Diffusion Magnetic Resonance Imaging-Based Biomarkers for Neurodegenerative Diseases

There has been an increasing prevalence of neurodegenerative diseases with the rapid increase in aging societies worldwide. Biomarkers that can be used to detect pathological changes before the development of severe neuronal loss and consequently facilitate early intervention with disease-modifying therapeutic modalities are therefore urgently needed. Diffusion magnetic resonance imaging (MRI) is a promising tool that can be used to infer microstructural characteristics of the brain, such as microstructural integrity and complexity, as well as axonal density, order, and myelination, through the utilization of water molecules that are diffused within the tissue, with displacement at the micron scale. Diffusion tensor imaging is the most commonly used diffusion MRI technique to assess the pathophysiology of neurodegenerative diseases. However, diffusion tensor imaging has several limitations, and new technologies, including neurite orientation dispersion and density imaging, diffusion kurtosis imaging, and free-water imaging, have been recently developed as approaches to overcome these constraints. This review provides an overview of these technologies and their potential as biomarkers for the early diagnosis and disease progression of major neurodegenerative diseases.     

Record of mercury pollution in sediments of lakes Nakaumi and Shinji in Japan

Two sediment core profiles from lakes Shinji and Nakaumi were studied in order to understand the level of mercury (Hg) pollution in lakes in northwestern Japan. The sedimentation rates were established on the basis of the activity of [²¹⁰Pb] and [¹³¹Cs] in the sediments. In Lake Shinji, the highest level of Hg (130 ng g^–1) in the sediment was found at a depth of 20–22 cm, while 195 ng g^–1 was found at a depth of 10–12 cm in the core profiles from Lake Nakaumi. The relative increase in Hg concentration in lake sediments started after 1960 and significant contamination events occurred in the early 1960s. Mercury profiles in lake sediments from lakes Shinji and Nakaumi are found to reflect the anthropogenic Hg released into the environment in the 1950s and 1960s. A pronounced maximun concentration of Hg is found in both lakes, where sediment accumulation rates differ.     

Formation of monodisperse lead aerosols and identification of particle number concentration by ice nucleation

Lead aerosols were generated to investigate the conditions for the formation of monodisperse aerosols in nitrogen stream. Aerosols of high monodispersity could be obtained by vaporizing lead at a temperature in the range of 1000° to 1150°C and by flowing nitrogen at a rte of 1.5 l/min.In order to produce “lead iodide aerosols” portions of the lead aerosols were conducted into a test chamber in which the atmosphere of iodine vapor had previously been prepared. This mixture containing the aerosols with low concentration was moderately stirred under different temperatures.“The lead iodide aerosols” were sampled with a syringe to be injected into a modified Bigg's test device for ice nucleation. The aerosols injected rapidly changed into ice crystals, which could grow in size. As the number of ice crystals could give that of lead iodide aerosols, the reactivity of lead aerosols with iodine vapor was investigated under various temperatures. An increase in temperature during the ageing of lead aerosols with iodine vapor promoted their reactivity.     

Mercury oxidation by hydrochloric acid over TiO2 supported metal oxide catalysts in coal combustion flue gas

Mercury oxidation by hydrochloric acid over the metal oxides supported by anatase type TiO₂ catalysts, 1 wt.% MO_x/TiO₂ where M = V, Cr, Mn, Fe, Ni, Cu, and Mo, was investigated by the Hg⁰ oxidation and the NO reduction measurements both in the presence and absence of NH₃. The catalysts were characterized by BET surface area measurement and Raman spectroscopy. The metal oxides added to the catalyst were observed to disperse well on the TiO₂ surface. For all catalysts studied, the Hg⁰ oxidation by hydrochloric acid was confirmed to proceed. The activity of the catalysts was found to follow the trend MoO₃ ~ V₂O₅ > Cr₂O₃ > Mn₂O₃ > Fe₂O₃ > CuO > NiO. The Hg⁰ oxidation activity of all catalysts was depressed considerably by adding NH₃ to the reactant stream. This suggests that the metal oxide catalysts undergo the inhibition effect by NH₃. The activity trend of the Hg⁰ oxidation in the presence of NH₃ was different from that observed in its absence. A good correlation was found between the NO reduction and the Hg⁰ oxidation activities in the NH₃ present condition. The catalyst having high NO reduction activity such as V₂O₅/TiO₂ showed high Hg⁰ oxidation activity. The result obtained in this study suggests that the oxidation of Hg⁰ proceeds through the reaction mechanism, in which HCl competes for the active catalyst sites against NH₃. NH₃ adsorption may predominate over the adsorption of HCl in the presence of NH₃.     

Reliable indirect competitive ELISA used for a survey of ochratoxin A in green coffee from the North of Paraná State, Brazil.

