol/L, but only 21 AVDL determinations (3.1%) showed an increase in brain lactate. No correlation was found between AVDL and cerebral lactate concentration (p = 0.014, p = 0.719). Arteriojugular venous differences of lactate had a sensitivity and specificity of 3.3 and 97.7%, respectively, with a false-negative rate of 96.7% and a false-positive rate of 2.3%. Arteriojugular venous differences of lactate do not reliably reflect increased cerebral lactate production and consequently are not reliable in ruling out brain ischemia in patients with TBIs. The clinical use of this monitoring method in neurocritical care should be reconsidered.

Kinetic modeling of PET-FDG in the brain without blood sampling.

PubMed

Bentourkia, M'hamed

2006-12-01

The aim in this work is to report a new method to calculate parametric images from a single scan acquisition with positron emission tomography (PET) and fluorodeoxyglucose (FDG) in the human brain without blood sampling. It is usually practical for research or clinical purposes to inject the patient in an isolated room and to start the PET acquisition only for some 10-20 min, about 30 min after FDG injection. In order to calculate the cerebral metabolic rates for glucose (CMRG), usually several blood samples are required. The proposed method considers the relation between the uptake of the tracer in the cerebellum as a reference tissue and the population based input curve. Similar results were obtained for CMRG values with the present method in comparison to the usual autoradiographic and the non-linear least squares fitting of regions of interest.

Hyperspectral imaging solutions for brain tissue metabolic and hemodynamic monitoring: past, current and future developments

NASA Astrophysics Data System (ADS)

Giannoni, Luca; Lange, Frédéric; Tachtsidis, Ilias

2018-04-01

Hyperspectral imaging (HSI) technologies have been used extensively in medical research, targeting various biological phenomena and multiple tissue types. Their high spectral resolution over a wide range of wavelengths enables acquisition of spatial information corresponding to different light-interacting biological compounds. This review focuses on the application of HSI to monitor brain tissue metabolism and hemodynamics in life sciences. Different approaches involving HSI have been investigated to assess and quantify cerebral activity, mainly focusing on: (1) mapping tissue oxygen delivery through measurement of changes in oxygenated (HbO2) and deoxygenated (HHb) hemoglobin; and (2) the assessment of the cerebral metabolic rate of oxygen (CMRO2) to estimate oxygen consumption by brain tissue. Finally, we introduce future perspectives of HSI of brain metabolism, including its potential use for imaging optical signals from molecules directly involved in cellular energy production. HSI solutions can provide remarkable insight in understanding cerebral tissue metabolism and oxygenation, aiding investigation on brain tissue physiological processes.

A study on the antioxidant effect of Coriolus versicolor polysaccharide in rat brain tissues.

PubMed

Chen, Jiayu; Jin, Xiaoyan; Zhang, Liting; Yang, Linjun

2013-01-01

The objective of the study was to investigate the antioxidant effect of Chinese medicine Coriolus versicolor polysaccharide on brain tissue and its mechanism in rats. SOD, MDA and GSH-Px levels in rat brain tissues were determined with SD rats as the animal model. The results showed that Coriolus versicolor polysaccharide can reduce the lipid peroxidation level in brain tissues during exhaustive exercise in rats, and can accelerate the removal of free radicals. The study concluded that its antioxidant effect is relatively apparent.

Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy

NASA Astrophysics Data System (ADS)

Haar, Peter J.; Broaddus, William C.; Chen, Zhi-jian; Fatouros, Panos P.; Gillies, George T.; Corwin, Frank D.

2010-06-01

A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s)-1 in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized.

Primary cultures of astrocytes from fetal bovine brain.

PubMed

Ballarin, Cristina; Peruffo, Antonella

2012-01-01

We describe here a method to obtain primary cell cultures from the cerebral cortex and the hypothalamus of bovine fetuses. We report how tissue origin, developmental stages, and culture medium conditions influence cell differentiation and the prevalence of glial cells vs. neurons. We compare explants from early, middle, and late stages of development and two different fetal calf serum concentrations (1 and 10%) to identify the best conditions to obtain and grow viable astrocytes in culture. In addition, we describe how to cryopreserve and obtain viable cortical astrocytes from frozen fetal bovine brain samples.

Collecting and Storing Blood and Brain Tumor Tissue Samples From Children With Brain Tumors

ClinicalTrials.gov

2017-12-11

Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Germ Cell Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Newly Diagnosed Childhood Ependymoma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma

Human exposure to metals: levels in autopsy tissues of individuals living near a hazardous waste incinerator.

PubMed

Mari, Montse; Nadal, Martí; Schuhmacher, Marta; Barbería, Eneko; García, Francisco; Domingo, José L

2014-06-01

The concentrations of a number of metals were determined in the brain, bone, kidney, liver, and lung of 20 autopsied subjects who had lived, at least 10 years, in the neighborhood of a hazardous waste incinerator (HWI) in Tarragona (Catalonia, Spain). Results were compared with those obtained in 1998 (baseline survey) and previous surveys (2003 and 2007). Arsenic, Be, Ni, Tl, and V showed concentrations below the corresponding detection limits in all tissues. Cadmium showed the highest levels in the kidney, with a mean value of 21.15 μg/g. However, Cd was found below the detection limit in the brain and bone. Chromium showed similar concentrations in the kidney, brain, and lung (range of mean values, 0.57-0.66 μg/g) and higher in the bone (1.38 μg/g). In turn, Hg was below the detection limit in all tissues with the exception of the kidney, where the mean concentration was 0.15 μg/g (range, <0.05-0.58 μg/g). On the other hand, Mn could be detected in all tissues showing the highest levels in the liver and kidney (1.45 and 1.09 μg/g, respectively). Moreover, Pb showed the highest concentrations in bone (mean, 1.39 μg/g; range, <0.025-4.88 μg/g). Finally, Sn could be detected only in some tissue samples, reaching the highest values in the bone (0.17 μg/g). The current metal levels in human tissues from individuals living near the HWI of Tarragona are comparable and of a similar magnitude to previously reported results corresponding to general populations, as well as those of our previous surveys.

Automated pixel-wise brain tissue segmentation of diffusion-weighted images via machine learning.

PubMed

Ciritsis, Alexander; Boss, Andreas; Rossi, Cristina

2018-04-26

The diffusion-weighted (DW) MR signal sampled over a wide range of b-values potentially allows for tissue differentiation in terms of cellularity, microstructure, perfusion, and T 2 relaxivity. This study aimed to implement a machine learning algorithm for automatic brain tissue segmentation from DW-MRI datasets, and to determine the optimal sub-set of features for accurate segmentation. DWI was performed at 3 T in eight healthy volunteers using 15 b-values and 20 diffusion-encoding directions. The pixel-wise signal attenuation, as well as the trace and fractional anisotropy (FA) of the diffusion tensor, were used as features to train a support vector machine classifier for gray matter, white matter, and cerebrospinal fluid classes. The datasets of two volunteers were used for validation. For each subject, tissue classification was also performed on 3D T 1 -weighted data sets with a probabilistic framework. Confusion matrices were generated for quantitative assessment of image classification accuracy in comparison with the reference method. DWI-based tissue segmentation resulted in an accuracy of 82.1% on the validation dataset and of 82.2% on the training dataset, excluding relevant model over-fitting. A mean Dice coefficient (DSC) of 0.79 ± 0.08 was found. About 50% of the classification performance was attributable to five features (i.e. signal measured at b-values of 5/10/500/1200 s/mm 2 and the FA). This reduced set of features led to almost identical performances for the validation (82.2%) and the training (81.4%) datasets (DSC = 0.79 ± 0.08). Machine learning techniques applied to DWI data allow for accurate brain tissue segmentation based on both morphological and functional information. Copyright © 2018 John Wiley & Sons, Ltd.

Electroosmotic perfusion of tissue: sampling the extracellular space and quantitative assessment of membrane-bound enzyme activity in organotypic hippocampal slice cultures.

PubMed

Ou, Yangguang; Wu, Juanfang; Sandberg, Mats; Weber, Stephen G

2014-10-01

This review covers recent advances in sampling fluid from the extracellular space of brain tissue by electroosmosis (EO). Two techniques, EO sampling with a single fused-silica capillary and EO push-pull perfusion, have been developed. These tools were used to investigate the function of membrane-bound enzymes with outward-facing active sites, or ectoenzymes, in modulating the activity of the neuropeptides leu-enkephalin and galanin in organotypic-hippocampal-slice cultures (OHSCs). In addition, the approach was used to determine the endogenous concentration of a thiol, cysteamine, in OHSCs. We have also investigated the degradation of coenzyme A in the extracellular space. The approach provides information on ectoenzyme activity, including Michaelis constants, in tissue, which, as far as we are aware, has not been done before. On the basis of computational evidence, EO push-pull perfusion can distinguish ectoenzyme activity with a ~100 μm spatial resolution, which is important for studies of enzyme kinetics in adjacent regions of the rat hippocampus.

Differentiation of cancerous and normal brain tissue using label free fluorescence and Stokes shift spectroscopy

NASA Astrophysics Data System (ADS)

Zhou, Yan; Wang, Leana; Liu, Cheng-hui; He, Yong; Yu, Xinguang; Cheng, Gangge; Wang, Peng; Shu, Cheng; Alfano, Robert R.

2016-03-01

In this report, optical biopsy was applied to diagnose human brain cancer in vitro for the identification of brain cancer from normal tissues by native fluorescence and Stokes shift spectra (SSS). 77 brain specimens including three types of human brain tissues (normal, glioma and brain metastasis of lung cancers) were studied. In order to observe spectral changes of fluorophores via fluorescence, the selected excitation wavelength of UV at 300 and 340 nm for emission spectra and a different Stokes Shift spectra with intervals Δλ = 40 nm were measured. The fluorescence spectra and SSS from multiple key native molecular markers, such as tryptophan, collagen, NADH, alanine, ceroid and lipofuscin were observed in normal and diseased brain tissues. Two diagnostic criteria were established based on the ratios of the peak intensities and peak position in both fluorescence and SSS spectra. It was observed that the ratio of the spectral peak intensity of tryptophan (340 nm) to NADH (440 nm) increased in glioma, meningioma (benign), malignant meninges tumor, and brain metastasis of lung cancer tissues in comparison with normal tissues. The ratio of the SS spectral peak (Δλ = 40 nm) intensities from 292 nm to 366 nm had risen similarly in all grades of tumors.

Banking (on) the brain: from consent to authorisation and the transformative potential of solidarity.

PubMed

Harmon, Shawn H E; Mcmahon, Aisling

2014-01-01

Modern technologies and biomedicine ambitions have given rise to new models of medical research, including population biobanking. One example of biobanking is brain banking, which refers to the collection and storage of brain and spinal cord samples for research into neurological diseases. Obviously, brain banking involves taking brains and tissue from deceased people, a fact which complicates the role of recruiters and makes consent a poor tool for stakeholders. After contextualising brain banking and considering the public health issues at stake, this article explores the legal definitions and demands of, and actual processes around, consent in England/Wales/Northern Ireland and authorisation in Scotland, articulating and evaluating their conceptual and practical differences. It then argues for an expanded but improved operation of 'authorisation' in the brain banking (and broader biobanking) setting, adopting 'solidarity' as our foundation and the improvement of the 'public good' our objective. © The Author [2014]. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

Correlation between light scattering signal and tissue reversibility in rat brain exposed to hypoxia

NASA Astrophysics Data System (ADS)

Kawauchi, Satoko; Sato, Shunichi; Uozumi, Yoichi; Nawashiro, Hiroshi; Ishihara, Miya; Kikuchi, Makoto

2010-02-01

Light scattering signal is a potential indicator of tissue viability in brain because cellular and subcellular structural integrity should be associated with cell viability in brain tissue. We previously performed multiwavelength diffuse reflectance measurement for a rat global ischemic brain model and observed a unique triphasic change in light scattering at a certain time after oxygen and glucose deprivation. This triphasic scattering change (TSC) was shown to precede cerebral ATP exhaustion, suggesting that loss of brain tissue viability can be predicted by detecting scattering signal. In the present study, we examined correlation between light scattering signal and tissue reversibility in rat brain in vivo. We performed transcranial diffuse reflectance measurement for rat brain; under spontaneous respiration, hypoxia was induced for the rat by nitrogen gas inhalation and reoxygenation was started at various time points. We observed a TSC, which started at 140 +/- 15 s after starting nitrogen gas inhalation (mean +/- SD, n=8). When reoxygenation was started before the TSC, all rats survived (n=7), while no rats survived when reoxygenation was started after the TSC (n=8). When reoxygenation was started during the TSC, rats survived probabilistically (n=31). Disability of motor function was not observed for the survived rats. These results indicate that TSC can be used as an indicator of loss of tissue reversibility in brains, providing useful information on the critical time zone for treatment to rescue the brain.

BROADENING OF THE RF POWER-DENSITY WINDOW FOR CALCIUM-ION EFFLUX FROM BRAIN TISSUE

EPA Science Inventory

Blackman, et. al. have reported enhanced efflux of calcium ions from chicken forebrains, exposed in vitro in a 50 ohm stripline to 147 MHz radiation, modulated sinusoidally at 16 Hz. When the spacing between the sample tubes was 3.8 cm on center, enhancement occurred at an incide...

Molecular Determinants Fundamental to Axon Regeneration after SCI

DTIC Science & Technology

2012-06-01

gray arrow) and a 130kDa N-terminal processed neurocan fragment (black arrow) in chABC treated samples (Asher et. al., 2000). Zebrafish brain tissue...PTPRSREV: GTG TGT GTG CTG ATG AAG GTC GC (EXON 9). 275 bp product expected. We have also designed a forward primer in exon 6 with negative results

Organophosphate and carbamate insecticides in agricultural waters and cholinesterase (ChE) inhibition in common carp (Cyprinus carpio)

USGS Publications Warehouse

Gruber, S.J.; Munn, M.D.

1998-01-01

Cholinesterase (ChE) activity was used as a biomarker for assessing exposure of common carp (Cyprinus carpio) to organophosphate and carbamate insecticides from irrigated agricultural waters. Carp were collected from a lake (Royal Lake) that receives most of its water from irrigation return flows and from a reference lake (Billy Clapp Lake) outside of the irrigation system. Results indicated that the mean whole-brain ChE activity of carp from Royal Lake (3.47 μmol/min/g tissue) was 34.2% less than that of carp from Billy Clapp Lake (5.27 μmol/min/g tissue) (p = 0.003). The depressed ChE activity in brain tissue of Royal Lake carp was in response to ChE-inhibiting insecticides detected in water samples in the weeks prior to tissue sampling; the most frequently detected insecticides included chlorpyrifos, azinphos-methyl, carbaryl, and ethoprop. Neither sex nor size appears to be a covariable in the analysis; ChE activity was not correlated with fish length or weight in either lake and there was no significant difference in ChE activity between the two sexes within each lake. Although organophosphate and carbamate insecticides can break down rapidly in the environment, this study suggests that in agricultural regions where insecticides are applied for extended periods of the year, nontarget aquatic biota may be exposed to high levels of ChE-inhibiting insecticides for a period of several months.

The Relationship of Three-Dimensional Human Skull Motion to Brain Tissue Deformation in Magnetic Resonance Elastography Studies

PubMed Central

Badachhape, Andrew A.; Okamoto, Ruth J.; Durham, Ramona S.; Efron, Brent D.; Nadell, Sam J.; Johnson, Curtis L.; Bayly, Philip V.

2017-01-01

In traumatic brain injury (TBI), membranes such as the dura mater, arachnoid mater, and pia mater play a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is an imaging technique developed for noninvasive estimation of soft tissue material parameters. In MRE, dynamic deformation of brain tissue is induced by skull vibrations during magnetic resonance imaging (MRI); however, skull motion and its mode of transmission to the brain remain largely uncharacterized. In this study, displacements of points in the skull, reconstructed using data from an array of MRI-safe accelerometers, were compared to displacements of neighboring material points in brain tissue, estimated from MRE measurements. Comparison of the relative amplitudes, directions, and temporal phases of harmonic motion in the skulls and brains of six human subjects shows that the skull–brain interface significantly attenuates and delays transmission of motion from skull to brain. In contrast, in a cylindrical gelatin “phantom,” displacements of the rigid case (reconstructed from accelerometer data) were transmitted to the gelatin inside (estimated from MRE data) with little attenuation or phase lag. This quantitative characterization of the skull–brain interface will be valuable in the parameterization and validation of computer models of TBI. PMID:28267188

The Relationship of Three-Dimensional Human Skull Motion to Brain Tissue Deformation in Magnetic Resonance Elastography Studies.

PubMed

Badachhape, Andrew A; Okamoto, Ruth J; Durham, Ramona S; Efron, Brent D; Nadell, Sam J; Johnson, Curtis L; Bayly, Philip V

2017-05-01

In traumatic brain injury (TBI), membranes such as the dura mater, arachnoid mater, and pia mater play a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is an imaging technique developed for noninvasive estimation of soft tissue material parameters. In MRE, dynamic deformation of brain tissue is induced by skull vibrations during magnetic resonance imaging (MRI); however, skull motion and its mode of transmission to the brain remain largely uncharacterized. In this study, displacements of points in the skull, reconstructed using data from an array of MRI-safe accelerometers, were compared to displacements of neighboring material points in brain tissue, estimated from MRE measurements. Comparison of the relative amplitudes, directions, and temporal phases of harmonic motion in the skulls and brains of six human subjects shows that the skull-brain interface significantly attenuates and delays transmission of motion from skull to brain. In contrast, in a cylindrical gelatin "phantom," displacements of the rigid case (reconstructed from accelerometer data) were transmitted to the gelatin inside (estimated from MRE data) with little attenuation or phase lag. This quantitative characterization of the skull-brain interface will be valuable in the parameterization and validation of computer models of TBI.

Improved two-photon imaging of living neurons in brain tissue through temporal gating

PubMed Central

Gautam, Vini; Drury, Jack; Choy, Julian M. C.; Stricker, Christian; Bachor, Hans-A.; Daria, Vincent R.

