Automatic BIRCH thresholding with features transformation for hierarchical breast cancer clustering

<p>Breast cancer is one of the most common diseases diagnosed in women over the world. The balanced iterative reducing and clustering using hierarchies (BIRCH) has been widely used in many applications. However, clustering the patient records and selecting an optimal threshold for the hierarchical clusters still a challenging task. In addition, the existing BIRCH is sensitive to the order of data records and influenced by many numerical and functional parameters. Therefore, this paper proposes a unique BIRCH-based algorithm for breast cancer clustering. We aim at transforming the medical records using the breast screening features into sub-clusters to group the subject cases into malignant or benign clusters. The basic BIRCH clustering is firstly fed by a set of normalized features then we automate the threshold initialization to enhance the tree-based sub-clustering procedure. Additionally, we present a thorough analysis on the performance impact of tuning BIRCH with various relevant linkage functions and similarity measures. Two datasets of the standard breast cancer wisconsin (BCW) benchmarking collection are used to evaluate our algorithm. The experimental results show a clustering accuracy of 97.7% in 0.0004 seconds only, thereby confirming the efficiency of the proposed method in clustering the patient records and making timely decisions.</p>

Optimal Threshold of Homeostasis Model Assessment of Insulin Resistance to Identify Metabolic Syndrome in a Chinese Population Aged 45 Years or Younger

BackgroundMetabolic syndrome (MetS) is regarded as a major risk factor for diabetes mellitus and cardiovascular disease (CVD). The optimal threshold of the homeostasis model assessment of insulin resistance (HOMA-IR) has been established for predicting MetS in diverse populations and for different ages. This study assessed the serum HOMA-IR level in a healthy Chinese population aged ≤45 years to determine its relationship with metabolic abnormalities.MethodsCross-sectional study data were collected from health checkup records of Chinese adults aged ≥18 years between 2013 and 2016 at Xiamen Chang Gung Hospital. Participants completed a standardized questionnaire, which was followed by a health examination and blood sample collection. Exclusion criteria were as follows: history of known CVDs; liver, kidney, or endocrine diseases or recent acute illness; hypertension; hyperlipidemia; and pregnancy or lactation.ResultsThe clinical and laboratory characteristics of 5954 men and 4185 women were analyzed. Significant differences were observed in all assessed variables (all P &lt; 0.05). The optimal cutoff point of HOMA-IR for predicting MetS was 1.7 in men and 1.78 in women.ConclusionsWe aimed to determine the optimal cutoff point of HOMA-IR for predicting MetS in a healthy Chinese population aged ≤45 years. The findings of this study would provide an evidence-based threshold for evaluating metabolic syndromes and further implementing primary prevention programs, such as lifestyle changes in the target population.

The Impact of Corruption On Economic Growth: A Nonlinear Evidence

Several cross-country studies have found that corruption slows growth, but these findings are not universally robust. Therefore, the questions to be addressed are to what extent corruption can be tolerated and at what threshold it has a detrimental effect on an economy.This article investigates the impact of corruption on economic growth by testing the hypothesis that the relationship between these two variables is nonlinear. In this article, a panel data analysis has been used to examine 65 countries over the 1987 to 2018 period. Our findings are that corruption can have a positive effect on growth. The results indicate that beyond an optimal threshold, both high and low corruption levels can decrease economic growth. Under this optimal threshold, a moderate level of corruption, defined by the point of reversal of the curve of the marginal corruption effect on growth, could have advantages for economic growth.JEL: B23, C51, D73, O47.

Establishing Irreversible Electroporation Electric Field Potential Threshold in A Suspension In Vitro Model for Cardiac and Neuronal Cells

