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1.
Endocrine ; 2024 May 27.
Article in English | MEDLINE | ID: mdl-38801599

ABSTRACT

INTRODUCTION: Micro- and macrovascular complications are common among persons with type 2 diabetes. Recently there has been growing interest to investigate the potential of circulating small non-coding RNAs (sncRNAs) as contributors to the development of diabetic complications. In this study we investigate to what extent circulating sncRNAs levels associate with prevalent diabetic kidney disease (DKD) in persons with type 2 diabetes. METHODS: Plasma sncRNAs levels were determined using small RNA-seq, allowing detection of miRNAs, snoRNAs, piRNAs, tRNA fragments, and various other sncRNA classes. We tested for differentially expressed sncRNAs in persons with type 2 diabetes, with DKD (n = 69) or without DKD (n = 405). In secondary analyses, we also tested the association with eGFR, albuminuria (UACR), and the plasma proteome. RESULTS: In total seven sncRNAs were negatively associated with prevalent DKD (all PFDR ≤ 0.05). Including one microRNA (miR-143-5p), five snoRNAs (U8, SNORD118, SNORD24, SNORD107, SNORD87) and a piRNA (piR-019825 | DQ597218). Proteomic analyses showed that the seven sncRNAs, and especially the piRNA piR-019825, were associated with plasma levels of 24 proteins of which several have known associations with kidney function including TNF sR-I (TNFRFS1A), DAN (NBL1) and cystatin C (CST3). CONCLUSION: We have identified novel small non-coding RNAs, primarily from classes other than microRNAs, that are associated with diabetic kidney disease. Our results show that the involvement of small non-coding RNAs in DKD goes beyond the already known microRNAs and also involves other classes of sncRNA, in particular snoRNAs and the piRNA piR-019825, that have never been studied before in relation to kidney function.

2.
Resuscitation ; 194: 110086, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38097106

ABSTRACT

BACKGROUND: During stabilisation of preterm infants at birth, a face mask is used to provide respiratory support. However, application of these masks may activate cutaneous stretch receptors of the trigeminal nerve, causing apnoea and bradycardia. This study investigated the amount of force exerted on the face mask during non-invasive ventilation of preterm infants at birth and whether the amount of exerted force is associated with apnoea and bradycardia. METHODS: A prospective observational study was performed in preterm infants born <32 weeks of gestation who were stabilised at birth. During the first 10 minutes of respiratory support, we measured breathing and heart rate as well as the amount of force exerted on a face mask using a custom-made pressure sensor placed on top of the face mask. RESULTS: Thirty infants were included (median (IQR) gestational age(GA) 28+3 (27+0-30+0) weeks, birthweight 1104 (878-1275) grams). The median exerted force measured was 297 (198-377) grams, ranging from 0 to 1455 grams. Significantly more force was exerted on the face mask during positive pressure ventilation when compared to CPAP (410 (256-556) vs 286 (190-373) grams, p = 0.009). In a binary logistic regression model, higher forces were associated with an increased risk of apnoea (OR = 1.607 (1.556-1.661), p < 0.001) and bradycardia (OR = 1.140 (1.102-1.180), p < 0.001) during the first 10 minutes of respiratory support at birth. CONCLUSION: During mask ventilation, the median exerted force on a face mask was 297 grams with a maximum of 1455 grams. Higher exerted forces were associated apnoea and bradycardia during the first 10 minutes of respiratory support at birth.


Subject(s)
Apnea , Infant, Premature , Infant, Newborn , Humans , Apnea/etiology , Masks/adverse effects , Bradycardia/etiology , Positive-Pressure Respiration
3.
Stem Cell Res ; 67: 103031, 2023 03.
Article in English | MEDLINE | ID: mdl-36702081

ABSTRACT

We previously generated a doxycycline-inducible H2B-mTurq2 reporter in hiPSCs to track cells and study cell division and apoptosis. To improve visualization of cycling cells, we introduced a ubiquitously transcribed mScarletI-Geminin (GMMN) (1-110) into the previously untargeted second AAVS1 allele. Fusion to the N-terminal part of GMNN provided tightly controlled mScarletI expression during the cell cycle. mScarletI fluorescence increased gradually from the S-phase through the M-phase of the cell cycle and was lost at the metaphase-anaphase transition. The resulting hiPSC reporter line generated, which we named ProLiving, is a valuable tool to study cell division and cell cycle characteristics in living hiPSC-derived cells.


