Showing papers by "Hokkaido University published in 2001"
TL;DR: It is shown that expression of CONSTANS (CO), a gene that accelerates flowering in response to long days, is modulated by the circadian clock and day length, suggesting mechanisms by which day length regulates flowering time.
Abstract: Flowering is often triggered by exposing plants to appropriate day lengths. This response requires an endogenous timer called the circadian clock to measure the duration of the day or night. This timer also controls daily rhythms in gene expression and behavioural patterns such as leaf movements. Several Arabidopsis mutations affect both circadian processes and flowering time; but how the effect of these mutations on the circadian clock is related to their influence on flowering remains unknown. Here we show that expression of CONSTANS (CO), a gene that accelerates flowering in response to long days, is modulated by the circadian clock and day length. Expression of a CO target gene, called FLOWERING LOCUS T (FT), is restricted to a similar time of day as expression of CO. Three mutations that affect circadian rhythms and flowering time alter CO and FT expression in ways that are consistent with their effects on flowering. In addition, the late flowering phenotype of such mutants is corrected by overexpressing CO. Thus, CO acts between the circadian clock and the control of flowering, suggesting mechanisms by which day length regulates flowering time.
1,294 citations
TL;DR: These studies suggest that pox genes are induced via different signal transduction pathways from those of other known defense-related genes.
Abstract: 3Core Research for Evolutional Science and Technology (CREST), Chiyoda-ku, Tokyo, 101-0062 Japan ; Class III plant peroxidase (POX), a plant-specific oxidoreductase, is one of the many types of peroxidases that are widely distributed in animals, plants and microorganisms. POXs exist as isoenzymes in individual plant species, and each isoenzyme has variable amino acid sequences and shows diverse expression profiles, suggesting their involvement in various physiological processes. Indeed, studies have provided evidence that POXs participate in lignification, suberization, auxin catabolism, wound healing and defense against pathogen infection. Little, however, is known about the signal transduction for inducing expression of the pox genes. Recent studies have provided information on the regulatory mechanisms of wound- and pathogen-induced expression of some pox genes. These studies suggest that pox genes are induced via different signal transduction pathways from those of other known defense-related genes.
826 citations
TL;DR: It is suggested that, in activation studies with near-infrared spectroscopy, HbO(2) is the most sensitive indicator of changes in CBF, and the direction of change in deoxy-Hb is determined by the degree ofChanges in venous blood oxygenation and volume.
Abstract: Using a newly developed perfused rat brain model, we examined direct effects of each change in cerebral blood flow (CBF) and oxygen metabolic rate on cerebral hemoglobin oxygenation to interpret ne...
767 citations
TL;DR: Chitosan enhances the functions of inflammatory cells such as polymorphonuclear leukocytes (PMN), phagocytosis, production of osteopontin and leukotriene B4, macrophages, and fibroblasts, which promotes granulation and organization, therefore chitosans is beneficial for the large open wounds of animals.
717 citations
TL;DR: Results indicate that titanium, hafnium, niobium, tantalum and rhenium have good biocompatibility and osteoconductivity.
699 citations
TL;DR: It is shown that heme binds specifically to Bach1 and regulates its DNA‐binding activity, suggesting that increased levels of heme inactivate the repressor Bach1, resulting in induction of a host of genes with MAREs.
Abstract: Heme controls expression of genes involved in the synthesis of globins and heme. The mammalian transcription factor Bach1 functions as a repressor of the Maf recognition element (MARE) by forming antagonizing hetero-oligomers with the small Maf family proteins. We show here that heme binds specifically to Bach1 and regulates its DNA-binding activity. Deletion studies demonstrated that a heme-binding region of Bach1 is confined within its C-terminal region that possesses four dipeptide cysteine–proline (CP) motifs. Mutations in all of the CP motifs of Bach1 abolished its interaction with heme. The DNA-binding activity of Bach1 as a MafK hetero-oligomer was markedly inhibited by heme in gel mobility shift assays. The repressor activity of Bach1 was lost upon addition of hemin in transfected cells. These results suggest that increased levels of heme inactivate the repressor Bach1, resulting in induction of a host of genes with MAREs.
501 citations
TL;DR: In the case of the Tat, FHV, and octaarginine peptides, N-terminal stearylation of the peptides increases the transfection efficiency by approximately 100 times to reach the same order of magnitude as that of LipofectAMINE, one of the most efficient commercially available transfections agents.
