Proton Magnetic Resonance Spectroscopy Study Research Articles

Development and characterization of Brigatinib loaded solid lipid nanoparticles: In-vitro cytotoxicity against human carcinoma A549 lung cell lines

Brigatinib (BG) is a tyrosine kinase receptor inhibitor act as an antineoplastic agent by blocking the action of an abnormal protein that causes cancer cells to multiply. In the current study, nine formulae of BG loaded solid lipid nanoparticles (SLNs) were developed using 32 factorial design. SLNs were prepared by the solvent emulsification technique using stearic acid as lipid and soya- lecithin as a surfactant, both of these act as independent variables, whereas Particle size, polydispersity index (PDI), zeta potential, entrapment efficiency (EE) and drug loading (DL) were selected as responses. The particle size was found to be in the nano range (176−787 nm), fairly monodisperse (PDI indices 0.19−0.5), interparticle electrical stability was supported by zeta-potential (+1.78 mV to -15.4 mV), whereas EE and DL were in the range of (61.31–87.87 %) (3.35–31.01 %), respectively. Differential scanning calorimetry (DSC) thermograms indicated the amorphous state of BG in the SLN. Fourier transform infrared spectroscopy (FTIR) spectrums confirm non-interaction between drug and polymer while nuclear magnetic resonance (NMR) spectroscopy study revealed BG incorporation in the SLN. A scanning electron microscope (SEM) image exhibit a spherical shape of SLN. The in-vitro release profile demonstrates a sustained release pattern for the selected BS5 SLNs. MTT assay was performed on the optimized SLNs (BS5) and the results are indicative that BG loaded SLN (BS5) showed better cytotoxicity against A349 lung cell lines while compared to BG suspension and blank SLN. Thus, BG loaded SLNs can find Its better place in the non-small cell lung cancer treatment.

Prominence of the Instability of a Stabilizing Agent in the Changes in Physical State of a Hybrid Nanomaterial.

Shaping ability of hybrid nanomaterials is a key point for their further use in devices. It is therefore crucial to control it. To this end, it is necessary that the macroscopic properties of the material remain constant over time. Here, we evidence by multinuclear Magic-Angle Spinning Nuclear Magnetic Resonance spectroscopic study including 17 O isotope exchange that for a ZnO-alkylamine hybrid material, the partial carbonation of amine into ammonium carbamate molecules is behind the conversion from highly viscous liquid to a powdery solid when exposed to air. This carbonation induces modification and reorganization of the organic shell around the nanocrystals and affects significantly the macroscopic properties of the material such as it physical state, its solubility and colloidal stability. This study, straightforwardly extendable, highlights that the nature of the functional chemical group allowing connecting the stabilizing agent (SA) to the surface of the nanoparticles is of tremendous importance especially if the SA is reactive with molecules present in the environment.

IMPROVEMENT OF WATER SOLUBILITY AND IN VITRO DISSOLUTION RATE OF DEFLAZACORT BY COMPLEXATION WITH Β-CYCLODEXTRIN THROUGH FREEZE DRYING PROCESS

Deflazacort is a poorly water-soluble drug and is practically insoluble in water. The objective of this study was to improve the solubility of deflazacort by using as solubility enhancer β-cyclodextrin and also to study the effect of the water-soluble polymer PEG 4000 on solubility of the deflazacort:β-cyclodextrin binary system. The inclusion complexes of deflazacort with β-cyclodextrin in 1:1 w/w, 1:2 w/w and 1:3 w/w proportions were prepared by kneading, microwave irradiation and freeze-drying techniques. The in vitro dissolution study showed improved dissolution rate for deflazacort for freeze-dried binary deflazacort: β-cyclodextrin 1:2 w/w complex, as compared to ternary deflazacort:β-cyclodextrin: PEG 6000 1:2 w/w complexes, plain deflazacort, physical mixtures and complexes prepared by kneading and microwave technique. This was confirmed by Fourier transform infrared spectroscopy, differential scanning calorimetry, powder x-ray diffraction study, scanning electron microscopy and 1 H nuclear magnetic resonance spectroscopy study. Thus, deflazacort:β-cyclodextrin complex with improved solubility was successfully developed using freeze drying technique.