Subject(s)
Induced Pluripotent Stem Cells , Geminin/genetics , Geminin/metabolism , Induced Pluripotent Stem Cells/metabolism , Cell Cycle , Cell Division , Cell Cycle Proteins/genetics
4.
Stem Cell Res ; 57: 102592, 2021 Nov 03.
Article in English | MEDLINE | ID: mdl-34775202

ABSTRACT

An induced pluripotent stem cell (iPSC) line, in which a H2B-fluorescent protein fusion is temporally expressed, is a valuable tool to track cells and study cell divisions and apoptosis. To this end we introduced a 3rd generation "all-in-one" doxycycline-inducible H2B-mTurquoise2 vector into the AAVS1 locus of PAX3-Venus iPSCs via CRISPR/Cas9. H2B-mTurquoise2 expression is absent but readily induced by doxycycline allowing quantification of cell divisions and imaging of living cells. Besides being a universal reporter in iPSC-based differentiation and toxicity assays, the generated pluripotent and genomically normal LUMCi041-A-2 line is particularly suited to study PAX3-positive stages of development.

5.
Placenta ; 74: 32-35, 2018 12 15.
Article in English | MEDLINE | ID: mdl-30219583

ABSTRACT

INTRODUCTION: Smooth muscle in the decidua of fetal membranes (membrane myofibers, MMF) is not mentioned in standard textbooks. METHODS: The current report presents collected observations on 52 patients with MMF at 2 institutions between 2004 and 2017 - including placentas, postpartum curettages, and hysterectomies. RESULTS: Clinical presentations include observation of adherent membranes during delivery, disrupted and incomplete membranes in placentas submitted for examination, postpartum bleeding associated with retained fetal membranes, association with membrane hematomas and membrane hemosiderin, morbidly adherent fetal membranes in hysterectomies; and association with grossly adherent pieces of tissue or nodules in fetal membranes. DISCUSSION: Although MMF can be an incidental microscopic observation in a routine placenta, the suggested diagnostic terminology when there are clinical and/or gross presentations is Chorion Laeve Accreta (ChLA). Further study is needed but MMF appears to be the fetal membrane counterpart of BPMF(basal plate myofibers), possibly due to damage of subjacent myometrium by trophoblastic proteases, so that shear stress during delivery causes myofibers to come out attached to the decidua of fetal membranes. Neither the prevalence of MMF, nor its reliability as a marker for placenta accreta is addressed in this collection. Association of MMF with BPMF, and recurrence of MMF, are documented; but the true frequency of these phenomena remains to be established.


Subject(s)
Muscle, Smooth , Placenta Accreta/pathology , Placenta, Retained/pathology , Placenta/pathology , Adult , Female , Humans , Hysterectomy , Pregnancy , Young Adult
6.
J Neural Eng ; 15(5): 056026, 2018 10.
Article in English | MEDLINE | ID: mdl-30063219

ABSTRACT

OBJECTIVE: Brain-computer interface (BCI) technology is attracting increasing interest as a tool for enhancing recovery of motor function after stroke, yet the optimal way to apply this technology is unknown. Here, we studied the immediate and therapeutic effects of BCI-based training to control pre-movement sensorimotor rhythm (SMR) amplitude on robot-assisted finger extension in people with stroke. APPROACH: Eight people with moderate to severe hand impairment due to chronic stroke completed a four-week three-phase protocol during which they practiced finger extension with assistance from the FINGER robotic exoskeleton. In Phase 1, we identified spatiospectral SMR features for each person that correlated with the intent to extend the index and/or middle finger(s). In Phase 2, the participants learned to increase or decrease SMR features given visual feedback, without movement. In Phase 3, the participants were cued to increase or decrease their SMR features, and when successful, were then cued to immediately attempt to extend the finger(s) with robot assistance. MAIN RESULTS: Of the four participants that achieved SMR control in Phase 2, three initiated finger extensions with a reduced reaction time after decreasing (versus increasing) pre-movement SMR amplitude during Phase 3. Two also extended at least one of their fingers more forcefully after decreasing pre-movement SMR amplitude. Hand function, measured by the box and block test (BBT), improved by 7.3 ± 7.5 blocks versus 3.5 ± 3.1 blocks in those with and without SMR control, respectively. Higher BBT scores at baseline correlated with a larger change in BBT score. SIGNIFICANCE: These results suggest that learning to control person-specific pre-movement SMR features associated with finger extension can improve finger extension ability after stroke for some individuals. These results merit further investigation in a rehabilitation context.


