121 research outputs found
Patterns of occurrence of hybrids of Castanopsis cuspidata and C. sieboldii in the IBP Minamata Special Research Area , Kumamoto Prefecture , Japan
東海地方に分布するフモトミズナラ(Quercus serrata subsp. mongolicoides)の特異な根の伸長特性
Quercus serrata subsp. mongolicoides is one of the key species of the Tokai hilly land element of Tokai District, where the tree is semi-endemic. In this region, its roots elongate obliquely rather than vertically. To examine its root elongation pattern, I obtained acorns from Aichi and Tochigi Prefectures. For comparison, I also obtained Quercus crispula acorns from Gifu Prefecture and Quercus variabilis acorns from Aichi Prefecture. The acorns were planted, and their root growth was constrained in two dimensions. Seedlings were excavated after 4 months, and the angles of their roots from the vertical were measured. The root angles of Q. serrata subsp. mongolicoides from Aichi Prefecture averaged 33.2±10.3°, versus 26.3±9.9°for those from Tochigi Prefecture, 4.4±4.0° for Q. crispula, and 3.0±2.0° for Q. variabilis. The oblique root elongation habit of Q. serrata subsp. mongolicoides appears to be an adaptation to poor soils or to ridge habitats with poor soil. The origin of the subspecies may be in a region with thin and poor soils in the gravel and sand beds from the Tokai Group sediment.フモトミズナラ(Quercus serrata subsp. mongolicoides)は準固有種として東海地方に分布する東海丘陵要素の1種であり、その根は斜めに伸長することが知られている。その根の伸長特性を調べるために、愛知県豊田市の八草と、隔離分布する栃木県の小池でそれぞれ50個の堅果を採集し、名古屋大学の情報科学研究科の実験室でプランターに播種し、根の伸長実験を行った。栽培用のプランターに発芽した堅果を3列に並べ、その間を段ボール紙で根が2次元方向に伸びるように設定し、約4ヶ月後にプランターから取り出して根の鉛直方向からの角度を測定した。比較のために、穂高岳のミズナラと名古屋市東山丘陵のアベマキも同様の根の伸長実験を行った。その結果、フモトミズナラの根は鉛直方向から33.2± 10.3 °(愛知県産)および26.3± 9.9 °(栃木県産)とかなり斜めに伸長したのに対して、ミズナラとアベマキの根はそれぞれ4.4± 4.0 °と3.0± 2.0 °とほぼ鉛直方向に伸長した。このような特異な根の伸長特性は、東海地方のフモトミズナラが東海層群の砂礫層や花崗岩地帯の尾根や痩せ地に生育する上での適応と解釈した。また、その起源が花崗岩地帯ではなく東海層群の砂礫層である可能性について考察を行った
Changes in choroidal structure following intravitreal aflibercept therapy for retinal vein occlusion
Aims
To examine the choroidal change accompanying retinal vein occlusion (RVO) in detail, we measured changes in choroidal structure after intravitreal aflibercept (IVA) injections for RVO using binarisation of enhanced depth imaging optical coherence tomographic (EDI-OCT) images and assessed associations with clinical outcome.
Methods
Retrospective, observational case series. Forty treatment-naïve patients (10 central, 18 major branch and 12 macular branch RVO) were examined by EDI-OCT before and 1, 3 and 6 months after IVA injections. EDI-OCT images were binarised using ImageJ. Subfoveal cross-sectional areas of the luminal, stromal and total choroid over a 1500 µm span were measured and the stromal area to total choroidal area (S/C) ratio was calculated.
Results
Compared to normal contralateral eyes, afflicted eyes at baseline exhibited significantly greater stromal area (p<0.001), total choroidal area (p=0.001) and S/C ratio (p<0.001), but no difference in luminal area (p=0.083). The stromal area, S/C ratio and total choroidal area were significantly reduced in afflicted eyes at 1, 3 and 6 months after IVA (all p<0.006). Baseline S/C ratio was significantly correlated with baseline visual acuity (VA), baseline central retinal thickness (CRT) and VA and CRT improvement at 1, 3 and 6 months post-treatment even after adjusting for the axial length, age and sex (all p<0.012).
Conclusion
RVO induces substantial oedema of the choroidal stromal area that is detectable by binarisation of EDI-OCT images. This stromal oedema likely stems from high intraocular vascular endothelial growth factor levels. Changes in choroidal structure may be used to assess severity and prognosis of RVO
Changes of choroidal structure after treatment for primary intraocular lymphoma : retrospective, observational case series
Background: We report changes of choroidal structure determined by binarization of enhanced depth imaging optical coherence tomographic (EDI-OCT) images after treatment for primary intraocular lymphoma (PIOL).
Methods: Five eyes of four patients with PIOL were examined by EDI-OCT before and 6 months after intravitreal methotrexate injections. In addition, 15 eyes of 15 normal individuals controlled by age and refractive error were examined by EDI-OCT. Binarization of the EDI-OCT images was performed using publicly accessible software (ImageJ). The examined area of the subfoveal choroid was 1,500 μm wide, and the dark areas that represented the luminal areas were traced by the Niblack method. Wilcoxon signed rank test was used to determine the significance of changes in the subfoveal choroidal thickness, interstitial area, and luminal area. Mann–Whitney U test was used to compare the parameters in the eyes with pretreatment PIOL and normal control eyes.