Regional Myo-Inositol, Creatine, and Choline Levels Are Higher at Older Age and Scale Negatively with Visuospatial Working Memory: A Cross-Sectional Proton MR Spectroscopy Study at 7 Tesla on Normal Cognitive Ageing

Proton MR spectroscopy (1H-MRS) has been used to assess regional neurochemical brain changes during normal ageing, but results have varied. Exploiting the increased sensitivity at ultra-high field, we performed 1H-MRS in 60 healthy human volunteers to asses age-related differences in metabolite levels and their relation to cognitive ageing. Sex was balanced, and participants were assigned to a younger, middle, and older group according to their age, ranging from 18 to 79 years. They underwent 7T 1H-MRS of the ACC, DLPFC, hippocampus, and thalamus and performed a visuospatial working memory task outside the scanner. A multivariate ANCOVA revealed a significant overall effect of age group on metabolite levels in all regions. Higher levels in the middle than the younger group were observed for myo-inositol (mIns) in DLPFC and hippocampus and total choline (tCho) in ACC. Higher levels in the older than the younger group were observed for mIns in hippocampus and thalamus, total creatine (tCr) and tCho in ACC and hippocampus; lower levels of glutamate (Glu) were observed in DLPFC. Higher levels in the older than the middle group were observed for mIns in hippocampus, tCr in ACC and hippocampus, tCho in hippocampus, and total N-acetyl aspartate (tNAA) in hippocampus. Working memory performance correlated negatively with tCr and tCho levels in ACC and mIns levels in hippocampus and thalamus, but not with tNAA or glutamate levels. As NAA and Glu are commonly regarded to reflect neuronal health and function and concentrations of mIns, tCr, and tCho are higher in glia than neurons, the findings of this study suggest a potential in vivo connection between cognitive ageing and higher regional levels of glia-related metabolites.SIGNIFICANCE STATEMENT Neurochemical ageing is an integral component of age-related cognitive decline. Proton MR spectroscopy (1H-MRS) studies of in vivo neurochemical changes across the lifespan have, however, yielded inconclusive results. 1H-MRS at ultra-high field strength can potentially improve the consistency of findings. Using 7T 1H-MRS, we assessed levels of mIns, tCr, and tCho (glia-related metabolites) and tNAA and Glu (neuron-related metabolites) in ACC, DLPFC, hippocampus, and thalamus. We found higher levels of glia-related metabolites in all brain regions in older individuals. Working memory performance correlated negatively with regional levels of glia-related metabolites. This study is the first to investigate normal ageing in these brain regions using 7T 1H-MRS and findings indicate that glia-related metabolites could be valuable in cognitive ageing studies.

Effects of Thyroid Function on Phosphodiester Concentrations in Skeletal Muscle and Liver: An In Vivo NMRS Study.