470 citations
TL;DR: Using the concepts of chaotic dynamical systems, an interpretation of dynamic neural activity found in cortical and subcortical areas is presented in this article, which is quite different from the conventional one, cast in terms of simple behavior on low-dimensional attractors.
Abstract: Using the concepts of chaotic dynamical systems, we present an interpretation of dynamic neural activity found in cortical and subcortical areas. The discovery of chaotic itinerancy in high-dimensional dynamical systems with and without a noise term has motivated a new interpretation of this dynamic neural activity, cast in terms of the high-dimensional transitory dynamics among "exotic" attractors. This interpretation is quite different from the conventional one, cast in terms of simple behavior on low-dimensional attractors. Skarda and Freeman (1987) presented evidence in support of the conclusion that animals cannot memorize odor without chaotic activity of neuron populations. Following their work, we study the role of chaotic dynamics in biological information processing, perception, and memory. We propose a new coding scheme of information in chaos-driven contracting systems we refer to as Cantor coding. Since these systems are found in the hippocampal formation and also in the olfactory system, the proposed coding scheme should be of biological significance. Based on these intensive studies, a hypothesis regarding the formation of episodic memory is given.
459 citations
TL;DR: It is indicated that genotypes C and B are predominant in Japan, and there are significant differences in geographic distribution and clinical characteristics among the patients with the different genotypes.
414 citations
TL;DR: Neoxanthin and fucoxanthin were found to reduce cell viability through apoptosis induction in the human prostate cancer cells, suggesting that ingestion of leafy green vegetables and edible brown algae rich in neoxanth in and fu Coxanthin might have the potential to reduce the risk of prostate cancer.
Abstract: We investigated whether various carotenoids present in foodstuffs were potentially involved in cancer-preventing action on human prostate cancer. The effects of 15 kinds of carotenoids on the viability of three lines of human prostate cancer cells, PC-3, DU 145 and LNCaP, were evaluated. When the prostate cancer cells were cultured in a carotenoid-supplemented medium for 72 h at 20 micromol/L, 5,6-monoepoxy carotenoids, namely, neoxanthin from spinach and fucoxanthin from brown algae, significantly reduced cell viability to 10.9 and 14.9% for PC-3, 15.0 and 5.0% for DU 145, and nearly zero and 9.8% for LNCaP, respectively. Acyclic carotenoids such as phytofluene, zeta-carotene and lycopene, all of which are present in tomato, also significantly reduced cell viability. On the other hand, phytoene, canthaxanthin, beta-cryptoxanthin and zeaxanthin did not affect the growth of the prostate cancer cells. DNA fragmentation of nuclei in neoxanthin- and fucoxanthin-treated cells was detected by in situ TdT-mediated dUTP nick end labeling (TUNEL) assay. Neoxanthin and fucoxanthin were found to reduce cell viability through apoptosis induction in the human prostate cancer cells. These results suggest that ingestion of leafy green vegetables and edible brown algae rich in neoxanthin and fucoxanthin might have the potential to reduce the risk of prostate cancer.
411 citations
TL;DR: Competitive PCR assays were developed for the enumeration of the rumen cellulolytic bacterial species: Fibrobacter succinogenes, R. albus and R. flavefaciens and the population size of the three species did not change after the proportion of dietary alfalfa hay was increased.
Abstract: Competitive PCR assays were developed for the enumeration of the rumen cellulolytic bacterial species: Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens. The assays, targeting species-specific regions of 16S rDNA, were evaluated using DNA from pure culture and rumen digesta spiked with the relevant cellulolytic species. Minimum detection levels for F. succinogenes, R. albus and R. flavefaciens were 1–10 cells in pure culture and 103–4 cells per ml in mixed culture. The assays were reproducible and 11–13% inter- and intra-assay variations were observed. Enumeration of the cellulolytic species in the rumen and alimentary tract of sheep found F. succinogenes dominant (107 per ml of rumen digesta) compared to the Ruminococcus spp. (104–6 per ml). The population size of the three species did not change after the proportion of dietary alfalfa hay was increased. All three species were detected in the rumen, omasum, caecum, colon and rectum. Numbers of the cellulolytic species at these sites varied within and between animals.
01 Jan 2001
TL;DR: In this article, surface-enhanced infrared absorption (SEIRA) was introduced to emphasize the similarities with surfaceenhanced Raman scattering (SERS), and the electromagnetic interactions of the incident photon field with the metal and molecules played predominant roles in this effect.
