Selecting visually overlapping image pairs without any prior information is an essential task of large-scale structure from motion (SfM) pipelines. To address this problem, many state-of-the-art ...image retrieval systems adopt the idea of bag of visual words (BoVW) for computing image-pair similarity. In this paper, we present a method for improving the image pair selection using BoVW. Our method combines a conventional vector-based approach and a set-based approach. For the set similarity, we introduce a modified version of the Simpson (m-Simpson) coefficient. We show the advantage of this measure over three typical set similarity measures and demonstrate that the combination of vector similarity and the m-Simpson coefficient effectively reduces false positives and increases accuracy. To discuss the choice of vocabulary construction, we prepared both a sampled vocabulary on an evaluation dataset and a basic pre-trained vocabulary on a training dataset. In addition, we tested our method on vocabularies of different sizes. Our experimental results show that the proposed method dramatically improves precision scores especially on the sampled vocabulary and performs better than the state-of-the-art methods that use pre-trained vocabularies. We further introduce a method to determine the k value of top-k relevant searches for each image and show that it obtains higher precision at the same recall.
Molecular assessment using circulating tumor DNA (ctDNA) has not been well-defined. We recruited 61 pancreatic cancer (PC) patients who underwent initial computed tomography (CT) imaging study during ...first-line chemotherapy. Initial molecular assessment was performed using droplet digital PCR and defined as the change in KRAS-mutated ctDNA before and after treatments, which was classified into five categories: mNT, molecular negative; mCR, complete response; mPR, partial response; mSD, stable disease; mPD, progressive disease. Of 61 patients, 14 diagnosed with PD after initial CT imaging showed significantly worse therapeutic outcomes than 47 patients with disease control. In these 47 patients, initial molecular assessment exhibited significant differences in therapeutic outcomes between patients with and without ctDNA (mPD + mSD vs. mCR + mNT; 13.2 M vs. 21.7 M, P = 0.0029) but no difference between those with mPD and mSD + mCR + mNT, suggesting that the presence of ctDNA had more impact on the therapeutic outcomes than change in its number. Multivariate analysis revealed that it was the only independent prognostic factor (P = 0.0405). The presence of ctDNA in initial molecular assessment predicted early tumor progression and identified PC patients more likely to benefit from chemotherapy.
Gas movement around and/or through the photocatalyst is thought to be an inhibition factor to promote photocatalytic CO2 reduction performance. In this study, a hypothesis is put forward that the ...natural thermosiphon movement of gases around the photocatalyst can be improved by using black body material/surface. The black body material/surface that is placed underneath the photocatalyst in the reactor would be heated by absorbing light and then this heats up the gases to promote their movement around/through the photocatalyst. The aim of this study is to prove or disprove this hypothesis by conducting CO2 reduction performance of a TiO2 photocatalyst with NH3 under the conditions without black body material (W/O B.B.), with one black body material (W B.B.-1), and with three black body materials (W B.B.-3). The impact of molar ratio of CO2/NH3 on CO2 reduction performance is also investigated. This study revealed/proved that the hypothesis worked and that the CO2 reduction performance is promoted more with W B.B.-3 compared to that with W B.B.-1. The maximum concentration of formed CO with W B.B.-3 is two to five times as large as that under the condition W/O B.B.
Genome‑wide DNA hypomethylation is the most common molecular feature in human cancers associated with chromosomal instability (CIN), which is involved in the mechanisms that regulate pancreatic ...cancer (PC) metastasis. It was investigated whether genome‑wide DNA hypomethylation affects the phenotype in PC via CIN
, and its significance on the biological behavior of PC was verified. The relative demethylation level (RDL) of long interspersed nucleotide element‑1 (LINE‑1) in human PC cell lines was used to characterize DNA hypomethylation using methylation‑specific quantitative (q)PCR. CIN was estimated by changes in chromosomal copy number using comparative genomic hybridization analysis. Abnormal segregation of chromosomes was assessed by immunocytochemistry, and the DNA damage response was evaluated using the number of anti‑γH2AX positive cells. Invasion ability was assessed using a Matrigel invasion assay. Clinical specimens from 49 patients with PC who underwent curative surgery were evaluated for a correlation of DNA hypomethylation with clinical outcome. Successful induction of genome‑wide DNA hypomethylation in PC cells led to copy number changes in specific chromosomal regions. The number of cells with abnormal segregation of chromosomes significantly increased with the number of anti‑γH2AX positive cells. The invasive potential of these cells also significantly increased. The occurrence of occult distant metastasis in the clinical specimens and receiver operating characteristic analysis clearly identified those who were and were not likely to have occult distant metastasis, with high LINE‑1 RDL significantly correlated with the presence of occult distant metastasis (P=0.035) and poor prognosis (P=0.048). The significance of genome‑wide DNA hypomethylation on the biological behavior of PC, which promotes a more invasive phenotype via CIN
and predicts the susceptibility to occult distant metastasis and poor prognosis in patients with PC was revealed.