Thyroid function is clinically evaluated by determination of circulating concentrations of thyrotropin (thyroid-stimulating hormone; TSH) and free thyroxine (fT4). However, a tissue-specific effector substrate of thyroid function is lacking. Energy-rich phosphorus-containing metabolites (PM) and phospholipids (PL) might be affected by thyroid hormone action and can be noninvasively measured by 31P nuclear magnetic resonance spectroscopy (NMRS). To measure the actions of peripheral thyroid hormones on PM and PL tissue concentrations. A longitudinal, prospective pilot study was performed. Nine patients with hyperthyroidism (HYPER) and 4 patients with hypothyroidism (HYPO) were studied at baseline and 3 months after treatment. High-field 1H/31P NMRS was used to assess profiles of PM, PL, and flux through oxidative phosphorylase in liver and skeletal muscle, as well as ectopic tissue lipid content. The concentrations of total skeletal muscle (m-) and hepatic (h-) phosphodiesters (PDE) and one of the PDE constituents, glycerophosphocholine (GPC), were lower in HYPER compared with HYPO (m-PDE: 1.4 ± 0.4 mM vs 7.4 ± 3.5 mM, P = 0.003; m-GPC: 0.9 ± 0.3 mM vs 6.7 ± 3.5 mM, P = 0.003; h-PDE: 4.4 ± 1.4 mM vs 9.9 ± 3.9 mM, P = 0.012; h-GPC: 2.2 ± 1.0 mM vs 5.1 ± 2.4 mM, P = 0.024). Both h-GPC (rho = -0.692, P = 0.018) and h-GPE (rho = -0.633, P = 0.036) correlated negatively with fT4. In muscle tissue, a strong negative association between m-GPC and fT4 (rho = -0.754, P = 0.003) was observed. Thyroxine is closely negatively associated with the PDE concentrations in liver and skeletal muscle. Normalization of thyroid dysfunction resulted in a decline of PDE in hypothyroidism and an increase in hyperthyroidism. Thus, PDE might be a sensitive tool to estimate tissue-specific peripheral thyroid hormone action.

Investigations on 2-(4-Cyanophenylamino) acetic acid by FT-IR,FT-Raman, NMR and UV-Vis spectroscopy, DFT (NBO, HOMO-LUMO, MEP and Fukui function) and molecular docking studies

Extensive quantum chemical calculation have been carried out to investigate the Fourier Transform Infrared(FT-IR), Fourier Transform Raman(FT-RAMAN) and Nuclear magnetic resonance(NMR), and Ultra Violet-Visible(UV-vis) spectra of 2-(4-Cyanophenylamino) acetic acid. The molecular structure, fundamental vibrational frequencies and intensities of the vibrational bands were interpreted with the aid of optimizations and normal coordinate force field calculations based on density functional theory (DFT) and ab initio HF methods with 6–311++G(d,p) basis set. The theoretical vibrational wavenumbers are compared with the experimental values. The calculated HOMO-LUMO energies were found to be-6.2056 eV and -1.2901 eV which indicates the charge transfer within the molecule. Natural bond orbital analysis has been carried out to explain the charge transfer (or) delocalization of charge due to the intra molecular interactions. Molecular Electrostatic Potential (MEP), First order hyperpolarizability, and Fukui functions calculation were also performed. The thermodynamic properties of the title compound were studied for different temperatures. Molecular docking studies were made on the title compound to study the hydrogen bond interactions and the minimum binding energy was calculated.

Influence of Oxidation Degree of Graphene Oxide on Its Nuclear Relaxivity and Contrast in MRI.

Graphene oxide (GO) serves as a versatile platform for various applications, with the oxygen content of GO playing an important role in governing its properties. In the present study, different GO types covering a wide range of oxidation degree were prepared using our newly developed two-step method involving ball milling of graphite followed by its oxidation to GO. In addition to the variations in their physicochemical properties, the different GO types exhibited differences in proton relaxivity due to their paramagnetic nature. Nuclear magnetic resonance spectroscopy studies showed that the degree of oxidation of GO perturbs its nuclear relaxation properties and, together with intercalated Mn2+ ions, provides large contrast variation in magnetic resonance imaging (MRI). The study for the first time reveals that the surface chemistry of GO affects its relaxivity and opens up new avenues for developing tunable GO-based contrast agents in magnetic resonance imaging for diagnostics and therapies.

Characterization of hydrogenated dentin components by advanced 1H solid-state NMR experiments