Abstract: Molecules adsorbed on metal island films or particles exhibit 10-1000 times more intense infrared absorption than would be expected from conventional measurements without the metal. This effect is referred to as surface-enhanced infrared absorption (SEIRA) to emphasize the similarities with surface-enhanced Raman scattering (SERS). The electromagnetic interactions of the incident photon field with the metal and molecules play predominant roles in this effect. The chemical interactions of the molecules with the surface can give additional enhancement. The enhancement mechanisms and some applications of SEIRA.
TL;DR: Intrinsic signal imaging from inferotemporal cortex revealed that visually presented objects activated patches in a distributed manner, suggesting that an object is represented by a combination of cortical columns, each of which represents a visual feature (feature column).
Abstract: Intrinsic signal imaging from inferotemporal (IT) cortex, a visual area essential for object perception and recognition, revealed that visually presented objects activated patches in a distributed manner. When visual features of these objects were partially removed, the simplified stimuli activated only a subset of the patches elicited by the originals. This result, in conjunction with extracellular recording, suggests that an object is represented by a combination of cortical columns, each of which represents a visual feature (feature column). Simplification of an object occasionally caused the appearance of columns that were not active when viewing the more complex form. Thus, not all the columns related to a particular feature were necessarily activated by the original objects. Taken together, these results suggest that objects may be represented not only by simply combining feature columns but also by using a variety of combinations of active and inactive columns for individual features.
TL;DR: The present system provides the first example of an artificial photosynthetic system, which not only mimics light-harvesting and charge separation processes in photosynthesis but also acts as an efficient light-to-current converter in molecular devices.
Abstract: Three different kinds of mixed self-assembled monolayers have been prepared to mimic photosynthetic energy and electron transfer on a gold surface. Pyrene and boron−dipyrrin were chosen as a light-harvesting model. The mixed self-assembled monolayers of pyrene (or boron−dipyrrin) and porphyrin (energy acceptor model) reveal photoinduced singlet−singlet energy transfer from the pyrene (or boron−dipyrrin) to the porphyrin on the gold surface. The boron−dipyrrin has also been combined with a reaction center model, ferrocene−porphyrin−fullerene triad, to construct integrated artificial photosynthetic assemblies on a gold electrode using mixed monolayers of the respective self-assembled unit. The mixed self-assembled monolayers on the gold electrode have established a cascade of photoinduced energy transfer and multistep electron transfer, leading to the production of photocurrent output with the highest quantum yield (50 ± 8%, based on the adsorbed photons) ever reported for photocurrent generation at monolay...
TL;DR: The analysis of causative factors inducing osteogenesis and chondrogenesis in the BMP system concluded that the geometry of the carrier is crucially important and vasculature-inducing geometry should be considered in designing effective scaffolds for bone formation.
Abstract: Background: The effect of the geometry of extracellular matrices on bone morphogenetic protein (BMP)-induced osteogenesis has not been systematically studied. Geometry is crucially important for the scaffold in bone and joint tissue engineering. The purpose of this study was to elucidate principles of geometry of matrices in designing new scaffolds and matrices for use in reconstruction of bone and joints.
Methods: More than ten biomaterials with different geometries, including a unique device of honeycomb-shaped hydroxyapatite, were combined with BMPs of recombinant (rhBMP-2) or natural bovine origin (S300 BMP cocktail) and implanted subcutaneously into 4-week-old Wistar-King rats. The implanted pellets were removed at 1-4 weeks and analyzed for bone and cartilage formation by histological and biochemical methods.
Results: BMP-induced bone and cartilage induction was highly dependent on the geometric properties of the carrier. Some carriers such as porous particles or blocks of hydroxyapatite induced osteogenesis directly, without detectable chondrogenesis, whereas other carriers such as fibrous glass membrane induced cartilage exclusively. Still other carriers induced mostly cartilage followed by bone formation. Solid particles of hydroxyapatite and fibrous glass membrane with too tight a meshwork did not induce bone or cartilage. The optimal pore size for bone-forming efficacy in porous blocks of hydroxyapatite was a diameter of 300-400 lm. In straight tunnel structures with various diameters in honeycomb-shaped hydroxyapatite, tunnels with smaller diameters (90-120 mm) induced cartilage followed by bone formation, whereas those with larger diameters (350 mm) induced bone formation directly within the tunnels.