Subject(s)
Brain-Computer Interfaces , Fingers/physiopathology , Stroke Rehabilitation/methods , Adult , Aged , Aged, 80 and over , Algorithms , Cues , Electroencephalography , Exoskeleton Device , Female , Humans , Male , Middle Aged , Movement , Reaction Time , Recovery of Function , Robotics
7.
Public Health ; 151: 87-97, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28759883

ABSTRACT

The Canadian government decision to cancel the mandatory long-form census in 2010 (subsequently restored in 2015), along with similar discussions in the United Kingdom (UK) and the United States of America (USA), have brought the purpose and use of census data into focus for epidemiologists and public health professionals. Policy decision-makers should be well-versed in the public health importance of accurate and reliable census data for emergency preparedness planning, controlling disease outbreaks, and for addressing health concerns among vulnerable populations including the elderly, low-income, racial/ethnic minorities, and special residential groups (e.g., nursing homes). Valid census information is critical to ensure that policy makers and public health practitioners have the evidence needed to: (1) establish incidence rates, mortality rates, and prevalence for the full characterization of emerging health issues; (2) address disparities in health care, prevention strategies and health outcomes among vulnerable populations; and (3) plan and effectively respond in times of disaster and emergency. At a time when budget and sample size cuts have been implemented in the UK, a voluntary census is being debated in the US. In Canada, elimination of the mandatory long-form census in 2011 resulted in unreliable population enumeration, as well as a substantial waste of money and resources for taxpayers, businesses and communities. The purpose of this article is to provide a brief overview of recent international trends and to review the foundational role of the census in public health management and planning using historical and current examples of environmental contamination, cancer clusters and emerging infections. Citing a general absence of public health applications of the census in cost-benefit analyses, we call on policy makers to consider its application to emergency preparedness, outbreak response, and chronic disease prevention efforts. At the same time, we call on public health professionals to improve published estimates of monetary benefit (via either cost-benefit or cost-effectiveness analysis) to a given public health intervention.


Subject(s)
Censuses , Public Health , Cost-Benefit Analysis , Humans , Internationality
8.
Eur J Neurol ; 24(9): 1116-1124, 2017 09.
Article in English | MEDLINE | ID: mdl-28727225

ABSTRACT

BACKGROUND AND PURPOSE: The integrity of the blood-brain barrier (BBB) has been questioned in migraine, but BBB permeability has never been investigated during spontaneous migraine attacks. In the present study, BBB permeability during spontaneous attacks of migraine without aura was investigated compared to an interictal state. METHODS: Seventy-four patients suffering from migraine without aura were recruited to participate in this cross-sectional dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) study. The patients were instructed to report at the hospital for DCE-MRI scan during and outside of a spontaneous migraine attack. The primary end-point was a difference in the BBB permeability (ml/100 g/min) between the attack and the headache-free days. The permeability was assessed in five different regions of interest (ROIs) located in the anterior, middle and posterior cerebral area, brain stem, posterior pons and whole brain. The paired samples t test was used to compare Ki (permeability) values between the attack and headache-free days. RESULTS: Nineteen patients completed the study. Median time from onset of migraine attack to scan was 6.5 h (range 4.0-15.5 h). No change in the mean BBB permeability (ml/100 g/min) was found between the attack and the headache-free days in any of the measured ROIs. No relationship between the pain side or intensity and BBB permeability was found in 15 patients with unilateral pain during the examined attack. CONCLUSIONS: It was demonstrated that the BBB permeability during spontaneous migraine attacks without aura was unchanged.


