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Γεώργιος Νικολάου

University of Nicosia

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Damianos Neocleous

Ministry of Agriculture, Natural Resources and Environment

ΝK

Ν. Katsoulas

University of Thessaly

E. Kitta

University of Thessaly

John Spiliotis

Interbalkan Medical Center

Nikolaos Kopanakis

Metaxa Hospital

Elias Efstathiou

Metaxa Hospital

Andrea Gröne

Utrecht University

David Holzmann

University Hospital of Zurich

Alphons J.A.M. van Asten

Utrecht University

Constantinos Kittas

University of Thessaly

Cooperative Institutions

National and Kapodistrian University of Athens

University of Thessaly

University of Zurich

University of Cyprus

University Hospital of Zurich

University of Liverpool

University of Crete

University Hospital of Larissa

Cyprus Institute of Neurology and Genetics

Metaxa Hospital

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β2-Toxin of Clostridium perfringens in a Hamadryas Baboon (Papio hamadryas) with Enteritis

Journal of Zoo and Wildlife Medicine (2009)

Γεώργιος Νικολάου Marja Kik Alphons J.A.M. van Asten Andrea Gröne

An 11-yr-old female hamadryas baboon (Papio hamadryas) that died with a history of diarrhea and anorexia was submitted for necropsy. Major pathologic changes were restricted to the gastrointestinal tract. The small intestinal contents were watery and sanguinous, with a deepening of the red color in the large intestines. The intestinal mucosa was hyperemic. Microscopically, lesions consisted of surface epithelial cell necrosis in association with numerous rod-shaped bacteria and high numbers of Trichuris cynocephalus nematodes. Culturing of the small intestine yielded Clostridium perfringens. No other pathogenic bacteria were cultured using routine bacteriologic techniques. Polymerase chain reaction (PCR) analysis classified the Clostridium perfringens as type A cpb2-positive. Immunohistochemical examination with anti-β2-toxin antibodies revealed β2-toxin in close approximation with the intestinal lesions.

Clostridium perfringens

Intestinal mucosa

10.1638/2009-0081.1

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Paravertebral Malignant Peripheral Nerve Sheath Tumour (MPNST) in a Horse

Journal of Comparative Pathology (2012)

Γεώργιος Νικολάου Maarten de Bont Christiane Herden Udo Hetzel

Maximum parsimony

Sister group

10.1016/j.jcpa.2011.11.157

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Detection of O-Linked-N-Acetylglucosamine Modification and Its Associated Enzymes in Human Degenerated Intervertebral Discs

Asian Spine Journal (2017)

Γεώργιος Νικολάου Aristeidis Zibis Apostolos Fyllos Antonios Katsioulis Sotirios Sotiriou

Human herniated discs were obtained from discectomy specimens for the immunohistochemical detection of O-GlcNAc and O-GlcNAcase (OGA)/O-GlcNAc transferase (OGT).This study aimed to quantify the extent of O-GlcNAcylation and its associated enzymes (OGT/OGA) in human degenerated intervertebral discs.The O-GlcNAcylation of nuclear, cytoplasmic, and mitochondrial proteins as well as the effects of such post-translational modifications are currently the focus of extensive research. O-GlcNAcylation is believed to contribute to the etiology of chronic illnesses by acting as a nutrient and stress sensor in the cellular environment. Mature intervertebral disc cells are chondrocyte-like cells, and O-GlcNAc has been shown to promote chondrocyte apoptosis in vitro. We believe that O-GlcNAcylation is a key regulator of disc degeneration.Fifty-six specimens were fixed for 24 hours in a 10% solution of neutral-buffered formaldehyde, dehydrated, and embedded in paraffin. Tissue slices (4-µm-thick) were used for hematoxylin-eosin staining and immunohistochemistry.We found that O-GlcNAcylation of cytoplasmic proteins was less than that of nuclear proteins in both single cells and cell clusters. Cytoplasmic O-GlcNAcylation occurs subsequent to nuclear O-GlcNAcylation and is directly proportional to disc degeneration. OGT and O-GlcNAc expression levels were identical in all specimens examined.O-GlcNAc and OGA/OGT expression is shown to correlate for the first time with intervertebral disc cell degeneration. Increasing disc degeneration is associated with increasing O-GlcNAcylation in both nuclear and cytoplasmic proteins in human disc cells.

