Konstantinos Stefanidis
National and Kapodistrian University of Athens
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Featured researches published by Konstantinos Stefanidis.
Critical Care | 2009
Vasiliki Gerovasili; Konstantinos Stefanidis; Konstantinos Vitzilaios; Eleftherios Karatzanos; Panagiotis Politis; Apostolos Koroneos; Aikaterini Chatzimichail; Christina Routsi; Charis Roussos; Serafim Nanas
IntroductionCritically ill patients are characterized by increased loss of muscle mass, partially attributed to sepsis and multiple organ failure, as well as immobilization. Recent studies have shown that electrical muscle stimulation (EMS) may be an alternative to active exercise in chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF) patients with myopathy. The aim of our study was to investigate the EMS effects on muscle mass preservation of critically ill patients with the use of ultrasonography (US).MethodsForty-nine critically ill patients (age: 59 ± 21 years) with an APACHE II admission score ≥13 were randomly assigned after stratification upon admission to receive daily EMS sessions of both lower extremities (EMS-group) or to the control group (control group). Muscle mass was evaluated with US, by measuring the cross sectional diameter (CSD) of the vastus intermedius and the rectus femoris of the quadriceps muscle.ResultsTwenty-six patients were finally evaluated. Right rectus femoris and right vastus intermedius CSD decreased in both groups (EMS group: from 1.42 ± 0.48 to 1.31 ± 0.45 cm, P = 0.001 control group: from 1.59 ± 0.53 to 1.37 ± 0.5 cm, P = 0.002; EMS group: from 0.91 ± 0.39 to 0.81 ± 0.38 cm, P = 0.001 control group: from 1.40 ± 0.64 to 1.11 ± 0.56 cm, P = 0.004, respectively). However, the CSD of the right rectus femoris decreased significantly less in the EMS group (-0.11 ± 0.06 cm, -8 ± 3.9%) as compared to the control group (-0.21 ± 0.10 cm, -13.9 ± 6.4%; P < 0.05) and the CSD of the right vastus intermedius decreased significantly less in the EMS group (-0.10 ± 0.05 cm, -12.5 ± 7.4%) as compared to the control group (-0.29 ± 0.28 cm, -21.5 ± 15.3%; P < 0.05).ConclusionsEMS is well tolerated and seems to preserve the muscle mass of critically ill patients. The potential use of EMS as a preventive and rehabilitation tool in ICU patients with polyneuromyopathy needs to be further investigated.Trial Registrationclinicaltrials.gov: NCT00882830
Critical Care | 2011
Konstantinos Stefanidis; Stavros Dimopoulos; Elli-Sophia Tripodaki; Konstantinos Vitzilaios; Panagiotis Politis; Ploutarchos Piperopoulos; Serafim Nanas
IntroductionBedside lung sonography is a useful imaging tool to assess lung aeration in critically ill patients. The purpose of this study was to evaluate the role of lung sonography in estimating the nonaerated area changes in the dependent lung regions during a positive end-expiratory pressure (PEEP) trial of patients with early acute respiratory distress syndrome (ARDS).MethodsTen patients (mean ± standard deviation (SD): age 64 ± 7 years, Acute Physiology and Chronic Health Evaluation II (APACHE II) score 21 ± 4) with early ARDS on mechanical ventilation were included in the study. Transthoracic sonography was performed in all patients to depict the nonaerated area in the dependent lung regions at different PEEP settings of 5, 10 and 15 cm H2O. Lung sonographic assessment of the nonaerated lung area and arterial blood gas analysis were performed simultaneously at the end of each period. A control group of five early ARDS patients matched for APACHE II score was also included in the study.ResultsThe nonaerated areas in the dependent lung regions were significantly reduced during PEEP increases from 5 to 10 to 15 cm H2O (27 ± 31 cm2 to 20 ± 24 cm2 to 11 ± 12 cm2, respectively; P < 0.01). These changes were associated with a significant increase in arterial oxygen partial pressure (74 ± 15 mmHg to 90 ± 19 mmHg to 102 ± 26 mmHg; P < 0.001, respectively). No significant changes were observed in the nonaerated areas in the dependent lung regions in the control group.ConclusionsIn this study, we show that transthoracic lung sonography can detect the nonaerated lung area changes during a PEEP trial of patients with early ARDS. Thus, transthoracic lung sonography might be considered as a useful clinical tool in the management of ARDS patients.
