Bevezetés: A szívfrekvencia-variabilitás csökken hypertoniában vagy diabetes mellitusban szenvedők körében. A hypertonia és a diabetes mellitus egymással gyakori komorbiditást mutatnak. Nincs elegendő adat arról, hogy a kontrollhoz képest diabetes mellitusban nem szenvedő hypertoniás betegek körében hogyan változik a szívfrekvencia-variabilitás. Célkitűzés: A szerzők hypertoniában szenvedő diabeteses és nem diabeteses betegekben, valamint kontrollegyének-ben a szívfrekvencia-variabilitás vizsgálatát tűzték ki célul. Módszer: 130 hypertoniában, 48 hypertoniában és 2-es típusú diabetes mellitusban szenvedő beteget, valamint 87 kontrollszemélyt vontak be a vizsgálatba. A minimális, átlagos és maximális szívfrekvenciát, valamint az egymást követő RR-intervallumok időtartamának és 5 perces szegmensekben mért átlagának szórását határozták meg. Eredmények: Az átlagos minimális szívfrekvencia szignifi kánsan nem különbözött a csoportok között. A kontrollhoz képest a többi paraméter szignifi kánsan csökkent mind a hypertoniában, mind a hypertoniában és diabetesben szenvedő betegek csoportjában. A hypertoniás csoporthoz képest a hypertoniában és diabetesben szenvedő csoportban a paraméterek nem különböztek szignifi kánsan. Következtetések: Diabetes mellitusban nem szenvedő hypertoniás betegek körében a szívfrekvencia-variabilitás jelentősen beszűkül. Úgy tűnik, hogy hypertoniás betegek körében a 2-es típusú diabetes mellitus szignifi kánsan már nem csökkenti tovább a szívfrekvencia-variabilitást. Orv. Hetil., 2014, 155(22), 865-870. Kulcsszavak: hypertonia, diabetes mellitus, szívfrekvencia-variabilitás Heart rate variability is signifi cantly reduced in non-diabetic patients with hypertensionIntroductions: Heart rate variability is reduced among patients with hypertension or those with diabetes mellitus. Hypertension and diabetes show frequent co-morbidity, but it is still not entirely clear whether heart arte variability is reduced in non-diabetic patients with hypertension. Aim: The aim of the authors was to evaluate the heart rate variability in hypertensive patients with and without diabetes and in control subjects. Method: 130 patients with hypertension, 48 patients with hypertension and type 2 diabetes mellitus, and 87 control subjects were involved in the study. Minimum, mean and maximum heart rate, and parameters of heart rate variability were measured. Results: The mean of minimum heart rate did not differ signifi cantly between the three groups. However, all other parameters were signifi cantly reduced in patients with hypertension with and without diabetes as compared to the control group. No signifi cant differences were observed between hypertensive patients with and without diabetes mellitus. Conclusions: Heart rate variability is signifi cantly reduced in non-diabetic patients with hypertension. It seems that type 2 diabetes results in no further signifi cant reduction of heart rate variability in patients with hypertension.

Cell-based tissue reconstruction is an important field of regenerative medicine. Stem and progenitor cells derived from tooth-associated tissues have strong regeneration potential. However, their in vivo application requires the development of novel scaffolds that will provide a suitable three-dimensional (3D) environment allowing not only the survival of the cells but eliciting their proliferation and differentiation. Our aim was to study the viability and differentiation capacity of periodontal ligament cells (PDLCs) cultured on recently developed biocompatible and biodegradable poly(aspartamide) (PASP)-based hydrogels. Viability and behavior of PDLCs were investigated on PASP-based hydrogels possessing different chemical, physical and mechanical properties. Based on our previous results, the effect of thiol group density in the polymer matrix on cell viability, morphology and differentiation ability is in the focus of our article. The chemical composition and 3D structures of the hydrogels were determined by FT Raman spectroscopy and Scanning Electron Microscopy. Morphology of the cells was examined by phase contrast microscopy. To visualize cell growth and migration patterns through the hydrogels, two-photon microscopy were utilized. Cell viability analysis was performed according to a standardized protocol using WST-1 reagent. PDLCs were able to attach and grow on PASP-based hydrogels. An increase in gel stiffness enhanced adhesion and proliferation of the cells. However, the highest population of viable cells was observed on the PASP gels containing free thiol groups. The presence of thiol groups does not only enhance viability but also facilitates the osteogenic direction of the differentiating cells. These cell-gel structures seem to be highly promising for cell-based tissue reconstruction purposes in the field of regenerative medicine.

Polymer hydrogels are ideal scaffolds for both tissue engineering and drug delivery. A great advantage of poly(amino acid)-based hydrogels is their high similarity to natural proteins. However, their expensive and complicated synthesis often limits their application. The use of poly(aspartic acid) (PASP) seems an appropriate solution for this problem due to the relatively cheap and simple synthesis of PASP. Using amino acids not only as building blocks in the polymer backbone but also as cross-linkers can improve the biocompatibility and the biodegradability of the hydrogel. In this paper, PASP cross-linked with cystamine (CYS) and lysine-methylester (LYS) was introduced as fully amino acid-based polymer hydrogel. Gels were synthesized employing six different ratios of CYS and LYS. The pH dependent swelling degree and the concentration of the elastically active chain were determined. After reduction of the disulfide bonds of CYS, the presence of thiol side groups was also detected. To determine the concentration of the reactive cross-linkers in the hydrogels, a new method based on the examination of the swelling behavior was established. Using metoprolol as a model drug, cell proliferation and drug release kinetics were studied at different LYS contents and in the presence of thiol groups. The optimal ratio of cross-linkers for the proliferation of periodontal ligament cells was found to be 60−80% LYS and 20−40% CYS. The reductive conditions resulted in an increased drug release due to the cleavage of disulfide bridges in the hydrogels. Consequently, these hydrogels provide new possibilities in the fields of both tissue engineering and controlled drug delivery.

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