Semi-automatic Method For Quantification Research Articles

The value of the tumour-stroma ratio for predicting neoadjuvant chemoradiotherapy response in locally advanced rectal cancer: a case control study

BackgroundThe tumour-stroma ratio (TSR) is recognized as a practical prognostic factor in colorectal cancer. However, TSR assessment generally utilizes surgical specimens. This study aims to investigate whether the TSR evaluated from preoperative biopsy specimens by a semi-automatic quantification method can predict the response after neoadjuvant chemoradiotherapy (nCRT) of patients with locally advanced rectal cancer (LARC).MethodsA total of 248 consecutive patients diagnosed with LARC and treated with nCRT followed by resection were included. Haematoxylin and eosin (HE)-stained sections of biopsy specimens were collected, and the TSR was evaluated by a semi-automatic quantification method and was divided into three categories, using the cut-offs determined in the whole cohort to balance the proportion of patients in each category. The response to nCRT was evaluated on the primary tumour resection specimen by an expert pathologist using the four-tier tumour regression grade (TRG) system.ResultsThe TSR can discriminate patients that are major-responders (TRG 0–1) from patients that are non-responders (TRG 2–3). Patients were divided into stroma-low (33.5%), stroma-intermediate (33.9%), and stroma-high (32.7%) groups using 56.3 and 72.8% as the cutoffs. In the stroma-low group, 58 (69.9%) patients were major-responders, and only 39 (48.1%) patients were considered major-responders in the stroma-high group (P = 0.018). Multivariate analysis showed that the TSR was the only pre-treatment predictor of response to nCRT (adjusted odds ratio 0.40, 95% confidence interval 0.21–0.76, P = 0.002).ConclusionAn elevated TSR in preoperative biopsy specimens is an independent predictor of nCRT response in LARC. This semi-automatic quantified TSR could be easily translated into routine pathologic assessment due to its reproducibility and reliability.

P5392Epicardium derived cells promote sympathetic ganglionic outgrowth towards myocardium in vitro

Abstract Background The autonomic nerve system is essential to maintain homeostasis in the body. In the heart, autonomic innervation is important for adjusting the physiology to the continuously changing demands such as stress responses. After cardiac damage, excessive neurite outgrowth, referred to as autonomic hyperinnervation, can occur which is related to ventricular arrhythmias and sudden cardiac death. The cellular basis for this hyperinnervation is as yet unresolved. Here we hypothesize a role for epicardium derived cells (EPDCs) in stimulating sympathetic neurite outgrowth. Purpose To investigate the potential role of adult EPDCs in promoting sympathetic ganglionic outgrowth towards adult myocardium. Method Fetal murine superior cervical ganglia were dissected and co-cultured with activated adult mesenchymal epicardium-derived cells (EPDCs) or/and adult myocardium in a 3D collagen gel culture system. Four experiment groups were included: Group 1: Vehicle cultures (ganglia cultured without EPDC/myocardium) (n=48); Group 2: ganglia co-cultured with EPDCs (n=38); Group 3: ganglia co-cultured with myocardium (n=95); and group 4: ganglia co-cultured with both EPDCs and myocardium (n=96). The occurrence of neurite outgrowth was assessed in each group. The density of neurites that showed directional sprouting (i.e. sprouting towards myocardium) was assessed as well with a semi-automatic quantification method. Finally, sub-analyses were made by taking gender into account. Results Cervical ganglia cultured with EPDCs alone (group 2) showed increased neurite outgrowth compared to vehicle cultures (group 1), however the neurites did not show directional sprouting towards EPDCs. When co-cultured with myocardium (group 3), directional neurite outgrowth towards myocardium was observed. Compared to the ganglia-myocardium co-cultures, directional outgrowth was significantly increased in co-cultures combining myocardium and EPDCs (group 4), and the neurite density was also significantly augmented. Comparison between males and female ganglia demonstrated that more neurite outgrowth occurred in female-derived ganglia than in male-derived ganglia under the same co-culture conditions. Conclusion Activated adult EPDCs promote sympathetic ganglionic outgrowth in vitro. Sex differences exist in the response of ganglia to EPDCs, and female-derived ganglia appear more sensitive to EPDC-signalling. Results support a role of EPDCs in cardiac autonomic innervation and open avenues for exploring of their role in ventricular hyperinnervation after cardiac damage.