Respirology | 2011
Konstantinos Stefanidis; Stavros Dimopoulos; Serafim Nanas
Until recently, the sonographic visualization of pulmonary and pleural diseases was considered a poorly accessible method, due to the inability of sound to penetrate air‐filled lung. Despite its limitations, lung ultrasonography is becoming an important diagnostic tool in a growing number of pathological situations such as pneumonia, atelectasis, interstitial‐alveolar syndrome, pulmonary embolism, pneumothorax and pleural effusion. The low sensitivity of CXR and the difficulties of performing CT make this technique invaluable for bedside use in the intensive care unit. Lung ultrasonography is an easily repeatable and radiation‐free technique, and therefore, an attractive imaging tool for use on a daily basis, especially in the management of critically ill patients.
Journal of Pediatric and Adolescent Gynecology | 2012
M. Eleftheriadou; Lina Michala; Konstantinos Stefanidis; I. Iliadis; A. Lykeridou; Aris Antsaklis
STUDY OBJECTIVE The purpose of this study was the recording of physical activity and sedentary habits of adolescents with polycystic ovarian syndrome (PCOS). METHODS We performed a structured interview to assess the level of physical activity and sedentary habits of girls with PCOS. We used a group of healthy adolescents as controls. All girls had their age, height, weight, hip and waist circumference measured and their BMI calculated. RESULTS 81 girls (35 with PCOS and 46 controls) participated in the study. Girls with PCOS engaged in physical activities less than controls. Even when they did, the frequency and intensity of exercise was less. Also, girls with PCOS were less likely to be aware of the positive effects of exercise on their health. Girls in both groups were sedentary in excess of the 4 hours per day limit, which has been linked with obesity. CONCLUSION Healthy teenagers were involved in a sporting activity more often and more frequently than the PCOS group. Athletic and sedentary habits of adolescents with PCOS may interact with other factors leading to obesity.
International Scholarly Research Notices | 2013
Chrysafoula Kolofousi; Konstantinos Stefanidis; Demosthenes D. Cokkinos; Dimitrios Karakitsos; Eleni G. Antypa; Ploutarhos Piperopoulos
Renal transplantation is the treatment of choice for managing patients with end-stage kidney disease. Being submitted to a very serious surgical procedure, renal transplant recipients can only benefit from follow-up imaging and monitoring strategies. Ultrasound is considered as the principal imaging test in the evaluation of renal transplants. It is an easily applied bedside examination that can detect possible complications and guide further imaging or intervention. In this imaging review, we present essential information regarding the sonographic features of healthy renal transplants, detailing the surgical technique and how it affects the sonoanatomy. We focus on various complications that occur following renal transplantation and their sonographic features by reviewing pertinent literature sources and our own extensive imaging archives.
Gynecologic Oncology | 2008
Konstantinos Stefanidis; Dimitris Loutradis; Leandros-Vassilios F. Vassiliou; Vasiliki Anastasiadou; Erasmia Kiapekou; Vasilis Nikas; Giorgos Patris; G. Vlachos; Alexandros Rodolakis; Aris Antsaklis
OBJECTIVE The aim of this study was to assess the impact of nevirapine on a cervix carcinoma cell line. METHODS HeLa cells were cultured in Dulbeccos modified Eagle medium supplemented with 20% fetal bovine serum at 37 degrees C and humidified 10% CO(2) in air. Nevirapine was purified from commercially available Viramune (Boehringer-Ingelheim), diluted in dimethyl sulfoxide (DMSO, Sigma-Aldrich) in 350 microMu final concentration and added to cell cultures 5 h after seeding. The same DMSO volume (0.2% final concentration) was added to controls. RESULTS We found that nevirapine treatment induces reversible growth arrest and produces morphological changes in treated cells. In contrast with previous reports the observed effects of nevirapine did not correlate with promotion of differentiation, but with induction of premature senescence. Premature senescence as a response to anti-tumour treatment is a common effect of the most anti-cancer chemotherapeutics. Nevirapine treated cells strongly accumulated SA-b-Gal activity and also expressed increased levels of p53 and p21 when analyzed via RT-PCR. In order to further explore the potent mechanisms of premature senescence induction we performed pChk2-Thr68 immunofluorescence analysis and found that nevirapine treated cells exhibited increased number of nuclear foci, indicating activated DNA damage response. CONCLUSION We propose that at least in HeLa cell line nevirapine treatment exerts an effect far from the differentiation process, by introducing the cells into premature senescence. Based on these data, the effects of RT inhibitors should be further investigated since they may represent an additional agent against human cancer.
