Yusuke Fujita

A robust automatic crack detection method from noisy concrete surfaces

In maintenance of concrete structures, crack detection is important for the inspection and diagnosis of concrete structures. However, it is difficult to detect cracks automatically. In this paper, we propose a robust automatic crack-detection method from noisy concrete surface images. The proposed method includes two preprocessing steps and two detection steps. The first preprocessing step is a subtraction process using the median filter to remove slight variations like shadings from concrete surface images; only an original image is used in the preprocessing. In the second preprocessing step, a multi-scale line filter with the Hessian matrix is used both to emphasize cracks against blebs or stains and to adapt the width variation of cracks. After the preprocessing, probabilistic relaxation is used to detect cracks coarsely and to prevent noises. It is unnecessary to optimize any parameters in probabilistic relaxation. Finally, using the results from the relaxation process, a locally adaptive thresholding is performed to detect cracks more finely. We evaluate robustness and accuracy of the proposed method quantitatively using 60 actual noisy concrete surface images.

A Method for Crack Detection on a Concrete Structure

Recently, interest in automatic crack detection on concrete structure images for non-destructive inspection has been increasing. In general, there are various noises such as irregularly illuminated conditions, shading, blemishes and divots in the concrete images. These lead to difficulties for automatic crack detection. This paper presents two p re-processings in order to remove such noises for crack detection. First, slight variations like irregularly illuminated conditions and shading are removed from concrete images by the subtraction pre-processing with the smoothed image. Secondly, a line filter based on the Hessian matrix is used to emphasize line structures associated with cracks. Finally, thresholding processing is used to separate cracks from background. The performance of the proposed method is evaluated by ROC analysis with 50 real images. The experimental results show that the proposed method is effective for detecting cracks on noisy concrete images

New method for detection of gastric cancer by hyperspectral imaging: a pilot study

Abstract. We developed a new, easy, and objective method to detect gastric cancer using hyperspectral imaging (HSI) technology combining spectroscopy and imaging A total of 16 gastroduodenal tumors removed by endoscopic resection or surgery from 14 patients at Yamaguchi University Hospital, Japan, were recorded using a hyperspectral camera (HSC) equipped with HSI technology Corrected spectral reflectance was obtained from 10 samples of normal mucosa and 10 samples of tumors for each case The 16 cases were divided into eight training cases (160 training samples) and eight test cases (160 test samples) We established a diagnostic algorithm with training samples and evaluated it with test samples Diagnostic capability of the algorithm for each tumor was validated, and enhancement of tumors by image processing using the HSC was evaluated The diagnostic algorithm used the 726-nm wavelength, with a cutoff point established from training samples The sensitivity, specificity, and accuracy rates of the algorithm’s diagnostic capability in the test samples were 78.8% (63/80), 92.5% (74/80), and 85.6% (137/160), respectively Tumors in HSC images of 13 (81.3%) cases were well enhanced by image processing Differences in spectral reflectance between tumors and normal mucosa suggested that tumors can be clearly distinguished from background mucosa with HSI technology.

Medaka as a model for human nonalcoholic steatohepatitis

SUMMARY The global incidence of nonalcoholic steatohepatitis (NASH) is increasing and current mammalian models of NASH are imperfect. We have developed a NASH model in the ricefish medaka (Oryzias latipes), which is based on feeding the fish a high-fat diet (HFD). Medaka that are fed a HFD (HFD-medaka) exhibited hyperlipidemia and hyperglycemia, and histological examination of the liver revealed ballooning degeneration. The expression of lipogenic genes (SREBP-1c, FAS and ACC1) was increased, whereas the expression of lipolytic genes (PPARA and CPT1) was decreased. With respect to liver fatty acid composition, the concentrations of n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs had declined and the n-3:n-6 ratio was reduced. Treatment of HFD-medaka with the n-3 PUFA eicosapentaenoic acid (EPA) mitigated disease, as judged by the restoration of normal liver fatty acid composition and normal expression levels of lipogenic and lipolytic genes. Moreover, medaka that were fed a diet deficient in n-3 PUFAs developed NASH features. Thus, NASH can be induced in medaka by a HFD, and the proportion of n-3 PUFAs in the liver influences the progress of NASH pathology in these fish. Our model should prove helpful for the dissection of the causes of human NASH and for the design of new and effective therapies.