Subject(s)
Blood-Brain Barrier/diagnostic imaging , Migraine without Aura/diagnostic imaging , Adult , Blood-Brain Barrier/physiopathology , Brain/diagnostic imaging , Female , Humans , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Male , Middle Aged , Migraine without Aura/physiopathology , Pain Measurement , Permeability , Radionuclide Imaging , Young Adult
10.
Adv Exp Med Biol ; 875: 529-38, 2016.
Article in English | MEDLINE | ID: mdl-26611001

ABSTRACT

Like elephants, baleen whales produce low-frequency (LF) and even infrasonic (IF) signals, suggesting they may be particularly susceptible to underwater anthropogenic sound impacts. Analyses of computerized tomography scans and histologies of the ears in five baleen whale and two elephant species revealed that LF thresholds correlate with basilar membrane thickness/width and cochlear radii ratios. These factors are consistent with high-mass, low-stiffness membranes and broad spiral curvatures, suggesting that Mysticeti and Proboscidea evolved common inner ear adaptations over similar time scales for processing IF/LF sounds despite operating in different media.


Subject(s)
Aquatic Organisms/physiology , Ear/physiology , Elephants/physiology , Sound , Whales/physiology , Animals , Cochlea/anatomy & histology , Cochlea/physiology
11.
Oncogene ; 35(7): 833-45, 2016 Feb 18.
Article in English | MEDLINE | ID: mdl-25961927

ABSTRACT

The primary aim of this study was to evaluate the antitumor efficacy of the bromodomain inhibitor JQ1 in pancreatic ductal adenocarcinoma (PDAC) patient-derived xenograft (tumorgraft) models. A secondary aim of the study was to evaluate whether JQ1 decreases expression of the oncogene c-Myc in PDAC tumors, as has been reported for other tumor types. We used five PDAC tumorgraft models that retain specific characteristics of tumors of origin to evaluate the antitumor efficacy of JQ1. Tumor-bearing mice were treated with JQ1 (50 mg/kg daily for 21 or 28 days). Expression analyses were performed with tumors harvested from host mice after treatment with JQ1 or vehicle control. An nCounter PanCancer Pathways Panel (NanoString Technologies) of 230 cancer-related genes was used to identify gene products affected by JQ1. Quantitative RT-PCR, immunohistochemistry and immunoblots were carried out to confirm that changes in RNA expression reflected changes in protein expression. JQ1 inhibited the growth of all five tumorgraft models (P<0.05), each of which harbors a KRAS mutation; but induced no consistent change in expression of c-Myc protein. Expression profiling identified CDC25B, a regulator of cell cycle progression, as one of the three RNA species (TIMP3, LMO2 and CDC25B) downregulated by JQ1 (P<0.05). Inhibition of tumor progression was more closely related to decreased expression of nuclear CDC25B than to changes in c-Myc expression. JQ1 and other agents that inhibit the function of proteins with bromodomains merit further investigation for treating PDAC tumors. Work is ongoing in our laboratory to identify effective drug combinations that include JQ1.


Subject(s)
Antineoplastic Agents/pharmacology , Azepines/pharmacology , Carcinoma, Pancreatic Ductal/pathology , Pancreatic Neoplasms/pathology , Triazoles/pharmacology , Animals , Apoptosis/drug effects , Gene Expression/drug effects , Genes, myc , Humans , Immunoblotting , Immunohistochemistry , Mice , Mice, SCID , Nerve Tissue Proteins/antagonists & inhibitors , Oligonucleotide Array Sequence Analysis , Polymerase Chain Reaction , Receptors, Cell Surface/antagonists & inhibitors , Xenograft Model Antitumor Assays
12.
Oncogene ; 34(12): 1553-62, 2015 Mar 19.
Article in English | MEDLINE | ID: mdl-24704826

