Publications by authors named "Konstantinos Tsekouras"

European manufacturing firms have to cope with the new regulations that advocate a greener and more sustainable future with less emissions and at the same time enhance or at least maintain their productivity levels. A unique dataset is constructed by combining information on different firms' pollutants with their financial information during the 2011-2017 period. A non-radial directional distance function analysis is adopted with desirable and undesirable outputs to estimate environmental productivity growth and its components, which addresses the problem of heterogeneity.

View Article and Find Full Text PDF

Introduction: Kaposi sarcoma (KS) is a low-grade mesenchymal tumor involving the blood and the lymphatic vessels that primarily effaces the skin and is mediated by human herpesvirus-8 (HHV-8) in more than 90% of patients. There are 4 distinct types of KS. Compared with the classic and AIDS-related variants, chronic lymphocytic leukemia (CLL) associated with KS is a relatively rare clinical condition; thus, only a few cases have been reported.

View Article and Find Full Text PDF

Background: Surgical treatment of benign liver diseases (BLD) remains a field of conflict, due to increased risk and high complication rate. However, the introduction of minimally invasive surgery has led to increased number of patients with BLD being treated surgically, with similar outcomes and fewer complications. Current data support the application of laparoscopic surgery (LS) and robotic surgery (RS) in surgical treatment of liver malignancies, but there are insufficient data concerning the application of robotic surgery in BLD.

View Article and Find Full Text PDF

During the COVID-19 pandemic, the number of visits in emergency departments (ED) worldwide decreased significantly based on several studies. This study aims to compare the patient flow in the emergency surgery department during the COVID-19 pandemic and a control period in the emergency department of a public tertiary care hospital in Greece. The overall patient flow reduction regarding the ED visits between the two examined periods was 49.

View Article and Find Full Text PDF

We report a case of an uncommon type of dysphagia, due to esophagus compression by an aberrant right subclavian artery. This condition, known as dysphagia lusoria, was first recorded in 1787 by London physician David Bayford.

View Article and Find Full Text PDF

The liver performs critical physiological functions, including metabolizing and removing substances, such as toxins and drugs, from the bloodstream. Hepatotoxicity itself is intimately linked to abnormal hepatic transport, and hepatotoxicity remains the primary reason drugs in development fail and approved drugs are withdrawn from the market. For this reason, we propose to analyze, across liver compartments, the transport kinetics of fluorescein-a fluorescent marker used as a proxy for drug molecules-using intravital microscopy data.

View Article and Find Full Text PDF

The purpose of this study is to summarize the life and work of the French anatomist and surgeon Antoine Ferrein (1693-1769). Ferrein made an impact in the history of anatomy and physiology through his work and especially with the description of phonation, renal anatomy, and liver and biliary structure. He also made an impact on ophthalmology with the description of the eyelid and its diseases.

View Article and Find Full Text PDF

Extracellular DNA is engulfed by innate immune cells and digested by endosomal DNase II to generate an immune response. Quantitative information on endosomal stage-specific cargo processing is a critical parameter to predict and model the innate immune response. Biochemical assays quantify endosomal processing but lack organelle-specific information, while fluorescence microscopy has provided the latter without the former.

View Article and Find Full Text PDF

The patients with Hashimoto thyroiditis must be investigated mainly for secondary hyperparathyroidism due to vitamin D deficiency/insufficiency. Parathyroid scintigraphy has no place in the diagnosis of primary, secondary or tertiary hyperparathyroidism or in the decision for surgical treatment. Parathyroid scintigraphy is a useful preoperative technique for the localization of the pathological parathyroid glands.

View Article and Find Full Text PDF

Super-resolution microscopy provides direct insight into fundamental biological processes occurring at length scales smaller than light's diffraction limit. The analysis of data at such scales has brought statistical and machine learning methods into the mainstream. Here we provide a survey of data analysis methods starting from an overview of basic statistical techniques underlying the analysis of super-resolution and, more broadly, imaging data.

View Article and Find Full Text PDF

The Gram-negative Bdellovibrio bacteriovorus (BV) is a model bacterial predator that hunts other bacteria and may serve as a living antibiotic. Despite over 50 years since its discovery, it is suggested that BV probably collides into its prey at random. It remains unclear to what degree, if any, BV uses chemical cues to target its prey.

View Article and Find Full Text PDF

Photobleaching event counting is a single-molecule fluorescence technique that is increasingly being used to determine the stoichiometry of protein and RNA complexes composed of many subunits in vivo as well as in vitro. By tagging protein or RNA subunits with fluorophores, activating them, and subsequently observing as the fluorophores photobleach, one obtains information on the number of subunits in a complex. The noise properties in a photobleaching time trace depend on the number of active fluorescent subunits.

View Article and Find Full Text PDF

Objective: The aim of this study was to investigate vitamin D status by measuring serum 25(OH)D levels in euthyroid patients with Hashimoto's thyroiditis (HT) who lived and worked on the sunny island of Crete, Greece, and to evaluate whether vitamin D3 supplementation is beneficial for the management of HT patients with vitamin D deficiency.

Subjects And Methods: We studied 218 HT patients, euthyroid Caucasian Cretan Greek citizens: 180 females and 38 males. Among these patients, 186 (85.

View Article and Find Full Text PDF

Fluorescence correlation spectroscopy (FCS) is a noninvasive technique that probes the diffusion dynamics of proteins down to single-molecule sensitivity in living cells. Critical mechanistic insight is often drawn from FCS experiments by fitting the resulting time-intensity correlation function, G(t), to known diffusion models. When simple models fail, the complex diffusion dynamics of proteins within heterogeneous cellular environments can be fit to anomalous diffusion models with adjustable anomalous exponents.

View Article and Find Full Text PDF

Recent studies have shown that the diffusivity of enzymes increases in a substrate-dependent manner during catalysis. Although this observation has been reported and characterized for several different systems, the precise origin of this phenomenon is unknown. Calorimetric methods are often used to determine enthalpies from enzyme-catalysed reactions and can therefore provide important insight into their reaction mechanisms.

View Article and Find Full Text PDF

Although targeting of cancer cells using drug-delivering nanocarriers holds promise for improving therapeutic agent specificity, the strategy of maximizing ligand affinity for receptors overexpressed on cancer cells is suboptimal. To determine design principles that maximize nanocarrier specificity for cancer cells, we studied a generalized kinetics-based theoretical model of nanocarriers with one or more ligands that specifically bind these overexpressed receptors. We show that kinetics inherent to the system play an important role in determining specificity and can in fact be exploited to attain orders of magnitude improvement in specificity.

View Article and Find Full Text PDF

The dynamic susceptibility contrast magnetic resonance imaging perfusion technique was used to investigate possible hemodynamic changes in normal appearing white matter and deep gray matter (DGM) of 30 patients with clinically isolated syndrome (CIS) and 30 patients with relapsing-remitting multiple sclerosis. Thirty normal volunteers were studied as controls. Cerebral blood volume, cerebral blood flow (CBF), and mean transit time values were estimated.

View Article and Find Full Text PDF