Rare-earth (Gd3+,Yb3+/Tm3+, Eu3+) co-doped hydroxyapatite as magnetic, up-conversion and down-conversion materials for multimodal imaging.

Taking advantage of the flexibility of the apatite structure, nano- and micro-particles of hydroxyapatite (HAp) were doped with different combinations of rare earth ions (RE3+ = Gd, Eu, Yb, Tm) to achieve a synergy among their magnetic and optical properties and to enable their application in preventive medicine, particularly diagnostics based on multimodal imaging. All powders were synthesized through hydrothermal processing at T ≤ 200 °C. An X-ray powder diffraction analysis showed that all powders crystallized in P63/m space group of the hexagonal crystal structure. The refined unit-cell parameters reflected a decrease in the unit cell volume as a result of the partial substitution of Ca2+ with smaller RE3+ ions at both cation positions. The FTIR analysis additionally suggested that a synergy may exist solely in the triply doped system, where the lattice symmetry and vibration modes become more coherent than in the singly or doubly doped systems. HAp:RE3+ optical characterization revealed a change in the energy band gap and the appearance of a weak blue luminescence (λex = 370 nm) due to an increased concentration of defects. The "up"- and the "down"-conversion spectra of HAp:Gd/Yb/Tm and HAp:Gd/Eu powders showed characteristic transitions of Tm3+ and Eu3+, respectively. Furthermore, in contrast to diamagnetic HAp, all HAp:RE3+ powders exhibited paramagnetic behavior. Cell viability tests of HAp:Gd/Yb/Tm and HAp:Gd/Eu powders in human dental pulp stem cell cultures indicated their good biocompatibility.

The role of echocardiography in the evaluation of cardiac re-modelling and differentiation between physiological and pathological hypertrophy in teenagers engaged in competitive amateur sports.

Aims "Athlete's heart" is a cardiac adaptation to long-term intensive training. The aims of this study were to show the prevalence of left ventricular hypertrophy in teenagers who participate in sports, to define the different types of cardiac re-modelling, and to differentiate between physiological and pathological hypertrophy. METHOD: Echocardiographic measurements were obtained by M-mode, two dimensional, and Doppler techniques of participants from sports and control groups. RESULTS: The echocardiographic examinations included 100 healthy teenagers taking part in dynamic sports such as football and basketball and 100 healthy teenagers taking part in static sports such as karate and judo. The control group (n=100) included healthy, sedentary teenagers. Sports participants had significantly higher left ventricular mass when compared with the control group, (p0.05). Respondents from both groups had E/A ratios (transmitral flow velocity ratio)>1, preserved diastolic function, and statistically they did not differ from the control group. CONCLUSION: Echocardiographic parameters show that physiological hypertrophy and cardiac re-modelling are present in teenagers who play sports. Unexpectedly, the prevalence of concentric and eccentric types of re-modelling is equally possible in the group of static sports participants.

Correlation between nonalcoholic fatty liver and cardiovascular disease in elderly hemodialysis patients.

PURPOSE: The number of elderly patients with end-stage kidney disease is on the rise. Nonalcoholic fatty liver disease (NAFLD) is characterized by parenchymal fat accumulation in patients without information about alcohol abuse. The aim of our study was to determine correlation between NAFLD and cardiovascular diseases in elderly hemodialysis patients. METHODS: The examination was organized as observational and cross-sectional study in elderly patients on hemodialysis. An abdominal ultrasound examination was made in order to define NAFLD. Intima-media thickness of the carotid arteries was quantified by Doppler ultrasound. Biochemical parameters, gender, anthropometric characteristics, duration, adequacy of hemodialysis, blood pressure, smoking and cardiovascular disease were determined. Respondents were divided into a group with NAFLD (37/72 patients, 51 %) and group without NAFLD (35/72 patients, 49 %). RESULTS: Patients with NAFLD have significantly more cardiovascular disease (p = 0.017) as well as significantly higher values of intima-media thickness of the carotid arteries (p = 0.03) in correlation with patients without NAFLD. Patients without NAFLD have a statistically lower triglyceride (p = 0.04), aspartate aminotransferase (p = 0.006), alanine aminotransferase (p = 0.013) and gamma-glutamyl transpeptidase (p = 0.029) compared to patients with NAFLD. Patients with cardiovascular disease have a higher risk of NAFLD; likewise, patients with NAFLD have a three times higher chance for developing cardiovascular diseases (OR 3.01). CONCLUSION: Elderly patients on hemodialysis with cardiovascular disease have a higher risk of NAFLD; likewise, patients with NAFLD have a three times higher chance for developing cardiovascular diseases.