A Positron Emission Tomography Analysis of Glucose Metabolism in Alzheimer's Disease Brain Using [18F] Fluorodeoxyglucose: A Parallel Study with Elemental Concentrations

Alzheimer's disease (AD) is a debilitating form of dementia which leads to impaired memory, thinking and behavior. This work examines elemental concentrations between "normal" and AD subjects as well as the hemispherical differences within the brain. Tissue samples from both hemispheres of the frontal lobe in both AD and normal subjects were examined for their trace element concentrations using PIXE and RBS analyses. Elemental concentrations were seen to differ between AD and normal brain tissue samples. While in the normal group concentrations were found to be significantly higher in the right hemisphere than in the left the converse was true in AD. A change in elemental concentrations may indicate possible alterations in the function of the blood brain barrier. This was examined by determining regional cerebral metabolic rates of glucose (rCMRGlu) using the in vivo technique of positron emission tomography (PET). Again variations between both hemispheres and between AD and normal were found.     

Hemispherical dominance of glucose metabolic rate in the brain of the 'normal' ageing population

In the 'normal' ageing brain a decrease in the cerebral metabolic rate has been determined across many brain regions. This study determines whether age differences would affect metabolic rates in regions and different hemispheres of the brain. The regional metabolic rate of glucose (rCMRGlu) was examined in a group of 72 subjects, ages 22 to 82 years, with 36 regions of interest chosen from both hemispheres of the cortex, midbrain and cerebellum. To determine metabolic rates the in-vivo technique of positron emission tomography (PET) was employed. Three age groups were chosen to compare hemispherical differences. In both young and intermediate age groups the left hemisphere had higher rCMRGlu values than those of the right for the majority of regions with, although less pronounced in the intermediate group. Importantly, the older age group displayed little difference between hemispheres. This revised version was published online in August 2006 with corrections to the Cover Date.     

Several methods to determine heavy metals in the human brain

The determination of naturally occurring heavy metals in various parts of the human brain is discussed. The patients had no diseases in their central nervous systems (five individuals, mean age 70 years). Twenty brain parts were selected from both hemispheres. The analysis was carried out by graphite furnace atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and instrumental neutron activation analysis methods. Accuracy and precision of the applied techniques were tested by using standard reference materials. Two digestion methods were used to dissolve the brain samples for ICP-AES and GF-AAS. One was performed in a Parr-bomb and the second in a microwave oven. The present results show a non-homogeneous distribution of the essential elements (Cu, Fe, Mn, Zn) in normal human brain. Corresponding regions in both hemispheres showed an almost identical concentration of these elements. In the case of toxic elements (Pb, Cd) an average value in different brain regions can not be established because of the high variability of individual data. This study indicates that beside differences in Pb and Cd intake with foods or cigarette smoke inhalation, the main factors of the high inter-individual variability of these element concentrations in human brain parts may be a marked difference in individual elimination or accumulation capabilities.     

Hierarchical clustering into groups of human brain regions according to elemental composition

Thirteen brain regions were dissected from both hemispheres of fifteen ‘normal’ ageing subjects (8 females, 7 males) of mean age 79±7 years. Elemental compositions were determined by simultaneous application of particle induced X-ray emissions (PIXE) and Rutherford backscattering (RBS) analyses using a 2 MeV, 4nA proton beam scaned over 4 mm² of the sample surface. Elemental concentrations were found to be dependent upon the brain region and hemisphere studied. Hierarchical cluster analysis was applied to group the brain regions according to the sample concentrations of eight elements. The resulting dendrogram is preseted and its clusters related to the sample compositions of grey and white matter.     

卒中后癫痫的静息态脑功能磁共振成像研究

本文探讨了静息态脑功能磁共振成像(rs-fMRI)检查在评价卒中后癫痫患者静息态脑功能改变中的应用价值。选择2017年5月~2019年5月我院收治的80例卒中后癫痫患者作为观察组,另选择同期健康体检者53例作为对照组。两组均完成rs-fMRI检查,采集相关数据,计算并比较两组被试全脑低频振幅(ALFF)值。分别以大脑(小脑)ALFF差异区作为种子区,计算并比较其与小脑(大脑)所有体素之间静息态功能连接(rsFC)。与对照组比较,卒中后癫痫患者右侧楔前叶、左侧额中回的ALFF明显升高,而右侧海马、右侧小脑脚2区、左侧小脑4/5区的ALFF明显降低(P<0.05)。以各大脑ALFF差异区(右侧海马、右侧楔前叶、左侧额中回)作为种子区域,卒中后癫痫患者依次对应在左侧小脑8区、右侧小脑4/5区的rsFC值明显升高(P<0.05);以各小脑ALFF差异区(右侧小脑脚2区、左侧小脑4/5区)作为种子区域,卒中后癫痫患者依次对应在左侧额下回、右侧颞中回的rsFC值明显降低(P<0.05)。结果表明,卒中后癫痫患者大脑和小脑之间多个脑区功能连通性发生改变,rs-fMRI检查可客观评价患者静息态脑功能变化,为患者的临床诊疗及预后评估提供影像学依据。     