2015-01-01

We optimize two-photon imaging of living neurons in brain tissue by temporally gating an incident laser to reduce the photon flux while optimizing the maximum fluorescence signal from the acquired images. Temporal gating produces a bunch of ~10 femtosecond pulses and the fluorescence signal is improved by increasing the bunch-pulse energy. Gating is achieved using an acousto-optic modulator with a variable gating frequency determined as integral multiples of the imaging sampling frequency. We hypothesize that reducing the photon flux minimizes the photo-damage to the cells. Our results, however, show that despite producing a high fluorescence signal, cell viability is compromised when the gating and sampling frequencies are equal (or effectively one bunch-pulse per pixel). We found an optimum gating frequency range that maintains the viability of the cells while preserving a pre-set fluorescence signal of the acquired two-photon images. The neurons are imaged while under whole-cell patch, and the cell viability is monitored as a change in the membrane’s input resistance. PMID:26504651

High-sensitivity terahertz imaging of traumatic brain injury in a rat model

NASA Astrophysics Data System (ADS)

Zhao, Hengli; Wang, Yuye; Chen, Linyu; Shi, Jia; Ma, Kang; Tang, Longhuang; Xu, Degang; Yao, Jianquan; Feng, Hua; Chen, Tunan

2018-03-01

We demonstrated that different degrees of experimental traumatic brain injury (TBI) can be differentiated clearly in fresh slices of rat brain tissues using transmission-type terahertz (THz) imaging system. The high absorption region in THz images corresponded well with the injured area in visible images and magnetic resonance imaging results. The THz image and absorption characteristics of dehydrated paraffin-embedded brain slices and the hematoxylin and eosin (H&E)-stained microscopic images were investigated to account for the intrinsic differences in the THz images for the brain tissues suffered from different degrees of TBI and normal tissue aside from water. The THz absorption coefficients of rat brain tissues showed an increase in the aggravation of brain damage, particularly in the high-frequency range, whereas the cell density decreased as the order of mild, moderate, and severe TBI tissues compared with the normal tissue. Our results indicated that the different degrees of TBI were distinguishable owing to the different water contents and probable hematoma components distribution rather than intrinsic cell intensity. These promising results suggest that THz imaging has great potential as an alternative method for the fast diagnosis of TBI.

Transcriptome-Wide Mega-Analyses Reveal Joint Dysregulation of Immunologic Genes and Transcription Regulators in Brain and Blood in Schizophrenia

PubMed Central

Hess, Jonathan L.; Tylee, Daniel S.; Barve, Rahul; de Jong, Simone; Ophoff, Roel A.; Kumarasinghe, Nishantha; Tooney, Paul; Schall, Ulrich; Gardiner, Erin; Beveridge, Natalie Jane; Scott, Rodney J.; Yasawardene, Surangi; Perera, Antionette; Mendis, Jayan; Carr, Vaughan; Kelly, Brian; Cairns, Murray; Tsuang, Ming T.; Glatt, Stephen J.

2016-01-01

The application of microarray technology in schizophrenia research was heralded as paradigm-shifting, as it allowed for high-throughput assessment of cell and tissue function. This technology was widely adopted, initially in studies of postmortem brain tissue, and later in studies of peripheral blood. The collective body of schizophrenia microarray literature contains apparent inconsistencies between studies, with failures to replicate top hits, in part due to small sample sizes, cohort-specific effects, differences in array types, and other confounders. In an attempt to summarize existing studies of schizophrenia cases and non-related comparison subjects, we performed two mega-analyses of a combined set of microarray data from postmortem prefrontal cortices (n = 315) and from ex-vivo blood tissues (n = 578). We adjusted regression models per gene to remove non-significant covariates, providing best-estimates of transcripts dysregulated in schizophrenia. We also examined dysregulation of functionally related gene sets and gene co-expression modules, and assessed enrichment of cell types and genetic risk factors. The identities of the most significantly dysregulated genes were largely distinct for each tissue, but the findings indicated common emergent biological functions (e.g. immunity) and regulatory factors (e.g., predicted targets of transcription factors and miRNA species across tissues). Our network-based analyses converged upon similar patterns of heightened innate immune gene expression in both brain and blood in schizophrenia. We also constructed generalizable machine-learning classifiers using the blood-based microarray data. Our study provides an informative atlas for future pathophysiologic and biomarker studies of schizophrenia. PMID:27450777

Transcriptome-wide mega-analyses reveal joint dysregulation of immunologic genes and transcription regulators in brain and blood in schizophrenia.

PubMed

Hess, Jonathan L; Tylee, Daniel S; Barve, Rahul; de Jong, Simone; Ophoff, Roel A; Kumarasinghe, Nishantha; Tooney, Paul; Schall, Ulrich; Gardiner, Erin; Beveridge, Natalie Jane; Scott, Rodney J; Yasawardene, Surangi; Perera, Antionette; Mendis, Jayan; Carr, Vaughan; Kelly, Brian; Cairns, Murray; Tsuang, Ming T; Glatt, Stephen J

2016-10-01

The application of microarray technology in schizophrenia research was heralded as paradigm-shifting, as it allowed for high-throughput assessment of cell and tissue function. This technology was widely adopted, initially in studies of postmortem brain tissue, and later in studies of peripheral blood. The collective body of schizophrenia microarray literature contains apparent inconsistencies between studies, with failures to replicate top hits, in part due to small sample sizes, cohort-specific effects, differences in array types, and other confounders. In an attempt to summarize existing studies of schizophrenia cases and non-related comparison subjects, we performed two mega-analyses of a combined set of microarray data from postmortem prefrontal cortices (n=315) and from ex-vivo blood tissues (n=578). We adjusted regression models per gene to remove non-significant covariates, providing best-estimates of transcripts dysregulated in schizophrenia. We also examined dysregulation of functionally related gene sets and gene co-expression modules, and assessed enrichment of cell types and genetic risk factors. The identities of the most significantly dysregulated genes were largely distinct for each tissue, but the findings indicated common emergent biological functions (e.g. immunity) and regulatory factors (e.g., predicted targets of transcription factors and miRNA species across tissues). Our network-based analyses converged upon similar patterns of heightened innate immune gene expression in both brain and blood in schizophrenia. We also constructed generalizable machine-learning classifiers using the blood-based microarray data. Our study provides an informative atlas for future pathophysiologic and biomarker studies of schizophrenia. Published by Elsevier B.V.

Measuring aberrations in the rat brain by coherence-gated wavefront sensing using a Linnik interferometer

PubMed Central

Wang, Jinyu; Léger, Jean-François; Binding, Jonas; Boccara, A. Claude; Gigan, Sylvain; Bourdieu, Laurent

2012-01-01

Aberrations limit the resolution, signal intensity and achievable imaging depth in microscopy. Coherence-gated wavefront sensing (CGWS) allows the fast measurement of aberrations in scattering samples and therefore the implementation of adaptive corrections. However, CGWS has been demonstrated so far only in weakly scattering samples. We designed a new CGWS scheme based on a Linnik interferometer and a SLED light source, which is able to compensate dispersion automatically and can be implemented on any microscope. In the highly scattering rat brain tissue, where multiply scattered photons falling within the temporal gate of the CGWS can no longer be neglected, we have measured known defocus and spherical aberrations up to a depth of 400 µm. PMID:23082292

Measuring aberrations in the rat brain by coherence-gated wavefront sensing using a Linnik interferometer.

PubMed

Wang, Jinyu; Léger, Jean-François; Binding, Jonas; Boccara, A Claude; Gigan, Sylvain; Bourdieu, Laurent

2012-10-01

Aberrations limit the resolution, signal intensity and achievable imaging depth in microscopy. Coherence-gated wavefront sensing (CGWS) allows the fast measurement of aberrations in scattering samples and therefore the implementation of adaptive corrections. However, CGWS has been demonstrated so far only in weakly scattering samples. We designed a new CGWS scheme based on a Linnik interferometer and a SLED light source, which is able to compensate dispersion automatically and can be implemented on any microscope. In the highly scattering rat brain tissue, where multiply scattered photons falling within the temporal gate of the CGWS can no longer be neglected, we have measured known defocus and spherical aberrations up to a depth of 400 µm.

Oral uridine-5'-monophosphate (UMP) increases brain CDP-choline levels in gerbils.

PubMed

Cansev, Mehmet; Watkins, Carol J; van der Beek, Eline M; Wurtman, Richard J

2005-10-05

We examined the biochemical pathways whereby oral uridine-5'-monophosphate (UMP) increases membrane phosphatide synthesis in brains of gerbils. We previously showed that supplementing PC12 cells with uridine caused concentration-related increases in CDP-choline levels, and that this effect was mediated by elevations in intracellular uridine triphosphate (UTP) and cytidine triphosphate (CTP). In the present study, adult gerbils received UMP (1 mmol/kg), a constituent of human breast milk and infant formulas, by gavage, and plasma samples and brains were collected for assay between 5 min and 8 h thereafter. Thirty minutes after gavage, plasma uridine levels were increased from 6.6 +/- 0.58 to 32.7 +/- 1.85 microM (P < 0.001), and brain uridine from 22.6 +/- 2.9 to 89.1 +/- 8.82 pmol/mg tissue (P < 0.001). UMP also significantly increased plasma and brain cytidine levels; however, both basally and following UMP, these levels were much lower than those of uridine. Brain UTP, CTP, and CDP-choline were all elevated 15 min after UMP (from 254 +/- 31.9 to 417 +/- 50.2, [P < 0.05]; 56.8 +/- 1.8 to 71.7 +/- 1.8, [P < 0.001]; and 11.3 +/- 0.5 to 16.4 +/- 1, [P < 0.001] pmol/mg tissue, respectively), returning to basal levels after 20 and 30 min. The smallest UMP dose that significantly increased brain CDP-choline was 0.05 mmol/kg. These results show that oral UMP, a uridine source, enhances the synthesis of CDP-choline, the immediate precursor of PC, in gerbil brain.

Analysis of the influence of handset phone position on RF exposure of brain tissue.

PubMed

Ghanmi, Amal; Varsier, Nadège; Hadjem, Abdelhamid; Conil, Emmanuelle; Picon, Odile; Wiart, Joe

2014-12-01

Exposure to mobile phone radio frequency (RF) electromagnetic fields depends on many different parameters. For epidemiological studies investigating the risk of brain cancer linked to RF exposure from mobile phones, it is of great interest to characterize brain tissue exposure and to know which parameters this exposure is sensitive to. One such parameter is the position of the phone during communication. In this article, we analyze the influence of the phone position on the brain exposure by comparing the specific absorption rate (SAR) induced in the head by two different mobile phone models operating in Global System for Mobile Communications (GSM) frequency bands. To achieve this objective, 80 different phone positions were chosen using an experiment based on the Latin hypercube sampling (LHS) to select a representative set of positions. The averaged SAR over 10 g (SAR10 g) in the head, the averaged SAR over 1 g (SAR1 g ) in the brain, and the averaged SAR in different anatomical brain structures were estimated at 900 and 1800 MHz for the 80 positions. The results illustrate that SAR distributions inside the brain area are sensitive to the position of the mobile phone relative to the head. The results also show that for 5-10% of the studied positions the SAR10 g in the head and the SAR1 g in the brain can be 20% higher than the SAR estimated for the standard cheek position and that the Specific Anthropomorphic Mannequin (SAM) model is conservative for 95% of all the studied positions. © 2014 Wiley Periodicals, Inc.

Effects of high-pressure oxygen therapy on brain tissue water content and AQP4 expression in rabbits with cerebral hemorrhage.

PubMed

Wu, Jing; Chen, Jiong; Guo, Hua; Peng, Fang

2014-12-01

To investigate the effects of different atmosphere absolutes (ATA) of high-pressure oxygen (HPO) on brain tissue water content and Aquaporin-4 (AQP4) expression in rabbits with cerebral hemorrhage. 180 New Zealand white rabbits were selected and randomly divided into normal group (n = 30), control group (n = 30) and cerebral hemorrhage group (n = 120), and cerebral hemorrhage group was divided into group A, B, C and D with 30 rabbits in each group. The groups received 1.0, 1.8, 2.0 and 2.2 ATA of HPO treatments, respectively. Ten rabbits in each group were killed at first, third and fifth day to detect the brain tissue water content and change of AQP4 expression. In cerebral hemorrhage group, brain tissue water content and AQP4 expression after model establishment were first increased, then decreased and reached the maximum on third day (p < 0.05). Brain tissue water content and AQP4 expression in control group and cerebral hemorrhage group were significantly higher than normal group at different time points (p < 0.05). In contrast, brain tissue water content and AQP4 expression in group C were significantly lower than in group A, group B, group D and control group (p < 0.05). In control group, AQP4-positive cells significantly increased after model establishment, which reached maximum on third day, and positive cells in group C were significantly less than in group A, group B and group D. We also found that AQP4 expression were positively correlated with brain tissue water content (r = 0.719, p < 0.05) demonstrated by significantly increased AQP4 expression along with increased brain tissue water content. In conclusion, HPO can decrease AQP4 expression in brain tissue of rabbits with cerebral hemorrhage to suppress the progression of brain edema and promote repairing of injured tissue. 2.0 ATA HPO exerts best effects, which provides an experimental basis for ATA selection of HPO in treating cerebral hemorrhage.

A pilot microdialysis study in brain tumor patients to assess changes in intracerebral cytokine levels after craniotomy and in response to treatment with a targeted anti-cancer agent.

PubMed

Portnow, Jana; Badie, Behnam; Liu, Xueli; Frankel, Paul; Mi, Shu; Chen, Mike; Synold, Timothy W

2014-05-01

Intracerebral microdialysis enables continuous measurement of changes in brain biochemistry. In this study intracerebral microdialysis was used to assess changes in cytokine levels after tumor resection and in response to treatment with temsirolimus. Brain tumor patients undergoing craniotomy participated in this non-therapeutic study. A 100 kDa molecular weight cut-off microdialysis catheter was placed in peritumoral tissue at the time of resection. Cohort 1 underwent craniotomy only. Cohort 2 received a 200 mg dose of intravenous temsirolimus 48 h after surgery. Dialysate samples were collected continuously for 96 h and analyzed for the presence of 30 cytokines. Serial blood samples were collected to measure systemic cytokine levels. Dialysate samples were obtained from six patients in cohort 1 and 4 in cohort 2. Seventeen cytokines could be recovered in dialysate samples from at least 8 of 10 patients. Concentrations of interleukins and chemokines were markedly elevated in peritumoral tissue, and most declined over time, with IL-8, IP-10, MCP-1, MIP1β, IL-6, IL-12p40/p70, MIP1α, IFN-α, G-CSF, IL-2R, and vascular endothelial growth factor significantly (p < 0.05) decreasing over 96 h following surgery. No qualitative changes in intracerebral or serum cytokine concentrations were detected after temsirolimus administration. This is the first intracerebral microdialysis study to evaluate the time course of changes in macromolecule levels in the peritumoral microenvironment after a debulking craniotomy. Initial elevations of peritumoral interleukins and chemokines most likely reflected an inflammatory response to both tumor and surgical trauma. These findings have implications for development of cellular therapies that are administered intracranially at the time of surgery.

Liquid microjunction surface sampling coupled with high-pressure liquid chromatography-electrospray ionization-mass spectrometry for analysis of drugs and metabolites in whole-body thin tissue sections.

PubMed

Kertesz, Vilmos; Van Berkel, Gary J

2010-07-15

In this work, a commercially available autosampler was adapted to perform direct liquid microjunction (LMJ) surface sampling followed by a high-pressure liquid chromatography (HPLC) separation of the extract components and detection with electrospray ionization mass spectrometry (ESI-MS). To illustrate the utility of coupling a separation with this direct liquid extraction based surface sampling approach, four different organs (brain, lung, kidney, and liver) from whole-body thin tissue sections of propranolol dosed and control mice were examined. The parent drug was observed in the chromatograms of the surface sampling extracts from all the organs of the dosed mouse examined. In addition, two isomeric phase II metabolites of propranolol (an aliphatic and an aromatic hydroxypropranolol glucuronide) were observed in the chromatograms of the extracts from lung, kidney, and liver. Confirming the presence of one or the other or both of these glucuronides in the extract from the various organs was not possible without the separation. These drug and metabolite data obtained using the LMJ surface sampling/HPLC-MS method and the results achieved by analyzing similar samples by conventional extraction of the tissues and subsequent HPLC-MS analysis were consistent. The ability to directly and efficiently sample from thin tissue sections via a liquid extraction and then perform a subsequent liquid phase separation increases the utility of this liquid extraction surface sampling approach.

Regionally Impaired Redox Homeostasis in the Brain of Rats Subjected to Global Perinatal Asphyxia: Sustained Effect up to 14 Postnatal Days.

PubMed

Lespay-Rebolledo, Carolyne; Perez-Lobos, Ronald; Tapia-Bustos, Andrea; Vio, Valentina; Morales, Paola; Herrera-Marschitz, Mario

2018-06-29

The present report evaluates the effect of global perinatal asphyxia on several parameters of oxidative stress and cell viability in rat brain tissue sampled at an extended neonatal period up to 14 days, a period characterised by intensive neuritogenesis, synaptogenesis, synaptic consolidation, pruning and delayed cell death. Perinatal asphyxia was induced by immersing foetus-containing uterine horns removed by a caesarean section from on term rat dams into a water bath at 37 °C for 21 min. Asphyxia-exposed and sibling caesarean-delivered foetuses were manually resucitated and nurtured by surrogate dams for 1 to 14 postnatal (P) days. Brain samples (mesencephalon, telencephalon and hippocampus) were assayed for glutathione (reduced and oxidated levels; spectrophotometry), tissue reducing capacity (potassium ferricyanide reducing assay, FRAP), catalase (the key enzyme protecting against oxidative stress and reactive oxygen species, Western blots and ELISA) and cleaved caspase-3 (the key executioner of apoptosis, Western blots) levels. It was found that global PA produced a regionally specific and sustained increase in GSSG/GSH ratio, a regionally specific decrease in tissue reducing capacity and a regionally and time specific decrease of catalase activity and increase of cleaved caspase-3 levels. The present study provides evidence for regionally impaired redox homeostasis in the brain of rats subjected to global PA, an effect observed up to P14, mainly affecting mesencephalon and hippocampus, suggesting a sustained oxidative stress after the posthypoxia period. The oxidative stress observed postnatally can in part be associated to a respiratory apneic-like deficit, since there was a statistically significant decrease in respiration frequency in AS compared to CS neonates, also up to P14, together with the signs of a decreased peripheral blood perfusion (pink-blue skin colour in AS, compared to the pink colour observed in all CS neonates). It is proposed that PA implies a long-term metabolic insult, triggered by the length of hypoxia, the resuscitation/reoxigenation manoevres, but also by the developmental stage of the affected brain regions, and the integrity of cardiovascular and respiratory physiological functions, which are fundamental for warrantying a proper development.

