Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
LanguageLanguage
-
SubjectSubject
-
Item TypeItem Type
-
DisciplineDiscipline
-
YearFrom:-To:
-
More FiltersMore FiltersIs Peer Reviewed
Done
Filters
Reset
16
result(s) for
"Kontogiorgis, C."
Sort by:
Resource use during systematic review production varies widely: a scoping review
by
Riva, N.
,
Thomas, J.
,
Kontogiani, M.
in
Biomedical Research - standards
,
Biomedical Research - statistics & numerical data
,
Citation indexes
2021
•Evidence on resource use is limited to studies reporting mostly on the resource “time” and not always under real life conditions.•Administration and project management, study selection, data extraction, and critical appraisal seem to be very resource intensive, varying with the number of included studies, while protocol development, literature search, and study retrieval take less time.•Lack of experience and domain knowledge, lack of collaborative and supportive software, as well as lack of good communication and management can increase resource use during the systematic review process.
We aimed to map the resource use during systematic review (SR) production and reasons why steps of the SR production are resource intensive to discover where the largest gain in improving efficiency might be possible.
We conducted a scoping review. An information specialist searched multiple databases (e.g., Ovid MEDLINE, Scopus) and implemented citation-based and grey literature searching. We employed dual and independent screenings of records at the title/abstract and full-text levels and data extraction.
We included 34 studies. Thirty-two reported on the resource use—mostly time; four described reasons why steps of the review process are resource intensive. Study selection, data extraction, and critical appraisal seem to be very resource intensive, while protocol development, literature search, or study retrieval take less time. Project management and administration required a large proportion of SR production time. Lack of experience, domain knowledge, use of collaborative and SR-tailored software, and good communication and management can be reasons why SR steps are resource intensive.
Resource use during SR production varies widely. Areas with the largest resource use are administration and project management, study selection, data extraction, and critical appraisal of studies.
Journal Article
Matrix Metalloproteinase Inhibitors: A Review on Pharmacophore Mapping and (Q)Sars Results
by
C. Kontogiorgis
,
P. Papaioannou
,
D. Hadjipavlou-Litina
in
Autoimmune diseases
,
Binding Sites
,
Bioavailability
2005
The matrix metalloproteinases (MMPs) are a family of more than 20 enzymes that are intimately involved in tissue remodelling. These zinc-containing endopeptidases consist of several subsets of enzymes, including collagenase, stromelysins and gelatinases and are involved in the degradation of the extracellullar matrix (ECM) that forms the connective material between cells and around tissues. Disease processes associated with the MMPs are generally related to imbalance between the inhibition and activation of MMPs resulting in excessive degradation of the ECM. These indications include osteoarthritis rheumatoid arthritis, tumour metastasis and congestive heart failure. Inhibitors for these enzymes have been developed for the treatment of a starthingly wide array of disease process where matrix remodelling plays a key role. There are three major components to most MMP inhibitorsthe zinc binding group ZBG, the peptidic backbone and the pocket occupying side chain. Most MMPs inhibitors are classified according to their ZBG. Inhibitors interactions at active-site zinc plays a critical role in defining the binding mode and relative inhibitor potency. The majority of MMP inhibitors reported in the literature contain an effective zinc binding group (e.g. hydroxamic acid, carboxylic acid, sulfhydryl group) that is either generally substituted with a peptide-like structure that mimics the substrates that they cleave or appended to smaller side chains that may interact with specific subsites (e.g., P1, P2, P3) within the active site. Although carboxylates exhibit weaker zinc binding properties than hydroxamates, they are known to show better oral bioavailability and are less prone to metabolic degradation. The expected loss of binding affinity after replacement of hydroxamates against carboxylates is faced by adequate choice of elongated S1 directed substituents. The need for novel selective MMP inhibitors makes them an attractive target for the QSAR and molecular modelling. 3-D QSAR models were derived using CoMFA, CoMSIA and GRID approaches leading to the identification of binding regions where steric, electronic or hydrophobic effects are important for affinity. Some structural requirements essential for achieving high binding affinity and selectivity are: an acidic unit tightly anchored through four contact points, bidentate chelation of Zn2+, carbonyl groups for hydrogen bonding, more than two extra units for hydrogen bonds, a hydrophobic moiety.
Journal Article
Perspectives on the impact of regulatory measures on national COVID-19 vaccination programs: a qualitative study from six EU member states
by
Leonardo Alves, T.
