Publications by authors named "Kakia Nikolaou"
Background: Increasing scientific evidence shows the significant role of epigenetic mechanisms in drug use disorder, abstinence and relapse. Studies on human subjects are limited compared to those on animals, for various reasons such as poly-substance abuse, high drop-out rate and technical difficulties.
Objectives: Our goal was to evaluate whether a monitored abstinence period of 21 days could induce changes in global DNA methylation in chronic heroin users.
The neuropeptide Oxytocin (ΟΤ) is involved as a neurohormone, a neurotransmitter, or a neuromodulator in an extensive range of central and peripheral effects, complex emotional and social human behaviors, memory and learning processes. It is implicated in homeostatic, neuroadaptive processes associated with stress responses and substance use via interactions with the hypothalamic-pituitary-adrenal (HPA) axis and the dopamine mesolimbic reward stress system. This chapter reviews the preclinical and clinical literature on the complicated relationships between endogenous and exogenous opioids and ΟΤ systems and attempts to highlight key findings to date on the effectiveness of intranasal OT administration to treat opioid use disorders.
View Article and Find Full Text PDFPre-clinical studies show that, following chronic opioid exposure, oxytocin neurons exhibit over-excitation upon withdrawal, causing an increase in oxytocin brain and plasma levels. Relevant clinical data on humans are scarce. This study investigates the opioid withdrawal stress effect on oxytocin plasma levels in humans.
View Article and Find Full Text PDFBackground: Opioids influence bone metabolism in several ways and osteoporosis associated with the long-term use of opioids is believed to be multifactorial.
Objectives: To investigate the effect of opioid dependence on conventional and novel biochemical parameters of bone metabolism. To evaluate whether the concomitant HCV infection affects these parameters.
Unlabelled: Abstract Context: Although opiate abuse is known to affect matrix metalloproteinases (MMPs), data on these enzymes and their tissue inhibitors in heroin addicts are scarce.
Objective: In the present study, we determined serum concentrations of MMP-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in heroin users, and compared them with healthy individuals. We evaluated whether 21 d of abstinence are adequate to reverse the effect of opiates and we compared seropositive with seronegative, for anti-HCV antibodies, heroin users.
Background: Opiate abuse has been linked to oxidative stress, through the separate evaluation of oxidants and antioxidants.
Objectives: To determine prooxidant-antioxidant balance (PAB) in chronic heroin users in a single assay, easily applied in a clinical setting. Specifically, to examine whether PAB values correlate with the duration of abuse or with the presence of anti-HCV antibodies.
Background: Although chronic heroin abuse has been extensively linked to oxidative stress, and while plasma 15-F(2t)-IsoP is considered a good indicator of oxidative stress, there remain few references in the literature about the plasma concentration of this marker in heroin dependent subjects.
Objectives: To determine plasma 15-F(2t)-IsoP, as a marker of oxidative stress, in chronic heroin users, and to examine whether the values of this marker correlate with the duration of heroin use or with the presence of anti-HCV antibodies.
Methods: Forty-two chronic heroin users and twenty two healthy control subjects were recruited for this study.