Rekurzív sorozatok és diofantoszi problémák = Recursive sequences and Diophantine problems

A 2005-2008-as periódusban, azaz az OTKA 4 éve alatt a kutatócsoportunk a szerződésben vállalt témák kutatásával foglalkozott. Így, tanulmányoztuk a polinomiális-exponenciális diofantikus egyenleteket, a lineáris rekurziókat, a balansz számokat, az unimodális sorozatokat és a lineáris rekurziókhoz kapcsolódó polinomsorzatok polinomjai gyökeit és azok lokalizációját. A kutatócsoport létszáma végig 5 fő volt (témavezető: Mátyás Ferenc PhD; tagok: Liptai Kálmán PhD, Szalay László PhD, Olajos Péter PhD és Orosz Gyuláné PhD. Az OTKA támogatásával írtunk 20 cikket, ebből már megjelent 16 és további 4 van megjelenés alatt, tönbb rangos nemzetközi számelméleti konferencián tarthattunk előadásokat kutatási eredményeinkből. A megtartott (hazai és külföldi) konferencia-előadásaink száma 27. Az OTKA csoportunk nemzetközi számelméleti konferenciát szervezett Egerben (2007) és Sopronban (2008). Részt vettünk továbbá az Explicit Methods in Number Theory (Bordeaux, 2007) és a Winter School on Explicit Methods in Number Theory (Debrecen, 2009. január) workshop-okon. Összefoglalva elmondható, hogy az OTKA támogatást a terveknek megfelelően használtuk, az elért eredményeink a jövőre nézve is biztatóak. | In the period 2005-2008 the research team delt with the polynomial-exponential Diophantine equations, linear recurreces, balancing numbers, unimodular sequences and estimations of the absoluta values of zeros of polynomials whose the coefficients belong to given binary linear recursive sequences of integers. The research team had 5 members, namely Ferenc Mátyás PhD (teamleader), Kálmán Liptai PhD, László Szalay PhD, Péter Olajos PhD and Mrs. Gyuláné Orosz PhD. We have written 21 scientific papers and we have held 27 conference lectures on international conferences of number theory. We also took part in the work of two workshops, these were: Explicit Methods in Number Theory (Bordeaux, 2007) and Winter School on Explicit Methods in Number Theory (Debrecen, 2009, January). Summarizing, we can say that our research work was succesfull and we can belive in a similar continuation

Alacsony D-vitamin-szint a Semmelweis Egyetem betegei körében

Even in developed countries the prevalence of subjects with suboptimal vitamin D levels is high. The aim of this retrospective data analysis was to evaluate the prevalence of severe and moderate vitamin D deficiencies (defined as vitamin D levels<15 ng/ml and 15-30 ng/ml, respectively) among patients evaluated at Semmelweis University during a period between April, 2009 and March, 2010. Methods and results: The average vitamin D level of 5808 subjects (3936 women and 1872 men) was 25.5 +/- 10.9 ng/ml. The prevalence of moderate and severe vitamin D deficiency in whole population was 72% and 12%, respectively. Higher than normal vitamin D levels were measured in 0.8% of subjects. Female gender, older age and winter season were independent risk factors for vitamin D deficiency. Vitamin D levels were measured repeatedly in 1307 subjects. Interestingly, vitamin D levels measured later were lower compared to those measured at the first time (27.07+/-13.2 vs. 25.9+/-9.11 ng/ml, p<0.001). The prevalence of severe and moderate vitamin D deficiency was 8.1 and 71.5 per cent when vitamin D levels were measured at the second time. Of the 110 patients with severe vitamin D deficiency measured repeatedly only 11 patients (10%) presented with normal vitamin D levels at the second time. Conclusions: These data indicate that severe and moderate vitamin D deficiencies are common in patients evaluated at Semmelweis University. Repeated measurements of vitamin D levels raise the notion that the efficacy of supplementation used for correction of vitamin D levels is not optimal

Az erektilis diszfunkció és a koronária-ateroszklerózis kapcsolata

Az erektilis diszfunkció és a kardiovaszkuláris érbetegségek összefüggése szoros és a 40–50 év közötti férfiak 15%-át érinti. Esetünkben egy új keletű merevedési zavarban szenvedő férfi esetét mutatjuk be, akinek nem voltak mellkasi panaszai és CT-angiográfia/koronarográfia igazolta a koronária-ateroszklerózist és a nem szignifikáns szűkületek miatt konzervatívan lett kezelve

Effects of whole-body 50-Hz magnetic field exposure on mouse Leydig cells.