The protective effect of different airway humidification liquids to lung after tracheotomy in traumatic brain injury: The role of pulmonary surfactant protein-A (SP-A).

PubMed

Su, Xinyang; Li, Zefu; Wang, Meilin; Li, Zhenzhu; Wang, Qingbo; Lu, Wenxian; Li, Xiaoli; Zhou, Youfei; Xu, Hongmei

2016-02-10

The purpose of this study was to establish a rat model of a brain injury with tracheotomy and compared the wetting effects of different airway humidification liquids, afterward, the best airway humidification liquid was selected for the clinical trial, thus providing a theoretical basis for selecting a proper airway humidification liquid in a clinical setting. Rats were divided into a sham group, group A (0.9% NaCl), group B (0.45% NaCl), group C (0.9% NaCl+ambroxol) and group D (0.9% NaCl+Pulmicort). An established rat model of traumatic brain injury with tracheotomy was used. Brain tissue samples were taken to determine water content, while lung tissue samples were taken to determine wet/dry weight ratio (W/D), histological changes and expression levels of SP-A mRNA and SP-A protein. 30 patients with brain injury and tracheotomy were selected and divided into two groups based on the airway humidification liquid instilled in the trachea tube, 0.45% NaCl and 0.9% NaCl+ambroxol. Blood was then extracted from the patients to measure the levels of SP-A, interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α). The difference between group C and other groups in lung W/D and expression levels of SP-A mRNA and SP-A protein was significant (P<0.05). In comparison, the histological changes showed that the lung tissue damage was smallest in group C compared to the three other groups. Aspect of patients, 0.45% NaCl group and 0.9% NaCl+ambroxol group were significantly different in the levels of SP-A, IL-6, IL-8 and TNF-α (P<0.01). In the present study, 0.9% NaCl+ambroxol promote the synthesis and secretion of pulmonary surfactant, and has anti-inflammatory and antioxidant effects, which inhibit the release of inflammatory factors and cytokines, making it an ideal airway humidification liquid. Copyright © 2015 Elsevier B.V. All rights reserved.

Monitoring brain temperature by time-resolved near-infrared spectroscopy: pilot study

NASA Astrophysics Data System (ADS)

Bakhsheshi, Mohammad Fazel; Diop, Mamadou; St. Lawrence, Keith; Lee, Ting-Yim

2014-05-01

Mild hypothermia (HT) is an effective neuroprotective strategy for a variety of acute brain injuries. However, the wide clinical adaptation of HT has been hampered by the lack of a reliable noninvasive method for measuring brain temperature, since core measurements have been shown to not always reflect brain temperature. The goal of this work was to develop a noninvasive optical technique for measuring brain temperature that exploits both the temperature dependency of water absorption and the high concentration of water in brain (80%-90%). Specifically, we demonstrate the potential of time-resolved near-infrared spectroscopy (TR-NIRS) to measure temperature in tissue-mimicking phantoms (in vitro) and deep brain tissue (in vivo) during heating and cooling, respectively. For deep brain tissue temperature monitoring, experiments were conducted on newborn piglets wherein hypothermia was induced by gradual whole body cooling. Brain temperature was concomitantly measured by TR-NIRS and a thermocouple probe implanted in the brain. Our proposed TR-NIRS method was able to measure the temperature of tissue-mimicking phantoms and brain tissues with a correlation of 0.82 and 0.66 to temperature measured with a thermometer, respectively. The mean difference between the TR-NIRS and thermometer measurements was 0.15°C±1.1°C for the in vitro experiments and 0.5°C±1.6°C for the in vivo measurements.

Gadolinium-based Contrast Media, Cerebrospinal Fluid and the Glymphatic System: Possible Mechanisms for the Deposition of Gadolinium in the Brain.

PubMed

Taoka, Toshiaki; Naganawa, Shinji

2018-04-10

After Kanda's first report in 2014 on gadolinium (Gd) deposition in brain tissue, a considerable number of studies have investigated the explanation for the observation. Gd deposition in brain tissue after repeated administration of gadolinium-based contrast medium (GBCM) has been histologically proven, and chelate stability has been shown to affect the deposition. However, the mechanism for this deposition has not been fully elucidated. Recently, a hypothesis was introduced that involves the 'glymphatic system', which is a coined word that combines 'gl' for glia cell and 'lymphatic' system. According to this hypothesis, the perivascular space functions as a conduit for cerebrospinal fluid to flow into the brain parenchyma. The perivascular space around the arteries allows cerebrospinal fluid to enter the interstitial space of the brain tissue through water channels controlled by aquaporin 4. The cerebrospinal fluid entering the interstitial space clears waste proteins from the tissue. It then flows into the perivascular space around the vein and is discharged outside the brain. In addition to the hypothesis regarding the glymphatic system, some reports have described that after GBCM administration, some of the GBCM distributes through systemic blood circulation and remains in other compartments including the cerebrospinal fluid. It is thought that the GBCM distributed into the cerebrospinal fluid cavity via the glymphatic system may remain in brain tissue for a longer duration compared to the GBCM in systemic circulation. Glymphatic system may of course act as a clearance system for GBCM from brain tissue. Based on these findings, the mechanism for Gd deposition in the brain will be discussed in this review. The authors speculate that the glymphatic system may be the major contributory factor to the deposition and clearance of gadolinium in brain tissue.

Gadolinium-based Contrast Media, Cerebrospinal Fluid and the Glymphatic System: Possible Mechanisms for the Deposition of Gadolinium in the Brain

PubMed Central

Taoka, Toshiaki; Naganawa, Shinji

2018-01-01

After Kanda’s first report in 2014 on gadolinium (Gd) deposition in brain tissue, a considerable number of studies have investigated the explanation for the observation. Gd deposition in brain tissue after repeated administration of gadolinium-based contrast medium (GBCM) has been histologically proven, and chelate stability has been shown to affect the deposition. However, the mechanism for this deposition has not been fully elucidated. Recently, a hypothesis was introduced that involves the ‘glymphatic system’, which is a coined word that combines ‘gl’ for glia cell and ‘lymphatic’ system. According to this hypothesis, the perivascular space functions as a conduit for cerebrospinal fluid to flow into the brain parenchyma. The perivascular space around the arteries allows cerebrospinal fluid to enter the interstitial space of the brain tissue through water channels controlled by aquaporin 4. The cerebrospinal fluid entering the interstitial space clears waste proteins from the tissue. It then flows into the perivascular space around the vein and is discharged outside the brain. In addition to the hypothesis regarding the glymphatic system, some reports have described that after GBCM administration, some of the GBCM distributes through systemic blood circulation and remains in other compartments including the cerebrospinal fluid. It is thought that the GBCM distributed into the cerebrospinal fluid cavity via the glymphatic system may remain in brain tissue for a longer duration compared to the GBCM in systemic circulation. Glymphatic system may of course act as a clearance system for GBCM from brain tissue. Based on these findings, the mechanism for Gd deposition in the brain will be discussed in this review. The authors speculate that the glymphatic system may be the major contributory factor to the deposition and clearance of gadolinium in brain tissue. PMID:29367513

Association between polychlorinated biphenyls and Parkinson's disease neuropathology.

PubMed

Hatcher-Martin, Jaime M; Gearing, Marla; Steenland, Kyle; Levey, Allan I; Miller, Gary W; Pennell, Kurt D

2012-10-01

Polychlorinated biphenyls (PCBs) are synthetic chemicals primarily used as coolants and insulators in electrical equipment. Although banned for several decades, PCBs continue to exist in the environment because of their long half-life, continued presence in items produced before the ban, and poor disposal practices. Epidemiological and experimental studies have identified exposure to PCBs as a potential risk factor for Parkinson's disease, perhaps more so in females. The objective of this work was to examine the association between PCB levels in post-mortem human brain tissue and the diagnosis of Parkinson's disease, as well as the degree of nigral depigmentation. We also sought to determine if this association was more significant when patients were stratified by sex. Post-mortem brain samples from control patients and those diagnosed with Parkinson's disease were obtained from the Emory University Brain Bank and from the Nun Study. Concentrations of eight prevalent PCB congeners were extracted from post-mortem brain tissue and analyzed using gas chromatography-mass spectrometry. PCB congeners 153 and 180 were significantly elevated in the brains of Parkinson's disease patients. When stratified by sex, the female Parkinson's disease group demonstrated significantly elevated concentrations of total PCBs and specifically congeners 138, 153, and 180 compared to controls, whereas PCB concentrations in males were not significantly different between control and Parkinson's disease groups. In a separate population of women (Nun Study) who had no clinical signs or symptoms of PD, elevated concentrations total PCB and congeners 138, 153 and 180 were also observed in post-mortem brain tissue exhibiting moderate nigral depigmentation compared to subjects with mild or no depigmentation. These quantitative data demonstrate an association between brain PCB levels and Parkinson's disease-related pathology. Furthermore, these data support epidemiological and laboratory studies reporting a link between PCB exposure and an increased risk for Parkinson's disease, including greater susceptibility of females. Copyright © 2012 Elsevier Inc. All rights reserved.

Association between polychlorinated biphenyls and Parkinson’s disease neuropathology

PubMed Central

Hatcher-Martin, Jaime M.; Gearing, Marla; Steenland, Kyle; Levey, Allan I.; Miller, Gary W.; Pennell, Kurt D.

2012-01-01

Polychlorinated biphenyls (PCBs) are synthetic chemicals primarily used as coolants and insulators in electrical equipment. Although banned for several decades, PCBs continue to exist in the environment because of their long half-life, continued presence in items produced before the ban, and poor disposal practices. Epidemiological and experimental studies have identified exposure to PCBs as a potential risk factor for Parkinson’s disease, perhaps more so in females. The objective of this work was to examine the association between PCB levels in post-mortem human brain tissue and the diagnosis of Parkinson’s disease, as well as the degree of nigral depigmentation. We also sought to determine if this association was more significant when patients were stratified by sex. Post-mortem brain samples from control patients and those diagnosed with Parkinson’s disease were obtained from the Emory University Brain Bank and from the Nun Study. Concentrations of eight prevalent PCB congeners were extracted from post-mortem brain tissue and analyzed using gas chromatography-mass spectrometry. PCB congeners 153 and 180 were significantly elevated in the brains of Parkinson’s disease patients. When stratified by sex, the female Parkinson’s disease group demonstrated significantly elevated concentrations of total PCBs and specifically congeners 138, 153, and 180 compared to controls, whereas PCB concentrations in males were not significantly different between control and Parkinson’s disease groups. In a separate population of women (Nun Study) who had no clinical signs or symptoms of PD, elevated concentrations total PCB and congeners 138, 153 and 180 were also observed in post-mortem brain tissue exhibiting moderate nigral depigmentation compared to subjects with mild or no depigmentation. These quantitative data demonstrate an association between brain PCB levels and Parkinson’s disease-related pathology. Furthermore, these data support epidemiological and laboratory studies reporting a link between PCB exposure and an increased risk for Parkinson’s disease, including greater susceptibility of females. PMID:22906799

Cerebral arterial oxygen saturation measurements using a fiber-optic pulse oximeter.

PubMed

Phillips, J P; Langford, R M; Chang, S H; Maney, K; Kyriacou, P A; Jones, D P

2010-10-01

A pilot investigation was undertaken to assess the performance of a novel fiber-optic cerebral pulse oximetry system. A fiber-optic probe designed to pass through the lumen of a cranial bolt of the type used to make intracranial pressure measurements was used to obtain optical reflectance signals directly from brain tissue. Short-duration measurements were made in six patients undergoing neurosurgery. These were followed by a longer duration measurement in a patient recovering from an intracerebral hematoma. Estimations of cerebral arterial oxygen saturation derived from a frequency domain-based algorithm are compared with simultaneous pulse oximetry (SpO2) and hemoximeter (SaO2) blood samples. The short-duration measurements showed that reliable photoplethysmographic signals could be obtained from the brain tissue. In the long-duration study, the mean (±SD) difference between cerebral oxygen saturation (ScaO2) and finger SpO2 (in saturation units) was -7.47(±3.4)%. The mean (±SD) difference between ScaO2 and blood SaO2 was -7.37(±2.8)%. This pilot study demonstrated that arterial oxygen saturation may be estimated from brain tissue via a fiber-optic pulse oximeter used in conjunction with a cranial bolt. Further studies are needed to confirm the clinical utility of the technique.

Mathematical modelling of blood-brain barrier failure and edema

NASA Astrophysics Data System (ADS)

Waters, Sarah; Lang, Georgina; Vella, Dominic; Goriely, Alain

2015-11-01

Injuries such as traumatic brain injury and stroke can result in increased blood-brain barrier permeability. This increase may lead to water accumulation in the brain tissue resulting in vasogenic edema. Although the initial injury may be localised, the resulting edema causes mechanical damage and compression of the vasculature beyond the original injury site. We employ a biphasic mixture model to investigate the consequences of blood-brain barrier permeability changes within a region of brain tissue and the onset of vasogenic edema. We find that such localised changes can indeed result in brain tissue swelling and that the type of damage that results (stress damage or strain damage) depends on the ability of the brain to clear edema fluid.

A Commonly Carried Genetic Variant in the Delta Opioid Receptor Gene, OPRD1, is Associated with Smaller Regional Brain Volumes: Replication in Elderly and Young Populations

PubMed Central

Roussotte, Florence F.; Jahanshad, Neda; Hibar, Derrek P.; Sowell, Elizabeth R.; Kohannim, Omid; Barysheva, Marina; Hansell, Narelle K.; McMahon, Katie L.; de Zubicaray, Greig I.; Montgomery, Grant W.; Martin, Nicholas G.; Wright, Margaret J.; Toga, Arthur W.; Jack, Clifford R.; Weiner, Michael W.; Thompson, Paul M.

2014-01-01

Delta opioid receptors are implicated in a variety of psychiatric and neurological disorders. These receptors play a key role in the reinforcing properties of drugs of abuse, and polymorphisms in OPRD1 (the gene encoding delta opioid receptors) are associated with drug addiction. Delta opioid receptors are also involved in protecting neurons against hypoxic and ischemic stress. Here, we first examined a large sample of 738 elderly participants with neuroimaging and genetic data from the Alzheimer’s Disease Neuroimaging Initiative. We hypothesized that common variants in OPRD1 would be associated with differences in brain structure, particularly in regions relevant to addictive and neurodegenerative disorders. One very common variant (rs678849) predicted differences in regional brain volumes. We replicated the association of this single-nucleotide polymorphism with regional tissue volumes in a large sample of young participants in the Queensland Twin Imaging study. Although the same allele was associated with reduced volumes in both cohorts, the brain regions affected differed between the two samples. In healthy elderly, exploratory analyses suggested that the genotype associated with reduced brain volumes in both cohorts may also predict cerebrospinal fluid levels of neurodegenerative biomarkers, but this requires confirmation. If opiate receptor genetic variants are related to individual differences in brain structure, genotyping of these variants may be helpful when designing clinical trials targeting delta opioid receptors to treat neurological disorders. PMID:23427138

Responses of the Human Brain to Mild Dehydration and Rehydration Explored In Vivo by 1H-MR Imaging and Spectroscopy.

PubMed

Biller, A; Reuter, M; Patenaude, B; Homola, G A; Breuer, F; Bendszus, M; Bartsch, A J

2015-12-01

As yet, there are no in vivo data on tissue water changes and associated morphometric changes involved in the osmo-adaptation of normal brains. Our aim was to evaluate osmoadaptive responses of the healthy human brain to osmotic challenges of de- and rehydration by serial measurements of brain volume, tissue fluid, and metabolites. Serial T1-weighted and (1)H-MR spectroscopy data were acquired in 15 healthy individuals at normohydration, on 12 hours of dehydration, and during 1 hour of oral rehydration. Osmotic challenges were monitored by serum measures, including osmolality and hematocrit. MR imaging data were analyzed by using FreeSurfer and LCModel. On dehydration, serum osmolality increased by 0.67% and brain tissue fluid decreased by 1.63%, on average. MR imaging morphometry demonstrated corresponding decreases of cortical thickness and volumes of the whole brain, cortex, white matter, and hypothalamus/thalamus. These changes reversed during rehydration. Continuous fluid ingestion of 1 L of water for 1 hour within the scanner lowered serum osmolality by 0.96% and increased brain tissue fluid by 0.43%, on average. Concomitantly, cortical thickness and volumes of the whole brain, cortex, white matter, and hypothalamus/thalamus increased. Changes in brain tissue fluid were related to volume changes of the whole brain, the white matter, and hypothalamus/thalamus. Only volume changes of the hypothalamus/thalamus significantly correlated with serum osmolality. This is the first study simultaneously evaluating changes in brain tissue fluid, metabolites, volume, and cortical thickness. Our results reflect cellular volume regulatory mechanisms at a macroscopic level and emphasize that it is essential to control for hydration levels in studies on brain morphometry and metabolism in order to avoid confounding the findings. © 2015 by American Journal of Neuroradiology.