UGT1A1*6, 1A7*3, and 1A9*22 genotypes predict severe neutropenia in FOLFIRI-treated metastatic colorectal cancer in two prospective studies in Japan

Retrospective studies have suggested that UDP‐glucuronosyltransferase (UGT)1A1, UGT1A7, and UGT1A9 predict severe toxicity and efficacy of irinotecan‐containing regimens. We prospectively evaluated the impact of UGT1A genotypes and haplotypes on severe toxicity and efficacy in patients treated with fluorouracil, leucovorin, and irinotecan combination chemotherapy (FOLFIRI) for metastatic colorectal cancer (mCRC) from the two prospective multicenter phase II studies in Japan. The FLIGHT1 study was a first‐line FOLFIRI trial, and FLIGHT2 was a FOLFOX‐refractory, second‐line FOLFIRI trial. A total of 73 patients agreed to additional analysis, and were genotyped for UGT1A polymorphisms, UGT1A1*28 (TA6>TA7), UGT1A1*6 (211G>A), UGT1A1*27 (686C>A), UGT1A1*60 (−3279T>G), UGT1A1*93 (−3156G>A), UGT1A7 (−57T>G), UGT1A7*3 (387T>G, 622T>C), and UGT1A9*22 (T9>T10). Of 73 patients, 34 developed G3/4 severe hematological toxicities. The toxicities were significantly more frequent in patients with UGT1A1*6 (211A), UGT1A7 (387G), and UGT1A9*22 reference alleles (T9). Haplotype I, which consists of all favorable alleles, was associated with a significant reduction in hematologic toxicity (P = 0.031). In contrast, haplotype II, which contains four high‐risk alleles, showed significantly higher hematologic toxicity than the other haplotypes (P = 0.010). Six out of seven patients who were homozygous for UGT1A1*28 or *6 experienced severe hematological toxicity despite the fact that their response rate was not impaired (42.9%). We concluded that UGT1A polymorphisms, especially UGT1A1*6, are important for the prediction of severe toxicity of FOLFIRI in northeast Asian populations. In this regard, haplotype analyses should substantially impact the prediction of severe hematological toxicities of FOLFIRI. (Clinical Trial Registration: UMIN000002388 and UMIN000002476).

Methylated cyclin D2 gene circulating in the blood as a prognosis predictor of hepatocellular carcinoma.

BACKGROUND Prognosis of hepatocellular carcinoma (HCC) remains poor because of high recurrence rate. We examined preoperatively the methylated CCND2 gene levels present in the serum following release from HCC cells as a prognosis predictor in patients undergoing curative hepatectomy. METHODS Quantitative real-time RT-PCR and quantitative methylation-specific PCR were used to measure methylated CCND2 gene and its mRNA levels. RESULTS The CCND2 mRNA levels were down-regulated in HCC with early intrahepatic recurrence (IHR) within 1year of curative hepatectomy. We also identified that this down-regulation was due to promoter hypermethylation. In 70 HCC patients who underwent curative hepatectomy, 39 patients sero-positive for the methylated CCND2 gene (>70pg/ml serum) exhibited a significantly shorter disease-free survival (DFS) period (P=0.02) than the 31 patients who were sero-negative for the methylated CCND2 gene. None of the sero-negative patients demonstrated early IHR, and this method of serum testing did not produce any false-negative predictions for early IHR. Multivariate analysis showed that the serum level of methylated CCND2 was an independent risk factor for DFS (hazard ratio of 1.866, 95% CI: 1.106-3.149). CONCLUSION Methylated CCND2 gene in the serum serves as a prognosis predictor of HCC after curative hepatectomy.

A Robust Method for Automatically Detecting Cracks on Noisy Concrete Surfaces

Automatic crack detection from concrete surface images is very effective for nondestructive testing. In our previous work, we proposed two preprocessing methods for automatic crack detection from noisy concrete surfaces. In this paper, we propose an automatic crack detection method after the preprocessings. The proposed method consists of two steps. One is relaxation process to prevent noises, and the other is a improved locally adaptive thresholding to detect cracks exactly. We evaluate the performance of the proposed method using 60 actual noisy concrete surface images, compared to those of the conventional thresholding techniques. Experimental results show that the robustness and the accuracy of the proposed method are good.