The performance of an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a monoclonal antibody (mAb) for ochratoxin A (OTA) detection was evaluated in a comparative study with high-performance liquid chromatography (HPLC) analysis using 68 freshly harvested coffee samples from the North of Paraná State, Brazil. The anti-OTA mAb showed high specificity and low cross-reactivity with OTA analogues (OTB and OTalpha), but cross-reacted with OTC. This ic-ELISA showed a detection limit of 3.75 ngg-1 sample, when compared to 0.80 ngg-1 by HPLC, with an ic-ELISA/HPLC correlation coefficient of 0.90. As regards OTA analysis of these coffee samples, natural contamination was detected in 10 samples (14.7%) by both methods, where the ic-ELISA values (range 3.9-7.3 ngg-1) were 1.1 to 1.6-fold higher than HPLC data (2.7-4.7 ngg-1). Five samples (7.4%) were OTA positive (range 0.84-1.30 ngg-1) only by HPLC assay, probably due to the higher detection limit reached by ic-ELISA. OTA was undetectable in 53 samples (77.9%) by both methods, while all positive samples (range 0.84-7.30 ngg-1) showed OTA levels lower than 8 ngg-1 (maximum limit recommended by the European Union). The matrix interference of green coffee was minimized by dilution of sample extracts before carrying out the ELISA assay. This mAb-based ic-ELISA can be effectively applied for OTA screening in coffee, because it is simple, sensitive and sample preparation is easy.     

Clinical and molecular genetic study in seven Japanese families with spinocerebellar ataxia type 6

This study examined the effect of thyrotrophin-releasing hormone (TRH) administration on thermoregulation in the newborn. Twin lambs were either delivered near-term by caesarean section or born vaginally at term. Colonic temperature, O2 consumption, CO2 production, breathing and heart rates, plus plasma thyroid hormone and nonesterified fatty acid (NEFA) concentrations and thermogenic activity (i.e. GDP binding) of brown adipose tissue (BAT) were measured. In caesarean section delivered lambs colonic temperature decreased rapidly after birth, a response that was greater in the group designated for TRH treatment, in which colonic temperature fell to below 36.0 degrees C at 80 min of life, prior to TRH administration. At this age colonic temperature had been restored to a mean of 38.70 degrees C in controls. TRH had no influence on the composition or thermogenic activity of BAT. The incidence of shivering was not influenced by TRH, but treated lambs maintained a higher rate of O2 consumption and ventilation compared with controls after colonic temperature had been restored to 38.56 degrees C. TRH appeared to promote fat oxidation as O2 consumption remained unchanged and CO2 production declined by a greater rate in treated lambs, resulting in a lower respiratory quotient compared to controls. Heart rate and plasma concentrations of NEFA increased following TRH administration although this did not result in values greater than controls. Normothermic lambs born vaginally had BAT with a greater thermogenic activity, higher plasma thyroid hormone and NEFA concentrations compared with caesarean section delivered lambs, but a thermogenic response was not observed to TRH despite a rise in thyroid hormone concentrations. In conclusion, TRH can improve thermoregulation, an effect that could be linked to an increase in fat oxidation.     

Hydrocarbons with a homoconjugated polyene system and their monoepoxy derivatives: Sex attractants of geometrid and noctuid moths distributed in Japan

Although several sex pheromones of the family Geometridae have been characterized, investigations on Japanese species are limited. In order to obtain more information, screening using known sex pheromones and their analogs was carried out. The (Z,Z,Z)-3,6,9-triunsaturated and (Z,Z)-6,9-diunsaturated hydrocarbons with straight C¹⁹-C²¹ chains were synthesized by the Grignard coupling reaction as a key step starting from linolenic and linoleic acids, respectively. Oxidation of the homoconjugated trienes withm-chloroperoxybenzoic acid yielded a 111 mixture of three monoepoxy derivatives that could be separated by silica gel chromatography. The chemical structure of each positional isomer was confirmed using two-dimensional NMR techniques and MS measurements, which enabled characteristic fragment ions from the isomers to be identified. Field tests using lures incorporating only one of the above six hydrocarbons or nine epoxides were carried out in a forest in Tokyo. Consequently, attraction of male moths of 14 geometrid species in addition to four species in another family, the Noctuidae, was observed. It was concluded that hydrocarbons with a homoconjugated polyene system and the monoepoxy derivatives are important components of sex pheromones produced by Japanese lepidopterous insects, particularly the geometrid moths.     

Lingual Epithelial Stem Cells and Organoid Culture of Them

As tongue cancer is one of the major malignant cancers in the world, understanding the mechanism of maintenance of lingual epithelial tissue, which is known to be the origin of tongue cancer, is unquestionably important. However, the actual stem cells that are responsible for the long-term maintenance of the lingual epithelium have not been identified. Moreover, a simple and convenient culture method for lingual epithelial stem cells has not yet been established. Recently, we have shown that Bmi1-positive cells, residing at the second or third layer of the epithelial cell layer at the base of the interpapillary pit (IPP), were slow-cycling and could supply keratinized epithelial cells for over one year, indicating that Bmi1-positive cells are long-term lingual epithelial stem cells. In addition, we have developed a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Here, we discuss current progress in the identification of lingual stem cells and future applications of the lingual culture system for studying the regulatory mechanisms of the lingual epithelium and for regenerative medicine.