Intervertebral Disc

Degeneration (medical)

10.4184/asj.2017.11.6.863

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Effects of greenhouse microclimate on irrigation scheduling of hydroponic crops under a mediterranean climate

Γεώργιος Νικολάου

Αναμφισβήτητα, οι εκτός εδάφους θερμοκηπιακές καλλιέργειες συνεισφέρουν θετικά στην απόδοση των καλλιεργειών, στην αύξηση του δείκτη αποτελεσματικής χρήσης του νερού, στον περιορισμό της χρήσης αγροχημικών και στην προστασία του περιβάλλοντος. Παρόλα αυτά ακόμα και η "γεωργία ακριβείας", χρήζει βελτιώσεων στον τομέα της υδροπονίας και ειδικότερα στον προγραμματισμό της άρδευσης, αφού ποσοστό 30-40% του θρεπτικού διαλύματος στα ανοικτού τύπου υδροπονικά συστήματα απορρέει στο περιβάλλον. Γνωρίζοντας τις συνθήκες περιβάλλοντος θερμοκηπίου όπως ο δροσισμός και η αλληλεπίδρασή του με την καλλιέργεια, ο προγραμματισμός της άρδευσης σχεδιάζεται λαμβάνοντας υπόψη το υψηλό ενεργειακό κόστος λειτουργίας και της κατανάλωσης νερού, υπό τις ξηροθερμικές συνθήκες που επικρατούν στις Μεσογειακές περιοχές. Τα πειράματα που έγιναν, είχαν ως στόχο να μελετήσουν την επίδραση του περιβάλλοντος του θερμοκηπίου, στον προγραμματισμό της άρδευσης υπό τις Μεσογειακές συνθήκες. Συνολικά έγιναν 4 πειράματα. Το πρώτο έχει διεξαχθεί μεταξύ Απριλίου-Ιουνίου 2014, το δεύτερο και τρίτο μεταξύ Οκτωβρίου-Δεκεμβρίου 2014 και Μαρτίου-Ιουνίου 2015 και το τελευταίο μεταξύ Απριλίου-Ιουνίου 2016. Από τα πειράματα έχει αποδειχθεί ότι η εφαρμογή της ίδιας ημερήσιας δόσης νερού σε διαφορετικές συχνότητες άρδευσης, δεν επηρεάζει την παραγωγή της υδροπονικής καλλιέργειας αγγουριού. Παρ’ όλα αυτά έχει διαπιστωθεί ότι η αύξηση της συχνότητας άρδευσης με μικρότερες ποσότητες θρεπτικού διαλύματος (0.192 Kg m-2), είναι θεμιτή αφού μειώνεται ο βαθμός απορροής κατά 24% σε σύγκριση με άρδευση με μεγαλύτερες ποσότητες θρεπτικού διαλύματος (0.448 Kg m-2) σε πιο αραιά διαστήματα. Η επίδραση των διαφορετικών συστημάτων δροσισμού που έχουν μελετηθεί (π.