Collecting information about molecular organisation on biological materials such as bone and dentin represents a major challenge in attaining a better understanding of their mechanical properties. To that end, solid state Nuclear Magnetic Resonance (ssNMR) spectroscopic study is an appropriate strategy to provide atomic structural details on these amorphous composite materials. However, species like water molecules and hydroxyl groups are usually observed through 1H magic angle spinning (MAS) ssNMR that suffers from poor resolution due to strong signal overlapping, making their identification difficult.This paper proposes a set of ssNMR experiments for 1H characterization of the main components of human dentin, based on homo- and hetero-nuclear dipolar couplings and composed mostly of fast 1D experiments. The 1H assignment is assisted by straightforward sample modifications: vacuum drying, deuterium exchange and demineralization. These experiments allow the hydrogen signal edition of dentin species like water molecules, HPO42− and OH− groups, depending on their localization (bound to the organic phase, linked to apatite or at the interface) and their dynamic behaviour. This ssNMR toolbox has the potential to provide important structural and dynamic information on chemical and physical modifications of biomaterials. Statement of SignificanceMolecular characterisation of apatitic biomaterials by biophysical techniques is extremely difficult due to their complex and amorphous nature. It is, however, crucial to obtain such information if we want to understand their mechanical properties in relation to their physical state, for example their hydration levels. In this article we used a set of solid state NMR experiments and sample modifications to distinguish 1H signal of human dentin components with a particular attention to water molecules, known for their major role in biomaterial structuring.

Site-Dependent Spin Delocalization and Evidence of Ferrimagnetism in Atomically Precise Au25(SR)180 Clusters as Seen by Solution 13C NMR Spectroscopy.

We report a simple but detailed solution 13C nuclear magnetic resonance spectroscopic study of atomically precise neutral Au25(SR)180 (SR = alkyl thiolate) clusters. The paramagnetic 13C Knight shift of alkyl chain carbons, which is proportional to the local electron spin density, exhibits an electron spin delocalization that exponentially decays along the alkyl chain. The magnitude and decay constant of the observed electron spin delocalization, although largely independent of alkyl chain length, depend on where, that is, "in" versus "out" (vide infra) position, the alkyl chain is bound, in agreement with density functional theory calculations. Notably, the determined position-dependent decay constants, 1.70/Å and 0.41/Å for "in" and "out" ligands, respectively, not only could have important ramifications in molecular spintronics but are also comparable to measured decay constants in molecular electrical conductance of alkyl chains, potentially offering an alternative, simple method for estimating the latter. Moreover, the negative intercept temperatures of linear fits of reciprocal 13C (as well its bound 1H) Knight shift versus temperature strongly suggest the existence of local ferrimagnetism in individual Au25(SR)180 clusters.

Metabolite abnormalities in psychosis risk: A meta-analysis of proton magnetic resonance spectroscopy studies.

Accumulating evidence implicates that individuals at high-risk of psychosis have already exhibited pathophysiological changes in brain metabolites including glutamate, gamma-Aminobutyric Acid (GABA), N-Acetylaspartate (NAA), creatine (Cr), myo-inositol (MI) and choline (Cho). These changes may contribute to the development of schizophrenia and associate with psychotic genes. However, specific metabolic changes of brain sub-regions in individuals at risk have still been controversial. Thus, the current study aimed to investigate the brain metabolic changes including glutamate, Glx, GABA, GABA/Glx, NAA, Cr, MI and Cho levels in individuals at risk by conducting a case-control meta-analysis and meta-regression of proton magnetic resonance spectroscopy studies. Primary outcomes revealed that individuals at risk exhibited increased Cr levels at the rostral medial prefrontal cortex (rmPFC), decreased NAA and Cr levels at the thalamus, and increased MI levels at the dorsolateral prefrontal cortex. Sub-group analyses further indicated that individuals with clinical high-risk (CHR) exhibited increased Cr levels at the medial prefrontal cortex (mPFC) and decreased Glx levels at the thalamus, while individuals with genetic risk (siblings of psychiatric patients) exhibited significant increased Glx and MI levels at the mPFC. However, GABA, GABA/Glx and Cho levels showed no significant result. These findings suggest that the dysfunctional metabolites at the mPFC and the thalamus may be an essential neurobiological basis at the early stage of psychosis.

In Vivo 1 H MR Spectroscopy of Biliary Components of Human Gallbladder at 7T.