The main goal of this study was to evaluate the possible effect of whole-body magnetic field (MF) exposure on the steroidogenic capacity of Leydig cells in vitro. In four separate experiments, male CFLP mice were exposed to sinusoidal 50-Hz, 100-µT MF. The duration of exposure was 23.5 h/day over a period of 14 days. At the end of the exposure, interstitial (Leydig) cells were isolated from the testicles of the sham-exposed and exposed animals. The cells were cultured for 48 h in the presence or absence of 1, 10, or 100 mIU/ml human chorionic gonadotropin (hCG). The luteinizing hormone (LH) analog hCG was used to check the testosterone (T) response of the sham-exposed controls and to evaluate the possible effect of the whole-body MF exposure on the steroidogenic capacity of Leydig cells in vitro. Testosterone content of the culture media and blood sera was measured by radioimmunoassay (RIA). In the cultures obtained from MFexposed animals, the hCG-stimulated T response was significanly higher (p &lt; 0.01) compared with the sham-exposed controls, while the basal T production of cells and the level of serum T remained unaltered. No MF exposure-related histopathological alterations were found in testicles, epididymes, adrenals, prostates, and pituitary glands. The MF exposure did not affect the animal growth rate and the observed hematologic and serum chemical variables. Our results indicate a presumably direct effect of whole-body MF exposure on the hCG-stimulated steroidogenic response of mouse Leydig cells. KEYWORDS: ELF magnetic fields, power-line frequency, testosterone, Leydig cell culture, radioimmunoassay, hCG, histology, hematology, serum chemistry DOMAINS: microscopy, cell and tissue culture, endocrinology, hematology, reproduction, biophysics INTRODUCTION In the last decades, utilization of electricity has increased and diffused in both households and industries. The frequency of the current used in these systems is 0-300 Hz. This frequency interval is termed ©2004 with author. Forgács et al.: Magnetic Field Effect on Mouse Leydig Cells TheScientificWorldJOURNAL (2004) 4(S2), 83-90 extremely low frequency magnetic field (ELF-MF), which is a nonionizing radiation having photon energy too weak to break the atomic bonds. One of the most important fields of research in this topic is the investigation of the possible biological effects of power-line frequency (50/60 Hz) MF. At these frequencies, male and female reproductive functions have been proposed as possibly sensitive targets for the biological actions of MF. However, experimental data on male reproduction are quite limited and contradictory. Kato et al. [5] also found increased T levels in rats that they left for 5 weeks, 3 h/day in a 50-Hz/0.8-mT MF. In addition, statistical difference was found between the control and exposed animals with respect to head with lack of hook and isolated head type sperm. Besides this, they observed decreased spermatogenesis in some seminiferous tubules, congestion in blood vessels of the interstitium, and increases in interstitial edema and Sertoli cells. Al-Akhras et al. [6] observed a partly reversible reduction in male rat fertility after 90-day exposure to a 50-Hz MF of 25 µT. However, this working group did not find any MF exposure-related effects on the fertility of male mice at the same parameters of exposure Heredia-Rojas et al. [10] observed a statistically significant decrease in elongated spermatids obtained from rats 28 days after exposure to sinusoidal 50-Hz, 1.7-mT MF for 4 h. The authors suggested a possible cytotoxic and/or cytostatic effect of the applied MF on differentiating spermatogonia. In our previous experiments, we found that in vitro exposure to sinusoidal 50-Hz, 100-µT MF was able to stimulate the basal T production of primary mouse Leydig cell culture The main goal of this study was to evaluate the possible direct effect of whole-body 50-Hz MF exposure on the in vitro steroidogenic capacity of cultured Leydig cells. MATERIALS AND METHODS Animals CFLP mice (HUMAN, Gödöllő, Hungary) weighing 32-37 g (8-9 weeks old) were kept in a room with a 12:12 light/dark photoperiod, temperature of 20-23°C, and relative humidity of 50-60%. In each experiment, 10-13 sham-exposed and another 10-13 exposed mice were kept in plastic cages and allowed free access to standard laboratory pellets (Altromin) and tap water. The MF exposure was carried out in four repeated experiments. Magnetic Field Exposure The sinusoidal, 50-Hz MF was generated by a pair of double-wound coils connected to an internally developed, stabilized AC-current generator. The coils were embedded in molded epoxy resin to avoid vibration. The inner diameter of the coils was 42 cm. The distance between the two parallel coils, mounted horizontally above and below the mouse cage, was 32 cm. The orientation of MF was vertical 84 Forgács et al.: Magnetic Field Effect on Mouse Leydig Cells TheScientificWorldJOURNAL Body weights were recorded on the first and the last day of the treatment. Following the termination of exposure, between 10:30 and 11:00 a.m., mice were anesthetized with 60 mg/kg ip. pentobarbital (RhonePoulenc Rorer, Vitry sur Seine, France) and testicles, epididymes, adrenals, prostates, and pituitary glands were removed and blood samples were taken. After surgery, the animals were overdosed with pentobarbital. Interstitial Cell Preparation and Incubation Interstitial cells were prepared and cultured from the right testicles of the animals. (The left testicles were used for histology.) For isolation of interstitial cells by mechanical dissociation without enzyme treatment, the method of Stoklosowa[13] was used with some modification, as described earlier Testosterone Radioimmunoassay Quantification of T directly from aliquots of the cell culture media was performed by RIA. In addition, blood samples were taken from randomly selected animals to check the T levels of blood sera Histological Techniques Testes (left), epididymes, adrenals, prostates, and pituitary glands were fixed in buffered formol saline for histological examination. These tissues were dehydrated in ethanol, embedded in paraffin wax, and stained with hematoxylin and eosin. 