Previous neurophysiological studies performed in macaque monkeys have revealed complex somatosensory responses in the secondary somatosensory area (SII), such as large receptive fields (RFs), as well ...as bilateral ones. However, systematic analyses of neurons with large RFs have not been performed. In the present study, we recorded single-unit activities in SII of awake macaque monkeys to investigate systematically large RFs by dividing the whole body into four body regions (head, trunk, forelimb, and hindlimb). Recorded neurons were classified into two types, according to whether the RFs were confined to one body region: single (n = 817) and combined (n = 282) body-region types. These two types were distinct in terms of the percentage of bilateral RFs: 55% in the single-region type and 90% in the combined type, demonstrating that two types of RF enlargement occur simultaneously in the combined type, namely, RF convergence from different body regions and RF convergence from both hemibodies. Among the combined-type RFs, two tendencies of RF convergence were found: 1) the distal parts of the limbs (i.e., hand and foot) and the mouth are interconnected, and 2) the trunk RFs extend continuously toward the distal parts of the limb and head to cover the entire body surface. Our distribution analysis on unfolded maps clarified that neurons having RFs with these two tendencies were distributed within specific subregions in SII.
Background
Antimicrobial photodynamic therapy (aPDT) is a new treatment method for the removal of infectious pathogens using a photosensitizer and light of a specific wavelength, e.g., toluidine blue ...with a wavelength of about 600 nm. We explored a new photosensitizer and focused on indocyanine green (ICG), which has high absorption at a wavelength of 800–805 nm. We investigated the bactericidal effect of PDT on Porphyromonas gingivalis using a new photosensitizer, ICG‐loaded nanospheres with an 805 nm wavelength low‐level diode laser irradiation.
Methods
We designed ICG‐loaded nanospheres coated with chitosan (ICG‐Nano/c) as a photosensitizer. A solution containing Porphyromonas gingivalis (108 CFU/mL) with or without ICG‐Nano/c (or ICG) was prepared and irradiated with a diode laser or without laser irradiation as a negative control. The irradiation settings were 0.5 W with a duty ratio of 10%, for 3–100 ms in repeated pulse (RPT) or continuous wave mode. CFU were counted after 7 d of anaerobic culture.
Results
We observed that ICG‐Nano/c could adhere to the surface of P. gingivalis. When ICG‐Nano/c was used for aPDT, irradiation with RPT 100 ms mode gave the lowest increase in temperature. Laser irradiation with ICG‐Nano/c significantly reduced the number of P. gingivalis (i.e., approximately 2‐log10 bacterial killing). The greatest bactericidal effect was found in the RPT 100 ms group. However, laser irradiation (RPT 100 ms) with ICG, as well as without photosensitizer, had no effect on the number of bacteria.
Conclusions
Within the limits of this study, ICG‐Nano/c with low‐level diode laser (0.5 W; 805 nm) irradiation showed an aPDT‐like effect, which might be useful for a potential photodynamic periodontal therapy.
Background and Objective
T‐helper type 17 (Th17) cells produce interleukin‐17 (IL‐17) and help to protect against inflammation and infection in periodontal disease. Furthermore, while follicular ...dendritic cell‐secreted protein (FDC‐SP) may be involved in the inflammation of periodontal tissue, the biological role of FDP‐SP in periodontal disease is still unknown. The purpose of the present study was to clarify the expression of IL‐17 and FDC‐SP in experimental periodontitis in rats.
Material and Methods
Seven‐week‐old male Wistar rats were divided into baseline control, sham and test groups. Experimental periodontitis was induced by placing a ligature in the mesiopalatal area, and untreated rats served as a baseline control group. Morphological changes in alveolar bone were investigated 7, 14 and 28 d after treatment. Expression of the Rankl, osteoprotegerin (Opg) and Il17 genes was analyzed 5 and 7 d after the induction of experimental periodontitis.
Results
Alveolar bone resorption progressed in the test group for 7 d, but not thereafter. At 5 d after the induction of periodontitis, the Rankl/Opg mRNA ratio and the expression of IL‐17 in the test group were significantly increased compared with the respective values in the baseline control group; however, there were no significant differences between the test and control groups at 7 d. The expression of FDC‐SP was significantly decreased in the test group compared with the baseline control group at 5 and 7 d after the induction of periodontitis, and this value had returned to normal levels at 14 and 28 d.
Conclusion
These results suggest that both IL‐17 and FDC‐SP could be involved in the inflammatory response, and FDC‐SP in the junctional epithelium might play an important role in the Th17 cell‐related immune response.
Earlier studies pointed out that in the primary somatosensory cortex (SI) the receptive fields (RF) of bilateral neurons were related exclusively to the body midline. We recently found a substantial ...number of neurons with bilateral RFs on hand digits, shoulders/arms or legs/feet in the caudalmost part (areas 2 and 5) of the postcentral gyrus in awake macaque monkeys. The RFs of these neurons were generally of the most complex types found in this region of the cortex, and thus they were considered to be at the highest level along the hierarchical chain of information processing. We conclude that there are two types of bilateral RFs in the postcentral gyrus, one representing the midline structures such as the intraoral cavity, chin or trunk and the other related to limb structures such as fingers, hands, arms, shoulders, legs and girdles. Functional significance of the bilateral activity could be understood in behavioral context as it is seen more extensively in the body parts where bilateral coordination is essential.
Recent studies of the postcentral and additional somatosensory cortices support a hierarchical scheme for information processing. In the postcentral gyrus, the complexity of receptive field ...properties increases with caudal progression from area 1. It has been reported that the anterior bank of the intraparietal sulcus, the caudalmost part of the postcentral gyrus, is responsible for the systematic integration of bilateral body parts, as well as of somatic and visualinformation.
Depth profiling of hydrogen under an atmospheric pressure Yonemura, H.; Kitaoka, Y.; Sekiba, D. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
04/2011, Volume:
269, Issue:
7
Journal Article
Peer reviewed
Nuclear reaction analysis of hydrogen with a use of the
1H(
15N,αγ)
12C reaction was performed under a atmospheric condition. A 100
nm-thick silicon nitride membrane coated with gold of 10
nm was ...used for the extraction of the
15N beam into the sample chamber filled with gas molecules. Hydrogen contained in a Y film with a thickness of 80
nm was detected in N
2 of 10
5
Pa. This nuclear reaction analysis (NRA) setup was also applied to H
2 gas, and the yield curve revealed a plateau feature. The plateau level was, furthermore, found to be constant independent of the H
2 pressure. We show that this plateau intensity can be used to obtain the detection efficiency of a NRA setup.