BackgroundPrevious in vivo proton MR spectroscopy (MRS) studies have demonstrated the possibility of quantifying amide groups of conjugated bile acids (NHCBA), olefinic lipids and cholesterol (OLC), choline‐containing phospholipids (CCPLs), taurine and glycine conjugated bile acids (TCBA, GCBA), methylene group of lipids (ML), and methyl groups of bile acids, lipids, and cholesterol (BALC1.0, BALC0.9, and TBAC) in the gallbladder, which may be useful for the study of cholestatic diseases and cholangiopathies. However, these studies were performed at 1.5T and 3T, and higher magnetic fields may offer improved spectral resolution and signal intensity.PurposeTo develop a method for gallbladder MRS at 7T.Study TypeRetrospective, technical development.PopulationTen healthy subjects (five males and five females), two patients with primary biliary cholangitis (PBC) (one male and one female), and one patient with primary sclerosing cholangitis (PSC) (female).Field Strength/SequenceFree‐breathing single‐voxel MRS with a modified stimulated echo acquisition mode (STEAM) sequence at 7T.AssessmentPostprocessing was based on the T2 relaxation of water in the gallbladder and in the liver. Concentrations of biliary components were calculated using water signal. All data were corrected for T2 relaxation times measured in healthy subjects.Statistical TestsThe range of T2 relaxation time and concentration per bile component, and the resulting mean and standard deviation, were calculated.ResultsThe concentrations of gallbladder components in healthy subjects were: NHCBA: 93 ± 66 mM, OLC: 154 ± 124 mM, CCPL: 42 ± 17 mM, TCBA: 48 ± 35 mM, GCBA: 67 ± 32 mM, ML: 740 ± 391 mM, BALC1.0: 175 ± 92 mM, BALC0.9: 260 ± 138 mM, and TBAC: 153 ± 90 mM. Mean concentrations of all bile components were found to be lower in patients.Data ConclusionThis work provides a protocol for designing future MRS investigations of the bile system in vivo.Evidence Level2Technical Efficacy Stage1

S7. INVESTIGATING THE LINK BETWEEN THE PERIPHERAL ENDOCANNABINOID SYSTEM AND CENTRAL GLUTAMATERGIC NEUROTRANSMISSION IN EARLY PSYCHOSIS: A 7T-MRS STUDY

BackgroundMeta-analytic evidence showed increased levels of peripheral endocannabinoid metabolites in psychotic illness. Alterations in the endocannabinoid system are believed to compromise glutamate and dopamine transmission, which play a central role in pathophysiological models of psychosis. I will present preliminary data from an ongoing high-field proton magnetic resonance spectroscopy (MRS) study aimed at investigating the association between peripheral levels of endocannabinoid system metabolites and central glutamate metabolism in individuals at their first non-affective psychotic episode (NA-FEP) and healthy controls.MethodsWe expect to recruit 17 NA-FEP and 20 healthy controls by January 2020. Currently, we recruited 12 NA-FEP and 18 healthy controls from two different research facilities (Imperial College London and University of Oxford) as part of a cross-sectional study. Participants underwent MRS scanning at 7-T with voxels placed in right dorsolateral prefrontal cortex (right-DLPFC), anterior cingulate cortex (ACC), and occipital cortex. Neuro-metabolites will be calculated using the unsuppressed water signal as reference. Endocannabinoid metabolites were quantified from serum samples, collected during the same imaging session.ResultsAnalyses are ongoing. Based on previous evidence, expected findings are: (i) reduced glutamate levels in the ACC and right-DLPFC of NA-FEP compared to controls; (ii) increased peripheral endocannabinoid metabolites in NA-FEP compared to controls; and (iii) inverse association between peripheral endocannabinoid metabolites and glutamate levels in ACC and right-DLPFC in NA-FEPDiscussionThis study will help clarifying the contribution of peripheral endocannabinoid system to central brain mechanisms of key relevance for psychotic illness. It will also add further evidence on the limited literature on high-resolution characterisation of brain metabolites in early psychosis. Strengths of the study include: (i) use of high-field MRS, which allows the estimation of glutamate-related compounds at higher precision than at lower field strength; (ii) reduced heterogeneity of the clinical sample (only male and NA-FEP). Limitations: small sample size and cross-sectional design.