ABSTRACT

Progressive metastatic disease is a major cause of mortality for patients diagnosed with multiple types of solid tumors. One of the long-term goals of our laboratory is to identify  molecular interactions that regulate metastasis, as a basis for developing agents that inhibit this process. Toward this goal, we recently demonstrated that intercellular adhesion molecule-2 (ICAM-2) converted neuroblastoma (NB) cells from a metastatic to a non-metastatic phenotype, a previously unknown function for ICAM-2. Interestingly, ICAM-2 suppressed metastatic but not tumorigenic potential in preclinical models, supporting a novel mechanism of regulating metastasis. We hypothesized that the effects of ICAM-2 on NB cell phenotype depend on the interaction of ICAM-2 with the cytoskeletal linker protein α-actinin. The goal of the study presented here was to evaluate the impact of α-actinin binding to ICAM-2 on the phenotype of NB tumor cells. We used in silico approaches to examine the likelihood that the cytoplasmic domain of ICAM-2 binds directly to α-actinin. We then expressed variants of ICAM-2 with mutated α-actinin-binding domains, and compared the impact of ICAM-2 and each variant on NB cell adhesion, migration, anchorage-independent growth, co-precipitation with α-actinin and production of localized and disseminated tumors in vivo. The in vitro and in vivo characteristics of cells expressing ICAM-2 variants with modified α-actinin-binding domains differed from cells expressing ICAM-2 wild type (WT) and also from cells that expressed no detectable ICAM-2. Like the WT protein, ICAM-2 variants inhibited cell adhesion, migration and colony growth in vitro. However, unlike the WT protein, ICAM-2 variants did not completely suppress development of disseminated NB tumors in vivo. The data suggest the presence of α-actinin-dependent and α-actinin-independent mechanisms, and indicate that the interaction of ICAM-2 with α-actinin is critical to conferring an ICAM-2-mediated non-metastatic phenotype in NB cells.


Subject(s)
Actins/metabolism , Antigens, CD/metabolism , Cell Adhesion Molecules/metabolism , Neuroblastoma/pathology , Animals , Antigens, CD/chemistry , Antigens, CD/genetics , Binding Sites , Cell Adhesion , Cell Adhesion Molecules/chemistry , Cell Adhesion Molecules/genetics , Cell Line, Tumor , Female , Humans , Mice , Mice, SCID , Models, Molecular , Mutation , Neoplasm Metastasis , Neuroblastoma/metabolism , Protein Binding
13.
Chem Commun (Camb) ; 50(90): 13967-70, 2014 Nov 21.
Article in English | MEDLINE | ID: mdl-25265968

ABSTRACT

An iron(IV) tetrazene complex has been synthesized that is an important addition to a previously proposed catalytic aziridination cycle. It provides two key insights about the aziridination: an iron(IV) imide is formed and this imide can bind an additional ligand in the cis position.


Subject(s)
Aziridines/chemical synthesis , Organometallic Compounds/chemistry , Aziridines/chemistry , Catalysis , Crystallography, X-Ray , Models, Molecular , Molecular Structure , Organometallic Compounds/chemical synthesis
14.
Dalton Trans ; 43(21): 7687-90, 2014 Jun 07.
Article in English | MEDLINE | ID: mdl-24733683

ABSTRACT

The first tetracarbene complexes of group 13 and 14 metals have been synthesized by employing dianionic macrocyclic tetracarbene ligands. The tin, indium, and aluminium tetracarbene complexes are structurally analogous to their porphyrin or salen analogues. The aluminium complex is the first example of multiple NHCs bound to this metal centre.

15.
J Neurol ; 261(8): 1461-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24221642

ABSTRACT

Stroke is a leading cause of serious long-term disability in adults and is the second leading cause of death worldwide. Early reperfusion and neuroprotection techniques have been the focus of much effort with the aim of very acute treatment of the stroke. Targeting different mechanisms, pharmacological therapies have the potential to reduce disability in a large fraction of patients who survive the acute stroke. The brain's capacity to reorganize after stroke through plasticity mechanisms can be modulated by pharmacological agents. A number of therapeutic interventions are under study, including small molecules, growth factors, and monoclonal antibodies. Recently it has been shown that the SSRI fluoxetine improved motor deficit in patients with ischaemic stroke and hemiplegia which appeared to be independent of the presence of depression. In this context, it is of major importance to support innovative research in order to promote the emergence of new pharmacological treatments targeting neurological recovery after stroke, as opposed to acute de-occlusion and neuroprotection. This paper is the work of a group of 14 scientists with aim of (1) addressing key areas of the basic and clinical aspects of human brain plasticity after stroke and potential pharmacological targets for recovery, (2) asking questions about the most appropriate characteristics of clinical trials testing drugs in post stroke recovery and (3) proposing recommendations for future clinical trials.