Aims: Irreversible electroporation is an ablation technique being adapted for the treatment of atrial fibrillation. Currently, there are many differences reported in the in vitro and pre-clinical literature for the effective voltage threshold for ablation. The aim of this study is a direct comparison of different cell types within the cardiovascular system and identification of optimal voltage thresholds for selective cell ablation. Methods: Monophasic voltage pulses were delivered in a cuvette suspension model. Cell viability and live–dead measurements of three different neuronal lines, cardiomyocytes, and cardiac fibroblasts were assessed under different voltage conditions. The immediate effects of voltage and the evolution of cell death was measured at three different time points post ablation. Results: All neuronal and atrial cardiomyocyte lines showed cell viability of less than 20% at an electric field of 1000 V/cm when at least 30 pulses were applied with no significant difference amongst them. In contrast, cardiac fibroblasts showed an optimal threshold at 1250 V/cm with a minimum of 50 pulses. Cell death overtime showed an immediate or delayed cell death with a proportion of cell membranes re-sealing after three hours but no significant difference was observed between treatments after 24 h. Conclusions: The present data suggest that understanding the optimal threshold of irreversible electroporation is vital for achieving a safe ablation modality without any side-effect in nearby cells. Moreover, the evolution of cell death post electroporation is key to obtaining a full understanding of the effects of IRE and selection of an optimal ablation threshold.

The Number of Parties and Decision-Making in Legislatures

This paper proposes a model of a legislature, formed by several parties, which has to vote for or against a certain bill in the presence of a lobbyist interested in a certain vote outcome. We show that the ease with which the lobbyist can manipulate a legislature decision increases with the number of elected parties, and, consequently, decreases with an electoral threshold. On the other hand, a lower electoral threshold increases the representativeness of a legislature. We combine these two effects in a notion of fairness. We show the existence of an electoral threshold that optimizes the fairness of a political system, which is close to 1–5%. Namely, the optimal threshold (in our sense) is close to thresholds that exist in most parliamentary democracies.

Predictive Factors for Metastasis of Skin Melanoma of Varying Thickness According to Breslow to Sentinel Lymph Nodes

Purpose: To evaluate the prognostic factors in patients with Breslow skin melanoma of various thicknesses that affect the incidence of metastases in the signal lymph nodes (SLN).Material and methods: From November 2018 to November 2020, 324 patients with diagnosed melanoma of the skin of various localization and stages were examined and operated on. We used lymphotropic colloidal radiopharmaceutical (RPh) labeled with 99mTc. RPh with an activity of 150 MBq was administered one day before the operation intradermally around the scar of resected melanoma or peritumorally at 4 points in the case of a primary tumor. Lymphoscintigraphy was performed 1–3 hours after the RP injection on a Symbia E or Symbia E gamma camera (Siemens, Germany). Anteroposterior and lateral static polypositional scintigraphy was performed to determine the topography and mark the SLN. 324 planar studies were performed. In 259 cases, an additional study was performed SPECT (including SPECT / CT) on a Symbia T2 device (Siemens, Germany). Surgical intervention was performed the next day, taking into account the data of intraoperative radiometry using a domestic specialized hand-held gamma detector Radical (Amplituda, Russia).Results: The mean primary melanoma Breslow thickness was 2.77 ± 2.2 mm (range 0.2–13.0 mm). Localization of SLN: axillary (n = 161. 51 %), inguinal (n = 100. 31 %), cervical (n = 16. 5 %), submandibular (n = 9. 3 %), supraclavicular (n = 4. 1 %), more than one basin (n = 34. 9 %). In the group of melanomas <0.75 mm thick, no SLN metastases were found, among 0.75–1 mm melanomas, one positive lymph node with metastasis (SLN+) was found, in the largest group of melanomas of medium thickness (1–3.5 mm) — 25 (17 %). The largest percentage of metastases in SLN is determined in thick melanomas (>3.5 mm) — 17 (28 %), which is consistent with the data of foreign literature, while SLN is most often affected with a Breslow tumor thickness of more than 7 mm.In the group with negative sentinel lymph nodes (SLN–), the average tumor thickness according to Breslow was 2.6 ± 2.0 mm, in the SLN+ group — 4.0 ± 2.9 mm, the differences between the groups are statistically significant, which is confirmed by the result of one-way analysis of variance.The optimal threshold value of tumor thickness according to Breslow for the isolation of patients with a positive prognosis of metastasis in the SLN is 2.0 mm. It is characterized by the maximum levels of sensitivity (79 %) and specificity (59.1 %). An older age of patients (over 35 years old) is also associated with an increased incidence of metastases in the SLN, but this indicator is not statistically significant. Most often, SLN metastases were detected when the primary tumor was localized in the back (more often in men) and lower extremities (more often in women), while they are thicker (> 3.5 mm).Conclusion: 1. According to the ROC-analysis, the optimal threshold value of the tumor thickness according to Breslow for the isolation of patients with a positive prognosis of metastasis in the SLN is 2.0 mm. It is characterized by the maximum levels of sensitivity (79 %) and specificity (59.1 %). 2. Statistically significant prognostic factors of metastasis in SLN: localization of the primary tumor in the back (more often in men) and lower extremities (more often in women); Breslow thickness over 3.5 mm. 3. The absence of the influence of gender and age was noted, with a slight predominance of women in both groups.