Glutamatergic hypo-function in the left superior and middle temporal gyri in early schizophrenia: a data-driven three-dimensional proton spectroscopic imaging study.

Proton magnetic resonance spectroscopy (1H-MRS) studies have examined glutamatergic abnormalities in schizophrenia, mostly in single voxels. Though the critical brain nodes remain unknown, schizophrenia involves networks with broad abnormalities. Hence, glutamine plus glutamate (Glx) and other metabolites were examined with whole-brain 1H-MRS, in early schizophrenia. Three dimensional 1H-MRS was acquired in young schizophrenia subjects (N = 36, 19 antipsychotic-naïve and 17 antipsychotic-treated) and healthy controls (HC, N = 29). Glx (as well as N-acetylaspartate, choline, myo-inositol and creatine) group contrasts from all individual voxels that met spectral quality, were analyzed in common brain space, followed by cluster-corrected level alpha-value (CCLAV ≤ 0.05). Schizophrenia subjects had lower Glx in the left superior (STG) and middle temporal gyri (16 voxels, CCLAV = 0.04) and increased creatine in two clusters involving left temporal, parietal and occipital regions (32, and 18 voxels, CCLAV = 0.02 and 0.04, respectively). Antipsychotic-treated and naïve patients (vs HC) had similar Glx reductions (8/16 vs 10/16 voxels respectively, but CCLAV’s > 0.05). However, creatine was higher in antipsychotic-treated vs HC’s in a larger left hemisphere cluster (100 voxels, CCLAV = 0.01). Also in treated patients, choline was increased in left middle frontal gyrus (18 voxels, CCLAV = 0.04). Finally in antipsychotic-naive patients, NAA was reduced in right frontal gyri (19 voxels, CCLAV = 0.05) and myo-inositol was reduced in the left cerebellum (34 voxels, CCLAV = 0.02). We conclude that data-driven spectroscopic brain examination supports that reductions in Glx in the left STG may be critical to the pathophysiology of schizophrenia. Postmortem and neuromodulation schizophrenia studies focusing on left STG, may provide critical mechanistic and therapeutic advancements, respectively.

Hippocampal glutamate and hippocampus subfield volumes in antipsychotic-naive first episode psychosis subjects and relationships to duration of untreated psychosis

Evidence points toward a relationship between longer duration of untreated psychosis (DUP) and worse long-term outcomes in patients with first episode psychosis (FEP), but the underlying neurobiology remains poorly understood. Proton magnetic resonance spectroscopy studies have reported altered hippocampus glutamatergic neurotransmission, and structural MRI as reported hippocampal atrophy that may be associated with memory impairment in schizophrenia. Here, we quantify left hippocampus glutamate (Glx) and left hippocampus subfield volumes in 54 antipsychotic-naive FEP and 41 healthy controls (HC), matched on age, sex, and parental occupation. While there were no significant group difference in Glx levels, hippocampal Glx levels were significantly higher in those who underwent a long DUP (>12 months) compared to those with a short DUP, and compared to HC. Compared to HC, FEP had significantly reduced whole hippocampus volume, as well as of CA1, CA4, granule cell layer, subiculum, and presubiculum subfields. Smaller whole hippocampal volume, as well as CA1, molecular layer, subiculum, presubiculum, and hippocampal tail volumes were significantly associated with longer DUP. However, we found no significant association between hippocampal Glx levels and hippocampal volume or subfields, suggesting that these alterations are not related, or their relationship does not follow a linear pattern. However, our results strongly suggest that one or several pathophysiological processes underlie the DUP. Importantly, our data highlight the critical need for reducing the DUP and for early pharmacological intervention with the hope to prevent structural deficits and, hopefully, improve clinical outcomes.

A combined NMR, MD and DFT conformational analysis of 9-O-acetyl sialic acid-containing GM3 ganglioside glycan and its 9-N-acetyl mimic.