Spectral staining of tumor tissue by fiber optic FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Salzer, Reiner; Steiner, Gerald; Kano, Angelique; Richter, Tom; Bergmann, Ralf; Rodig, Heike; Johannsen, Bernd; Kobelke, Jens

2003-07-01

Infrared (IR) optical fiber have aroused great interest in recent years because of their potential in in-vivo spectroscopy. This potential includes the ability to be flexible, small and to guide IR light in a very large range of wavelengths. Two types - silver halide and chalcogenide - infrared transmitting fibers are investigated in the detection of a malignant tumor. As a test sample for all types of fibers we used a thin section of an entire rat brain with glioblastoma. The fibers were connected with a common infrared microscope. Maps across the whole tissue section with more than 200 spectra were recorded by moving the sample with an XY stage. Data evaluation was performed using fuzzy c-means cluster analysis (FCM). The silver halide fibers provided excellent results. The tumor was clearly discernible from healthy tissue. Chalcogenide fibers are not suitable to distinguish tumor from normal tissue because the fiber has a very low transmittance in the important fingerprint region.

Flexible, foldable, actively multiplexed, high-density electrode array for mapping brain activity in vivo.

PubMed

Viventi, Jonathan; Kim, Dae-Hyeong; Vigeland, Leif; Frechette, Eric S; Blanco, Justin A; Kim, Yun-Soung; Avrin, Andrew E; Tiruvadi, Vineet R; Hwang, Suk-Won; Vanleer, Ann C; Wulsin, Drausin F; Davis, Kathryn; Gelber, Casey E; Palmer, Larry; Van der Spiegel, Jan; Wu, Jian; Xiao, Jianliang; Huang, Yonggang; Contreras, Diego; Rogers, John A; Litt, Brian

2011-11-13

Arrays of electrodes for recording and stimulating the brain are used throughout clinical medicine and basic neuroscience research, yet are unable to sample large areas of the brain while maintaining high spatial resolution because of the need to individually wire each passive sensor at the electrode-tissue interface. To overcome this constraint, we developed new devices that integrate ultrathin and flexible silicon nanomembrane transistors into the electrode array, enabling new dense arrays of thousands of amplified and multiplexed sensors that are connected using fewer wires. We used this system to record spatial properties of cat brain activity in vivo, including sleep spindles, single-trial visual evoked responses and electrographic seizures. We found that seizures may manifest as recurrent spiral waves that propagate in the neocortex. The developments reported here herald a new generation of diagnostic and therapeutic brain-machine interface devices.

Exploring the origins of echo-time-dependent quantitative susceptibility mapping (QSM) measurements in healthy tissue and cerebral microbleeds.

PubMed

Cronin, Matthew J; Wang, Nian; Decker, Kyle S; Wei, Hongjiang; Zhu, Wen-Zhen; Liu, Chunlei

2017-04-01

Quantitative susceptibility mapping (QSM) is increasingly used to measure variation in tissue composition both in the brain and in other areas of the body in a range of disease pathologies. Although QSM measurements were originally believed to be independent of the echo time (TE) used in the gradient-recalled echo (GRE) acquisition from which they are derived; recent literature (Sood et al., 2016) has shown that these measurements can be highly TE-dependent in a number of brain regions. In this work we systematically investigate possible causes of this effect through analysis of apparent frequency and QSM measurements derived from data acquired at multiple TEs in vivo in healthy brain regions and in cerebral microbleeds (CMBs); QSM data acquired in a gadolinium-doped phantom; and in QSM data derived from idealized simulated phase data. Apparent frequency measurements in the optic radiations (OR) and central corpus callosum (CC) were compared to those predicted by a 3-pool white matter model, however the model failed to fully explain contrasting frequency profiles measured in the OR and CC. Our results show that TE-dependent QSM measurements can be caused by a failure of phase unwrapping algorithms in and around strong susceptibility sources such as CMBs; however, in healthy brain regions this behavior appears to result from intrinsic non-linear phase evolution in the MR signal. From these results we conclude that care must be taken when deriving frequency and QSM measurements in strong susceptibility sources due to the inherent limitations in phase unwrapping; and that while signal compartmentalization due to tissue microstructure and content is a plausible cause of TE-dependent frequency and QSM measurements in healthy brain regions, better sampling of the MR signal and more complex models of tissue are needed to fully exploit this relationship. Copyright © 2017 Elsevier Inc. All rights reserved.

The cytokine temporal profile in rat cortex after controlled cortical impact

PubMed Central

Dalgard, Clifton L.; Cole, Jeffrey T.; Kean, William S.; Lucky, Jessica J.; Sukumar, Gauthaman; McMullen, David C.; Pollard, Harvey B.; Watson, William D.

2012-01-01

Cerebral inflammatory responses may initiate secondary cascades following traumatic brain injury (TBI). Changes in the expression of both cytokines and chemokines may activate, regulate, and recruit innate and adaptive immune cells associated with secondary degeneration, as well as alter a host of other cellular processes. In this study, we quantified the temporal expression of a large set of inflammatory mediators in rat cortical tissue after brain injury. Following a controlled cortical impact (CCI) on young adult male rats, cortical and hippocampal tissue of the injured hemisphere and matching contralateral material was harvested at early (4, 12, and 24 hours) and extended (3 and 7 days) time points post-procedure. Naïve rats that received only anesthesia were used as controls. Processed brain homogenates were assayed for chemokine and cytokine levels utilizing an electrochemiluminescence-based multiplex ELISA platform. The temporal profile of cortical tissue samples revealed a multi-phasic injury response following brain injury. CXCL1, IFN-γ, TNF-α levels significantly peaked at four hours post-injury compared to levels found in naïve or contralateral tissue. CXCL1, IFN-γ, and TNF-α levels were then observed to decrease at least 3-fold by 12 hours post-injury. IL-1β, IL-4, and IL-13 levels were also significantly elevated at four hours post-injury although their expression did not decrease more than 3-fold for up to 24 hours post-injury. Additionally, IL-1β and IL-4 levels displayed a biphasic temporal profile in response to injury, which may suggest their involvement in adaptive immune responses. Interestingly, peak levels of CCL2 and CCL20 were not observed until after four hours post-injury. CCL2 levels in injured cortical tissue were significantly higher than peak levels of any other inflammatory mediator measured, thus suggesting a possible use as a biomarker. Fully elucidating chemokine and cytokine signaling properties after brain injury may provide increased insight into a number of secondary cascade events that are initiated or regulated by inflammatory responses. PMID:22291617

The cytokine temporal profile in rat cortex after controlled cortical impact.

PubMed

Dalgard, Clifton L; Cole, Jeffrey T; Kean, William S; Lucky, Jessica J; Sukumar, Gauthaman; McMullen, David C; Pollard, Harvey B; Watson, William D

2012-01-01

Cerebral inflammatory responses may initiate secondary cascades following traumatic brain injury (TBI). Changes in the expression of both cytokines and chemokines may activate, regulate, and recruit innate and adaptive immune cells associated with secondary degeneration, as well as alter a host of other cellular processes. In this study, we quantified the temporal expression of a large set of inflammatory mediators in rat cortical tissue after brain injury. Following a controlled cortical impact (CCI) on young adult male rats, cortical and hippocampal tissue of the injured hemisphere and matching contralateral material was harvested at early (4, 12, and 24 hours) and extended (3 and 7 days) time points post-procedure. Naïve rats that received only anesthesia were used as controls. Processed brain homogenates were assayed for chemokine and cytokine levels utilizing an electrochemiluminescence-based multiplex ELISA platform. The temporal profile of cortical tissue samples revealed a multi-phasic injury response following brain injury. CXCL1, IFN-γ, TNF-α levels significantly peaked at four hours post-injury compared to levels found in naïve or contralateral tissue. CXCL1, IFN-γ, and TNF-α levels were then observed to decrease at least 3-fold by 12 hours post-injury. IL-1β, IL-4, and IL-13 levels were also significantly elevated at four hours post-injury although their expression did not decrease more than 3-fold for up to 24 hours post-injury. Additionally, IL-1β and IL-4 levels displayed a biphasic temporal profile in response to injury, which may suggest their involvement in adaptive immune responses. Interestingly, peak levels of CCL2 and CCL20 were not observed until after four hours post-injury. CCL2 levels in injured cortical tissue were significantly higher than peak levels of any other inflammatory mediator measured, thus suggesting a possible use as a biomarker. Fully elucidating chemokine and cytokine signaling properties after brain injury may provide increased insight into a number of secondary cascade events that are initiated or regulated by inflammatory responses.

Differential metabolism of 4-hydroxynonenal in liver, lung and brain of mice and rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Ruijin; Dragomir, Ana-Cristina; Mishin, Vladimir

2014-08-15

The lipid peroxidation end-product 4-hydroxynonenal (4-HNE) is generated in tissues during oxidative stress. As a reactive aldehyde, it forms Michael adducts with nucleophiles, a process that disrupts cellular functioning. Liver, lung and brain are highly sensitive to xenobiotic-induced oxidative stress and readily generate 4-HNE. In the present studies, we compared 4-HNE metabolism in these tissues, a process that protects against tissue injury. 4-HNE was degraded slowly in total homogenates and S9 fractions of mouse liver, lung and brain. In liver, but not lung or brain, NAD(P)+ and NAD(P)H markedly stimulated 4-HNE metabolism. Similar results were observed in rat S9 fractionsmore » from these tissues. In liver, lung and brain S9 fractions, 4-HNE formed protein adducts. When NADH was used to stimulate 4-HNE metabolism, the formation of protein adducts was suppressed in liver, but not lung or brain. In both mouse and rat tissues, 4-HNE was also metabolized by glutathione S-transferases. The greatest activity was noted in livers of mice and in lungs of rats; relatively low glutathione S-transferase activity was detected in brain. In mouse hepatocytes, 4-HNE was rapidly taken up and metabolized. Simultaneously, 4-HNE-protein adducts were formed, suggesting that 4-HNE metabolism in intact cells does not prevent protein modifications. These data demonstrate that, in contrast to liver, lung and brain have a limited capacity to metabolize 4-HNE. The persistence of 4-HNE in these tissues may increase the likelihood of tissue injury during oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a highly reactive aldehyde. • Rodent liver, but not lung or brain, is efficient in degrading 4-hydroxynonenal. • 4-hydroxynonenal persists in tissues with low metabolism, causing tissue damage.« less

Allele-Skewed DNA Modification in the Brain: Relevance to a Schizophrenia GWAS

PubMed Central

Gagliano, Sarah A.; Ptak, Carolyn; Mak, Denise Y.F.; Shamsi, Mehrdad; Oh, Gabriel; Knight, Joanne; Boutros, Paul C.; Petronis, Arturas

2016-01-01

Numerous recent studies have suggested that phenotypic effects of DNA sequence variants can be mediated or modulated by their epigenetic marks, such as allele-skewed DNA modification (ASM). Using Affymetrix SNP microarrays, we performed a comprehensive search of ASM effects in human post-mortem brain and sperm samples (total n = 256) from individuals with major psychosis and control individuals. Depending on the phenotypic category of the brain samples, 1.4%–7.5% of interrogated SNPs exhibited ASM effects. Next, we investigated ASM in the context of genetic studies of schizophrenia and detected that brain ASM SNPs were significantly overrepresented among sub-threshold SNPs from a schizophrenia genome-wide association study (GWAS). Brain ASM SNPs showed a much stronger enrichment in a schizophrenia GWAS than in 17 large GWASs of non-psychiatric diseases and traits, arguing that ASM effects are at least partially tissue specific. Studies of germline and control brain ASM SNPs supported a causal association between ASM and schizophrenia. Finally, significantly higher proportions of ASM SNPs than of non-ASM SNPs were detected at loci exhibiting epigenetic signatures of enhancers and promoters, and they were overrepresented within transcription factor binding regions and DNase I hypersensitive sites. All of these findings collectively indicate that ASM SNPs should be prioritized in follow-up GWASs. PMID:27087318

Dyspepsia treatment with Al compounds widely used in clinical practice — an animal model approach

NASA Astrophysics Data System (ADS)

Pinheiro, T.; Canena, J.; Reis, J.; Santos, A. M.; Pinto, A. S.; Quina, M. G.; Reis, M. A.; Alves, L. C.

1996-04-01

The potential toxic effects of Al to organs and tissues used in drugs commonly applied in dyspepsia as therapeutic, have been studied. Brain, liver, kidney and serum samples obtained from Wistar rats treated with two commercial Al complexes were studied and compared with equivalent samples collected from healthy animals receiving a placebo. The major alterations found, connected with the persistent intake of medicaments based on Al compounds, are relative to the accumulation of Al in liver and kidney. Also, the Al levels increase in brain and serum of rats supplemented with one of the Al complexes used. In the liver and kidney samples analyzed alterations in the Cu and Zn content levels were observed. Furthermore, a tendency to the decrease of Fe content in kidney and an increase of the Mn levels in brain is observed. The elemental alterations found are probably related to the intake of the drugs tested and are dependent on the type of the Al complex administered. The results obtained suggest that the long term use of these medicaments in the clinical practice should be thought over.

Persistence of highly pathogenic avian influenza virus (H7N1) in infected chickens: feather as a suitable sample for diagnosis.

PubMed

Busquets, Núria; Abad, F Xavier; Alba, Anna; Dolz, Roser; Allepuz, Alberto; Rivas, Raquel; Ramis, Antonio; Darji, Ayub; Majó, Natàlia

2010-09-01

Selection of an ideal sample is a vital element in early detection of influenza infection. Rapid identification of infectious individuals or animals is crucial not only for avian influenza virus (AIV) surveillance programmes, but also for treatment and containment strategies. This study used a combination of quantitative real-time RT-PCR with an internal positive control and a cell-titration system to examine the presence of virus in different samples during active experimental AIV infection and its persistence in the infected carcasses. Oropharyngeal/cloacal swabs as well as feather pulp and blood samples were collected from 15-day-old chicks infected with H7N1 highly pathogenic AIV (HPAIV) and the kinetics of virus shedding during active infection were evaluated. Additionally, several samples (muscle, skin, brain, feather pulp and oropharyngeal and cloacal swabs) were examined to assess the persistence of virus in the HPAIV-infected carcasses. Based on the results, feather pulp was found to be the best sample to detect and isolate HPAIV from infected chicks from 24 h after inoculation onwards. Kinetic studies on the persistence of virus in infected carcasses revealed that tissues such as muscle could potentially transmit infectious virus for 3 days post-mortem (p.m.), whilst other tissues such as skin, feather pulp and brain retained their infectivity for as long as 5-6 days p.m. at environmental temperature (22-23 degrees C). These results strongly favour feather as a useful sample for HPAIV diagnosis in infected chickens as well as in carcasses.

Cadmium contamination of tissues and organs of delphinids species (Stenella attenuata)--influence of biological and ecological factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andre, J.M.; Amiard, J.C.; Amiard-Triquet, C.

1990-12-01

Based on a sample of 27 dolphins (Stenella attenuata) captured in the Eastern tropical zone of the Pacific Ocean, this study was carried out to analyze the cadmium accumulation levels and distribution in 12 organs or tissue samples. The average cadmium concentrations were between 0.2 mg Cd.kg-1 in the brain and muscle and 48 mg Cd.kg-1 in the kidneys. For most of organs and tissues the average values were between 1 and 5 mg Cd.kg-1. Kidneys, liver, muscle, and intestine contained almost 85% of the total cadmium burden of all tissues considered in this study. Most of the biological andmore » ecological factors taken into account (age, sex, total weight, and length of the dolphins, weight of the organs, place and date of capture) interacted with the cadmium concentrations and burdens in the collected organs or tissues. Three factors appear to be of prime importance: age, body weight, and geographical location of the area of capture.« less

Tissue-specific uptake and bioconcentration of the oral contraceptive norethindrone in two freshwater fishes.

PubMed

Nallani, Gopinath C; Paulos, Peter M; Venables, Barney J; Edziyie, Regina E; Constantine, Lisa A; Huggett, Duane B

2012-02-01

The environmental presence of the oral contraceptive norethindrone (NET) has been reported and shown to have reproductive effects in fish at environmentally realistic exposure levels. The current study examined bioconcentration potential of NET in fathead minnow (Pimephales promelas) and channel catfish (Ictalurus punctatus). Fathead minnows were exposed to 50 μg/l NET for 28 days and allowed to depurate in clean water for 14 days. In a minimized 14-day test design, catfish were exposed to 100 μg/l NET for 7 days followed by 7-day depuration. In the fathead test, tissues (muscle, liver, and kidneys) were sampled during the uptake (days 1, 3, 7, 14, and 28) and depuration (days 35 and 42) phases. In the catfish test, muscle, liver, gill, brain, and plasma were collected during the uptake (days 1, 3, and 7) and depuration (day 14) stages. NET tissue levels were determined by gas chromatography-mass spectrometry (GC-MS). Accumulation of NET in tissues was greatest in liver followed by plasma, gill, brain, and muscle. Tissue-specific bioconcentration factors (BCFs) ranged from 2.6 to 40.8. Although NET has been reported to elicit reproductive effects in fish, the present study indicated a low potential to bioconcentrate in aquatic biota.

Cell Membrane Tracking in Living Brain Tissue Using Differential Interference Contrast Microscopy.

PubMed

Lee, John; Kolb, Ilya; Forest, Craig R; Rozell, Christopher J

2018-04-01

Differential interference contrast (DIC) microscopy is widely used for observing unstained biological samples that are otherwise optically transparent. Combining this optical technique with machine vision could enable the automation of many life science experiments; however, identifying relevant features under DIC is challenging. In particular, precise tracking of cell boundaries in a thick ( ) slice of tissue has not previously been accomplished. We present a novel deconvolution algorithm that achieves the state-of-the-art performance at identifying and tracking these membrane locations. Our proposed algorithm is formulated as a regularized least squares optimization that incorporates a filtering mechanism to handle organic tissue interference and a robust edge-sparsity regularizer that integrates dynamic edge tracking capabilities. As a secondary contribution, this paper also describes new community infrastructure in the form of a MATLAB toolbox for accurately simulating DIC microscopy images of in vitro brain slices. Building on existing DIC optics modeling, our simulation framework additionally contributes an accurate representation of interference from organic tissue, neuronal cell-shapes, and tissue motion due to the action of the pipette. This simulator allows us to better understand the image statistics (to improve algorithms), as well as quantitatively test cell segmentation and tracking algorithms in scenarios, where ground truth data is fully known.