Subject(s)
Clinical Trials as Topic , Neuroprotective Agents/therapeutic use , Recovery of Function/drug effects , Stroke/drug therapy , Clinical Trials as Topic/methods , Clinical Trials as Topic/standards , Clinical Trials as Topic/trends , Humans
16.
Neuroimage Clin ; 4: 182-9, 2014.
Article in English | MEDLINE | ID: mdl-24371801

ABSTRACT

OBJECTIVES: To investigate whether blood-brain barrier (BBB) permeability is disrupted in normal appearing white matter in MS patients, when compared to healthy controls and whether it is correlated with MS clinical characteristics. METHODS: Dynamic contrast-enhanced MRI was used to measure BBB permeability in 27 patients with MS and compared to 24 matched healthy controls. RESULTS: Permeability measured as K(trans) was significantly higher in periventricular normal appearing white matter (NAWM) and thalamic gray matter in MS patients when compared to healthy controls, with periventricular NAWM showing the most pronounced difference. Recent relapse coincided with significantly higher permeability in periventricular NAWM, thalamic gray matter, and MS lesions. Immunomodulatory treatment and recent relapse were significant predictors of permeability in MS lesions and periventricular NAWM. Our results suggest that after an MS relapse permeability gradually decreases, possibly an effect of immunomodulatory treatment. CONCLUSIONS: Our results emphasize the importance of BBB pathology in MS, which we find to be most prominent in the periventricular NAWM, an area prone to development of MS lesions. Both the facts that recent relapse appears to cause widespread BBB disruption and that immunomodulatory treatment seems to attenuate this effect indicate that BBB permeability is intricately linked to the presence of MS relapse activity. This may reveal further insights into the pathophysiology of MS.


Subject(s)
Blood-Brain Barrier/physiopathology , Multiple Sclerosis/pathology , Adult , Capillary Permeability/physiology , Contrast Media , Female , Humans , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Male , Middle Aged , Perfusion Imaging , Severity of Illness Index , White Matter/pathology
17.
J Chromatogr A ; 1322: 18-28, 2013 Dec 27.
Article in English | MEDLINE | ID: mdl-24268820

ABSTRACT

The production of recombinant pharmaceutical proteins in plants benefits from the low cost of upstream production and the greater scalability of plants compared to fermenter-based systems. Now that manufacturing processes that comply with current good manufacturing practices have been developed, plants can compete with established platforms on equal terms. However, the costs of downstream processing remain high, in part because of the dedicated process steps required to remove plant-specific process-related impurities. We therefore investigated whether the ideal strategy for the chromatographic removal of tobacco host cell proteins can be predicted by quantitative structure-activity relationship (QSAR) modeling to reduce the process development time and overall costs. We identified more than 100 tobacco proteins by mass spectrometry and their structures were reconstructed from X-ray crystallography, nuclear magnetic resonance spectroscopy and/or homology modeling data. The resulting three-dimensional models were used to calculate protein descriptors, and significant descriptors were selected based on recently-published retention data for model proteins to develop QSAR models for protein retention on anion, cation and mixed-mode resins. The predicted protein retention profiles were compared with experimental results using crude tobacco protein extracts. Because of the generic nature of the method, it can easily be transferred to other expression systems such as mammalian cells. The quality of the models and potential improvements are discussed.


Subject(s)
Nicotiana/metabolism , Plant Proteins/isolation & purification , Quantitative Structure-Activity Relationship , Crystallography, X-Ray , Mass Spectrometry , Nuclear Magnetic Resonance, Biomolecular , Plant Proteins/genetics , Plant Proteins/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Nicotiana/genetics
18.
J Phys Chem A ; 116(41): 10082-9, 2012 Oct 18.
Article in English | MEDLINE | ID: mdl-22650370

ABSTRACT

L(2,3)-edge X-ray magnetic circular dichroism (XMCD) spectra have been measured for the well-defined dilute Ni(II) and Mn(II) ions doped into a MgO crystal, with sub-Kelvin dilution refrigerator cooling and 2 T magnetic field magnetization. A 30-element Ge array X-ray detector has been used to measure the XMCD for these dilute ions, whose concentrations are 1400 ppm for Ni(II) and 10,000 ppm for Mn(II). Large XMCD effects have been observed for both Ni(II) and Mn(II), and multiplet simulation described the observed spectra. The fluorescence-detected L-edge absorption spectrum and XMCD of Ni(II) in MgO are comparable with both theoretical calculations and the total electron yield measured ions in similar chemical environments, at least qualitatively validating the use of the sensitive fluorescence detection technique for studying XMCD for dilute 3d metal ions, such as various metalloproteins. Sum rule analyses on the XMCD spectra are also performed. In addition, these XMCD measurements have also been used to obtain the sample's magnetization curve and the beamline's X-ray helicity curve. This study also illustrated that bend magnet beamlines are still useful in examining XMCD on dilute and paramagnetic metal sites.


