Relationships Between Wood Density and Annual Growth Rate Components in Balsam Fir (Abies Balsamea)

This study examined relationships of wood density components with annual growth rate components (or annual ring width components) in juvenile wood and mature wood of balsam fir [Abies balsamea (L.) Mill.]. The relationships were studied at two different levels: 1) inter-tree level (between trees), and 2) intra-tree level (within a tree). In addition, juvenile-mature wood correlations for these characteristics were investigated. Wood density and annual ring width components of individual growth rings were measured by X-ray densitometry. Based on tree averages (at the inter-tree level), wood density is significantly correlated with its components (earlywood density, latewood density) and latewood percentage in both juvenile wood and mature wood; and earlywood density and latewood percentage are the two most important parameters in determining the overall wood density of the tree. Wood density, however, is not significantly correlated with annual growth rate (ring width) in either juvenile wood or mature wood, although a weakly negative correlation tends to strengthen in mature wood. This suggests that the relationship between wood density and annual growth rate in this species may vary with cambial age. Intra-ring wood density variation (IDV) shows a positive correlation with wood density traits, latewood width, and latewood percentage in both juvenile wood and mature wood, whereas a weakly negative correlation of IDV with ring width and earlywood width exists in balsam fir. Latewood traits are the most important parameters in determining the intra-ring wood density uniformity. At the intra-tree level (based on ring averages within a tree), relationships between wood density components and ring width components are similar to those found between the trees, although some relationships, to some extent, vary with tree. For each wood density trait, the juvenile-mature wood correlation is significant but moderate. For this species, earlywood density in juvenile wood seems to be the best parameter for predicting mature wood density

材質管理システムの確立にむけた木材の基礎的性質の変動に関する研究

第1章 緒論 第2章 スギ材における基礎的性質の品種特性 第3章 生育林分の相違を要因にしたときのスギ品種の基礎的性質のバラツキ 第4章 ヒノキおよびカラマツの基礎的性質のバラツキ 第5章 間伐がカラマツ材の基礎的性質と木部形成へおよぼす影響 第6章 枝打ちがカラマツ材の基礎的性質へおよぼす影響 第7章 総合考察Made available in DSpace on 2012-09-06T04:22:46Z (GMT). No. of bitstreams: 2 koga1.pdf: 12342044 bytes, checksum: 4f8f76f42622d743827d50d0de351f90 (MD5) koga2.pdf: 8108164 bytes, checksum: dc5d2573fcbfac6937634cd8e197d4f5 (MD5) Previous issue date: 1999-12-16主1-参

Brain pericytes among cells constituting the blood-brain barrier are highly sensitive to tumor necrosis factor-α, releasing matrix metalloproteinase-9 and migrating in vitro

<p>Abstract</p> <p>Background</p> <p>Increased matrix metalloproteinase (MMP)-9 in the plasma and brain is associated with blood-brain barrier (BBB) disruption through proteolytic activity in neuroinflammatory diseases. MMP-9 is present in the brain microvasculature and its vicinity, where brain microvascular endothelial cells (BMECs), pericytes and astrocytes constitute the BBB. Little is known about the cellular source and role of MMP-9 at the BBB. Here, we examined the ability of pericytes to release MMP-9 and migrate in response to inflammatory mediators in comparison with BMECs and astrocytes, using primary cultures isolated from rat brains.</p> <p>Methods</p> <p>The culture supernatants were collected from primary cultures of rat brain endothelial cells, pericytes, or astrocytes. MMP-9 activities and levels in the supernatants were measured by gelatin zymography and western blot, respectively. The involvement of signaling molecules including mitogen-activated protein kinases (MAPKs) and phosphoinositide-3-kinase (PI3K)/Akt in the mediation of tumor necrosis factor (TNF)-α-induced MMP-9 release was examined using specific inhibitors. The functional activity of MMP-9 was evaluated by a cell migration assay.</p> <p>Results</p> <p>Zymographic and western blot analyses demonstrated that TNF-α stimulated pericytes to release MMP-9, and this release was much higher than from BMECs or astrocytes. Other inflammatory mediators [interleukin (IL)-1β, interferon-γ, IL-6 and lipopolysaccharide] failed to induce MMP-9 release from pericytes. TNF-α-induced MMP-9 release from pericytes was found to be mediated by MAPKs and PI3K. Scratch wound healing assay showed that in contrast to BMECs and astrocytes the extent of pericyte migration was significantly increased by TNF-α. This pericyte migration was inhibited by anti-MMP-9 antibody.</p> <p>Conclusion</p> <p>These findings suggest that pericytes are most sensitive to TNF-α in terms of MMP-9 release, and are the major source of MMP-9 at the BBB. This pericyte-derived MMP-9 initiated cellular migration of pericytes, which might be involved in pericyte loss in the damaged BBB.</p