Effects of the Variation in Brain Tissue Mechanical Properties on the Intracranial Response of a 6-Year-Old Child

PubMed Central

Cui, Shihai; Li, Haiyan; Li, Xiangnan; Ruan, Jesse

2015-01-01

Brain tissue mechanical properties are of importance to investigate child head injury using finite element (FE) method. However, these properties used in child head FE model normally vary in a large range in published literatures because of the insufficient child cadaver experiments. In this work, a head FE model with detailed anatomical structures is developed from the computed tomography (CT) data of a 6-year-old healthy child head. The effects of brain tissue mechanical properties on traumatic brain response are also analyzed by reconstruction of a head impact on engine hood according to Euro-NCAP testing regulation using FE method. The result showed that the variations of brain tissue mechanical parameters in linear viscoelastic constitutive model had different influences on the intracranial response. Furthermore, the opposite trend was obtained in the predicted shear stress and shear strain of brain tissues caused by the variations of mentioned parameters. PMID:26495031

Brain cancer probed by native fluorescence and stokes shift spectroscopy

NASA Astrophysics Data System (ADS)

Zhou, Yan; Liu, Cheng-hui; He, Yong; Pu, Yang; Li, Qingbo; Wang, Wei; Alfano, Robert R.

2012-12-01

Optical biopsy spectroscopy was applied to diagnosis human brain cancer in vitro. The spectra of native fluorescence, Stokes shift and excitation spectra were obtained from malignant meningioma, benign, normal meningeal tissues and acoustic neuroma benign tissues. The wide excitation wavelength ranges were used to establish the criterion for distinguishing brain diseases. The alteration of fluorescence spectra between normal and abnormal brain tissues were identified by the characteristic fluorophores under the excitation with UV to visible wavelength range. It was found that the ratios of the peak intensities and peak position in both spectra of fluorescence and Stokes shift may be used to diagnose human brain meninges diseases. The preliminary analysis of fluorescence spectral data from cancer and normal meningeal tissues by basic biochemical component analysis model (BBCA) and Bayes classification model based on statistical methods revealed the changes of components, and classified the difference between cancer and normal human brain meningeal tissues in a predictions accuracy rate is 0.93 in comparison with histopathology and immunohistochemistry reports (gold standard).

4D (x-y-z-t) imaging of thick biological samples by means of Two-Photon inverted Selective Plane Illumination Microscopy (2PE-iSPIM)

PubMed Central

Lavagnino, Zeno; Sancataldo, Giuseppe; d’Amora, Marta; Follert, Philipp; De Pietri Tonelli, Davide; Diaspro, Alberto; Cella Zanacchi, Francesca

2016-01-01

In the last decade light sheet fluorescence microscopy techniques, such as selective plane illumination microscopy (SPIM), has become a well established method for developmental biology. However, conventional SPIM architectures hardly permit imaging of certain tissues since the common sample mounting procedure, based on gel embedding, could interfere with the sample morphology. In this work we propose an inverted selective plane microscopy system (iSPIM), based on non-linear excitation, suitable for 3D tissue imaging. First, the iSPIM architecture provides flexibility on the sample mounting, getting rid of the gel-based mounting typical of conventional SPIM, permitting 3D imaging of hippocampal slices from mouse brain. Moreover, all the advantages brought by two photon excitation (2PE) in terms of reduction of scattering effects and contrast improvement are exploited, demonstrating an improved image quality and contrast compared to single photon excitation. The system proposed represents an optimal platform for tissue imaging and it smooths the way to the applicability of light sheet microscopy to a wider range of samples including those that have to be mounted on non-transparent surfaces. PMID:27033347

Characterizing viscoelastic mechanical properties of highly compliant polymers and biological tissues using impact indentation.

PubMed

Mijailovic, Aleksandar S; Qing, Bo; Fortunato, Daniel; Van Vliet, Krystyn J

2018-04-15

Precise and accurate measurement of viscoelastic mechanical properties becomes increasingly challenging as sample stiffness decreases to elastic moduli <1 kPa, largely due to difficulties detecting initial contact with the compliant sample surface. This limitation is particularly relevant to characterization of biological soft tissues and compliant gels. Here, we employ impact indentation which, in contrast to shear rheology and conventional indentation, does not require contact detection a priori, and present a novel method to extract viscoelastic moduli and relaxation time constants directly from the impact response. We first validate our approach by using both impact indentation and shear rheology to characterize polydimethylsiloxane (PDMS) elastomers of stiffness ranging from 100 s of Pa to nearly 10 kPa. Assuming a linear viscoelastic constitutive model for the material, we find that the moduli and relaxation times obtained from fitting the impact response agree well with those obtained from fitting the rheological response. Next, we demonstrate our validated method on hydrated, biological soft tissues obtained from porcine brain, murine liver, and murine heart, and report the equilibrium shear moduli, instantaneous shear moduli, and relaxation time constants for each tissue. Together, our findings provide a new and straightforward approach capable of probing local mechanical properties of highly compliant viscoelastic materials with millimeter scale spatial resolution, mitigating complications involving contact detection or sample geometric constraints. Characterization and optimization of mechanical properties can be essential for the proper function of biomaterials in diverse applications. However, precise and accurate measurement of viscoelastic mechanical properties becomes increasingly difficult with increased compliance (particularly for elastic moduli <1 kPa), largely due to challenges detecting initial contact with the compliant sample surface and measuring response at short timescale or high frequency. By contrast, impact indentation has highly accurate contact detection and can be used to measure short timescale (glassy) response. Here, we demonstrate an experimental and analytical method that confers significant advantages over existing approaches to extract spatially resolved viscoelastic moduli and characteristic time constants of biological tissues (e.g., brain and heart) and engineered biomaterials. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Fluorescence lifetime spectroscopy for guided therapy of brain tumors.

PubMed

Butte, Pramod V; Mamelak, Adam N; Nuno, Miriam; Bannykh, Serguei I; Black, Keith L; Marcu, Laura

2011-01-01

This study evaluates the potential of time-resolved laser induced fluorescence spectroscopy (TR-LIFS) as intra-operative tool for the delineation of brain tumor from normal brain. Forty two patients undergoing glioma (WHO grade I-IV) surgery were enrolled in this study. A TR-LIFS prototype apparatus (gated detection, fast digitizer) was used to induce in-vivo fluorescence using a pulsed N2 laser (337 nm excitation, 0.7 ns pulse width) and to record the time-resolved spectrum (360-550 nm range, 10 nm interval). The sites of TR-LIFS measurement were validated by conventional histopathology (H&E staining). Parameters derived from the TR-LIFS data including intensity values and time-resolved intensity decay features (average fluorescence lifetime and Laguerre coefficients values) were used for tissue characterization and classification. 71 areas of tumor and normal brain were analyzed. Several parameters allowed for the differentiation of distinct tissue types. For example, normal cortex (N=35) and normal white matter (N=12) exhibit a longer-lasting fluorescence emission at 390 nm (τ390=2.12±0.10 ns) when compared with 460 nm (τ460=1.16±0.08 ns). High grade glioma (grades III and IV) samples (N=17) demonstrate emission peaks at 460 nm, with large variation at 390 nm while low grade glioma (I and II) samples (N=7) demonstrated a peak fluorescence emission at 460 nm. A linear discriminant algorithm allowed for the classification of low-grade gliomas with 100% sensitivity and 98% specificity. High-grade glioma demonstrated a high degree of heterogeneity thus reducing the discrimination accuracy of these tumors to 47% sensitivity and 94% specificity. Current findings demonstrate that TR-LIFS holds the potential to diagnose brain tumors intra-operatively and to provide a valuable tool for aiding the neurosurgeon-neuropathologist team in to rapidly distinguish between tumor and normal brain during surgery. Copyright © 2010 Elsevier Inc. All rights reserved.

A Dense Poly(ethylene glycol) Coating Improves Penetration of Large Polymeric Nanoparticles within Brain Tissue

PubMed Central

Nance, Elizabeth A.; Woodworth, Graeme F.; Sailor, Kurt A.; Shih, Ting-Yu; Xu, Qingguo; Swaminathan, Ganesh; Xiang, Dennis; Eberhart, Charles; Hanes, Justin

2013-01-01

Prevailing opinion suggests that only substances up to 64 nm in diameter can move at appreciable rates through the brain extracellular space (ECS). This size range is large enough to allow diffusion of signaling molecules, nutrients, and metabolic waste products, but too small to allow efficient penetration of most particulate drug delivery systems and viruses carrying therapeutic genes, thereby limiting effectiveness of many potential therapies. We analyzed the movements of nanoparticles of various diameters and surface coatings within fresh human and rat brain tissue ex vivo and mouse brain in vivo. Nanoparticles as large as 114-nm in diameter diffused within the human and rat brain, but only if they were densely coated with poly(ethylene glycol) (PEG). Using these minimally adhesive PEG-coated particles, we estimated that human brain tissue ECS has some pores larger than 200 nm, and that more than one-quarter of all pores are ≥100 nm. These findings were confirmed in vivo in mice, where 40- and 100-nm, but not 200-nm, nanoparticles, spread rapidly within brain tissue, only if densely coated with PEG. Similar results were observed in rat brain tissue with paclitaxel-loaded biodegradable nanoparticles of similar size (85 nm) and surface properties. The ability to achieve brain penetration with larger nanoparticles is expected to allow more uniform, longer-lasting, and effective delivery of drugs within the brain, and may find use in the treatment of brain tumors, stroke, neuroinflammation, and other brain diseases where the blood-brain barrier is compromised or where local delivery strategies are feasible. PMID:22932224

Evaluation of endogenous species involved in brain tumors using multiphoton photoacoustic spectroscopy

NASA Astrophysics Data System (ADS)

Dahal, Sudhir; Cullum, Brian M.

2013-05-01

It has been shown that using non-resonant multiphoton photoacoustic spectroscopy (NMPPAS), excised brain tumor (grade III astrocytoma) and healthy tissue can be differentiated from each other, even in neighboring biopsy samples[1, 2]. Because of this, this powerful technique offers a great deal of potential for use as a surgical guidance technique for tumor margining with up to cellular level spatial resolution[3]. NMPPAS spectra are obtained by monitoring the non-radiative relaxation pathways via ultrasonic detection, following two-photon excitation with light in the optical diagnostic window (740nm-1100nm). Based upon significant differences in the ratiometric absorption of the tissues following 970nm and 1100nm excitation, a clear classification of the tissue can be made. These differences are the result of variations in composition and oxidation state of certain endogenous biochemical species between healthy and malignant tissues. In this work, NADH, NAD+ and ATP were measured using NMPPAS in model gelatin tissue phantoms to begin to understand which species might be responsible for the observed spectral differences in the tissue. Each species was placed in specific pH environments to provide control over the ratio of oxidized to reduced forms of the species. Ratiometric analyses were then conducted to account for variability caused due to instrumental parameters. This paper will discuss the potential roles of each of the species for tumor determination and their contribution to the spectral signature.

Effect of echo artifacts on characterization of pulsatile tissues in neonatal cranial ultrasonic movies

NASA Astrophysics Data System (ADS)

Fukuzawa, Masayuki; Takahashi, Kazuki; Tabata, Yuki; Kitsunezuka, Yoshiki

2016-04-01

Effect of echo artifacts on characterization of pulsatile tissues has been examined in neonatal cranial ultrasonic movies by characterizing pulsatile intensities with different regions of interest (ROIs). The pulsatile tissue, which is a key point in pediatric diagnosis of brain tissue, was detected from a heartbeat-frequency component in Fourier transform of a time-variation of 64 samples of echo intensity at each pixel in a movie fragment. The averages of pulsatile intensity and power were evaluated in two ROIs: common fan-shape and individual cranial-shape. The area of pulsatile region was also evaluated as the number of pixels where the pulsatile intensity exceeds a proper threshold. The extracranial pulsatile region was found mainly in the sections where mirror image was dominant echo artifact. There was significant difference of pulsatile area between two ROIs especially in the specific sections where mirror image was included, suggesting the suitability of cranial-shape ROI for statistical study on pulsatile tissues in brain. The normalized average of pulsatile power in the cranial-shape ROI exhibited most similar tendency to the normalized pulsatile area which was treated as a conventional measure in spite of its requirement of thresholding. It suggests the potential of pulsatile power as an alternative measure for pulsatile area in further statistical study of pulsatile tissues because it was neither affected by echo artifacts nor threshold.

A Validated UPLC-MS-MS Assay for the Rapid Determination of Lorcaserin in Plasma and Brain Tissue Samples.

PubMed

Bajrai, Amal A; Ezzeldin, Essam; Al-Rashood, Khalid A; Raish, Mohammad; Iqbal, Muzaffar

2016-03-01

Lorcaserin is a novel, potent and highly efficacious 5-HT2C receptor agonist, recently approved by US Food and Drug Administration for the treatment of obesity. It has some abuse potential also and is listed as a Schedule IV drug in the Controlled Substances Act. Herein, a sensitive, selective and reliable UPLC-MS-MS assay was developed and validated for the quantitative analysis of lorcaserin in rat plasma and brain tissue using carbamazepine as an internal standard (IS). After the extraction of samples by protein precipitation, both lorcaserin and IS were separated on an Acquity BEH™ C18 (50 × 2.1 mm, 1.7 µm) column using a mobile phase consisting of acetonitrile-10 mM ammonium acetate-formic acid (85:15:0.1, v/v/v) at a flow rate of 0.25 mL/min. Detection and quantification were performed on a positive electrospray ionization interface in the multiple-reaction monitoring (MRM) mode. The MS-MS ion transitions were monitored at m/z 195.99 > 143.91 for lorcaserin and m/z 237.00 > 178.97 for IS, respectively. The calibration curves were linear over a concentration range of 1.08-500 ng/mL in plasma and 3.07-500 ng/mL in brain tissue homogenates, respectively. All the validation parameters results were within the acceptable range described in guidelines for bioanalytical method validation. The assay was successfully applied in a pharmacokinetic study of lorcaserin after oral administration in rats. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Occurrence of specific environmental risk factors in brain tissues of sudden infant death and sudden intrauterine unexpected death victims assessed with gas chromatography-tandem mass spectrometry.

PubMed

Termopoli, Veronica; Famiglini, Giorgio; Palma, Pierangela; Magrini, Laura; Cappiello, Achille

2015-03-01

Sudden infant death syndrome (SIDS) and sudden intrauterine unexpected death syndrome (SIUDS) are an unresolved teaser in the social-medical and health setting of modern medicine and are the result of multifactorial interactions. Recently, prenatal exposure to environmental contaminants has been associated with negative pregnancy outcomes, and verification of their presence in fetal and newborn tissues is of crucial importance. A gas chromatography-tandem mass spectrometry (MS/MS) method, using a triple quadrupole analyzer, is proposed to assess the presence of 20 organochlorine pesticides, two organophosphate pesticides, one carbamate (boscalid), and a phenol (bisphenol A) in human brain tissues. Samples were collected during autopsies of infants and fetuses that died suddenly without any evident cause. The method involves a liquid-solid extraction using n-hexane as the extraction solvent. The extracts were purified with Florisil cartridges prior to the final determination. Recovery experiments using lamb brain spiked at three different concentrations in the range of 1-50 ng g(-1) were performed, with recoveries ranging from 79 to 106%. Intraday and interday repeatability were evaluated, and relative standard deviations lower than 10% and 18%, respectively, were obtained. The selectivity and sensitivity achieved in multiple reaction monitoring mode allowed us to achieve quantification and confirmation in a real matrix at levels as low as 0.2-0.6 ng g(-1). Two MS/MS transitions were acquired for each analyte, using the Q/q ratio as the confirmatory parameter. This method was applied to the analysis of 14 cerebral cortex samples (ten SIUDS and four SIDS cases), and confirmed the presence of several selected compounds.

Uncertainty quantification for constitutive model calibration of brain tissue.

PubMed

Brewick, Patrick T; Teferra, Kirubel

2018-05-31

The results of a study comparing model calibration techniques for Ogden's constitutive model that describes the hyperelastic behavior of brain tissue are presented. One and two-term Ogden models are fit to two different sets of stress-strain experimental data for brain tissue using both least squares optimization and Bayesian estimation. For the Bayesian estimation, the joint posterior distribution of the constitutive parameters is calculated by employing Hamiltonian Monte Carlo (HMC) sampling, a type of Markov Chain Monte Carlo method. The HMC method is enriched in this work to intrinsically enforce the Drucker stability criterion by formulating a nonlinear parameter constraint function, which ensures the constitutive model produces physically meaningful results. Through application of the nested sampling technique, 95% confidence bounds on the constitutive model parameters are identified, and these bounds are then propagated through the constitutive model to produce the resultant bounds on the stress-strain response. The behavior of the model calibration procedures and the effect of the characteristics of the experimental data are extensively evaluated. It is demonstrated that increasing model complexity (i.e., adding an additional term in the Ogden model) improves the accuracy of the best-fit set of parameters while also increasing the uncertainty via the widening of the confidence bounds of the calibrated parameters. Despite some similarity between the two data sets, the resulting distributions are noticeably different, highlighting the sensitivity of the calibration procedures to the characteristics of the data. For example, the amount of uncertainty reported on the experimental data plays an essential role in how data points are weighted during the calibration, and this significantly affects how the parameters are calibrated when combining experimental data sets from disparate sources. Published by Elsevier Ltd.