The impairment of the stability of the chromosomal structure facilitates the abnormal segregation of chromosomes, thus increasing the risk of carcinogenesis. Chromosomal stability during segregation ...is managed by appropriate methylation at the centromere of chromosomes. Insufficient methylation, or hypomethylation, results in chromosomal instability. The centromere consists of satellite alpha repetitive sequences, which are ideal targets for DNA hypomethylation, resulting in the overexpression of satellite alpha transcript (SAT). The overexpression of SAT has been reported to induce the abnormal segregation of chromosomes. In this study, we verified the oncogenic pathway via chromosomal instability involving DNA hypomethylation and the overexpression of SAT. For this purpose, we constructed lentiviral vectors expressing SAT and control viruses and then infected human mammary epithelial cells with these vectors. The copy number alterations and segregation errors of chromosomes were evaluated by microarray-based comparative genomic hybridization (array CGH) and immunocytochemistry, respectively. The levels of hypomethylation of satellite alpha sequences were determined by MethyLight polymerase chain reaction. Clinical specimens from 45 patients with breast cancer were recruited to verify the data in vitro. The results of immunocytochemistry revealed that the incidence of segregation errors was significantly higher in the cells overexpressing SAT than in the controls. An array CGH identified the specific chromosomes of 8q and 20q as frequent sites of copy number alterations in cells with SAT overexpression, although no such sites were noted in the controls, which was consistent with the data from clinical specimens. A regression analysis revealed that the expression of SAT was significantly associated with the levels of hypomethylation of satellite alpha sequences. On the whole, the overexpression of SAT led to chromosomal instability via segregation errors at specific chromosomes in connection with DNA hypomethylation, which was also recognized in clinical specimens of patients with breast cancer. Thus, this oncogenic pathway may be involved in the development of breast cancer. Key words: satellite alpha transcript, chromosomal instability, DNA hypomethylation, centromere, development of breast cancer
Abstract
Introduction
The drain output volume (DOV) after pancreaticoduodenectomy (PD) is an easily assessable indicator in clinical settings. We explored the utility of the DOV as a possible warning ...sign of complications after PD.
Methods
A total of 404 patients undergoing PD were considered for inclusion. The predictability of the DOV for overall morbidity, major complications, intraabdominal infection (IAI), clinically relevant (CR) postoperative pancreatic fistula (POPF), CR delayed gastric emptying (DGE), CR chyle leak (CL), and CR post-pancreatectomy hemorrhaging (PPH) was evaluated.
Results
One hundred (24.8%) patients developed major complications, and 131 (32.4%) developed IAI. Regarding CR post-pancreatectomy complications, 75 (18.6%) patients developed CR-POPF, 23 (5.7%) developed CR-DGE, 20 (5.0%) developed CR-CL, and 28 (6.9%) developed CR-PPH. The median DOV on postoperative day (POD) 1 and POD 3 was 266 and 234.5 ml, respectively. A low DOV on POD 1 was an independent predictor of CR-POPF, and a high DOV on POD 3 was an independent predictor of CR-CL. A receiver operating characteristics (ROC) analysis revealed that the DOV on POD 1 had a negative predictive value (area under the curve AUC 0.655, sensitivity 65.0%, specificity 65.3%, 95% confidence interval CI: 0.587–0.724), with a calculated optimal cut-off value of 227 ml. An ROC analysis also revealed that the DOV on POD 3 had a positive predictive value (AUC 0.753, sensitivity 70.1%, specificity 75.0%, 95% CI: 0.651–0.856), with a calculated optimal cut-off value of 332 ml.
Conclusion
A low DOV on POD 1 might be a postoperative warning sign for CR-POPF, similar to high drain amylase (DA) on POD 1, high DA on POD 3, and high CRP on POD 3. When the DOV on POD 1 after PD was low, surgeons should evaluate the reasons of a low DOV. A high DOV on POD 3 was a postoperative warning sign CR-CL, and might require an appropriate management of protein loss.