O-Acetylation of carbohydrates such as sialic acids is common in nature, but its role is not clearly understood due to the lability of O-acetyl groups. We demonstrated previously that 9-acetamido-9-deoxy-N-acetylneuraminic acid (Neu5Ac9NAc) is a chemically and biologically stable mimic of the 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac2) of the corresponding sialoglycans. Here, a systematic nuclear magnetic resonance (NMR) spectroscopic and molecular dynamics (MD) simulation study was undertaken for Neu5,9Ac2-containing GM3 ganglioside glycan (GM3-glycan) and its Neu5Ac9NAc analog. GM3-glycan with Neu5Ac as the non-O-acetyl form of Neu5,9Ac2 was used as a control. Complete 1H and 13C NMR chemical shift assignments, three-bond 1H-13C trans-glycosidic coupling constants (3JCH), accurate 1H-1H coupling constants (3JHH), nuclear Overhauser effects and hydrogen bonding detection were carried out. Results show that structural modification (O- or N-acetylation) on the C-9 of Neu5Ac in GM3 glycan does not cause significant conformational changes on either its glycosidic dihedral angles or its secondary structure. All structural differences are confined to the Neu5Ac glycerol chain, and minor temperature-dependent changes are seen in the aglycone portion. We also used Density Functional Theory (DFT) quantum mechanical calculations to improve currently used 3JHH Karplus relations. Furthermore, OH chemical shifts were assigned at -10°C and no evidence of an intramolecular hydrogen bond was observed. The results provide additional evidence regarding structural similarities between sialosides containing 9-N-acetylated and 9-O-acetylated Neu5Ac and support the opportunity of using 9-N-acetylated Neu5Ac as a stable mimic to study the biochemical role of 9-O-acetylated Neu5Ac.

An in vivo proton magnetic resonance spectroscopy study with optimized echo-time technique for concurrent quantification and T2 measurement targeting glutamate in the rat brain.

The present study applied in vivo proton magnetic resonance spectroscopy (1H MRS) to concurrently measure the concentration and T2 relaxation time of glutamate with the concept of optimized-for-quantification-and-T2-measurement-of-glutamate (OpQT2-Glu). 7T MRS scans of the OpQT2-Glu were acquired from the prefrontal cortex of five rats. The echo-time-(TE)-specific J-modulation of glutamate was investigated by spectral simulations and analyses for selecting the eight TEs appropriate for T2 estimation of glutamate. The OpQT2-Glu results were compared to those of the typical short-TE MRS and T2 measurements. No significant differences were observed between the OpQT2-Glu and typical short-TE MRS (p > 0.050). The estimated glutamate T2 (67.75ms) of the OpQT2-Glu was similar to the multiple TE MRS for the T2 measurement (71.58ms) with enhanced signal-to-noise ratio and reliability. The results revealed that the quantification reliability of the OpQT2-Glu was comparable to that of the single short-TE MRS and its estimation reliability for the T2 relaxation time of glutamate was enhanced compared to the multiple TE MRS for T2 measurement. Despite certain limitations, the quantification and T2 estimation of glutamate can be concurrently performed within an acceptable scan time via high-field in vivo 1H MRS with the OpQT2-Glu.

Increased myoinositol in the anterior cingulate cortex of veterans with a history of traumatic brain injury: a proton magnetic resonance spectroscopy study.