Quantifying the motion of magnetic particles in excised tissue: Effect of particle properties and applied magnetic field

NASA Astrophysics Data System (ADS)

Kulkarni, Sandip; Ramaswamy, Bharath; Horton, Emily; Gangapuram, Sruthi; Nacev, Alek; Depireux, Didier; Shimoji, Mika; Shapiro, Benjamin

2015-11-01

This article presents a method to investigate how magnetic particle characteristics affect their motion inside tissues under the influence of an applied magnetic field. Particles are placed on top of freshly excised tissue samples, a calibrated magnetic field is applied by a magnet underneath each tissue sample, and we image and quantify particle penetration depth by quantitative metrics to assess how particle sizes, their surface coatings, and tissue resistance affect particle motion. Using this method, we tested available fluorescent particles from Chemicell of four sizes (100 nm, 300 nm, 500 nm, and 1 μm diameter) with four different coatings (starch, chitosan, lipid, and PEG/P) and quantified their motion through freshly excised rat liver, kidney, and brain tissues. In broad terms, we found that the applied magnetic field moved chitosan particles most effectively through all three tissue types (as compared to starch, lipid, and PEG/P coated particles). However, the relationship between particle properties and their resulting motion was found to be complex. Hence, it will likely require substantial further study to elucidate the nuances of transport mechanisms and to select and engineer optimal particle properties to enable the most effective transport through various tissue types under applied magnetic fields.

Brain tissue segmentation based on DTI data

PubMed Central

Liu, Tianming; Li, Hai; Wong, Kelvin; Tarokh, Ashley; Guo, Lei; Wong, Stephen T.C.

2008-01-01

We present a method for automated brain tissue segmentation based on the multi-channel fusion of diffusion tensor imaging (DTI) data. The method is motivated by the evidence that independent tissue segmentation based on DTI parametric images provides complementary information of tissue contrast to the tissue segmentation based on structural MRI data. This has important applications in defining accurate tissue maps when fusing structural data with diffusion data. In the absence of structural data, tissue segmentation based on DTI data provides an alternative means to obtain brain tissue segmentation. Our approach to the tissue segmentation based on DTI data is to classify the brain into two compartments by utilizing the tissue contrast existing in a single channel. Specifically, because the apparent diffusion coefficient (ADC) values in the cerebrospinal fluid (CSF) are more than twice that of gray matter (GM) and white matter (WM), we use ADC images to distinguish CSF and non-CSF tissues. Additionally, fractional anisotropy (FA) images are used to separate WM from non-WM tissues, as highly directional white matter structures have much larger fractional anisotropy values. Moreover, other channels to separate tissue are explored, such as eigenvalues of the tensor, relative anisotropy (RA), and volume ratio (VR). We developed an approach based on the Simultaneous Truth and Performance Level Estimation (STAPLE) algorithm that combines these two-class maps to obtain a complete tissue segmentation map of CSF, GM, and WM. Evaluations are provided to demonstrate the performance of our approach. Experimental results of applying this approach to brain tissue segmentation and deformable registration of DTI data and spoiled gradient-echo (SPGR) data are also provided. PMID:17804258

Accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue.

PubMed

Zhang, Jing; Fan, Yimeng; He, Min; Ma, Xuelei; Song, Yanlin; Liu, Ming; Xu, Jianguo

2017-05-30

Raman spectroscopy could be applied to distinguish tumor from normal tissues. This meta-analysis was conducted to assess the accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue. PubMed and Embase were searched to identify suitable studies prior to Jan 1st, 2016. We estimated the pooled sensitivity, specificity, positive and negative likelihood ratios (LR), diagnostic odds ratio (DOR), and constructed summary receiver operating characteristics (SROC) curves to identity the accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue. A total of six studies with 1951 spectra were included. For glioma, the pooled sensitivity and specificity of Raman spectroscopy were 0.96 (95% CI 0.94-0.97) and 0.99 (95% CI 0.98-0.99), respectively. The area under the curve (AUC) was 0.9831. For meningioma, the pooled sensitivity and specificity were 0.98 (95% CI 0.94-1.00) and 1.00 (95% CI 0.98-1.00), respectively. The AUC was 0.9955. This meta-analysis suggested that Raman spectroscopy could be an effective and accurate tool for differentiating glioma and meningioma from normal brain tissue, which would help us both avoid removal of normal tissue and minimize the volume of residual tumor.

The landscape of genomic imprinting across diverse adult human tissues.

PubMed

Baran, Yael; Subramaniam, Meena; Biton, Anne; Tukiainen, Taru; Tsang, Emily K; Rivas, Manuel A; Pirinen, Matti; Gutierrez-Arcelus, Maria; Smith, Kevin S; Kukurba, Kim R; Zhang, Rui; Eng, Celeste; Torgerson, Dara G; Urbanek, Cydney; Li, Jin Billy; Rodriguez-Santana, Jose R; Burchard, Esteban G; Seibold, Max A; MacArthur, Daniel G; Montgomery, Stephen B; Zaitlen, Noah A; Lappalainen, Tuuli

2015-07-01

Genomic imprinting is an important regulatory mechanism that silences one of the parental copies of a gene. To systematically characterize this phenomenon, we analyze tissue specificity of imprinting from allelic expression data in 1582 primary tissue samples from 178 individuals from the Genotype-Tissue Expression (GTEx) project. We characterize imprinting in 42 genes, including both novel and previously identified genes. Tissue specificity of imprinting is widespread, and gender-specific effects are revealed in a small number of genes in muscle with stronger imprinting in males. IGF2 shows maternal expression in the brain instead of the canonical paternal expression elsewhere. Imprinting appears to have only a subtle impact on tissue-specific expression levels, with genes lacking a systematic expression difference between tissues with imprinted and biallelic expression. In summary, our systematic characterization of imprinting in adult tissues highlights variation in imprinting between genes, individuals, and tissues. © 2015 Baran et al.; Published by Cold Spring Harbor Laboratory Press.

The Identification of Aluminum in Human Brain Tissue Using Lumogallion and Fluorescence Microscopy

PubMed Central

Mirza, Ambreen; King, Andrew; Troakes, Claire; Exley, Christopher

2016-01-01

Aluminum in human brain tissue is implicated in the etiologies of neurodegenerative diseases including Alzheimer’s disease. While methods for the accurate and precise measurement of aluminum in human brain tissue are widely acknowledged, the same cannot be said for the visualization of aluminum. Herein we have used transversely-heated graphite furnace atomic absorption spectrometry to measure aluminum in the brain of a donor with Alzheimer’s disease, and we have developed and validated fluorescence microscopy and the fluor lumogallion to show the presence of aluminum in the same tissue. Aluminum is observed as characteristic orange fluorescence that is neither reproduced by other metals nor explained by autofluorescence. This new and relatively simple method to visualize aluminum in human brain tissue should enable more rigorous testing of the aluminum hypothesis of Alzheimer’s disease (and other neurological conditions) in the future. PMID:27472886

Changes in brain anatomy during the course of PTSD

PubMed Central

Cardenas, Valerie A.; Samuelson, Kristin; Lenoci, Maryann; Studholme, Colin; Neylan, Thomas C.; Marmar, Charles R.; Schuff, Norbert; Weiner, Michael W.

2011-01-01

The goal of this study was to determine whether PTSD was associated with an increase in time-related decline in macrostructural brain volume and whether these changes were associated with accelerated cognitive decline. To quantify brain structure, 3 dimensional T1-weighted MRI scans were performed at baseline and again after a minimum of 24 months in 25 patients with PTSD and 22 controls. Longitudinal changes in brain volume were measured using deformation morphometry. For the group as a whole PTSD+ patients did not show significant ongoing brain atrophy compared to PTSD-. PTSD+ patients were then subgrouped into those with decreasing or increasing symptoms. We found little evidence for brain markers of accelerated atrophy in PTSD+ veterans whose symptoms improved over time, with only a small left parietal region showing greater ongoing tissue loss than PTSD-. PTSD patients whose symptoms increased over time showed accelerated atrophy throughout the brain, particularly brainstem and frontal and temporal lobes. Lastly, for the sample as a whole greater rates of brain atrophy were associated with greater rates of decline in verbal memory and delayed facial recognition. PMID:21683556

Comprehensive Analysis of Transcription Dynamics from Brain Samples Following Behavioral Experience

PubMed Central

Turm, Hagit; Mukherjee, Diptendu; Haritan, Doron; Tahor, Maayan; Citri, Ami

2014-01-01

The encoding of experiences in the brain and the consolidation of long-term memories depend on gene transcription. Identifying the function of specific genes in encoding experience is one of the main objectives of molecular neuroscience. Furthermore, the functional association of defined genes with specific behaviors has implications for understanding the basis of neuropsychiatric disorders. Induction of robust transcription programs has been observed in the brains of mice following various behavioral manipulations. While some genetic elements are utilized recurrently following different behavioral manipulations and in different brain nuclei, transcriptional programs are overall unique to the inducing stimuli and the structure in which they are studied1,2. In this publication, a protocol is described for robust and comprehensive transcriptional profiling from brain nuclei of mice in response to behavioral manipulation. The protocol is demonstrated in the context of analysis of gene expression dynamics in the nucleus accumbens following acute cocaine experience. Subsequent to a defined in vivo experience, the target neural tissue is dissected; followed by RNA purification, reverse transcription and utilization of microfluidic arrays for comprehensive qPCR analysis of multiple target genes. This protocol is geared towards comprehensive analysis (addressing 50-500 genes) of limiting quantities of starting material, such as small brain samples or even single cells. The protocol is most advantageous for parallel analysis of multiple samples (e.g. single cells, dynamic analysis following pharmaceutical, viral or behavioral perturbations). However, the protocol could also serve for the characterization and quality assurance of samples prior to whole-genome studies by microarrays or RNAseq, as well as validation of data obtained from whole-genome studies. PMID:25225819

A Multivariate Evaluation of Factors Affecting the Quality of Freshly Frozen Tissue Specimens.

PubMed

Wang, Tong-Hong; Chen, Chin-Chuan; Liang, Kung-Hao; Chen, Chi-Yuan; Chuang, Wen-Yu; Ueng, Shir-Hwa; Chu, Pao-Hsien; Huang, Chung-Guei; Chen, Tse-Ching; Hsueh, Chuen

2017-08-01

Well-prepared and preserved freshly frozen specimens are indispensable materials for clinical studies. To manage specimen quality and to understand the factors potentially affecting specimen quality during preservation processes, we analyzed the quality of RNA and genomic DNA of various tissues collected between 2002 and 2011 in Linkou Chang Gung Memorial Hospital, Taiwan. During this period, a total of 1059 freshly frozen specimens from eight major cancer categories were examined. It was found that preservation duration, organ origin, and tissue type could all influence the quality of RNA samples. The increased preservation period correlated with decreased RNA quality; the brain, breast, and stomach RNA specimens displayed faster degradation rates than those of other organs, and RNA specimens isolated from tumor tissues were apparently more stable than those of other tissues. These factors could all be used as quality predictors of RNA quality. In contrast, almost all analyses revealed that the genomic DNA samples had good quality, which was not influenced by the aforementioned factors. The results assisted us in determining preservation factors that affect specimen quality, which could provide evidence for improving processes of sample collection and preservation. Furthermore, the results are also useful for researchers to adopt as the evaluation criteria for choosing specimen collection and preservation strategies.

Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf

NASA Astrophysics Data System (ADS)

Shi, Lingyan; Rodríguez-Contreras, Adrián; Budansky, Yury; Pu, Yang; An Nguyen, Thien; Alfano, Robert R.

2014-06-01

Two-photon (2P) excitation of the second singlet (S) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S2 state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.

Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf.

PubMed

Shi, Lingyan; Rodríguez-Contreras, Adrián; Budansky, Yury; Pu, Yang; Nguyen, Thien An; Alfano, Robert R

2014-06-01

Two-photon (2P) excitation of the second singlet (S₂) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S₂ state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S₂ state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.

Enhanced detection of infectious prions by direct ELISA from the brains of asymptomatic animals using DRM2-118 monoclonal antibody and Gdn-HCl

USDA-ARS?s Scientific Manuscript database

In this report we describe improved methods for the detection of infectious prions by immunoassay for the diagnosis of transmissible spongiform encephalopathies (TSEs) from asymptomatic animals. Tissue samples obtained as part of ongoing TSE surveillance efforts are often unsuitable for histopathol...

Aging Shapes the Population-Mean and -Dispersion of Gene Expression in Human Brains

PubMed Central

Brinkmeyer-Langford, Candice L.; Guan, Jinting; Ji, Guoli; Cai, James J.

2016-01-01

Human aging is associated with cognitive decline and an increased risk of neurodegenerative disease. Our objective for this study was to evaluate potential relationships between age and variation in gene expression across different regions of the brain. We analyzed the Genotype-Tissue Expression (GTEx) data from 54 to 101 tissue samples across 13 brain regions in post-mortem donors of European descent aged between 20 and 70 years at death. After accounting for the effects of covariates and hidden confounding factors, we identified 1446 protein-coding genes whose expression in one or more brain regions is correlated with chronological age at a false discovery rate of 5%. These genes are involved in various biological processes including apoptosis, mRNA splicing, amino acid biosynthesis, and neurotransmitter transport. The distribution of these genes among brain regions is uneven, suggesting variable regional responses to aging. We also found that the aging response of many genes, e.g., TP37 and C1QA, depends on individuals' genotypic backgrounds. Finally, using dispersion-specific analysis, we identified genes such as IL7R, MS4A4E, and TERF1/TERF2 whose expressions are differentially dispersed by aging, i.e., variances differ between age groups. Our results demonstrate that age-related gene expression is brain region-specific, genotype-dependent, and associated with both mean and dispersion changes. Our findings provide a foundation for more sophisticated gene expression modeling in the studies of age-related neurodegenerative diseases. PMID:27536236

Assignment of the molecular origins of CEST signals at 2 ppm in rat brain.

PubMed

Zhang, Xiao-Yong; Xie, Jingping; Wang, Feng; Lin, Eugene C; Xu, Junzhong; Gochberg, Daniel F; Gore, John C; Zu, Zhongliang

2017-09-01

Chemical exchange saturation transfer effects at 2 ppm (CEST@2ppm) in brain have previously been interpreted as originating from creatine. However, protein guanidino amine protons may also contribute to CEST@2ppm. This study aims to investigate the molecular origins and specificity of CEST@2ppm in brain. Two experiments were performed: (i) samples containing egg white albumin and creatine were dialyzed using a semipermeable membrane to demonstrate that proteins and creatine can be separated by this method; and (ii) tissue homogenates of rat brain with and without dialysis to remove creatine were studied to measure the relative contributions of proteins and creatine to CEST@2ppm. The experiments indicate that dialysis can successfully remove creatine from proteins. Measurements on tissue homogenates show that, with the removal of creatine via dialysis, CEST@2ppm decreases to approximately 34% of its value before dialysis, which indicates that proteins and creatine have comparable contribution to the CEST@2ppm in brain. However, considering the contribution from peptides and amino acids to CEST@2ppm, creatine may have much less contribution to CEST@2ppm. The contribution of proteins, peptides, and amino acids to CEST@2ppm cannot be neglected. The CEST@2ppm measurements of creatine in rat brain should be interpreted with caution. Magn Reson Med 78:881-887, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Pesticide concentrations in snail kite eggs and nestlings in Florida

USGS Publications Warehouse

Sykes, P.W.

1985-01-01

From 1970-1977, unhatched snail kite eggs and young that were found dead at nests in Florida were analyzed by gas chromatography for residues of organochlorine pollutants. The 1970 and 1974 material showed measurable amounts of p,p'-DDE, p,p'-DDD, p,p'-DDT, and dieldrin. Dieldrin and polychlorinated biphenyl (PCB) residues were less than 0.1 ppm in the eggs and were detected in only one sample of muscle tissue at 0.11 ppm. Concentrations in ppm wet weight of p,p'-DDE, p,p' DDD, p,p'-DDT, dieldrin, and PCB for two samples of muscle and three of brain tissue (all 1977 material) were not detected at the limit of quantification (0.05 ppm).

Genetic variation and gene expression across multiple tissues and developmental stages in a non-human primate

PubMed Central

Jasinska, Anna J.; Zelaya, Ivette; Service, Susan K.; Peterson, Christine B.; Cantor, Rita M.; Choi, Oi-Wa; DeYoung, Joseph; Eskin, Eleazar; Fairbanks, Lynn A.; Fears, Scott; Furterer, Allison E.; Huang, Yu S.; Ramensky, Vasily; Schmitt, Christopher A.; Svardal, Hannes; Jorgensen, Matthew J.; Kaplan, Jay R.; Villar, Diego; Aken, Bronwen L.; Flicek, Paul; Nag, Rishi; Wong, Emily S.; Blangero, John; Dyer, Thomas D.; Bogomolov, Marina; Benjamini, Yoav; Weinstock, George M.; Dewar, Ken; Sabatti, Chiara; Wilson, Richard K.; Jentsch, J. David; Warren, Wesley; Coppola, Giovanni; Woods, Roger P.; Freimer, Nelson B.

2017-01-01

By analyzing multi-tissue gene expression and genome-wide genetic variation data in samples from a vervet monkey pedigree, we generated a transcriptome resource and produced the first catalogue of expression quantitative trait loci (eQTLs) in a non-human primate model. This catalogue contains more genome-wide significant eQTLs, per sample, than comparable human resources, and reveals sex and age-related expression patterns. Findings include a master regulatory locus that likely plays a role in immune function, and a locus regulating hippocampal long non-coding RNAs (lncRNAs), whose expression correlates with hippocampal volume. This resource will facilitate genetic investigation of quantitative traits, including brain and behavioral phenotypes relevant to neuropsychiatric disorders. PMID:29083405

Conformable actively multiplexed high-density surface electrode array for brain interfacing

DOEpatents

Rogers, John; Kim, Dae-Hyeong; Litt, Brian; Viventi, Jonathan

2015-01-13

Provided are methods and devices for interfacing with brain tissue, specifically for monitoring and/or actuation of spatio-temporal electrical waveforms. The device is conformable having a high electrode density and high spatial and temporal resolution. A conformable substrate supports a conformable electronic circuit and a barrier layer. Electrodes are positioned to provide electrical contact with a brain tissue. A controller monitors or actuates the electrodes, thereby interfacing with the brain tissue. In an aspect, methods are provided to monitor or actuate spatio-temporal electrical waveform over large brain surface areas by any of the devices disclosed herein.

Unifying framework for multimodal brain MRI segmentation based on Hidden Markov Chains.