,
Kos, M.
,
Andersen, A.
in
COVID-19
,
decision-making
,
national vaccination programs
2025
The European Medicines Agency (EMA) issued regulatory recommendations and communications in 2021 about the risk of thrombosis with thrombocytopenia syndrome (TTS) associated with COVID-19 adenoviral vector vaccines Vaxzevria and Jcovden. Little is known about how such measures impacted on national vaccination strategies and how they influenced decision-making processes of policy-makers and experts. The aim of this study was to evaluate the impact of regulatory actions for Vaxzevria and Jcovden on national vaccination strategies following the EMA's 2021 review on safety measures on TTS.
A grey literature review was performed to gather information on EMA's actions as well as changes to national vaccination strategies in Denmark, Greece, Latvia, the Netherlands, Portugal and Slovenia. Semi-structured interviews were held with experts who had either advisory or decision roles in national vaccination programmes to contextualise the results of the grey literature review and discuss their experiences. Interviews were coded and analysed on national levels.
EMA made various adaptations to product information and released safety warnings and other regulatory communications for both vaccines relating to TTS risk. Countries varied widely in changes made to national vaccination policies. Interviews revealed that experts relied mainly on their professional networks and information sources, other than the EMA, to inform their recommendations and/or decision-making.
EMA's regulatory actions were not the main source informing adaptations to national vaccination strategies. National decision-makers country reverted to their preferred sources. The use of varying sources explains some of the variations in the vaccination strategies.
Journal Article
Composition and Antioxidant Activity of Olive Leaf Extracts from Greek Olive Cultivars
by
Moustakas, A
,
Kontominas, M. G
,
Kiritsakis, A
in
Agriculture
,
Antioxidant activity
,
Antioxidants
2010
The olive leaf phenolic composition of the Greek cultivars koroneiki, megaritiki and kalamon was determined using LC/MS. Furthermore, the antioxidant activity of olive leaf extracts from the above three cultivars, using solvents of increasing polarity (petroleum ether, dichloromethane, methanol and methanol/water: 60/40) was evaluated using the stable free radical diphenylpicrylhydrazyl (DPPH) test. Furthermore the oxidative stability index (OSI) was compared to that of the synthetic antioxidant TBHQ and commercial oleoresin (rosemary extract). The ability of phenolic compounds to inhibit the lipoxygenase (LOX) activity was also investigated. The ten main components determined in the olive tree leaf extracts for the cultivars koroneiki and kalamon were: secologanoside, dimethyloleuropein, oleuropein diglucoside, luteolin-7-O-glucoside, rutin, oleuropein, oleuroside, quercetin, ligstroside and verbascoside. Respective compounds for the cultivar megaritiki were: secologanoside, dimethyloleuropein, oleuropein diglucoside, luteolin7-O-glucoside, oleuropein, oleuroside, quercetin and ligstroside. In all three cultivars, oleuropein represented the main phenolic component. The solvent polarity influenced the total amount of the phenolic compounds determined. When methanol/water (60/40) was used, as solvent, more phenolic compounds were determined. The total amounts of phenols determined in the extracts, obtained by successive extractions using the above solvents, were 6,094, 5,579 and 6,196 mg/kg (mg gallic acid/kg dried olive leaves) for the cultivars megaritiki, kalamon and koroneiki, respectively. Among all extracts, methanol/water extracts exhibited the highest antioxidant activity as shown through the application of the DPPH and OSI methods. The OSI antioxidant activity followed the sequence: synthetic antioxidant TBHQ > commercial oleoresin > olive tree leaf extracts > control. Likewise, methanol/water olive leaf extracts significantly inhibited soybean lipoxygenase, although some small differences in the activity among the olive leaf extracts of the different cultivars were observed. The solvent polarity as well as the amount of the extract influenced the inhibitory activity. A positive correlation was shown between the antioxidant activity of leaf extracts and the total phenol content.