Traumatic brain injury (TBI) is one of the most prevalent forms of morbidity in veterans and service members, with mild traumatic brain injury (mTBI) being the most common. The diagnosis of mTBI in veterans is difficult because of mixed etiologies and high comorbidity with other disorders such as posttraumatic stress disorder (PTSD), depression, and substance use. Advanced neuroimaging techniques such as magnetic resonance spectroscopy (MRS) may be useful in identifying neurochemical alterations in TBI, which may aid the development of new targets for therapeutic intervention. Veterans with (n = 53) and without a history of TBI (n = 26) underwent single-voxel proton magnetic resonance spectroscopy (1H MRS) at 3 Tesla in the anterior cingulate cortex (ACC) using a two-dimensional J-resolved point spectroscopy sequence in addition to completing a clinical battery. TBI diagnosis was made using the research version of the Ohio State University TBI Identification Method. An increased myoinositol (mI)/H2O ratio was observed in the ACC of the TBI group compared with the non-TBI group during the chronic stage of TBI (average of 139.7 mo after injury), which may be reflective of astrogliosis. Several metabolites in the ACC demonstrated significant associations with TBI variables, including number of TBI with loss of consciousness (LOC) and time since most severe TBI, suggesting that changes in some metabolites may be potential diagnostic and prognostic indicators.NEW & NOTEWORTHY In this study of veterans, we used a state-of-the-art neuroimaging tool to probe the neurometabolic profile of the anterior cingulate cortex in veterans with traumatic brain injury (TBI). We report significantly elevated myoinositol levels in veterans with TBI compared with those without TBI.

Effect of ethoxylation and lauryl alcohol on the self-assembly of sodium laurylsulfate: Significant structural and rheological transformation

Fatty alcohols are added to the surfactant solutions to modify foaming and lubrication properties, while the degree of ethoxylation is increased to improve mildness to the skin. However, it is envisioned that both parameters are capable of manipulating rheological and morphological properties. Therefore, an efficient control over the carbon chain length, amount of fatty alcohol and degree of ethoxylation could modify the surfactant self-assembly in an unprecedented way. The present work is focused on understanding the structural transformation, intermolecular interactions and rheological properties of the colloidal systems containing various amounts of lauryl alcohol (LA), and surfactant with varying degrees of ethoxylation. Combined small-angle neutron scattering (SANS), nuclear magnetic resonance (NMR) spectroscopy, rheological and morphological studies were performed to elucidate these properties. The results reveal that an increase in LA content increases the system viscosity ultimately forming a gel, and drives the assembly pattern of the surfactant from ellipsoidal micellar to lamellar via a vesicular and vesicular/lamellar mixed intermediates. On the other hand, higher degrees of ethoxylation delay the onset of morphological transformation and gel formation. The interplay between hydrophobic and polar interactions coupled with hydrogen bonding interactions drive the overall rheological and morphological transformations. Therefore, fine-tuning residual chemicals can offer a novel tool for optimization of the product formulation.

Confocal microscopic and nuclear magnetic resonance (NMR) spectroscopic studies of tea leaves treated with green synthesized silver nanoparticles

Confocal microscopic and nuclear magnetic resonance (NMR) spectroscopic studies of tea leaves treated with green synthesized silver nanoparticles

N-Acetyl-Aspartate in the Dorsolateral Prefrontal Cortex Long After Concussion in Youth.

Despite increasing interest in the neurobiological effects of concussion in youth, a paucity of information is available regarding outcomes long after injury. The objective of this study was to determine the association between a history of concussion and the putative neuronal marker N-acetyl-aspartate (NAA) in the dorsolateral prefrontal cortex (DLPFC) in youth. Outpatient clinic in a children's hospital. Youth with concussion (N = 35, mean = 2.63, SD = 1.07 years postinjury) and youth with a nonconcussive orthopedic injury (N = 17) participated. A cross-sectional proton magnetic resonance spectroscopy (H-MRS) study. The primary outcome measure was NAA concentration in the right and left DLPFCs. We observed lower levels of NAA in the right DLPFC in youth with past concussion (F = 3.31, df = 4,51, P = .018) than in orthopedic controls but not in the left DLPFC (F = 2.04, df = 4,51, P = .105). The effect of lower NAA concentrations in the right DLPFC was primarily driven by youth with a single prior concussion versus those with multiple concussions. NAA in the left DLPFC, but not in right DLPFC, was associated with worse emotional symptoms in youth with concussion. The presence of lower levels of DLPFC NAA suggests potential association of concussion in youth, although further investigation is needed, given that the result is driven by those with a single (and not multiple) concussion. Exploration of applying MRS in other brain regions is also warranted.