Conclusions: BMP carriers were classified into three types: bone-inducing, cartilage-inducing, and cartilage-bone-inducing. From the analysis of causative factors inducing osteogenesis and chondrogenesis in the BMP system, we concluded that the geometry of the carrier is crucially important and vasculature-inducing geometry should be considered in designing effective scaffolds for bone formation. We propose a classification of geometry of the artificial extracellular matrices that is useful for designing a scaffold for tissue engineering of bone and related tissues.
Clinical Relevance: Conventional requisites of the BMP carriers for clinical use have mainly concerned the affinities of carriers with cells and biomolecules and their mechanical strength. The vasculature-inducing geometry of carriers adds a new criterion in designing systems for effective bone and joint reconstruction. The geometries of porous structures—their sizes, continuity, and straightness as verified by hydroxyapatite in this study—will be applicable for other biomaterials for clinical reconstruction therapy.
TL;DR: In this paper, a comprehensive report on a two-step synthesis of dimethyl carbonate (DMC) from epoxides, carbon dioxide and methanol using various basic metal oxide catalysts was given.
Abstract: This paper gives a comprehensive report on a two-step synthesis of dimethyl carbonate (DMC) from epoxides, carbon dioxide and methanol using various basic metal oxide catalysts. The first step is the reaction of ethylene oxide or propylene oxide with CO 2 to form the corresponding cyclic carbonates, and the second step is the transesterification reaction of the cyclic carbonates with methanol to DMC and glycols. Among the catalysts examined, MgO is the most active and selective for both these reactions. Other alcohols can be used for the second step, but the activity decreases as the carbon number of the alcohol increases. Although a one-pot synthesis of DMC, i.e. the sequential reaction of the epoxide, CO 2 and methanol, is also possible with MgO, the selectivity is low because of the alcoholysis of the epoxide. In contrast with the reactions of ethylene oxide and propylene oxide, when styrene oxide is used for the first reaction and for the one-pot synthesis, mandelic acid is produced. Basic properties of the metal oxide catalysts were measured by temperature programmed desorption of CO 2 . The relationship between the catalytic performance and the basic property is discussed.
TL;DR: It is shown that the unique function of IKKα in control of keratinocyte differentiation is not exerted through its IκB kinase activity or through NF-κB, but instead, IKK α controls production of a soluble factor that induces keratinocytes differentiation.
Abstract: The IKKalpha and IKKbeta catalytic subunits of IkappaB kinase (IKK) share 51% amino-acid identity and similar biochemical activities: they both phosphorylate IkappaB proteins at serines that trigger their degradation. IKKalpha and IKKbeta differ, however, in their physiological functions. IKKbeta and the IKKgamma/NEMO regulatory subunit are required for activating NF-kappaB by pro-inflammatory stimuli and preventing apoptosis induced by tumour necrosis factor-alpha (refs 5,6,7,8,9,10,11). IKKalpha is dispensable for these functions, but is essential for developing the epidermis and its derivatives. The mammalian epidermis is composed of the basal, spinous, granular and cornified layers. Only basal keratinocytes can proliferate and give rise to differentiated derivatives, which on full maturation undergo enucleation to generate the cornified layer. Curiously, keratinocyte-specific inhibition of NF-kappaB, as in Ikkalpha-/- mice, results in epidermal thickening but does not block terminal differentiation. It has been proposed that the epidermal defect in Ikkalpha-/- mice may be due to the failed activation of NF-kappaB. Here we show that the unique function of IKKalpha in control of keratinocyte differentiation is not exerted through its IkappaB kinase activity or through NF-kappaB. Instead, IKKalpha controls production of a soluble factor that induces keratinocyte differentiation.
Journal Article•
TL;DR: It is suggested that constitutive expression of HIF-1alpha contributes to the survival and proliferation of pancreatic cancer cells in hypoxia and glucose deprivation through the activation of anaerobic metabolism.