An environmental pollution study of Indian metropolitan cities and Industrial surroundings by INAA

The process of urbanization and industrialization during las two decades has resulted in increased level of air pollution causing hazards to human health. Instrumental neutron activation analysis (INAA) using short and long term irradiation has been employed for the determination of more than 30 elements in suspended particulate matter (SPM) from six metropolitan cities and three industrial surroundings. A comparison of mean elemental contents in dust particulates from commercial, industrial and residential zones of Delhi, Calcutta, Madras, Cochin, Bombay and Nagpur cities has shown wide variation in toxic pollutant (As, Br, Cr, Cu, Hg and Sb) concentrations. Coastal areas have shown higher concentrations of Na, K, Cl and Br. Highly industrialized Bombay showed highest levels of Br, Cl, Cr, Fe, Mg, P, Rb and Sc. Mean elemental contents in fugitive and ambient dust of a cement factory and thermal power station (both in central India) are widely different. SPM levels in fugitive dust of the two industrial surroundings are higher by an order of magnitude compared to ambient air. Analysis of ambient air dust from a paper mill showed highest concentrations of Hg, Sb and Zn. Elemental data have been compared with those of Urban Particulate Matter (SRM 1648), Coal Fly Ash (SRM 1633a) and Vehicle Exhaust Particulate (NIES No. 8) which were analysed for quality control. An attempt has been made to attribute the elemental contents to possible sources of origin.     

微型化学实验与创新教育

从思维科学的角度来看,采用微型化学实验进行化学教学,能促进学生左右脑的协调发展,是培养学生创造性思维和创新能力,实施素质教育的有效途径。     

Analytical and statistical analysis of elemental composition of lichens

The elemental composition of lichens from remote southern South America regions has been studied with analytical and statistical techniques to determine if the values obtained reflect species, growth forms or habitat characteristics. The enrichment factors are calculated discriminated by species and collection site and compared with data available in the literature. The elemental concentrations are standardized and compared for different species. The information was statistically processed, a cluster analysis was performed using the three first principal axes of the PCA; the three groups formed are presented. Their relationship with the species, collection sites and the lichen growth forms are interpreted.     

Determination of elements in different parts of goat brain using k 0 instrumental neutron activation analysis

Researcher’s interest is increasing worldwide to study the role of trace elements in brain tissues. This paper discusses the application of k ₀-instrumental neutron activation analysis to study the distribution of trace elements in seven different anatomical regions of goat brain. These regions include cerebellum, cerebrum, medulla oblongata, meninges, midbrain, pons and thalamus. The analysis protocol followed 1 h irradiation at 10 MW material testing type nuclear research reactor with nominal thermal neutron flux of 2 × 10¹³ cm^?2 s^?1. A total of 14 elements, namely Br, Co, Cr, Eu, Fe, Hg, K, Na, Rb, Sb, Sc, Se, Tb and Zn were determined in all parts. Reliability of the method was assessed by analyzing biological reference material IAEA-336 (lichen). On comparing the analytical results with the healthy human brain data, it showed that eight elements (Eu, K, Na, Rb, Sb, Sc, Se, Tb) were found with relatively higher elemental concentrations in human brain. Principal component analysis revealed distribution of seven parts in different three groups having similar elemental concentrations of elements.     

Environmental pollution study by multielemental neutron activation analysis of garden soil samples from Nagpur City, India

A multielemental instrumental neutron activation analysis (INAA) method has been employed for the determination of 30 elements in seven garden soil samples from Nagpur City and two intercomparison soil standards from IAEA, Vienna and Institute of Radioecology and Applied Nuclear Techniques (IRANT), Slovak Republic. Environmental implications of elemental concentrations in different soils have been discussed.     

Trace element concentration differences in regions of human brain by INAA

Studies have shown that there is a potential relationship between the levels of trace elements in cerebral tissues and neurological disorders. However, there are few publications available on the elemental composition of these tissues as well as for different regions of the brain. The aim of this study was to investigate trace element differences in various regions of the human brain from an elderly population of normal individuals. Brain samples from 31 individuals of both genders, aged 51–95 years were provided by the Brain Bank of the Brazilian Aging Study Group of the São Paulo University, Medical School. The tissues from the regions of the hippocampus, cerebellum and frontal, parietal, temporal, occipital cortex were dissected using a titanium knife, ground, freeze-dried and then analyzed by instrumental neutron activation analysis (INAA). Samples and element standards were irradiated with a neutron flux at the IEA-R1 nuclear research reactor for Br, Fe, K, Na, Rb, Se and Zn determinations. One-way ANOVA test (p < 0.05) was used to compare the results which showed significant differences for several elements among the brain regions. Most of our brain analysis results agreed with the literature data. The results were also submitted for brain region classification by cluster analysis.     