Subject(s)
Fluorescence , Magnesium Oxide/chemistry , Magnetic Fields , Manganese/chemistry , Metalloproteins/chemistry , Nickel/chemistry , Circular Dichroism , X-Rays
19.
Curr Med Chem ; 19(19): 3163-87, 2012.
Article in English | MEDLINE | ID: mdl-22612701

ABSTRACT

The main obstacle in the treatment of central nervous system diseases is represented by a limited passage of diagnostic and therapeutic agents across the blood-brain barrier, which separates the blood stream from the cerebral parenchyma and maintains the homeostasis of the brain. The growing knowledge about the brain capillary endothelium and the discovery of specific mechanisms for the uptake of substances enables the development of various strategies to enhance the drug delivery rate into the brain. Among the different strategies, nanoparticles are promising candidates for drug delivery to the brain due to their potential in encapsulating drugs and thereby disguising their permeation limiting characteristics. Furthermore a surface functionalization of many nanoparticles can easily be achieved allowing the active targeting of nanoparticles to the brain. For this non-invasive approach, the surface functionalization of nanoparticles with biomolecules has shown promising potential for effective drug delivery to the brain. This review indexes the main classes of biomolecules used for the surface functionalization of nanoparticles and discusses their potential as drug delivery systems for an enhanced passage of diagnostic and therapeutic agents into the brain parenchyma.


Subject(s)
Brain Diseases/drug therapy , Brain Diseases/metabolism , Brain/metabolism , Central Nervous System Agents/administration & dosage , Drug Delivery Systems/methods , Nanoparticles/administration & dosage , Nanoparticles/chemistry , Animals , Biological Transport , Blood-Brain Barrier/metabolism , Brain/blood supply , Central Nervous System Agents/chemistry , Central Nervous System Agents/pharmacokinetics , Humans
20.
Eur J Neurol ; 19(5): 718-24, 2012 May.
Article in English | MEDLINE | ID: mdl-22221491

ABSTRACT

BACKGROUND AND PURPOSE: Recovery after stroke occurs on the basis of specific molecular events. Genetic polymorphisms associated with impaired neural repair or plasticity might reduce recovery from stroke and might also account for some of the intersubject variability in stroke recovery. This study hypothesized that the ApoE ε4 polymorphism and the val(66) met polymorphism for brain-derived neurotrophic factor (BDNF) are each associated with poorer outcome after stroke. Associations with mitochondrial genotype were also explored. METHODS: Genotypes were determined in 255 stroke patients who also received behavioral evaluations in the Glycine Antagonist In Neuroprotection (GAIN) clinical trials. The primary outcome measure was recovery during the first month post-stroke, as this is the time when neural repair is at a maximum and so when genetic influences might have their largest impact. Two secondary outcome measures at 3 months post-stroke were also examined. RESULTS: Genotype groups were similar acutely post-stroke. Presence of the ApoE ε4 polymorphism was associated with significantly poorer recovery over the first month post-stroke (P = 0.023) and with a lower proportion of subjects with minimal or no disability (modified Rankin score 0-1, P = 0.01) at 3 months post-stroke. Indeed, those with this polymorphism were approximately half as likely to achieve minimal or no disability (18.2%) versus those with polymorphism absent (35.5%). Findings were confirmed in multivariate models. Results suggested possible effects from the val(66) met BDNF polymorphism and from the R0 mitochondrial DNA haplotype. CONCLUSIONS: Genetic factors, particularly the ApoE ε4 polymorphism, might contribute to variability in outcomes after stroke.


Subject(s)
Apolipoprotein E4/genetics , Polymorphism, Genetic , Recovery of Function/genetics , Stroke/genetics , Stroke/physiopathology , Aged , Aged, 80 and over , Americas/epidemiology , Brain-Derived Neurotrophic Factor/genetics , DNA Mutational Analysis , DNA, Mitochondrial/genetics , Female , Follow-Up Studies , Genetic Testing , Genotype , Humans , Male , Methionine/genetics , Middle Aged , Multivariate Analysis , Outcome Assessment, Health Care , Valine/genetics
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