Abstract: Hypovasculature is an outstanding characteristic of pancreatic cancers in imaging diagnosis, suggesting that blood supply is poor in pancreatic cancer tissues. Despite poor blood supply, pancreatic cancer cells survive and proliferate in severe hypoxia and nutrient deprivation. To demonstrate how pancreatic cancer cells adapt themselves to hypoxia and nutrient deprivation, we investigated the expression of hypoxia-inducible factor 1alpha (HIF-1alpha) protein and HIF-1-inducible genes in human pancreatic cancer cell lines in comparison with other cancer cell lines. We found that HIF-1alpha protein was constitutively expressed in 15 of 20 pancreatic cancer cell lines (75%) but in none of other cancer cell lines tested in this study. The cells with constitutive expression of HIF-1alpha were more resistant to apoptosis induced by hypoxia and glucose deprivation than those without constitutive expression of HIF-1alpha. Transfection with HIF-1alpha transformed the latter cells resistant to apoptosis and increased in vivo tumorigenicity. Furthermore, anaerobic metabolism-associated genes, Glut1 and aldolase A, were more highly expressed in the cells with constitutive expression of HIF-1alpha than in the cells without it. These results suggest that constitutive expression of HIF-1alpha contributes to the survival and proliferation of pancreatic cancer cells in hypoxia and glucose deprivation through the activation of anaerobic metabolism.
TL;DR: Results indicate that DJ-1 is a positive regulator of the androgen receptor, which is a novel candidate of the oncogene product that transformed mouse NIH3T3 cells in cooperation with an activated ras.
TL;DR: In this article, a multiplexer-demultiplexer (MUX-DEMUX) based on photonic crystal (PC) waveguide couplers is proposed.
Abstract: A multiplexer-demultiplexer (MUX-DEMUX) based on PC waveguide couplers is proposed, and its wavelength demultiplexing properties are theoretically investigated. First, a two-channel MUX-DEMUX is designed and characterized, and then, by cascading, two stages of photonic crystal (PC) waveguide couplers with different coupling coefficients are constructed. The device sizes are expected to be drastically reduced from a scale of a few tens of micrometers to a scale of a few hundreds of micrometers in a MUX-DEMUX.
TL;DR: In this paper, a ground-based network that has been in use since 1997 to observe Asian dust during springtime is described, and the results of the observation are discussed regarding the transport mechanism of Asian dust in east Asia using an online tracer model.
Abstract: We coordinated a ground-based network that has been in use since 1997 to observe Asian dust during springtime. Huge Asian dust events that occurred in the middle of April 1998 were captured by this network. In this paper we present the organization of the network; a description of the instruments, including the lidar, sky radiometer, and optical particle counter; and the results of the observation, and offer discussions regarding the transport mechanism of Asian dust in east Asia using an on-line tracer model. We discussed the time series of the surface concentration and the height distribution of the dust. A cutoff cyclone generated during the dust episode was responsible for trapping and sedimentation during the transportation of the Asian dust, particularly in the southern parts of China and Japan. Horizontal dust images derived from NOAA/AVHRR clearly revealed the structure of the vortex. The lidar network observation confirmed the general pattern of dust height distribution in this event; the height of the major dust layer was about 3 km over Japan but was higher (4 to 5 km) in Seoul and Hefei. A thin dust layer in the upper troposphere was also commonly observed in Hefei and Japan. Evidence of the coexistence of dust and cirrus was shown by the polarization lidar. The lidar network observation of Asian dust and satellite remote sensing provide key information for the study of the transport mechanism of Asian dust. Further extension of the lidar network toward the interior of the continent and the Pacific Rim would reveal the greater global mechanism of the transportation.
TL;DR: In this paper, a new current control method based on the internal model principle in control theory is proposed for tracking an arbitrary number of harmonics: a DC component or fundamental frequency component signal.
Abstract: A new current control method based on the internal model principle in control theory is proposed. It introduces a sinusoidal internal model into the control system. It does not use any coordinate transformations. The method can be used for tracking an arbitrary number of harmonics: a DC component or fundamental frequency component signal. It is applied to a single-phase pulsewidth modulation inverter and active filter. The validity is confirmed by simulation and experimental results.
TL;DR: In this article, a review of nanometer-scale molecular self-organization and mesoscopic pattern formation is reviewed from the view point of nanotechnology of bottom-up materials fabrication.
Abstract: Recent progresses in nanometer-scale molecular self-organization and mesoscopic pattern formation are reviewed from the view point of nanotechnology of bottom-up materials fabrication. Nanometer-scale layer-by-layer self-assemblies on nanoparticles will provide wide applications in many fields. The micro-contact printing technique is effectively used for up-sizing the nanostructured molecular assemblies as submicrometer- and micrometer-scale patterns. Dissipative structures formed in non-equilibrium systems as self-organized spatio-temporal structures are newly employed for the mesoscopic patterning of the nanostructured molecular assemblies.