Hierarchical clustering of Alzheimer and “normal” brains using elemental concentrations and glucose metabolism determined by PIXE, INAA and PET

Brain tissue samples, obtained from the Alzheimer Disease Brain Bank,Institute of Psychiatry, London, were taken from both left and right hemispheresof three regions of the cerebrum, namely the frontal, parietal and occipitallobes for both Alzheimer and 'normal' subjects. Trace elementconcentrations in the frontal lobe were determined for twenty six Alzheimer(15 male, 11 female) and twenty six 'normal' (8 male, 18 female)brain tissue samples. In the parietal lobe ten Alzheimer (2 male, 8 female)and ten 'normal' (8 male, 2 female) samples were taken along withten Alzheimer (4 male, 6 female) and ten 'normal' (6 male, 4 female)from the occipital lobe. For the frontal lobe trace element concentrationswere determined using proton induced X-ray emission (PIXE) analysis whilein parietal and occipital regions instrumental neutron activation analysis(INAA) was used. Additionally eighteen Alzheimer (9 male, 9 female) and eighteenage matched 'normal' (8 male, 10 female) living subjects wereexamined using positron emission tomography (PET) in order to determine regionalcerebral metabolic rates of glucose (rCMRGlu). The rCMRGlu of 36 regions ofthe brain was investigated including frontal, occipital and parietal lobesas in the trace element study. Hierarchical cluster analysis was applied tothe trace element and glucose metabolism data to discover which variablesin the resulting dendrograms displayed the most significant separation betweenAlzheimer and 'normal' subjects.     

Elemental composition of vegetables cultivated in illegal mining towns in Ghana using neutron activation analysis

The elemental concentrations of 12 elements from five species of the most consumed vegetables in Ghana cultivated in five mining and three non-mining towns have been analyzed using neutron activation analysis. About 50% of the total concentrations recorded for cadmium and arsenic for the various towns and vegetables were found to be above the World Health Organization (WHO) permissible levels. The statistical methods employed in this work also provided more understanding on the geographical distribution of the elements, vegetables and sampling towns. The principal component analysis of our data showed two major clusters consisting of gold mining towns and non-gold mining towns in relation to the elemental concentrations of vegetables cultivated in these towns.     

Evaluation of soil to tea plant elemental correlation using instrumental neutron activation analysis

Instrumental neutron activation analysis using relative and k ₀-based internal monostandard methods were employed for determination of concentrations of 12 elements in soil and tea plants collected from three different tea producing regions in India namely Assam, Darjeeling and Kangra. A total of 17 tea leaf samples along with corresponding soil samples were analyzed for elemental content. The obtained concentration data was used for the soil–plant elemental correlation studies. Positive correlation was observed between elemental concentrations of tea plants and the associated soil with Pearson correlation coefficient values in the range 0.6–0.9 for ten elements. Variations in transfer factor values were also observed according to the geo-chemical variation.     

Concentrations of elements in brain tumours

The aim of our experiments was to investigate the possible elemental concentration changes in brain tumours (glioblastoma multiforme). Our project also incorporated the determination of the regional distribution of elements in normal human brains. 17 elements (Na, K, Ca, Mg, Fe, P, S, Al, B, Ba, Co, Cr, Ni, Mn, Pb, Sr, Zn) have been measured in 21 different regions of 20 normal brains and in clinically and histopathologically selected brain regions of patients with brain tumours. Analyses were carried out by instrumental neutron activation analysis (INAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Quality control was ensured by using NBS Bovine Liver 1577a standard reference material. Comparison between the healthy and brain tumour concentration data using statistical evaluation revealed only a few elements (e.g. B, Zn, Sr) which showed significant differences as a consequence of the brain tumour.     

Studies on leaching behaviour of sodium borosilicate glasses by neutron activation: Effects of groundwater composition,pH, surface area to volume ratio,and temperature

Static leaching experiments have been conducted to evaluate the durability of sodium borosilicate glass as the host matrix for immobilized high-level radioactive wastes. Simulated granitic groundawater, synthetic Grande Ronde basaltic groundwater and distilled deionized water have been used. The results indicated a strong influence of the leachant composition through both its pH and nature as well as concentrations of the ions present on the leach rate. The roles of silicon, boron and a few other elements on leaching have been examined. Three surface area to volume ratios (SA/V) and two temperatures were investigated. Total mass loss and normalized elemental mass loss results showed that the rate of release decreased with increased SA/V ratio in the three leachants at both temperatures. The rate of leaching at 90 °C was 5–30 times higher than that at 40 °C. Activation energies for the glass at three SA/V ratios have been calculated.     