Reproductive Biology and Endocrinology | 2012
Michail Varras; Katerina Polonifi; Marina Mantzourani; Konstantinos Stefanidis; Zacharias Papadopoulos; Christodoulos Akrivis; Aris Antsaklis
BackgroundThe purpose of the study was to determine the incidence of survivin gene expression in human granulosa cells during ovarian stimulation in Greek women with normal FSH levels, undergoing IVF or ICSI and to discover any correlation between levels of gene expression and clinical parameters, efficacy of ovulation or outcomes of assisted reproduction.MethodsTwenty nine women underwent ovulation induction for IVF or ICSI and ET with standard GnRH analogue-recombinant FSH protocol. Infertility causes were male and tubal factor. Cumulus–mature oocyte complexes were denuded and the granulosa cells were analyzed for each patient separately using quantitative reverse transcription polymerase chain reaction analysis for survivin gene expression with internal standard the ABL gene.ResultsThe ABL and survivin mRNA were detected in granulosa cells in 93.1%. The expression levels of survivin were significantly lower in normal women (male infertility factor) compared to women with tubal infertility factor (p = 0.007). There was no additional statistically significant correlation between levels of survivin expression and estradiol levels or dosage of FSH for ovulation induction or number of dominant follicles aspirated or number of retrieved oocytes or embryo grade or clinical pregnancy rates respectively.ConclusionsHigh levels of survivin mRNA expression in luteinized granulosa cells in cases with tubal infertility seem to protect ovaries from follicular apoptosis. A subpopulation of patients with low levels of survivin mRNA in granulosa cells might benefit with ICSI treatment to bypass possible natural barriers of sperm-oocyte interactions.
Gynecological Endocrinology | 2008
Konstantinos Stefanidis; D. Loutradis; Anastasiadou; Ritsa Bletsa; Erasmia Kiapekou; P. Drakakis; Beretsos P; Elenis E; Mesogitis S; Aris Antsaklis
Background/aims. The present clinical and molecular study aimed at investigating the presence of the genes encoding oxytocin receptor (OT-R) and Oct-4 in human amniotic fluid cells. Methods. Amniotic fluid samples were obtained from amniocentesis. Cells from human amniotic fluid samples were analyzed for mRNA expression of OT-R and Oct-4 via reverse transcription–polymerase chain reaction (RT-PCR). Immunocytochemistry was also performed with OT-R and Oct-4 antibodies. Results. RT-PCR from 10 independent amniocentesis samples demonstrated the expression of OT-R and Oct-4 mRNA. The cells also showed strong immunoreactivity for molecular markers of OT-R and Oct-4. Conclusion. OT-R and Oct-4 are expressed in human amniotic fluid cells. The role of oxytocin in the physiology and pathophysiology of amniotic fluid cells remains to be settled.
Critical Care Research and Practice | 2012
Michael Blaivas; Konstantinos Stefanidis; Serafim Nanas; John Poularas; Mitchell S. Wachtel; Rubin Cohen; Dimitrios Karakitsos
Background-Aim. Upper extremity deep vein thrombosis (UEDVT) is an increasingly recognized problem in the critically ill. We sought to identify the prevalence of and risk factors for UEDVT, and to characterize sonographically detected thrombi in the critical care setting. Patients and Methods. Three hundred and twenty patients receiving a subclavian or internal jugular central venous catheter (CVC) were included. When an UEDVT was detected, therapeutic anticoagulation was started. Additionally, a standardized ultrasound scan was performed to detect the extent of the thrombus. Images were interpreted offline by two independent readers. Results. Thirty-six (11.25%) patients had UEDVT and a complete scan was performed. One (2.7%) of these patients died, and 2 had pulmonary embolism (5.5%). Risk factors associated with UEDVT were presence of CVC [(odds ratio (OR) 2.716, P = 0.007)], malignancy (OR 1.483, P = 0.036), total parenteral nutrition (OR 1.399, P = 0.035), hypercoagulable state (OR 1.284, P = 0.045), and obesity (OR 1.191, P = 0.049). Eight thrombi were chronic, and 28 were acute. We describe a new sonographic sign which characterized acute thrombosis: a double hyperechoic line at the interface between the thrombus and the venous wall; but its clinical significance remains to be defined. Conclusion. Presence of CVC was a strong predictor for the development of UEDVT in a cohort of critical care patients; however, the rate of subsequent PE and related mortality was low.
Fertility and Sterility | 2011
Erasmia Kiapekou; Evangelia Zapanti; Dionysia Voukelatou; Theodora Mavreli; Konstantinos Stefanidis; Peter Drakakis; George Mastorakos; Dimitris Loutradis
The expression of corticotropin-releasing hormone (CRH) receptor 1 messenger RNA in stages of follicle growth was examined by reverse transcriptase-polymerase chain reaction in long-term cultures of early preantral mouse follicles with and without CRH addition. Corticotropin-releasing hormone receptor 1 is present in stages of mouse follicle growth, whereas 10(-9), 10(-7), and 10(-6) mol/L CRH inhibits oocyte maturation in vitro, an effect reversed by antalarmin addition.