χ. δυναμικός εξαερισμός σε σύγκριση με το σύστημα της υγρής παρειάς) σε δύο καλλιεργητικές περιόδους του έτους (φθινόπωρό, άνοιξη-καλοκαίρι) απέδειξαν ότι είναι δυνατή η αποφυγή χρήσης του συστήματος της υγρής παρειάς, αφού το σύστημα του δυναμικού εξαερισμού αφαιρούσε το πλεονάζον θερμικό φορτίο. Επιπρόσθετα έχει διαπιστωθεί ότι η διαπνοή της καλλιέργειας ήταν στατιστικά μεγαλύτερη εκεί όπου εφαρμοζόταν δυναμικός εξαερισμός, και στις δύο καλλιεργητικές περιόδους, μειώνοντας το ποσοστό της απορροής. Η καλλιέργεια κατά την περίοδο άνοιξης-καλοκαιριού παρουσίασε περισσότερη παραγωγή, όπως αναμενόταν κατά 53-84% στις διάφορες μεταχειρίσεις, όμως χαμηλότερο δείκτη παραγωγικότητας του νερού. Παράλληλα, οι χαμηλότερες δόσεις άρδευσης που εξετάστηκαν, με στόχο τη διατήρηση του νερού της απορροής κοντά στο 20-25% αντί μεταξύ 35-40%, δεν επηρέασαν αρνητικά την παραγωγή. Παρά το γεγονός ότι η σκίαση με άσπρη μπογιά θεωρείται η πιο οικονομική λύση από πλευράς εξοικονόμησης ενέργειας και νερού, σε σύγκριση με άλλες μεθόδους δροσισμού, η σκίαση επηρέασε αρνητικά την παραγωγή μειώνοντας παράλληλα και τον δείκτη αποτελεσματικότητας της άρδευσης, αν και στατιστικός οι διαφορές δεν ήταν σημαντικές συγκρίνοντας με το σύστημα της υγρής παρειάς. Παρόλα αυτά, ο συνολικός δείκτης κατανάλωσης νερού κυμάνθηκε στα ίδια επίπεδα μεταξύ των δύο συστημάτων δροσισμού, αφού μεγάλες ποσότητες νερού χρειάστηκε να εξατμιστούν από το σύστημα της υγρής παρειάς με μέση υπολογιζόμενη ποσότητα τα 72 λ. μ-2. Στην παρούσα διατριβή έχει βαθμονομηθεί και δοκιμαστεί η απλοποιημένη σχέση εκτίμησης της διαπνοής Penman-Monteith (συντελεστές α και β), σε διαφορετικά περιβάλλοντα θερμοκηπίου (π.χ. με δροσισμό, με μόνο δυναμικό εξαερισμό) και σε διαφορετικές περιόδους του έτους. Τα αποτελέσματα υπογράμμισαν τη σημασία της βαθμονόμησης του μοντέλου όπως αυτή επηρεάζεται από το περιβάλλον του θερμοκηπίου. Παράλληλα, εντοπίστηκε η στενή συσχέτιση που έχει η θερμοκρασία του φύλλου με τη διαπνοή και προτάθηκε ένα νέο μοντέλο εκτίμησης της διαπνοής ανά τακτά χρονικά διαστήματα (10 λεπτά), βασισμένο σε αναπροσαρμογή της απλοποιημένης σχέσης, παρακάμπτοντας μετρήσεις εκτίμησης του ελλείμματος κορεσμού της ατμόσφαιρας και της εισερχόμενης ηλιακής ακτινοβολίας. Τέλος, κατά τη διάρκεια των πειραμάτων έχουν χρησιμοποιηθεί φυτοαισθητήρες και έχει αποδειχθεί η στενή συσχέτιση μεταξύ προγραμματισμού της άρδευσης (ποσότητας-συχνότητας), με τη θερμοκρασία του φύλλου, τη μεταβολή της διαμέτρου του βλαστού αλλά και με τη θερμοκρασία του υποστρώματος.

