SYMEON TOURNIS

Dr. SYMEON TOURNIS

orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2005 in The Journal of Clinical Endocrinology & Metabolism
Verified
Journal Article
Closed access
IFIoannis G. Fatouros
Ioannis G. Fatouros
STSYMEON TOURNIS
SYMEON TOURNIS
DLD. Leontsini
D. Leontsini
AJA. Z. Jamurtas
A. Z. Jamurtas
MSM. Sxina
M. Sxina
AMA. Mitrakou
A. Mitrakou
Adiponectin and leptin are closely related to weight control and energy balance, whereas exercise affects elderly metabolic regulation and functional capacity. The objective of this study was to investigate leptin and adiponectin responses in elderly males after exercise training and detraining. The study design was a 1-yr randomized controlled trial. The study was performed at the Laboratory of Physical Education and Sport Science Department. Fifty inactive men [age, 65-78 yr; body mass index (BMI), 28.7-30.2 kg/m2] were recruited from a volunteer database by word of mouth and fliers sent to medical practitioners, physiotherapists, and nursing homes in the local community. Participants were randomly assigned to a control (n = 10), low-intensity (n = 14), moderate-intensity (n = 12), or high-intensity training (HI; n = 14) group. Resistance training (6 months, 3 d/wk, 10 exercises/three sets) was followed by 6 months of detraining. Strength, exercise energy cost, skinfold sum, body weight, maximal oxygen consumption, resting metabolic rate (RMR), and plasma leptin and adiponectin were determined at baseline and after training and detraining. Strength, maximal oxygen consumption, RMR, and exercise energy cost increased (P < 0.05) after training in an intensity-dependent manner. Skinfold sum and BMI were reduced by resistance training (P < 0.05), with HI being more effective (P < 0.05) than moderate-intensity/low-intensity training. Leptin was diminished (P < 0.05) by all treatments, whereas adiponectin increased (P < 0.05) only in HI. Detraining maintained training-induced changes only in HI. The percent leptin decrease was associated (P < 0.05) with the percent BMI decrease and the percent RMR increase, whereas the percent adiponectin increase was associated (P < 0.05) with the percent BMI decrease. Resistance training and detraining may alter leptin and adiponectin responses in an intensity-dependent manner. Leptin and adiponectin changes were strongly associated with RMR and anthropometric changes.

1 March 2018 in Metabolism
Verified
Journal Article
Closed access
STSYMEON TOURNIS
SYMEON TOURNIS
ADAnastasia D. Dede
Anastasia D. Dede

1 December 2014 in Metabolism
Verified
Journal Article
Closed access
ADAnastasia D. Dede
Anastasia D. Dede
STSYMEON TOURNIS
SYMEON TOURNIS
IDIsmene Dontas
Ismene Dontas
GTGeorge Trovas
George Trovas

24 April 2018 in Hormones
Verified
Journal Article
Closed access
PDF file
CSChristos Savvidis
Christos Savvidis
STSYMEON TOURNIS
SYMEON TOURNIS
ADAnastasia D. Dede
Anastasia D. Dede

1 October 2011 in Hormones
Verified
Journal Article
Closed access
SIStathopoulos P. Ioannis
Stathopoulos P. Ioannis
LCLiakou G. Chrysoula
Liakou G. Chrysoula
KAKatsalira Aikaterini
Katsalira Aikaterini
TGTrovas George
Trovas George
LGLyritis P. George
Lyritis P. George
STSYMEON TOURNIS
SYMEON TOURNIS
The unique pharmacokinetics of bisphosphonates (BPs) in conjunction with their use by an increasing number of women at reproductive age has raised serious concerns about their safety during pregnancy and lactation. Bisphosphonates cross the placenta. Animal studies have shown adverse effects on both the fetus and the mother, mostly at doses much higher than those commonly used in humans. Protracted parturition, maternal mortality, embryolethality, severe general underdevelopment and marked skeletal retardation of the fetuses (increased amount of diaphyseal bone trabeculae, decreased diaphyseal length), small fetal weight and abnormal tooth growth have been observed. We conducted a thorough research of the literature in order to identify human studies concerning this issue. We identified a total of 78 cases involving fetuses whose mothers had been exposed to BPs before conception or during pregnancy, along with 7 cases of BPs exposure prior to or during lactation. The vast majority of mothers and infants did not demonstrate serious adverse effects. However, there were cases of shortened gestational age, low neonatal birth weight and transient hypocalcaemia of the newborns, while the very few reported cases of spontaneous abortions and congenital anomalies probably resulted from maternal underlying diseases and concomitant medication. The administration of bisphosphonates in pregnancy should be assessed in view of their potential hazardous effects on both mother and fetus. In cases of absolute or relative indications of BPs prior to pregnancy, close observation of the mother and the infant, especially during the first two weeks of life, is imperative for the successful outcome of pregnancy.

1 May 2006 in The Journal of Clinical Endocrinology & Metabolism
Verified
Journal Article
Closed access
ICIoannis Charopoulos
Ioannis Charopoulos
STSYMEON TOURNIS
SYMEON TOURNIS
GTGeorge Trovas
George Trovas
PRPanagiota Raptou
Panagiota Raptou
PKPhilippos Kaldrymides
Philippos Kaldrymides
GLGeorge P. Lyritis
George P. Lyritis
Context: Primary hyperparathyroidism (PH) is characterized by inappropriate PTH elevation with or without hypercalcemia. Bone disease involves catabolic action at cortical sites, whereas cancellous sites and geometry might be relatively preserved. Objective: Our objective was to examine the effect of PH on quantitative and qualitative bone characteristics using peripheral quantitative computed tomography at the tibia in postmenopausal women with PH and healthy controls. Design and Setting: We conducted a cross-sectional study at a tertiary referral center. Patients: Fifty-two postmenopausal women with PH and 56 healthy controls, comparable for age and anthropometric measures, participated. Intervention: There was no intervention. Main Outcome Measure: We assessed volumetric bone mineral density (vBMD), bone mineral content (BMC), cortical thickness, cortical and trabecular area, peri- and endosteal circumference, and polar stress strength index assessed by peripheral quantitative computed tomography of the left tibia at 4% (cancellous), 14% (transition zone), and 38% (cortical) from the distal end. Results: At 4%, there was a significant decrease of trabecular BMC and vBMD (P < 0.001), effect particularly evident in hypercalcemic patients, whereas trabecular area was comparable. At 38%, cortical BMC (P < 0.01), vBMD (P < 0.01), area (P < 0.05), and thickness (P < 0.001) were reduced in the PH group, particularly in hypercalcemic patients. Endosteal circumference increased (P < 0.001), whereas periosteal circumference was comparable, indicating cancellization of cortical bone. At 14%, polar stress strength index was significantly decreased (P < 0.01) in hypercalcemic patients, indicating impairment of bone mechanical properties. Conclusions: Normocalcemic PH is characterized by catabolic actions at both cortical and cancellous sites (38 and 4%, respectively), an effect accentuated in hypercalcemic patients. Cortical geometric properties are adversely affected even in normocalcemic patients, whereas trabecular properties are generally preserved.