PubMed

Bricq, S; Collet, Ch; Armspach, J P

2008-12-01

In the frame of 3D medical imaging, accurate segmentation of multimodal brain MR images is of interest for many brain disorders. However, due to several factors such as noise, imaging artifacts, intrinsic tissue variation and partial volume effects, tissue classification remains a challenging task. In this paper, we present a unifying framework for unsupervised segmentation of multimodal brain MR images including partial volume effect, bias field correction, and information given by a probabilistic atlas. Here-proposed method takes into account neighborhood information using a Hidden Markov Chain (HMC) model. Due to the limited resolution of imaging devices, voxels may be composed of a mixture of different tissue types, this partial volume effect is included to achieve an accurate segmentation of brain tissues. Instead of assigning each voxel to a single tissue class (i.e., hard classification), we compute the relative amount of each pure tissue class in each voxel (mixture estimation). Further, a bias field estimation step is added to the proposed algorithm to correct intensity inhomogeneities. Furthermore, atlas priors were incorporated using probabilistic brain atlas containing prior expectations about the spatial localization of different tissue classes. This atlas is considered as a complementary sensor and the proposed method is extended to multimodal brain MRI without any user-tunable parameter (unsupervised algorithm). To validate this new unifying framework, we present experimental results on both synthetic and real brain images, for which the ground truth is available. Comparison with other often used techniques demonstrates the accuracy and the robustness of this new Markovian segmentation scheme.

Finite difference time domain (FDTD) modeling of implanted deep brain stimulation electrodes and brain tissue.

PubMed

Gabran, S R I; Saad, J H; Salama, M M A; Mansour, R R

2009-01-01

This paper demonstrates the electromagnetic modeling and simulation of an implanted Medtronic deep brain stimulation (DBS) electrode using finite difference time domain (FDTD). The model is developed using Empire XCcel and represents the electrode surrounded with brain tissue assuming homogenous and isotropic medium. The model is created to study the parameters influencing the electric field distribution within the tissue in order to provide reference and benchmarking data for DBS and intra-cortical electrode development.

Low dose X -ray effects on catalase activity in animal tissue

NASA Astrophysics Data System (ADS)

Focea, R.; Nadejde, C.; Creanga, D.; Luchian, T.

2012-12-01

This study was intended to investigate the effect of low-dose X ray-irradiation upon the activity of catalase (CAT) in freshly excised chicken tissues (liver, kidney, brain, muscle). The tissue samples were irradiated with 0.5Gy and 2Gy respectively, in a 6 MV photon beam produced by a clinical linear accelerator (VARIAN CLINAC 2100SC). The dose rate was of 260.88cGy/min. at 100 cm source to sample distance. The catalase level was assayed spectrophotometrically, based on reaction kinetics, using a catalase UV assay kit (SIGMA). Catalase increased activity in various tissue samples exposed to the studied X ray doses (for example with 24 % in the liver cells, p<0.05) suggested the stimulation of the antioxidant enzyme biosynthesis within several hours after exposure at doses of 0.5 Gy and 2 Gy; the putative enzyme inactivation could also occur (due to the injuries on the hydrogen bonds that ensure the specificity of CAT active site) but the resulted balance of the two concurrent processes indicates the cell ability of decomposing the hydrogen peroxide-with benefits for the cell physiology restoration for the chosen low dose radiation.

Dynamic change in cerebral microcirculation and focal cerebral metabolism in experimental subarachnoid hemorrhage in rabbits.

PubMed

Song, Jin-Ning; Chen, Hu; Zhang, Ming; Zhao, Yong-Lin; Ma, Xu-Dong

2013-03-01

Regional cerebral blood flow (rCBF) in the cerebral metabolism and energy metabolism measurements can be used to assess blood flow of brain cells and to detect cell activity. Changes of rCBF in the cerebral microcirculation and energy metabolism were determined in an experimental model of subarachnoid hemorrhage (SAH) model in 56 large-eared Japanese rabbits about 12 to 16-month old. Laser Doppler flowmetry was used to detect the blood supply to brain cells. Internal carotid artery and vein blood samples were used for duplicate blood gas analysis to assess the energy metabolism of brain cells. Cerebral blood flow (CBF) was detected by single photon emission computed tomography (SPECT) perfusion imaging using Tc-99m ethyl cysteinate dimer (Tc-99m ECD) as an imaging reagent. The percentage of injected dose per gram of brain tissue was calculated and analyzed. There were positive correlations between the percentage of radionuclide injected per gram of brain tissue and rCBF supply and cerebral metabolic rate for oxygen (P < 0.05). However, there was a negative correlation between radioactivity counts per unit volume detected on the SPECT rheoencephalogram and lactic acid concentration in the homolateral internal carotid artery and vein. In summary, this study found abnormal CBF in metabolism and utilization of brain cells after SAH, and also found that deterioration of energy metabolism of brain cells played a significant role in the development of SAH. There are matched reductions in CBF and metabolism. Thus, SPECT imaging could be used as a noninvasive method to detect CBF.

Thalamic atrophy in antero-medial and dorsal nuclei correlates with six-month outcome after severe brain injury☆

PubMed Central

Lutkenhoff, Evan S.; McArthur, David L.; Hua, Xue; Thompson, Paul M.; Vespa, Paul M.; Monti, Martin M.

2013-01-01

The primary and secondary damage to neural tissue inflicted by traumatic brain injury is a leading cause of death and disability. The secondary processes, in particular, are of great clinical interest because of their potential susceptibility to intervention. We address the dynamics of tissue degeneration in cortico-subcortical circuits after severe brain injury by assessing volume change in individual thalamic nuclei over the first six-months post-injury in a sample of 25 moderate to severe traumatic brain injury patients. Using tensor-based morphometry, we observed significant localized thalamic atrophy over the six-month period in antero-dorsal limbic nuclei as well as in medio-dorsal association nuclei. Importantly, the degree of atrophy in these nuclei was predictive, even after controlling for full-brain volume change, of behavioral outcome at six-months post-injury. Furthermore, employing a data-driven decision tree model, we found that physiological measures, namely the extent of atrophy in the anterior thalamic nucleus, were the most predictive variables of whether patients had regained consciousness by six-months, followed by behavioral measures. Overall, these findings suggest that the secondary non-mechanical degenerative processes triggered by severe brain injury are still ongoing after the first week post-trauma and target specifically antero-medial and dorsal thalamic nuclei. This result therefore offers a potential window of intervention, and a specific target region, in agreement with the view that specific cortico-thalamo-cortical circuits are crucial to the maintenance of large-scale network neural activity and thereby the restoration of cognitive function after severe brain injury. PMID:24273723

In vivo evaluation of needle force and friction stress during insertion at varying insertion speed into the brain.

PubMed

Casanova, Fernando; Carney, Paul R; Sarntinoranont, Malisa

2014-11-30

Convection enhanced delivery (CED) infuses drugs directly into brain tissue. Needle insertion is required and results in tissue damage which can promote flowback along the needle track and improper targeting. The goal of this study was to evaluate friction stress (calculated from needle insertion force) as a measure of tissue contact and damage during needle insertion for varying insertion speeds. Forces and surface dimpling during needle insertion were measured in rat brain in vivo. Needle retraction forces were used to calculate friction stresses. These measures were compared to track damage from a previous study. Differences between brain tissues and soft hydrogels were evaluated for varying insertion speeds: 0.2, 2, and 10mm/s. In brain tissue, average insertion force and surface dimpling increased with increasing insertion speed. Average friction stress along the needle-tissue interface decreased with insertion speed (from 0.58 ± 0.27 to 0.16 ± 0.08 kPa). Friction stress varied between brain regions: cortex (0.227 ± 0.27 kPa), external capsule (0.222 ± 0.19 kPa), and CPu (0.383 ± 0.30 kPa). Hydrogels exhibited opposite trends for dimpling and friction stress with insertion speed. Previously, increasing needle damage with insertion speed has been measured with histological methods. Friction stress appears to decrease with increasing tissue damage and decreasing tissue contact, providing the potential for in vivo and real time evaluation along the needle track. Force derived friction stress decreased with increasing insertion speed and was smaller within white matter regions. Hydrogels exhibited opposite trends to brain tissue. Copyright © 2014 Elsevier B.V. All rights reserved.

Non-invasive intraoperative optical coherence tomography of the resection cavity during surgery of intrinsic brain tumors

NASA Astrophysics Data System (ADS)

Giese, A.; Böhringer, H. J.; Leppert, J.; Kantelhardt, S. R.; Lankenau, E.; Koch, P.; Birngruber, R.; Hüttmann, G.

2006-02-01

Optical coherence tomography (OCT) is a non-invasive imaging technique with a micrometer resolution. It allows non-contact / non-invasive analysis of central nervous system tissues with a penetration depth of 1-3,5 mm reaching a spatial resolution of approximately 4-15 μm. We have adapted spectral-domain OCT (SD-OCT) and time-domain OCT (TD-OCT) for intraoperative detection of residual tumor during brain tumor surgery. Human brain tumor tissue and areas of the resection cavity were analyzed during the resection of gliomas using this new technology. The site of analysis was registered using a neuronavigation system and biopsies were taken and submitted to routine histology. We have used post image acquisition processing to compensate for movements of the brain and to realign A-scan images for calculation of a light attenuation factor. OCT imaging of normal cortex and white matter showed a typical light attenuation profile. Tumor tissue depending on the cellularity of the specimen showed a loss of the normal light attenuation profile resulting in altered light attenuation coefficients compared to normal brain. Based on this parameter and the microstructure of the tumor tissue, which was entirely absent in normal tissue, OCT analysis allowed the discrimination of normal brain tissue, invaded brain, solid tumor tissue, and necrosis. Following macroscopically complete resections OCT analysis of the resection cavity displayed the typical microstructure and light attenuation profile of tumor tissue in some specimens, which in routine histology contained microscopic residual tumor tissue. We have demonstrated that this technology may be applied to the intraoperative detection of residual tumor during resection of human gliomas.

Utility of spatially-resolved atmospheric pressure surface sampling and ionization techniques as alternatives to mass spectrometric imaging (MSI) in drug metabolism.

PubMed

Blatherwick, Eleanor Q; Van Berkel, Gary J; Pickup, Kathryn; Johansson, Maria K; Beaudoin, Marie-Eve; Cole, Roderic O; Day, Jennifer M; Iverson, Suzanne; Wilson, Ian D; Scrivens, James H; Weston, Daniel J

2011-08-01

Tissue distribution studies of drug molecules play an essential role in the pharmaceutical industry and are commonly undertaken using quantitative whole body autoradiography (QWBA) methods. The growing need for complementary methods to address some scientific gaps around radiography methods has led to increased use of mass spectrometric imaging (MSI) technology over the last 5 to 10 years. More recently, the development of novel mass spectrometric techniques for ambient surface sampling has redefined what can be regarded as "fit-for-purpose" for MSI in a drug metabolism and disposition arena. Together with a review of these novel alternatives, this paper details the use of two liquid microjunction (LMJ)-based mass spectrometric surface sampling technologies. These approaches are used to provide qualitative determination of parent drug in rat liver tissue slices using liquid extraction surface analysis (LESA) and to assess the performance of a LMJ surface sampling probe (LMJ-SSP) interface for quantitative assessment of parent drug in brain, liver and muscle tissue slices. An assessment of the utility of these spatially-resolved sampling methods is given, showing interdependence between mass spectrometric and QWBA methods, in particular there emerges a reason to question typical MSI workflows for drug metabolism; suggesting the expedient use of profile or region analysis may be more appropriate, rather than generating time-intensive molecular images of the entire tissue section.

Enhancement of Sexual Behavior in Female Rats by Neonatal Transplantation of Brain Tissue from Males

NASA Astrophysics Data System (ADS)

Arendash, Gary W.; Gorski, Roger A.

1982-09-01

Transplantation of preoptic tissue from male rat neonates into the preoptic area of female littermates increased masculine and feminine sexual behavior in the recipients during adulthood. This suggests that functional connections develop between the transplanted neural tissue and the host brain. A new intraparenchymal brain transplantation technique was used to achieve these results.

Multimodal optical coherence tomography for in vivo imaging of brain tissue structure and microvascular network at glioblastoma

NASA Astrophysics Data System (ADS)

Yashin, Konstantin S.; Kiseleva, Elena B.; Gubarkova, Ekaterina V.; Matveev, Lev A.; Karabut, Maria M.; Elagin, Vadim V.; Sirotkina, Marina A.; Medyanik, Igor A.; Kravets, L. Y.; Gladkova, Natalia D.

2017-02-01

In the case of infiltrative brain tumors the surgeon faces difficulties in determining their boundaries to achieve total resection. The aim of the investigation was to evaluate the performance of multimodal OCT (MM OCT) for differential diagnostics of normal brain tissue and glioma using an experimental model of glioblastoma. The spectral domain OCT device that was used for the study provides simultaneously two modes: cross-polarization and microangiographic OCT. The comparative analysis of the both OCT modalities images from tumorous and normal brain tissue areas concurrently with histologic correlation shows certain difference between when accordingly to morphological and microvascular tissue features.

Influence of strain rate on indentation response of porcine brain.

PubMed

Qian, Long; Zhao, Hongwei; Guo, Yue; Li, Yuanshang; Zhou, Mingxing; Yang, Liguo; Wang, Zhiwei; Sun, Yifan

2018-06-01

Knowledge of brain tissue mechanical properties may be critical for formulating hypotheses about some specific diseases mechanisms and its accurate simulations such as traumatic brain injury (TBI) and tumor growth. Compared to traditional tests (e.g. tensile and compression), indentation shows superiority by virtue of its pinpoint and nondestructive/quasi-nondestructive. As a viscoelastic material, the properties of brain tissue depend on the strain rate by definition. However most efforts focus on the aspect of velocity in the field of brain indentation, rather than strain rate. The influence of strain rate on indentation response of brain tissue is taken little attention. Further, by comparing different results from literatures, it is also obvious that strain rate rather than velocity is more appropriate to characterize mechanical properties of brain. In this paper, to systematically characterize the influence of strain rate, a series of indentation-relaxation tests n = 210) are performed on the cortex of porcine brain using a custom-designed indentation device. The mechanical response that correlates with indenter diameters, depths of indentation and velocities, is revealed for the indentation portion, and elastic behavior of brain tissue is analyzed as the function of strain rate. Similarly, a linear viscoelastic model with a Prony series is employed for the indentation-relaxation portion, wherein the brain tissue shows more viscous and responds more quickly with increasing strain rate. Understanding the effect of strain rate on mechanical properties of brain indentation may be far-reaching for brain injury biomechanics and accurate simulations, but be important for bridging between indentation results of different literatures. Copyright © 2018 Elsevier Ltd. All rights reserved.

Transcranial light-tissue interaction analysis

NASA Astrophysics Data System (ADS)

Aulakh, Kavleen; Zakaib, Scott; Willmore, William G.; Ye, Winnie N.

2016-03-01

The penetration depth of light plays a crucial role in therapeutic medical applications. In order to design effective medical photonic devices, an in-depth understanding of light's ability to penetrate tissues (including bone, skin, and fat) is necessary. The amount of light energy absorbed or scattered by tissues affects the intensity of light reaching an intended target in vivo. In this study, we examine the transmittance of light through a variety of cranial tissues for the purpose of determining the efficacy of neuro stimulation using a transcranial laser. Tissue samples collected from a pig were irradiated with a pulsed laser. We first determine the optimal irradiation wavelength of the laser to be 808nm. With varying peak and average power of the laser, we found an inverse and logarithmic relationship between the penetration depth and the intensity of the light. After penetrating the skin and skull of the pig, the light decreases in intensity at a rate of approximately 90.8 (+/-0.4) percent for every 5 mm of brain tissue penetrated. We also found the correlation between the irradiation time and dosage, using three different lasers (with peak power of 500, 1000, and 1500mW respectively). These data will help deduce what laser power is required to achieve a clinically-realistic model for a given irradiation time. This work is fundamental and the experimental data can be used to supplement existing and future research on the effects of laser light on brain tissue for the design of medical devices.

Near infrared Raman spectra of human brain lipids

NASA Astrophysics Data System (ADS)

Krafft, Christoph; Neudert, Lars; Simat, Thomas; Salzer, Reiner

2005-05-01

Human brain tissue, in particular white matter, contains high lipid content. These brain lipids can be divided into three principal classes: neutral lipids including the steroid cholesterol, phospholipids and sphingolipids. Major lipids in normal human brain tissue are phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, phosphatidic acid, sphingomyelin, galactocerebrosides, gangliosides, sulfatides and cholesterol. Minor lipids are cholesterolester and triacylglycerides. During transformation from normal brain tissue to tumors, composition and concentration of lipids change in a specific way. Therefore, analysis of lipids might be used as a diagnostic parameter to distinguish normal tissue from tumors and to determine the tumor type and tumor grade. Raman spectroscopy has been suggested as an analytical tool to detect these changes even under intra-operative conditions. We recorded Raman spectra of the 12 major and minor brain lipids with 785 nm excitation in order to identify their spectral fingerprints for qualitative and quantitative analyses.

VA's National PTSD Brain Bank: a National Resource for Research.

PubMed

Friedman, Matthew J; Huber, Bertrand R; Brady, Christopher B; Ursano, Robert J; Benedek, David M; Kowall, Neil W; McKee, Ann C

2017-08-25

The National PTSD Brain Bank (NPBB) is a brain tissue biorepository established to support research on the causes, progression, and treatment of PTSD. It is a six-part consortium led by VA's National Center for PTSD with participating sites at VA medical centers in Boston, MA; Durham, NC; Miami, FL; West Haven, CT; and White River Junction, VT along with the Uniformed Services University of Health Sciences. It is also well integrated with VA's Boston-based brain banks that focus on Alzheimer's disease, ALS, chronic traumatic encephalopathy, and other neurological disorders. This article describes the organization and operations of NPBB with specific attention to: tissue acquisition, tissue processing, diagnostic assessment, maintenance of a confidential data biorepository, adherence to ethical standards, governance, accomplishments to date, and future challenges. Established in 2014, NPBB has already acquired and distributed brain tissue to support research on how PTSD affects brain structure and function.