Microclimate

Irrigation scheduling

10.12681/eadd/47280

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A glycine substitution in the collagenous domain of Col4a3 in mice recapitulates late onset Alport syndrome

Matrix Biology Plus (2020)

Christoforos Odiatis Isavella Savva Myrtani Pieri Pavlos Ioannou Petros Petrou

Alport syndrome (AS) is a severe inherited glomerulopathy caused by mutations in the genes encoding the α-chains of type-IV collagen, the most abundant component of the extracellular glomerular basement membrane (GBM). Currently most AS mouse models are knockout models for one of the collagen-IV genes. In contrast, about half of AS patients have missense mutations, with single aminoacid substitutions of glycine being the most common. The only mouse model for AS with a homozygous knockin missense mutation, Col4a3-p.Gly1332Glu, was partly described before by our group. Here, a detailed in-depth description of the same mouse is presented, along with another compound heterozygous mouse that carries the glycine substitution in trans with a knockout allele. Both mice recapitulate essential features of AS, including shorten lifespan by 30–35%, increased proteinuria, increased serum urea and creatinine, pathognomonic alternate GBM thinning and thickening, and podocyte foot process effacement. Notably, glomeruli and tubuli respond differently to mutant collagen-IV protomers, with reduced expression in tubules but apparently normal in glomeruli. However, equally important is the fact that in the glomeruli the mutant α3-chain as well as the normal α4/α5 chains seem to undergo a cleavage at, or near the point of the mutation, possibly by the metalloproteinase MMP-9, producing a 35 kDa C-terminal fragment. These mouse models represent a good tool for better understanding the spectrum of molecular mechanisms governing collagen-IV nephropathies and could be used for pre-clinical studies aimed at better treatments for AS.

Alport syndrome

Slit diaphragm

10.1016/j.mbplus.2020.100053

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MULTIPLEX PCR FOR TOXIN TYPING OF CLOSTRIDIUM PERFRINGENS

Van Asten A.J.A.M.Cornelia W. van der Wiel Γεώργιος Νικολάου

Clostridium perfringens

Multiplex

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Salmonella Virchow Infection of the Chicken Elicits Cellular and Humoral Systemic and Mucosal Responses, but Limited Protection to Homologous or Heterologous Re-Challenge

Frontiers in Veterinary Science (2014)

Anne‐Marie Salisbury Gail Leeming Γεώργιος Νικολάου Anja Kipar Paul Wigley

Salmonella enterica serovar Virchow usually causes mild gastroenteritis in humans; however, it is frequently invasive and many isolates are resistant to a broad range of therapeutic antimicrobials. Poultry meat is considered a major source of human infection. In this study, we characterise the infection biology and immune response to S. Virchow in chickens and determine protection against homologous and heterologous re-challenge, with S. Virchow or S. Typhimurium. Following oral infection of 7-day-old chickens, S. Virchow colonised the gastrointestinal tract and the spleen. Infection elicited an increase in specific IgA, IgG and IgM antibodies and relative quantitative changes in several leukocyte populations, including CD3, CD4, CD8α, CD8β, MHC II, KuL01 and γδ TCR positive cells, both in the gastrointestinal tract and systemically. Increased expression of pro-inflammatory cytokines IL-1β and IL-6 and the chemokine CXCLi2 was also found. Primary infection with S. Virchow offered limited systemic protection against re-challenge with S. Virchow or S. Typhimurium, but no protection against caecal colonisation. In conclusion, S. Virchow exhibits similar infection biology and immune responses in the chicken to that previously described for S. Typhimurium. Unlike S. Typhimurium, S. Virchow infection is poorly protective to homologous and heterologous re-challenge. These findings suggest that S. Virchow is capable of colonising the chicken well and therefore, presents a risk of entering the food chain in meat production. Furthermore, the development of vaccines that protect effectively against S. Virchow and indeed multivalent vaccines that protect across all Salmonella serogroups in the chicken would appear to remain a challenging proposition.

Salmonella enterica

Heterologous

Salmonella infection

10.3389/fvets.2014.00006

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Advances in irrigation/fertigation techniques in greenhouse soilless culture systems (SCS)

Burleigh Dodds series in agricultural science (2021)

Γεώργιος Νικολάου Damianos Neocleous E. Kitta Ν. Katsoulas

The objective of this chapter is to describe the most common soilless culture system (SCS) irrigation and fertigation methods. The chapter summarizes common types of irrigation/fertigation system and types of management system. It then discusses the shift to real-time plant-based sensing and monitoring systems together with models to analyze this data and translate it into irrigation management decisions. A case study is included to illustrate these systems in practice. The chapter concludes by identifying new directions in the application of internet of things (IoT), artificial intelligence and phyto-sensing technologies to optimize input use.