Alterations in 18F-FDG accumulation into neck-related muscles after neck dissection for patients with oral cancers

Background: 18 F-fluoro-2-deoxy-D-glucose ( 18 F-FDG) accumulations are commonly seen in the neck-related muscles of the surgical and non-surgical sides after surgery with neck dissection (ND) for oral cancers, which leads to radiologists having difficulty in diagnosing the lesions. To examine the alterations in 18 F-FDG accumulation in neck-related muscles of patients after ND for oral cancer. Material and Methods: 18 F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) in neck-related muscles were retrospectively analyzed after surgical dissection of cervical lymph nodes in oral cancers. Results: According to the extent of ND of cervical lymph nodes, the rate of patients with 18 F-FDG-PET-positive areas increased in the trapezius, sternocleidomastoid, and posterior neck muscles of the surgical and/or non-surgical sides. In addition, SUVmax of 18 F-FDG-PET-positive areas in the trapezius and sternocleidomastoid muscles were increased according to the extent of the ND. Conclusions: In evaluating 18 F-FDG accumulations after ND for oral cancers, we should pay attention to the 18 F-FDG distributions in neck-related muscles including the non-surgical side as false-positive finding

Differences among epitopes recognized by neutralizing antibodies induced by SARS-CoV-2 infection or COVID-19 vaccination

SARS-CoV-2 has gradually acquired amino acid substitutions in its S protein that reduce the potency of neutralizing antibodies, leading to decreased vaccine efficacy. Here, we attempted to obtain mutant viruses by passaging SARS-CoV-2 in the presence of plasma samples from convalescent patients or vaccinees to determine which amino acid substitutions affect the antigenicity of SARS-CoV-2. Several amino acid substitutions in the S2 region, as well as the N-terminal domain (NTD) and receptor-binding domain (RBD), affected the neutralization potency of plasma samples collected from vaccinees, indicating that amino acid substitutions in the S2 region as well as those in the NTD and RBD affect neutralization by vaccine-induced antibodies. Furthermore, the neutralizing potency of vaccinee plasma samples against mutant viruses we obtained or circulating viruses differed among individuals. These findings suggest that genetic backgrounds of vaccinees influence the recognition of neutralizing epitopes

Antibody titers against SARS-CoV-2 decline, but do not disappear for several months

Background: To develop an effective vaccine against a novel viral pathogen, it is important to understand the longitudinal antibody responses against its first infection. Here we performed a longitudinal study of antibody responses against SARS-CoV-2 in symptomatic patients. Methods: Sequential blood samples were collected from 39 individuals at various timepoints between 0 and 154 days after onset. IgG or IgM titers to the receptor binding domain (RBD) of the S protein, the ectodomain of the S protein, and the N protein were determined by using an ELISA. Neutralizing antibody titers were measured by using a plaque reduction assay. Findings: The IgG titers to the RBD of the S protein, the ectodomain of the S protein, and the N protein peaked at about 20 days after onset, gradually decreased thereafter, and were maintained for several months after onset. Extrapolation modeling analysis suggested that the IgG antibodies were maintained for this amount of time because the rate of reduction slowed after 30 days post-onset. IgM titers to the RBD decreased rapidly and disappeared in some individuals after 90 days post-onset. All patients, except one, possessed neutralizing antibodies against authentic SARS-CoV-2, which they retained at 90 days after onset. The highest antibody titers in patients with severe infections were higher than those in patients with mild or moderate infections, but the decrease in antibody titer in the severe infection cohort was more remarkable than that in the mild or moderate infection cohort. Interpretation: Although the number of patients is limited, our results show that the antibody response against the first SARS-CoV-2 infection in symptomatic patients is typical of that observed in an acute viral infection