Journal Article
Non Steroidal Anti-Inflammatory and Anti-Allergy Agents
2002
Non steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used for inflammation therapy. The major drawback in using the NSAIDs is in their tendency to cause gastrointestinal toxicity. Since the roles of arachidonic acid (A.A) metabolites, as leukotrienes (Lts), prostaglandins (PGs) and thromboxanes (TXA2) as mediators of the inflammatory reaction were clarified, much effort has been made to develop inhibitors of the production of these chemical mediators as anti-inflammatory agents. These mediators also play important roles in some inflammatory or allergic diseases, acting either alone or in combination and inhibitors of 5-lipoxygenase (5-LOX) and / or cyclooxygenase isoforms 1,2 (COX-1,2) may be useful for the treatment of asthma, psoriasis and rheumatoid arthritis. Leukotrienes, the products of 5-LOX metabolism have been associated with immediate hypersensitivity reactions, anaphylaxis and asthma. In addition, active oxygen species (AOS) including superoxide anion (O2-), hydrogen peroxide, hydroxyl radical and ferric radical, mediate cell damage in a variety of pathophysiological conditions and are responsible for oxidative injury of enzymes, lipid membranes and DNA in living cells and tissues. Prostaglandins and leukotrienes in the arachidonate pathway linked with lipid peroxidation may amplify the oxidative damage. Nirtric oxide (NO) plays also a role as an efector in inflammation, since PG and NO thought to be important in maintaining mucosal integrity. Dual or selective inhibitors, specific receptor antagonists, AOS scavengers, and NO donors have been under development for therapeutic application. Several classes of inhibitors have been identified and at least 12 major chemical series are known to affect PGs production directly. In this review, we account on our research work concerning NSAIDs combined with a reference of the recent literature.
Journal Article
Impact of Foods and Dietary Supplements Containing Hydroxycinnamic Acids on Cardiometabolic Biomarkers: A Systematic Review to Explore Inter-Individual Variability
by
Kontogiorgis, Christos A.
,
Dall’Asta, Margherita
,
Deligiannidou, Georgia-Eirini
in
Acids
,
Adult
,
Aged
2019
Plant-based diets rich in bioactive compounds such as polyphenols have been shown to positively modulate the risk of cardiometabolic (CM) diseases. The inter-individual variability in the response to these bioactives may affect the findings. This systematic review aimed to summarize findings from existing randomized clinical trials (RCTs) evaluating the effect of hydroxycinnamic acids (HCAs) on markers of CM health in humans. Literature searches were performed in PubMed and the Web of Science. RCTs on acute and chronic supplementation of HCA-rich foods/extracts on CM biomarkers were included. Forty-four RCTs (21 acute and 23 chronic) met inclusion criteria. Comparisons were made between RCTs, including assessments based on population health status. Of the 44 RCTs, only seven performed analyses on a factor exploring inter-individual response to HCA consumption. Results demonstrated that health status is a potentially important effect modifier as RCTs with higher baseline cholesterol, blood pressure and glycaemia demonstrated greater overall effectiveness, which was also found in studies where specific subgroup analyses were performed. Thus, the effect of HCAs on CM risk factors may be greater in individuals at higher CM risk, although future studies in these populations are needed, including those on other potential determinants of inter-individual variability. PROSPERO, registration number CRD42016050790.
Journal Article
Quantitative Structure - Activity Relationships (QSARs) of Thrombin Inhibitors: Review, Evaluation and Comparative Analysis
by
Dimitra Hadjipavlou-Litina
,
Christos Kontogiorgis
in
Antithrombins - chemistry
,
Antithrombins - pharmacology
,
Biological and medical sciences
2003
Thrombin has become an important target for designing antithrombotic drugs in the recent years. Thus, we have undertaken a QSAR analysis aimed at individuating the physicochemical properties governing the inhibitory activity of such compounds. The QSAR equations for ten series of derivatives have been calculated and discussed. The series studied are all those that we found in the literature suitable for a QSAR study. The equations we obtained show that the main physicochemical properties affecting the inhibitory activity are almost the same for all the series and can be individuated by the use of proper parameters. The conclusions of this analysis can be summarized as follows: a) hydrophobicity plays a critical role, b) steric factors are also significant but in some cases the collinearity between steric and hydrophobic parameters does not allow one to draw any final conclusion.
Journal Article
Natural Products from the Mediterranean Area as Wound Healing Agents—In Vitro Studies: A Systematic Review
by
Constantinides, Theodoros C.