Fertigation

10.19103/as.2020.0076.10

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Effects of Cooling Systems on Greenhouse Microclimate and Cucumber Growth under Mediterranean Climatic Conditions

Agronomy (2019)

Γεώργιος Νικολάου Damianos Neocleous Ν. Katsoulas Constantinos Kittas

Two experiments were conducted in different cropping seasons under Mediterranean climatic conditions to investigate the impact of two cooling systems (fan-pad evaporative as opposed to fan ventilation) on greenhouse microclimate and soilless cucumber growth. The second objective of the experiment was to determine the most appropriate irrigation regime (between 0.24 and 0.32 L m−2) in relation to crop water uptake and greenhouse fertigation effluents. The use of a fan ventilation system enhanced the vapor pressure deficit; thus, the crop transpiration improved by 60% in relation to the transpiration rates of plants grown under the fan-pad system. Higher transpiration rates alleviated the heat load as the external–inside greenhouse air differences declined from 6.2 °C to 3 °C. The leaf–air temperature differential indicated that plants were not facing any water stress conditions for both cooling systems tested; however, fan ventilation reduced drainage emissions outflows (95% decrease) compared with evaporative cooling. Results also demonstrated that an irrigation regime of 0.24 L m−2 can be applied successfully in soilless cucumber crops, keeping the drainage to a minimum (20% of the nutrient solution supply). These results suggest that fan ventilation cooling system in conjugation with an appropriate irrigation regime prevents overheating and minimizes the nutrient and water losses in spring-grown soilless cucumber crops in Mediterranean greenhouses without compromising yield.

Microclimate

Fertigation

Hydroponics

Evaporative cooler

10.3390/agronomy9060300

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Citations (23)

Male breast cancer originating in an ectopic breast tissue in the umbilicus A Case Report.

PubMed (2016)

Nikolaos Kopanakis Olympia Tzaida Γεώργιος Νικολάου Dimitrios Ermidis Vasiliki Manou

Accessory breast tissue is a rare finding in the general population with an incidence of 1-2%. Carcinomas of accessory breast tissue account for ∼0.3% of breast cancers, 5% of which are arising within a supernumerary breast. They are usually diagnosed at a later stage compared with breast cancer, due to their rarity and low clinical suspicion.We present the case of a 58 years old male who was admitted to our hospital for an umbilical hernia, surgical repair. During surgery a small skin biopsy was excised and sent for pathological examination as routine procedure. The histological report revealed the presence of a poorly differentiated carcinoma. Immunochemical analysis confirmed adenocarcinoma of breast origin.Carcinomas of accessory breast tissue are rare and therefore they are usually of advanced stage in time of diagnosis. Few cases have been reported in literature of accessory breast tissue carcinomas in men. To the best of our knowledge, this is the only case in the literature, of ectopic breast tissue cancer in the umbilicus.Ectopic breast, Male breast cancer, Umbilicus.La sede ectopica di tessuto ghiandolare mammario è un’eventualità rara, con un’incidenza del 1-2% nella popolazione generale. I carcinomi insorti in questi tessuto mammari accessori rappresentano circa il 0,3% di tutti i cancri della mammella, 5% dei quali insorti su mammelle soprannumerarie. La loro diagnosi avviene in fase più avanzate che nel caso dei correnti cancri della mammelle in relazione alla loro rarità ed al basso livello di sospetto clinico. Qui è presentato il caso di un uomo di 58 anni ricoverato nel nostro ospedale per la riparazione chirurgica di un’ernia ombelicale. Durante l’intervento venne eseguita una piccola biopsia cutanea per esame istologico quale procedura usuale. Il referto istologico ha rivelato la presenza di un carcinoma scarsamente differenziato, che all’analisi immunoistochimica si è dimostrato essere un adenocarcinoma di origine mammaria. Si conferma la rarità dei carcinomi insorti su tessuto ghiandolare mammario accessorio, che sono per lo più in fase avanzata al momento della diagnosi. Pochi di questi casi sono riportati in letteratura in relazione a tessuto mammario accessorio nel sesso maschile, ed a nostra conoscenza questo è l’unico in letteratura di tessuto mammario carcinomatoso a sede ectopica nell’ombelico.

Male Breast Cancer

Breast carcinoma

Umbilical hernia

Presentation (obstetrics)

Breast tissue

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