TL;DR: The fixation device chosen for soft-tissue fixation appears to be more important than comparing it to the bone-patellar tendon-bone graft in anterior cruciate ligament (ACL) reconstruction, although this has yet to be conclusively proven.
Abstract: Purpose: The purpose of this study was to compare intraosseous graft healing between the doubled flexor tendon (FT) graft and the bone–patellar tendon–bone (BPTB) graft in anterior cruciate ligament (ACL) reconstruction. Type of Study: Randomized trial. Methods: A biomechanical and histologic study was conducted with 24 adult beagle dogs. Bilateral ACL reconstructions were performed in each animal. Autogenous doubled FT and BPTB grafts were used for the left and right knees, respectively. Each end of the 2 grafts was tethered with a polyester suture to a screw post with a washer. The animals were then allowed unrestricted activities in their cages. Eight animals were killed at 3, 6, and 12 weeks, respectively. Results: Histologically, the FT graft was anchored to the tunnel wall with newly formed collagen fibers resembling Sharpey's fibers by 12 weeks. These fibers were more abundant in the anterior (ventral) gap than in the posterior (dorsal) gap. In the BPTB graft, the bone plug was anchored with newly formed bone at 3 weeks, although osteocytes in the plug trabeculae were necrotic for 12 weeks. Degeneration of the tendon-bone junction in the plug progressed at 6 weeks. Tensile testing showed that the weakest site was different not only between the 2 grafts but also between the observation periods. In the FT graft, the weakest site was the graft-wall interface at 3 weeks and the intraosseously grafted tendon at 6 weeks. In the BPTB graft, the weakest site was the graft-wall interface at 3 weeks and the proximal site in the bone plug at 6 weeks. The ultimate failure load of the FT graft was significantly inferior (45.8%) to that of the BPTB graft at 3 weeks ( P =.021). At 6 weeks, the load of the FT graft was 85% that of the BPTB graft without a significant difference ( P =.395). Conclusions: As to the clinical relevance, the fixation device chosen for soft-tissue fixation appears to be more important than comparing it to the BPTB graft, although this has yet to be conclusively proven. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 5 (May-June), 2001: pp 461–476
Journal Article•
TL;DR: The results based on models showed a high FDG uptake and high GLUT-1 expression level not only in the tumor lesion but also in the inflammatory lesion.
Abstract: Although FDG uptake is closely related to the expression of the glucose transporter (GLUT) in malignant tumors, such a relationship has not been fully investigated in inflammatory lesions. The aim of our study was to determine the expression of GLUT subtypes in experimental inflammatory lesions and to compare the results with those in malignant tumors in relation to FDG accumulation. Methods: Rats were inoculated with a suspension of Staphylococcus aureus or allogenic hepatoma cells (KDH-8) into the left calf muscle. Five days after S. aureus inoculation (n 5 9) and 14 d after KDH-8 inoculation (n 5 11), [14C]FDG was injected intravenously and its accumulation in the infectious and tumor tissues was determined as the percentage activity of the injected dose per gram of tissue (%ID/g). The expression of glucose transporters (GLUT-1 to GLUT-5) was investigated by immunostaining the infectious tissues (n 5 6) and the tumor tissues (n 5 6). Immunohistochemical grading was assessed semiquantitatively by 5 observers. Results: The [ 14 C]FDG uptake was significantly higher in the tumor lesion than in the inflammatory lesion (2.04 6 0.38 %ID/g vs. 0.72 6 0.15 %ID/g; P , 0.0001). The tumor and inflammatory tissues highly expressed GLUT-1 and GLUT-3. The GLUT-1 expression level was significantly higher in the tumor tissue than in the inflammatory tissue (P , 0.05). Conclusion: The results based on our models showed a high FDG uptake and high GLUT-1 expression level not only in the tumor lesion but also in the inflammatory lesion. The higher GLUT-1 expression level in the tumor lesion may partially explain the higher FDG accumulation in the tumor than in the inflammatory lesion.
TL;DR: It is reported here that the GTP-bound form of kir/Gem, identified originally as a Ras-related small G-protein that binds CaM, inhibits high-voltage-activated Ca2+ channel activities by interacting directly with the β-subunit.