Granulocyte Colony-Stimulating Factor and Interleukin-1β are Important Cytokines in Repair of the Cirrhotic Liver after Bone Marrow Cell Infusion: Comparison of Humans and Model Mice:

We previously described the effectiveness of autologous bone marrow cell infusion (ABMi) therapy for patients with liver cirrhosis (LC). We analyzed chronological changes in 19 serum cytokines as well as levels of specific cytokines in patients after ABMi therapy and in a mouse model of cirrhosis generated using green fluorescent protein (GFP)/carbon tetrachloride (CCl4). We measured expression profiles of cytokines in serum samples collected from 13 patients before and at 1 day and 1 week after ABMi. Child–Pugh scores significantly improved in all of these patients. To analyze the meaning of early cytokine change, we infused GFP-positive bone marrow cells (BMCs) into mice with CCl4-induced LC and obtained serum and tissue samples at 1 day and as well as at 1, 2, 3, and 4 weeks later. We compared chronological changes in serum cytokine expression in humans and in the model mice at 1 day and 1 week after BMC infusion. Among 19 cytokine, both granulocyte colony-stimulating factor (G-CSF) and interleukin-1β (IL-1β) in serum was found to show the same chronological change pattern between human and mice model. Next, we examined changes in cytokine expression in cirrhosis liver before and at 1, 2, 3, and 4 weeks after BMC infusion. Both G-CSF and IL-1β were undetectable in the liver tissues before and at 1 week after BMC infusion but increased at 2 weeks and continued until 4 weeks after infusion. The infused BMCs induced an early decrease of both G-CSF and IL-1β in serum and an increase in the model mice with LC. These dynamic cytokine changes might be important to repair liver cirrhosis after BMC infusion.

Efficient detection of hepatocellular carcinoma by a hybrid blood test of epigenetic and classical protein markers

BACKGROUND There are few blood tests for an efficient detection of hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV) infection. METHODS The abilities of quantitative analyses of 7 genes hypermethylation in serum DNA, α-fetoprotein (AFP) and prothrombin-induced vitamin K absence II (PIVKA-II), and various combinations to detect HCC were evaluated in a training cohort of 164 HCV-infected patients (108 HCCs; 56 non-HCCs). An optimal hybrid detector, built using data for 2 methylated genes (SPINT2 and SRD5A2), AFP, and PIVKA-II, achieved the most satisfactory ability to detect HCC in the training cohort. We evaluated the ability of the optimal hybrid detector to detect HCC in an independent validation cohort of 258 consecutive HCV-infected patients (112 HCCs; 146 non-HCCs) who were newly enrolled in 4 distinct institutes. RESULTS In the validation cohort of 258 patients, accuracy, sensitivity, and specificity of the hybrid detector for detection of HCC were 81.4%, 73.2%, and 87.7%, respectively. Notably, even when detecting HCC ≤ 2 cm in diameter, the hybrid detector maintained markedly high abilities (84.6% accuracy, 72.2% sensitivity, 87.7% specificity). Youdens index (sensitivity+specificity - 1) for HCC ≤ 2cm was 0.60, vastly much superior to the 0.39 for AFP at a cut-off value of 20 ng/ml and the 0.28 for PIVKA-II at a cut-off value of 40 mAU/ml. CONCLUSIONS These results show that the optimal hybrid blood detector can detect HCV-related HCC more accurately.

Use of hyperspectral imaging technology to develop a diagnostic support system for gastric cancer

Abstract. Hyperspectral imaging (HSI) is a new technology that obtains spectroscopic information and renders it in image form. This study examined the difference in the spectral reflectance (SR) of gastric tumors and normal mucosa recorded with a hyperspectral camera equipped with HSI technology and attempted to determine the specific wavelength that is useful for the diagnosis of gastric cancer. A total of 104 gastric tumors removed by endoscopic submucosal dissection from 96 patients at Yamaguchi University Hospital were recorded using a hyperspectral camera. We determined the optimal wavelength and the cut-off value for differentiating tumors from normal mucosa to establish a diagnostic algorithm. We also attempted to highlight tumors by image processing using the hyperspectral camera’s analysis software. A wavelength of 770 nm and a cut-off value of 1/4 the corrected SR were selected as the respective optimal wavelength and cut-off values. The rates of sensitivity, specificity, and accuracy of the algorithm’s diagnostic capability were 71%, 98%, and 85%, respectively. It was possible to enhance tumors by image processing at the 770-nm wavelength. HSI can be used to measure the SR in gastric tumors and to differentiate between tumorous and normal mucosa.