IntroductionSurgical site infection (SSI) is one of the most common complications after gastrointestinal surgery, with a reported incidence of approximately 10%–25%, which is higher than the rates ...after other types of surgery. Intraoperative wound irrigation (IOWI) is a simple intervention for SSI prevention, and recent studies have reported that IOWI with aqueous povidone–iodine (PVP-I) is significantly more effective at reducing the incidence of SSI than saline. However, the evidence level of previous trials evaluating the efficacy of aqueous PVP-I solution for preventing SSI has been low.Methods and analysesWe propose a single-institute, prospective, randomised, blinded-endpoint trial to assess the superiority of IOWI with aqueous 10% PVP-I solution compared with normal saline for reducing SSI in clean-contaminated wounds after elective gastrointestinal surgery. In the study group, IOWI with 40 mL of aqueous 10% PVP-I solution is performed for 1 min before skin suture, and in the control group, IOWI with 100 mL of saline is performed for 1 min before skin suture. We hypothesise that IOWI with aqueous 10% PVP-I solution will achieve a 50% reduction in the incidence of SSIs. The target number of cases is set at 950. The primary outcome is the incidence of incisional SSI up to postoperative day 30 and will be analysed in the modified intention-to-treat set.Ethics and disseminationThis trial was designed and is being conducted by Saitama Medical Center, Jichi Medical University, with approval from the Bioethics Committee for Clinical Research, Saitama Medical Center, Jichi Medical University. Participant recruitment began in June 2019. The final results will be reported in international peer-reviewed journals immediately after trial completion.Trial registration numberUMIN000036889.
Incidence and clinical characteristics of synchronous colorectal cancer (sCRC) patients significantly vary among studies, likely due to differences in surveillance methodology. If remain undetected, ...sCRC can progress to more advanced stages seriously aggravating patient prognosis. We studied the incidence and clinicopathological characteristics of Japanese patients with sCRCs who underwent surgery for primary CRC and received exhaustive perioperative surveillance.
We recruited 1005 patients with surgically resected CRCs between January 2007 and December 2011. The associations of clinical and pathological factors with sCRC development were assessed by univariate and multivariate logistic regression.
Eighty-four patients (8.4 %) developed sCRCs, 16 of them (19.0 %) harboring three or more cancers. Companion sCRCs were smaller and earlier stage than the index lesion (P < 0.0001). In multivariate analysis, advanced age (odds ratio (OR) 1.03 per year; P = 0.009) and left colon tumor location (OR 1.78; P = 0.013) are associated with higher risk of sCRCs, particularly in females. Overall survival did not differ between solitary CRC and sCRC (P = 0.62).
Our results highlight the importance of perioperative colonoscopy examination to ensure the absence of sCRCs that, being small and early staged, are more difficult to detect. The incidence of sCRC, and notably of triple or more sCRCs, was higher than previously recognized. Because they are also significantly higher than expected by merely stochastic accumulation of individual cancerous lesions, we suggest that the occurrence of many sCRC reflects a hitherto uncharacterized predisposition condition.
Although epithelial-mesenchymal transition (EMT) has been implicated as the pivotal event in metastasis, there is insufficient evidence related to EMT in clinical settings. Intratumor heterogeneity ...may lead to underestimation of gene expression representing EMT. In the present study, we investigated the expression of EMT-associated genes and microRNAs in primary colorectal cancer while considering intratumor heterogeneity. One-hundred and thirty-three multiple spatially separated samples were obtained from 8 patients with metastatic colorectal cancers and 8 with non-metastatic colorectal cancers, from the tumor center (TC), invasive front (IF) and metastasis. Differences in gene and microRNA expression were investigated by microarray and quantitative reverse-transcription PCR. Gene expression microarray analysis detected 7920 sites showing differing levels of gene expression among the TC, IF and metastasis. Expression of the EMT-associated gene zinc-finger E-box-binding homeobox 1 (ZEB1) significantly increased in the IF (P<0.01). To exclude individual differences, the expression ratio between TC and IF in each tumor was applied to analysis. This approach enabled recognition of the activation of the VEGF and Wnt signaling pathways, which were involved in metastasis via promotion of EMT. While no activation of these pathways was seen at the TC, regardless of whether tumors were metastatic or non-metastatic, they were preferentially activated at the IF in metastatic tumors, where high ZEB1 expression was seen in connection with decreased miR-200c expression. Multiple sampling in a tumor revealed that heterogeneous ZEB1 expression induced by EMT-associated signaling pathways played a pivotal role in metastasis via regulation of miR-200c.
We report a rare case of a large Brunner’s gland hyperplasia (BGH) with severe anemia. A 33-year-old woman was transferred to our hospital with anemia and a duodenal mass. She had a 2-week history of ...melena and mild shortness of breath. Her hemoglobin level was 4.9 g/dl, and she required a blood transfusion. Abdominal computed tomography revealed a 7 cm tumor in the descending duodenum, and duodenoscopy revealed a polyp-like tumor with an ulcer at the duodenal bulb. We decided to perform surgery to prevent further bleeding. Intraoperatively, the tumor stalk was located at the anterior wall of the duodenal bulb; the ampulla was not involved, and we resected the tumor with the wall of the duodenal bulb. The resected tumor measured 7.0×4.0×2.3 cm, and pathologically, the tumor consisted of proliferated Brunner’s glands in a small amount of fibrous stroma. The histological diagnosis was BGH with no malignancy. Most cases of BGH are benign and asymptomatic; however, it is important to be aware that some patients have severe anemia, gastrointestinal obstruction, or malignant potential.
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