A semi-automatic method for quantification of respiratory variation in early mitral inflow velocity using real time phase contrast cardiac magnetic resonance - normal values and clinical feasibility

Background Echocardiography has shown that patients with constrictive pericarditis or hemodynamically significant pericardial effusion show an increased respiratory variation in early transmitral inflow velocity. The methodology for quantification of respiratory variation in early transmitral inflow velocity using real time phase contrast (RT-PC) cardiovascular magnetic resonance (CMR) images is currently cumbersome and manual. The aim of this study was to develop a method for quantifying the respiratory variation in early transmitral inflow velocity using semiautomatic analysis of RT-PC CMR images.

Quantification of Islet Loss During Immune Rejection Using Iron-Labeled Islet Cells by 3T MRI in the Rat Model

Background: Monitoring the fate of transplanted islets remains a major challenge in clinical islet transplantation (IT). We developed a MRI imaging protocol (3D difference ultra-short echo-time = dUTE), resulting in positive contrast images of superparamagnetic iron-oxide (SPIO) nanoparticles-labeled islets transplanted in rat. Our aim was to compare the evolution of the MRI signal in 3 types of IT in the rat model. Methods: Syngeneic and allogeneic SPIO-labeled islets (ferucarbotran, 280μg/ml iron) were injected intraportally into streptozotocin-induced diabetic Lewis rats. Xenogeneic human islets were transplanted into normoglycaemic rats and graft functionality was evaluated by serum human C-peptide levels. Images were performed on a 3T clinical scanner, from day 0 up to day 106. An intensity threshold was applied within the liver region, giving automatically the number of dUTE-enhanced pixels, allowing quantification. Histological studies included insulin, CD4 and CD8 staining and iron detection. Results: Decay rates for the 3 types of transplantation were different (Figure 1). The syngeneic graft signal showed a 20% decrease during the first 2 weeks and remained stable up thereafter. For allogeneic transplantation, islet rejection (G>20 mmol/l) occurred at day 7.7±0.5 and 41%±12 of the initial signal was lost. In the xenogeneic model, 43%±8 of the initial signal was lost by day 3, when significant basal and stimulated human C-peptide levels were not detected any longer. Islet rejection was confirmed by islet CD4+ and CD8+ cell infiltration and loss of insulin staining. When allogeneic transplanted rats are treated with anti-lymphocytic serum, glycemia remains normal but MRI signal shows a slight decrease corresponding to sub-clinical immune rejection. Conclusion: After intra-portal IT and during immune rejection, the loss of SPIO-labeled islets can be monitored with clinical-grade 3T MRI imaging using a semi-automatic quantification method. The decay of the signal is correlated with the graft function and histological findings.

A semi-automatic method for quantification and classification of erythrocytes infected with malaria parasites in microscopic images

Visual quantification of parasitemia in thin blood films is a very tedious, subjective and time-consuming task. This study presents an original method for quantification and classification of erythrocytes in stained thin blood films infected with Plasmodium falciparum. The proposed approach is composed of three main phases: a preprocessing step, which corrects luminance differences. A segmentation step that uses the normalized RGB color space for classifying pixels either as erythrocyte or background followed by an Inclusion-Tree representation that structures the pixel information into objects, from which erythrocytes are found. Finally, a two step classification process identifies infected erythrocytes and differentiates the infection stage, using a trained bank of classifiers. Additionally, user intervention is allowed when the approach cannot make a proper decision. Four hundred fifty malaria images were used for training and evaluating the method. Automatic identification of infected erythrocytes showed a specificity of 99.7% and a sensitivity of 94%. The infection stage was determined with an average sensitivity of 78.8% and average specificity of 91.2%.