Elemental analysis of the frontal lobe of “normal” brain tissue and that affected by Alzheimer's disease

Normal brain tissue and brain tissue affected by Alzheimer's disease has been taken from the frontal lobe of both hemispheres and their elemental compositions in terms of major, minor and trace elements compared. Brain samples were obtained from the MRC Alzheimer's Disease Brain Bank, London. 25 samples were taken from 18 individuals (5 males and 13 females) of mean age 79.9±7.3 years with pathologically confirmed Alzheimer'sdisease and 26 samples from 15 individuals (8 males and 7 females) of mean age 71.8±13.0 years with no pathological signs of Alzheimer's disease (normals). The elemental concentration of the samples were determined by the techniques of Rutherford backscattering (RBS) analysis, particle induced X-ray emission (PIXE) analysis and instrumental neutron activation analysis (INAA). Na, Mg, Al, Cl, K, Sc, Fe, Zn, Se, Br, Rb and Cs were detected by INAA and significant differences in concentrations were found between concentrations in normal and Alzheimer tissue for the elements. Na, Cl, K, Se, Br and Rb, P, S, Cl, K, Ca, Fe, Zn and Cd were detected by PIXE analysis and significant differences found for the elements P, S, Cl, K and Ca.     

Occurrence of difluorine F2 in nature--in situ proof and quantification by NMR spectroscopy

The most reactive chemical element, F(2), has been claimed not to occur in nature. First direct evidence from in?situ NMR spectroscopy now proves that elemental F(2) indeed occurs in nature as an occlusion in "antozonite" (right in the picture), a variant of fluorite (CaF(2), left).     

Cognitive impairment related changes in the elemental concentration in the brain of old rat

In order to evaluate the elemental concentration as a function of learning and memory deficiency, six different structures of the brain were analyzed by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). To evaluate the cognitive processes, the animals were tested in an adaptation of the Morris water maze. After the test, the animals were divided into two groups: cognitively healthy (control group) and cognitively impaired. The measurements were carried out at XRF beam line at Light Synchrotron Brazilian laboratory, Campinas, Brazil. The following elements were identified: Al, P, S, Cl, K, Ca, Ti, Cr, Fe, Cu, Zn, Br and Rb. K concentration was higher in all regions of the brain studied for control group than the cognitively impaired group. Moreover, the control group presented higher levels for P and Fe in the entorhinal cortex, in the temporal cortex (only P), in the hypothalamus and in the thalamus, than the cognitively impaired group. Br concentration in the animals which presented cognitive impairment was three times larger in the hypothalamus and thalamus, twice larger in temporal cortex and higher in visual cortex than the cognitively healthy group. Cu was more remarkable in the hippocampus and hypothalamus from the animals with cognitive impairment than the control group.We observed that the cognitively impaired group presented highest concentrations of Br and Cu in certain areas than the control group, on the other hand, this group presented highest levels of K for all brain areas studied.     

Development,validation and comparison of surrogate matrix and surrogate analyte approaches with UHPLC–MS/MS to simultaneously quantify dopamine,serotonin and γ‐aminobutyric acid in four rat brain regions

As biomarkers, endogenous neurotransmitters play critical roles in the process of neuropsychiatric diseases, and neurotransmitter levels in different brain regions can contribute to neurological disease diagnosis and treatment. Due to the lack of a blank matrix for endogenous neurotransmitters, surrogate‐matrix and surrogate‐analyte approaches have been used for the determination of neurotransmitters to solve this problem. In this study, we capitalised on the high accuracy, precision, and throughput of UHPLC‐MS/MS and developed new methods based on the two approaches. Both approaches satisfied FDA and EMA validation criterias after an appropriate parallelism assessment, and they were used to further quantify the three endogenous neurotransmitters, including dopamine (DA), serotonin (5‐HT) and γ‐aminobutyric acid (GABA) in rat brain four regions (cortex, striatum, hypothalamus and hippocampus) which represent the catecholamines, indolamines, and amino acids, respectively. Comparison of the results in the same rats (n = 10) showed there was no significant difference in DA, 5‐HT, or GABA levels between the two approaches (P > 0.05). The concentrations of DA and GABA were highest in striatum and hypothalamus, respectively, and the levels of 5‐HT were paralleled in striatum and hippocampus almost 2‐fold higher than other regions. This is the first study to compare these two approaches in the determination of endogenous neurotransmitter content in the rat brain, and the surrogate‐matrix approach proved to be simple, rapid, and reliable, considering cost, matrix similarity, and practicality.