Abstract: Voltage-dependent calcium (Ca2+) channels are involved in many specialized cellular functions1,2,3, and are controlled by intracellular signals such as heterotrimeric G-proteins4, protein kinases5,6 and calmodulin (CaM)7,8. However, the direct role of small G-proteins in the regulation of Ca2+ channels is unclear. We report here that the GTP-bound form of kir/Gem, identified originally as a Ras-related small G-protein that binds CaM9,10,11, inhibits high-voltage-activated Ca2+ channel activities by interacting directly with the β-subunit. The reduced channel activities are due to a decrease in α1-subunit expression at the plasma membrane. The binding of Ca2+/CaM to kir/Gem is required for this inhibitory effect by promoting the cytoplasmic localization of kir/Gem. Inhibition of L-type Ca2+ channels by kir/Gem prevents Ca2+-triggered exocytosis in hormone-secreting cells. We propose that the small G-protein kir/Gem, interacting with β-subunits, regulates Ca2+ channel expression at the cell surface.
TL;DR: In this paper, the transmetalation between diboron and [Cu(Cl)OAc]K was proposed as the key step in the reactions because CuOAc similarly mediated both addition reactions to enones and alkynes in the presence of LiCl.
TL;DR: The real-time tumor-tracking radiotherapy system was useful to analyze the movement of an internal marker and treatment with megavoltage X-rays was properly given when the tumor marker moved into the "permitted dislocation" zone from the planned position.
Abstract: Purpose: External radiotherapy for lung tumors requires reducing the uncertainty due to setup error and organ motion. We investigated the three-dimensional movement of lung tumors through an inserted internal marker using a real-time tumor-tracking system and evaluated the efficacy of this system at reducing the internal margin. Methods and Materials: Four patients with lung cancer were analyzed. A 2.0-mm gold marker was inserted into the tumor. The real-time tumor-tracking system calculates and stores three-dimensional coordinates of the marker 30 times/s. The system can trigger the linear accelerator to irradiate the tumor only when the marker is located within the predetermined “permitted dislocation.” The value was set at ±1 to ±3 mm according to the patient’s characteristics. We analyzed 10,413–14,893 data sets for each of the 4 patients. The range of marker movement during normal breathing (beam-off period) was compared with that during gated irradiation (beam-on period) by Student’s t test. Results: The range of marker movement during the beam-off period was 5.5–10.0 mm in the lateral direction (x), 6.8–15.9 mm in the craniocaudal direction (y) and 8.1–14.6 mm in the ventrodorsal direction (z). The range during the beam-on period was reduced to within 5.3 mm in all directions in all 4 patients. A significant difference was found between the mean of the range during the beam-off period and the mean of the range during the beam-on period in the x (p = 0.007), y (p = 0.025), and z (p = 0.002) coordinates, respectively. Conclusion: The real-time tumor-tracking radiotherapy system was useful to analyze the movement of an internal marker. Treatment with megavoltage X-rays was properly given when the tumor marker moved into the “permitted dislocation” zone from the planned position.
TL;DR: This work has studied how the plasmodium of Physarum polycephalum, a large amoeboid cell, is able to track the shortest path between two selected points in a labyrinth through a simple cellular mechanism based on interacting cellular rhythms.
TL;DR: In this paper, the authors tested the hypothesis that regional cerebrovascular reactivity (rCVR) to acetazolamide can be a reliable predictor of subsequent ischemic stroke in medically treated patients with internal carotid artery occlusion.
Abstract: Background and Purpose— The importance of hemodynamic parameters for predicting outcome in patients with occlusive carotid disease remains controversial. The present study was aimed at testing the hypothesis that regional cerebrovascular reactivity (rCVR) to acetazolamide can be a reliable predictor of subsequent ischemic stroke in medically treated patients with internal carotid artery or middle cerebral artery occlusion. Methods— Seventy-seven symptomatic patients were enrolled in this prospective, longitudinal cohort study. All patients met inclusion criteria of cerebral angiography, no or localized cerebral infarction on MRI or CT, and no or minimal neurological deficit. Regional cerebral blood flow (rCBF) and rCVR to acetazolamide were quantitatively determined by 133Xe SEPCT. All patients were categorized into 4 types on the basis of SPECT studies. Results— During an average follow-up period of 42.7 months, 16 total and 7 ipsilateral ischemic strokes occurred. The annual risks of total and ipsilater...