Fingolimod inhibits brain atrophy and promotes brain-derived neurotrophic factor in an animal model of multiple sclerosis.

PubMed

Smith, Paul A; Schmid, Cindy; Zurbruegg, Stefan; Jivkov, Magali; Doelemeyer, Arno; Theil, Diethilde; Dubost, Valérie; Beckmann, Nicolau

2018-05-15

Longitudinal brain atrophy quantification is a critical efficacy measurement in multiple sclerosis (MS) clinical trials and the determination of No Evidence of Disease Activity (NEDA). Utilising fingolimod as a clinically validated therapy we evaluated the use of repeated brain tissue volume measures during chronic experimental autoimmune encephalomyelitis (EAE) as a new preclinical efficacy measure. Brain volume changes were quantified using magnetic resonance imaging (MRI) at 7 Tesla and correlated to treatment-induced brain derived neurotrophic factor (BDNF) measured in blood, cerebrospinal fluid, spinal cord and brain. Serial brain MRI measurements revealed slow progressive brain volume loss in vehicle treated EAE mice despite a stable clinical score. Fingolimod (1 mg/kg) significantly ameliorated brain tissue atrophy in the cerebellum and striatum when administered from established EAE disease onwards. Fingolimod-dependent tissue preservation was associated with induction of BDNF specifically within the brain and co-localized with neuronal soma. In contrast, therapeutic teriflunomide (3 mg/kg) treatment failed to inhibit CNS autoimmune mediated brain degeneration. Finally, weekly anti-IL-17A antibody (15 mg/kg) treatment was highly efficacious and preserved whole brain, cerebellum and striatum volume. Fingolimod-mediated BDNF increases within the CNS may contribute to limiting progressive tissue loss during chronic neuroinflammation. Copyright © 2018 Elsevier B.V. All rights reserved.

Functional aspects of early brain development are preserved in tuberous sclerosis complex (TSC) epileptogenic lesions.

PubMed

Ruffolo, Gabriele; Iyer, Anand; Cifelli, Pierangelo; Roseti, Cristina; Mühlebner, Angelika; van Scheppingen, Jackelien; Scholl, Theresa; Hainfellner, Johannes A; Feucht, Martha; Krsek, Pavel; Zamecnik, Josef; Jansen, Floor E; Spliet, Wim G M; Limatola, Cristina; Aronica, Eleonora; Palma, Eleonora

2016-11-01

Tuberous sclerosis complex (TSC) is a rare multi-system genetic disease characterized by several neurological disorders, the most common of which is the refractory epilepsy caused by highly epileptogenic cortical lesions. Previous studies suggest an alteration of GABAergic and glutamatergic transmission in TSC brain indicating an unbalance of excitation/inhibition that can explain, at least in part, the high incidence of epilepsy in these patients. Here we investigate whether TSC cortical tissues could retain GABAA and AMPA receptors at early stages of human brain development thus contributing to the generation and recurrence of seizures. Given the limited availability of pediatric human brain specimens, we used the microtransplantation method of injecting Xenopus oocytes with membranes from TSC cortical tubers and control brain tissues. Moreover, qPCR was performed to investigate the expression of GABAA and AMPA receptor subunits (GABAA α1-5, β3, γ2, δ; GluA1, GluA2) and cation chloride co-transporters NKCC1 and KCC2. The evaluation of nine human cortical brain samples, from 15 gestation weeks to 15years old, showed a progressive shift towards more hyperpolarized GABAA reversal potential (EGABA). This shift was associated with a differential expression of the chloride cotransporters NKCC1 and KCC2. Furthermore, the GluA1/GluA2 mRNA ratio of expression paralleled the development process. On the contrary, in oocytes micro-transplanted with epileptic TSC tuber tissue from seven patients, neither the GABAA reversal potential nor the GluA1/GluA2 expression showed similar developmental changes. Our data indicate for the first time, that in the same cohort of TSC patients, the pattern of both GABAAR and GluA1/GluA2 functions retains features that are typical of an immature brain. These observations support the potential contribution of altered receptor function to the epileptic disorder of TSC and may suggest novel therapeutic approaches. Furthermore, our findings strengthen the novel hypothesis that other developmental brain diseases can share the same hallmarks of immaturity leading to intractable seizures. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantifying structural alterations in Alzheimer's disease brains using quantitative phase imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Lee, Moosung; Lee, Eeksung; Jung, JaeHwang; Yu, Hyeonseung; Kim, Kyoohyun; Yoon, Jonghee; Lee, Shinhwa; Jeong, Yong; Park, YongKeun

2017-02-01

Imaging brain tissues is an essential part of neuroscience because understanding brain structure provides relevant information about brain functions and alterations associated with diseases. Magnetic resonance imaging and positron emission tomography exemplify conventional brain imaging tools, but these techniques suffer from low spatial resolution around 100 μm. As a complementary method, histopathology has been utilized with the development of optical microscopy. The traditional method provides the structural information about biological tissues to cellular scales, but relies on labor-intensive staining procedures. With the advances of illumination sources, label-free imaging techniques based on nonlinear interactions, such as multiphoton excitations and Raman scattering, have been applied to molecule-specific histopathology. Nevertheless, these techniques provide limited qualitative information and require a pulsed laser, which is difficult to use for pathologists with no laser training. Here, we present a label-free optical imaging of mouse brain tissues for addressing structural alteration in Alzheimer's disease. To achieve the mesoscopic, unlabeled tissue images with high contrast and sub-micrometer lateral resolution, we employed holographic microscopy and an automated scanning platform. From the acquired hologram of the brain tissues, we could retrieve scattering coefficients and anisotropies according to the modified scattering-phase theorem. This label-free imaging technique enabled direct access to structural information throughout the tissues with a sub-micrometer lateral resolution and presented a unique means to investigate the structural changes in the optical properties of biological tissues.

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

NASA Astrophysics Data System (ADS)

Sajib, Saurav Z. K.; Oh, Tong In; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

2017-01-01

New methods for in vivo mapping of brain responses during deep brain stimulation (DBS) are indispensable to secure clinical applications. Assessment of current density distribution, induced by internally injected currents, may provide an alternative method for understanding the therapeutic effects of electrical stimulation. The current flow and pathway are affected by internal conductivity, and can be imaged using magnetic resonance-based conductivity imaging methods. Magnetic resonance electrical impedance tomography (MREIT) is an imaging method that can enable highly resolved mapping of electromagnetic tissue properties such as current density and conductivity of living tissues. In the current study, we experimentally imaged current density distribution of in vivo canine brains by applying MREIT to electrical stimulation. The current density maps of three canine brains were calculated from the measured magnetic flux density data. The absolute current density values of brain tissues, including gray matter, white matter, and cerebrospinal fluid were compared to assess the active regions during DBS. The resulting current density in different tissue types may provide useful information about current pathways and volume activation for adjusting surgical planning and understanding the therapeutic effects of DBS.

An improved high-throughput lipid extraction method for the analysis of human brain lipids.

PubMed

Abbott, Sarah K; Jenner, Andrew M; Mitchell, Todd W; Brown, Simon H J; Halliday, Glenda M; Garner, Brett

2013-03-01

We have developed a protocol suitable for high-throughput lipidomic analysis of human brain samples. The traditional Folch extraction (using chloroform and glass-glass homogenization) was compared to a high-throughput method combining methyl-tert-butyl ether (MTBE) extraction with mechanical homogenization utilizing ceramic beads. This high-throughput method significantly reduced sample handling time and increased efficiency compared to glass-glass homogenizing. Furthermore, replacing chloroform with MTBE is safer (less carcinogenic/toxic), with lipids dissolving in the upper phase, allowing for easier pipetting and the potential for automation (i.e., robotics). Both methods were applied to the analysis of human occipital cortex. Lipid species (including ceramides, sphingomyelins, choline glycerophospholipids, ethanolamine glycerophospholipids and phosphatidylserines) were analyzed via electrospray ionization mass spectrometry and sterol species were analyzed using gas chromatography mass spectrometry. No differences in lipid species composition were evident when the lipid extraction protocols were compared, indicating that MTBE extraction with mechanical bead homogenization provides an improved method for the lipidomic profiling of human brain tissue.

Effects of positive end-expiratory pressure on brain tissue oxygen pressure of severe traumatic brain injury patients with acute respiratory distress syndrome: A pilot study.

PubMed

Nemer, Sérgio Nogueira; Caldeira, Jefferson B; Santos, Ricardo G; Guimarães, Bruno L; Garcia, João Márcio; Prado, Darwin; Silva, Ricardo T; Azeredo, Leandro M; Faria, Eduardo R; Souza, Paulo Cesar P

2015-12-01

To verify whether high positive end-expiratory pressure levels can increase brain tissue oxygen pressure, and also their effects on pulse oxygen saturation, intracranial pressure, and cerebral perfusion pressure. Twenty traumatic brain injury patients with acute respiratory distress syndrome were submitted to positive end-expiratory pressure levels of 5, 10, and 15 cm H2O progressively. The 3 positive end-expiratory pressure levels were used during 20 minutes for each one, whereas brain tissue oxygen pressure, oxygen saturation, intracranial pressure, and cerebral perfusion pressure were recorded. Brain tissue oxygen pressure and oxygen saturation increased significantly with increasing positive end-expiratory pressure from 5 to 10 and from 10 to 15 cm H2O (P=.0001 and P=.0001 respectively). Intracranial pressure and cerebral perfusion pressure did not differ significantly with increasing positive end-expiratory pressure from 5 to 10 and from 10 to 15 cm H2O (P=.16 and P=.79 respectively). High positive end-expiratory pressure levels increased brain tissue oxygen pressure and oxygen saturation, without increase in intracranial pressure or decrease in cerebral perfusion pressure. High positive end-expiratory pressure levels can be used in severe traumatic brain injury patients with acute respiratory distress syndrome as a safe alternative to improve brain oxygenation. Copyright © 2015 Elsevier Inc. All rights reserved.

Liquid Microjunction Surface Sampling Coupled with High-Pressure Liquid Chromatography-Electrospray Ionization-Mass Spectrometry for Analysis of Drugs and Metabolites in Whole-Body Thin Tissue Sections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kertesz, Vilmos; Van Berkel, Gary J

2010-01-01

In this work, a commercially available autosampler was adapted to perform direct liquid microjunction (LMJ) surface sampling followed by a high-pressure liquid chromatography (HPLC) separation of the extract components and detection with electrospray ionization mass spectrometry (ESI-MS). To illustrate the utility of coupling a separation with this direct liquid extraction based surface sampling approach, four different organs (brain, lung, kidney, and liver) from whole-body thin tissue sections of propranolol dosed and control mice were examined. The parent drug was observed in the chromatograms of the surface sampling extracts from all the organs of the dosed mouse examined. In addition, twomore » isomeric phase II metabolites of propranolol (an aliphatic and an aromatic hydroxypropranolol glucuronide) were observed in the chromatograms of the extracts from lung, kidney, and liver. Confirming the presence of one or the other or both of these glucuronides in the extract from the various organs was not possible without the separation. These drug and metabolite data obtained using the LMJ surface sampling/HPLC-MS method and the results achieved by analyzing similar samples by conventional extraction of the tissues and subsequent HPLC-MS analysis were consistent.« less

Specific regions of the brain are capable of fructose metabolism.

PubMed

Oppelt, Sarah A; Zhang, Wanming; Tolan, Dean R

2017-02-15

High fructose consumption in the Western diet correlates with disease states such as obesity and metabolic syndrome complications, including type II diabetes, chronic kidney disease, and non-alcoholic fatty acid liver disease. Liver and kidneys are responsible for metabolism of 40-60% of ingested fructose, while the physiological fate of the remaining fructose remains poorly understood. The primary metabolic pathway for fructose includes the fructose-transporting solute-like carrier transport proteins 2a (SLC2a or GLUT), including GLUT5 and GLUT9, ketohexokinase (KHK), and aldolase. Bioinformatic analysis of gene expression encoding these proteins (glut5, glut9, khk, and aldoC, respectively) identifies other organs capable of this fructose metabolism. This analysis predicts brain, lymphoreticular tissue, placenta, and reproductive tissues as possible additional organs for fructose metabolism. While expression of these genes is highest in liver, the brain is predicted to have expression levels of these genes similar to kidney. RNA in situ hybridization of coronal slices of adult mouse brains validate the in silico expression of glut5, glut9, khk, and aldoC, and show expression across many regions of the brain, with the most notable expression in the cerebellum, hippocampus, cortex, and olfactory bulb. Dissected samples of these brain regions show KHK and aldolase enzyme activity 5-10 times the concentration of that in liver. Furthermore, rates of fructose oxidation in these brain regions are 15-150 times that of liver slices, confirming the bioinformatics prediction and in situ hybridization data. This suggests that previously unappreciated regions across the brain can use fructose, in addition to glucose, for energy production. Copyright © 2016 Elsevier B.V. All rights reserved.

Specific regions of the brain are capable of fructose metabolism

PubMed Central

Oppelt, Sarah A.; Zhang, Wanming; Tolan, Dean R.

2017-01-01

High fructose consumption in the Western diet correlates with disease states such as obesity and metabolic syndrome complications, including type II diabetes, chronic kidney disease, and nonalcoholic fatty acid liver disease. Liver and kidneys are responsible for metabolism of 40–60% of ingested fructose, while the physiological fate of the remaining fructose remains poorly understood. The primary metabolic pathway for fructose includes the fructose-transporting solute-like carrier transport proteins 2a (SLC2a or GLUT), including GLUT5 and GLUT9, ketohexokinase (KHK), and aldolase. Bioinformatic analysis of gene expression encoding these proteins (glut5, glut9, khk, and aldoC, respectively) identifies other organs capable of this fructose metabolism. This analysis predicts brain, lymphoreticular tissue, placenta, and reproductive tissues as possible additional organs for fructose metabolism. While expression of these genes is highest in liver, the brain is predicted to have expression levels of these genes similar to kidney. RNA in situ hybridization of coronal slices of adult mouse brains validate the in silico expression of glut5, glut9, khk, and aldoC, and show expression across many regions of the brain, with the most notable expression in the cerebellum, hippocampus, cortex, and olfactory bulb. Dissected samples of these brain regions show KHK and aldolase enzyme activity 5–10 times the concentration of that in liver. Furthermore, rates of fructose oxidation in these brain regions are 15–150 times that of liver slices, confirming the bioinformatics prediction and in situ hybridization data. This suggests that previously unappreciated regions across the brain can use fructose, in addition to glucose, for energy production. PMID:28034722

Comprehensive Analysis of Human Endogenous Retrovirus Group HERV-W Locus Transcription in Multiple Sclerosis Brain Lesions by High-Throughput Amplicon Sequencing

PubMed Central

Schmitt, Katja; Richter, Christin; Backes, Christina; Meese, Eckart; Ruprecht, Klemens

2013-01-01

Human endogenous retroviruses (HERVs) of the HERV-W group comprise hundreds of loci in the human genome. Deregulated HERV-W expression and HERV-W locus ERVWE1-encoded Syncytin-1 protein have been implicated in the pathogenesis of multiple sclerosis (MS). However, the actual transcription of HERV-W loci in the MS context has not been comprehensively analyzed. We investigated transcription of HERV-W in MS brain lesions and white matter brain tissue from healthy controls by employing next-generation amplicon sequencing of HERV-W env-specific reverse transcriptase (RT) PCR products, thus revealing transcribed HERV-W loci and the relative transcript levels of those loci. We identified more than 100 HERV-W loci that were transcribed in the human brain, with a limited number of loci being predominantly transcribed. Importantly, relative transcript levels of HERV-W loci were very similar between MS and healthy brain tissue samples, refuting deregulated transcription of HERV-W env in MS brain lesions, including the high-level-transcribed ERVWE1 locus encoding Syncytin-1. Quantitative RT-PCR likewise did not reveal differences in MS regarding HERV-W env general transcript or ERVWE1- and ERVWE2-specific transcript levels. However, we obtained evidence for interindividual differences in HERV-W transcript levels. Reporter gene assays indicated promoter activity of many HERV-W long terminal repeats (LTRs), including structurally incomplete LTRs. Our comprehensive analysis of HERV-W transcription in the human brain thus provides important information on the biology of HERV-W in MS lesions and normal human brain, implications for study design, and mechanisms by which HERV-W may (or may not) be involved in MS. PMID:24109235

Predicting Intracranial Pressure and Brain Tissue Oxygen Crises in Patients With Severe Traumatic Brain Injury.

PubMed

Myers, Risa B; Lazaridis, Christos; Jermaine, Christopher M; Robertson, Claudia S; Rusin, Craig G

2016-09-01

To develop computer algorithms that can recognize physiologic patterns in traumatic brain injury patients that occur in advance of intracranial pressure and partial brain tissue oxygenation crises. The automated early detection of crisis precursors can provide clinicians with time to intervene in order to prevent or mitigate secondary brain injury. A retrospective study was conducted from prospectively collected physiologic data. intracranial pressure, and partial brain tissue oxygenation crisis events were defined as intracranial pressure of greater than or equal to 20 mm Hg lasting at least 15 minutes and partial brain tissue oxygenation value of less than 10 mm Hg for at least 10 minutes, respectively. The physiologic data preceding each crisis event were used to identify precursors associated with crisis onset. Multivariate classification models were applied to recorded data in 30-minute epochs of time to predict crises between 15 and 360 minutes in the future. The neurosurgical unit of Ben Taub Hospital (Houston, TX). Our cohort consisted of 817 subjects with severe traumatic brain injury. Our algorithm can predict the onset of intracranial pressure crises with 30-minute advance warning with an area under the receiver operating characteristic curve of 0.86 using only intracranial pressure measurements and time since last crisis. An analogous algorithm can predict the start of partial brain tissue oxygenation crises with 30-minute advanced warning with an area under the receiver operating characteristic curve of 0.91. Our algorithms provide accurate and timely predictions of intracranial hypertension and tissue hypoxia crises in patients with severe traumatic brain injury. Almost all of the information needed to predict the onset of these events is contained within the signal of interest and the time since last crisis.