,
Kontogiorgis, Christos
,
Chorti-Tripsa, Eleftheria
in
Acids
,
Antioxidants
,
Biological activity
2025
Wound healing is a process that happens when lost tissue replenishes. For this process, both protective elements and wound healing accelerating factors are required. In recent years, the search for natural products that promote faster healing and prevent adverse effects has gained momentum. This is a systematic review, adhering to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) criteria, of the wound healing effects of natural products, with a focus on natural products from the Mediterranean region. This study sourced the PubMed and Scopus databases for eligible articles and publications over the last six years. Due to the information volume, only the in vitro studies were included in this review. The criteria set concluded in the 28 studies included. These studies showed that many natural products found in the Mediterranean have been studied for the treatment of wounds. The wound healing effect seems to be related to dose, type of wounded tissue, and application time. Moreover, half of the studies were additionally tested and shown antioxidant activity through DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and FRAP (Ferric Reducing Antioxidant Power) assays.
Journal Article
Physical Activity, Body Mass Index (BMI) and Abdominal Obesity of Pre-Adolescent Children in the Region of Thrace, NE Greece, in Relation to Socio-Demographic Characteristics
by
Dampoudani, Niki
,
Diamantoudi, Despoina
,
Kontogiorgis, Christos A.
in
Body mass index
,
Exercise
,
Obesity
2022
This study aimed to explore the prevalence of overweight, obesity, and abdominal obesity, and define predictive factors of their occurrence among pre-adolescents in the region of Thrace, NE Greece. A secondary aim was to record physical activity at different times (schooldays, weekends, holidays) and explore associations with characteristics such as gender, overweight and obesity, and socio-demographic conditions. A cross-sectional study was conducted involving children aged 11–12 years. Participating children were measured for height, weight, and waist circumference, and their parents answered a questionnaire. In total, 1929 children were included. Prevalence of overweight was 31.5%, prevalence of obesity 17%, and only 1% of children were underweight. Abdominal obesity was detected in 20.3% of the sample. Overweight and obesity were more frequent in males, who also had higher mean values of Body Mass Index-for-age z-scores (BMIaz) and Waist-to-Height ratio (WtHR). Obesity rates were higher among those not participating in physical activities; however, no significant difference was observed between normal-weight, overweight and obese children in the time spent for organized athletic activities or free play. Logistic regression analysis showed that the probability for overweight/obesity was higher in boys (OR = 1.39, 95% CI = 1.16–1.66) and lower in children whose fathers had a higher educational level (OR = 0.75, 95% CI = 0.60–0.93). The probability for abdominal obesity was also higher in boys (OR = 1.37, 95% CI = 1.10–1.72) and lower in children participating at least one hour/day in an organized physical activity (compared to those with no physical activity (OR = 0.66, 95% CI = 0.51–0.85), and whose father was exercising at least 1–2 times/week (OR = 0.76, 95% CI = 0.591–0.98). In conclusion, the prevalence of overweight and obesity among pre-adolescents in NE Greece was estimated at 48.5%. This is associated with the male gender and not participating in physical activities. The educational level and exercise habits of the father (but not of the mother) affect the probability of obesity and abdominal obesity, respectively.
Journal Article
Use of Edible, Medicinal, and Aromatic Plants in Various Health Disorders: A Cross-Sectional Evaluation among Inhabitants in the Area of Thrace, North-Eastern Greece
by
Kontogiorgis, Christos A.
,
Kyrgou, Chrysoula
,
Manolopoulos, Vangelis G.
in
Beverages
,
Coronaviruses
,
COVID-19
2022
Background: Medicinal and aromatical plants (MAPs) have been historically used as traditional remedies in many cultures in Europe and globally. The aim of this study was to evaluate the use of MAPs in various health disorders in association to dietary habits and other lifestyle factors among residents in Thrace, NE Greece. Methods: Data were collected through anonymous and voluntary responses to a structured online questionnaire, via convenience (snowball) sampling. Results: The 561 responders (age: 39.7 ± 11.6 y) were mostly female (59.7%), with higher education (69.8%), working as state or private employees (55.4%), and having low/medium income (77.1%). Overall, more than 70% were using MAPs in various symptoms and common health disorders, such as chamomile against common cold and the flu. More than 20 different MAPs were being used in smaller frequencies against various conditions. Key contributing factors to the consumption of MAPs were sex (female over male), employment (employed vs. unemployed), education (higher education vs. lower) and higher Body Mass Index (overweight and obese vs. normal), while consumption of fruit, fish, and vegetables was mainly associated with the use of MAPs as common items of diet and in health disorders. Conclusions: The use of MAPs as part of the diet and as traditional remedy is present in the examined population, while particular choices seem to be affected by sociodemographic and lifestyle factors.
Journal Article