Role of Apparent Diffusion Coefficient Gradient Within Diffusion Lesions in Outcomes of Large Stroke After Thrombectomy

Background and Purpose: The outcome of endovascular treatment in stroke patients with a large ischemic core is not always satisfactory. We evaluated whether the severity of baseline diffusion-weighted imaging abnormalities, as assessed by different apparent diffusion coefficient (ADC) thresholds, correlates with the clinical outcome in these patients after successful endovascular treatment. Methods: In 82 consecutive patients with a large vessel occlusion in the anterior circulation admitted ≤24 hours after onset, a baseline diffusion lesion volume (ADC ≤620×10 −6 mm 2 /s [ADC 620 ]) ≥50 mL and successful recanalization by endovascular treatment were retrospectively investigated. Lesion volumes of 3 ADC thresholds (ADC 620 , ADC ≤520×10 − 6 mm 2 /s [ADC 520 ], and ADC ≤540×10 −6 mm 2 /s [ADC 540 ]) were measured using an automated Olea software program. The performance of the ADC 520 /ADC 620 and ADC 540 /ADC 620 ratios in predicting the functional outcome was assessed by receiver operating characteristic curve analysis. The ADC ratio with optimal threshold showing better receiver operating characteristic performance was dichotomized at its median value into low versus high subgroup and its association with the outcome subsequently evaluated in a multivariable logistic regression model. Results: The median baseline diffusion lesion volume was 80.8 mL (interquartile range, 64.4–105.4). A good functional outcome (modified Rankin Scale score, ≤2) was achieved in 35 patients (42.7%). The optimal threshold for predicting the functional outcome was identified as ADC 540 /ADC 620 (area under the curve, 0.833) and dichotomized at 0.674. After adjusting for age, baseline National Institutes of Health Stroke Scale score, intravenous tissue-type plasminogen activator, baseline diffusion lesion volume, and onset-to-recanalization time, a low ADC 540 /ADC 620 was independently associated with a good functional outcome (adjusted odds ratio, 10.72 [95% CI, 3.06–37.50]; P <0.001). Conclusions: A low ADC 540 /ADC 620 , which may reflect less severe ischemic stress inside a diffusion lesion, may help to identify patients who would benefit from endovascular treatment despite having a large ischemic core.

Limited value of serum neutrophil-to-lymphocyte ratio in the diagnosis of chronic periprosthetic joint infection

Background Diagnosing chronic periprosthetic joint infection (PJI) is challenging. No single biomarker can accurately recognize PJI preoperatively in a timely manner. Therefore, the aim of the present study was to investigate the usefulness of the serum neutrophil-to-lymphocyte ratio (NLR) in aiding the diagnosis of chronic PJI. Materials and methods We retrospectively evaluated the medical records of 158 patients who had undergone revision arthroplasty (104 with aseptic mechanic failure and 54 with chronic PJI) from July 2011 to July 2020. Univariate analysis followed by multivariate logistic regression was applied to compare NLR, C-reactive protein (CRP), and erythrocyte sedimentation ratio (ESR) between the two groups. The receiver operating characteristic (ROC) curve was used to assess the diagnostic performance of NLR alone and in combination with CRP and ESR. Results NLR, CRP, and ESR were significantly higher in patients with chronic PJI than in the aseptic revision group (p < 0.05). ROC curve analysis revealed that NLR had a sensitivity of 57.41% and a specificity of 77.88% with an optimal threshold of 2.56. The optimal threshold for CRP and ESR was 7.00 mg/L (sensitivity 62.50% and specificity 83.12%) and 43 mm/h (sensitivity 59.38% and specificity 80.52%), respectively. The combined diagnostic value of NLR with CRP and ESR was shown to have no additional diagnostic value in predicting chronic PJI. Conclusion Compared with traditional inflammatory biomarkers (ESR and CRP), the value of serum NLR alone or combined with CRP and ESR for diagnosing chronic PJI is limited. Level of evidence Level 3.