Results: The subfoveal choroidal thickness was significantly decreased after treatment (P = 0.0431). In the binarized images, the interstitial area was significantly decreased after treatment (P = 0.0431), while the luminal area was not significantly changed (P = 0.8927). After delayed onset of PIOL, increased interstitial area, thickened choroid and unchanged luminal area were observed in one eye. The interstitial area and choroidal thickness were significantly increased in the eyes with pretreatment PIOL compared with the normal control eyes (P = 0.0207, P = 0.0495, respectively), while the luminal area was not significantly different (P = 0.2752).
Conclusions: After treatment for PIOL, the EDI-OCT images showed a thinner choroid, and binarization of the EDI-OCT images showed significantly decreased interstitial areas compared with the luminal areas. The binarized EDI-OCT images can provide useful information on choroidal structure in eyes with PIOL, and combining these images with intraocular interleukin levels or fundus autofluorescence images should provide valuable information for determining the PIOL activity
CHOROIDAL STRUCTURE IN RP
Purpose: To investigate the choroidal structures in the enhanced depth imaging optical coherence tomographic images in eyes with retinitis pigmentosa (RP) and to determine correlations between the choroidal structures and visual functions.
Methods: The enhanced depth imaging optical coherence tomographic images of 100 eyes with typical RP and 60 age-, sex-, and axial length–matched normal eyes were binarized using ImageJ. The cross-sectional luminal and stromal areas of the inner and outer subfoveal choroid of 1,500-µm width were measured. The inner choroid included the choriocapillaris and medium vessel layer, and the outer choroid included the larger vessel layer.
Results: In the inner choroid, the luminal area and the ratio of luminal/total choroidal area (L/C ratio) were significantly smaller in RP than in controls (P = 0.010, P < 0.001, respectively), whereas the stromal area was not significantly different (P = 0.114). The inner choroidal L/C ratio was significantly correlated with the best-corrected visual acuity, mean deviation, foveal sensitivity, width of the ellipsoid zone, and central foveal thickness in RP after adjusting for the axial length, age, and sex (all P < 0.005).
Conclusion: The significant correlations between the inner choroidal structures and the visual functions and retinal structures indicate that the choroidal structures are altered in association with the progression of RP
Discrimination of hybrids between Quercus variabilis and Q. acutissima by using stellate hairs, and analysis of the hybridization zone in the Chubu District of central Japan
To discriminate between Quercus variabilis, Q. acutissima, and their hybrids, we sampled 152 individuals in secondary forests in Japan, including a plantation of Q. acutissima in Nagoya City. We compared and identified the species and their hybrids on the basis of the density of stellate hairs on the undersurfaces of leaves. The den-sity was high in Q. variabilis, zero in Q. acutissima, and low in their hybrids. We also studied the distribution patterns of the two species and found that Q. variabilis grows at lower altitudes in warmer regions than does Q. acutissima, and that a hybridization zone exists where the ranges of the two species overlap. We discuss differ-ences in the distributions of the species on the basis of life-history features such as seed germination and seed-ling establishment. The results suggest that the main range of distribution of Q. acutissima corresponds to Kira’s Warm Temperate Deciduous Forest Zone, and that the unusual distribution pattern of Q. acutissima in warmer regions such as Kyushu may have resulted from planting of the species
Local relapse of nasopharyngeal cancer and Voxel-based analysis of FMISO uptake using PET with semiconductor detectors
Background: Hypoxic cancer cells are thought to be radioresistant and could impact local recurrence after radiotherapy (RT). One of the major hypoxic imaging modalities is [18F]fluoromisonidazole positron emission tomography (FMISO-PET). High FMISO uptake before RT could indicate radioresistant sites and might be associated with future local recurrence. The predictive value of FMISO-PET for intra-tumoral recurrence regions was evaluated using high-resolution semiconductor detectors in patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy (IMRT). Methods: Nine patients with local recurrence and 12 patients without local recurrence for more than 3 years were included in this study. These patients received homogeneous and standard doses of radiation to the primary tumor irrespective of FMISO uptake. The FMISO-PET image before RT was examined via a voxel-based analysis, which focused on the relationship between the degree of FMISO uptake and recurrence region. Results: In the pretreatment FMISO-PET images, the tumor-to-muscle ratio (TMR) of FMISO in the voxels of the tumor recurrence region was significantly higher than that of the non-recurrence region (p < 0.0001). In the recurrent patient group, a TMR value of 1.37 (95% CI: 1.36-1.39) corresponded to a recurrence rate of 30%, the odds ratio was 5.18 (4.87-5.51), and the area under the curve (AUC) of the receiver operating characteristic curve was 0.613. In all 21 patients, a TMR value of 2.42 (2.36-2.49) corresponded to an estimated recurrence rate of 30%, and the AUC was only 0.591. Conclusions: The uptake of FMISO in the recurrent region was significantly higher than that in the non-recurrent region. However, the predictive value of FMISO-PET before IMRT is not sufficient for up-front dose escalation for the intra-tumoral high-uptake region of FMISO. Because of the higher mean TMR of the recurrence region, a new hypoxic imaging method is needed to improve the sensitivity and specificity for hypoxia
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