85 Forgács et al.: Magnetic Field Effect on Mouse Leydig Cells TheScientificWorldJOURNAL (2004) 4(S2), 83-90 Hematology Blood was taken from aorta, collected in plastic Eppendorf tubes containing K 3 EDTA. White (WBC) and red (RBC) blood cells counts, hemoglobine concentration (HGB), volume of packed red cells (VPRC), and platelets (PLT) were determined using the Animal Blood Counter Vet abc™ (Roche). Serum Chemistry At sacrifice, free-flowing blood was collected in plastic Eppendorf tubes. After centrifugation, serum was removed and the samples were then analyzed for serum alkaline phosphatase, glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), cholesterol, and triglycerides by an auto analyzer instrument (A.L. Instruments, France). Statistics The data were analyzed by Student&apos;s t-test and ANOVA using GraphPad Prism 3.01 computer software. To eliminate heterogeneity of variance among the data of experiments performed at different times, T levels of the culture media were expressed in percent of sham-exposed, in vitro 100 mIU/ml hCGstimulated controls. A value of p &lt; 0.05 was considered to be significant. RESULTS Testosterone Production of Interstitial Cell Culture The Leydig cells used in all experiments were viable (&gt;90% viability; checked by trypan blue exclusion test) and steroidogenically active. The sham-exposed mean 100-mIU/ml hCG-stimulated T response (control, 100%) was 245.21 ± 35.92 ng/10 6 cells. In the Leydig cells obtained from animals subjected to MF exposure, a significant elevation in hCG-stimulated T response was seen over a 48-h culture, while the basal T production and initial cell yield remained unaltered Serum Testosterone Concentration of serum T was also checked in randomly selected animals (n = 19). The mean (±SEM) T level of the exposed animals (350.26 ± 47.40 pg/ml) was found not to be significantly different from the sham-exposed controls (364.89 ± 40.88 pg/ml). Histology No MF exposure-related histopathological alterations were found in testicles, epididymes, adrenals, prostates, and pituitary glands. Body Weight There was no significant difference in the body weights of exposed animals compared to the shamexposed controls on the first and the last day of the exposure. 86 Forgács et al.: Magnetic Field Effect on Mouse Leydig Cells TheScientificWorldJOURNAL Hematology The hematologic variables (mean ± SEM) of exposed and sham-exposed mice are summarized in Serum Chemistry The mean values (± SEM) of alkaline phosphatase, GOT, GPT, cholesterol, and triglycerides for exposed and sham-exposed mice are shown in 87 Forgács et al.: Magnetic Field Effect on Mouse Leydig Cells TheScientificWorldJOURNAL (2004) 4(S2), 83-90 DISCUSSION In toxicological experiments, in vitro measures of T production of Leydig cells seem to be more sensitive than in vivo indicators of testicular damage Physiological T production in male vertebrates is stimulated by LH (or its analog hCG) through interaction with specific receptor located on the Leydig cell plasma membrane. Hormone-receptor interaction stimulates the classical second messenger pathway involved in steroidogenesis: adenylate cyclase -cAMP -protein kinase A Our results indicate an elevated hCG-stimulated T response of Leydig cell cultures obtained from whole-body MF-exposed mice, while the basal T production of cells and the serum T level of the animals remained unaltered. These data suggest a presumably direct effect of whole-body MF exposure on Leydig cells. These results are in agreement with our previous findings about the effect of in vitro MF exposure on T response of mouse Leydig cells The mechanism of action of the applied MF exposure cannot be discerned from present results. The MF exposure might alter the sensitivity and/or density of LH receptors on the surface of the cell membrane of Leydig cells. It is known that the initial biochemical or metabolic state of the cell membrane, as well as the functional and supramolecular organization of its specific regions (cell contact areas, receptors), are sensitive targets of electric and electromagnetic field (EMF) exposures Second messengers of signal transduction processes, mainly cAMP and Ca 2+ , also seem to play a decisive role in this effect of MF exposure on steroidogenesis. A possible mechanism of action on steroidogenesis may be associated with the alterations in cAMP content and intercellular communication may be induced by the applied MF. Schimmelpfeng et al. MF exposure can alter the local Ca 2+ concentration in different types of cells The results of our experiments show that whole-body MF exposure is able to increase the steroidogenic responsiveness of mouse Leydig cells to LH at a flux density that does not elicit any histopathological alterations in the investigated organs or changes in hematology and serum chemistry. The level of serum T was unaltered probably due to the feedback mechanisms of hypothalamic-pituitarygonadal axis. Further investigations are required to clarify the subcellular action of applied MF in Leydig cells, as well as to establish the biological significance of this phenomenon. ACKNOWLEDGMENT

Az erektilis diszfunkció és a koronária-ateroszklerózis kapcsolata

Az erektilis diszfunkció és a kardiovaszkuláris érbetegségek összefüggése szoros és a 40–50 év közötti férfiak 15%-át érinti. Esetünkben egy új keletű merevedési zavarban szenvedő férfi esetét mutatjuk be, akinek nem voltak mellkasi panaszai és CT-angiográfia/koronarográfia igazolta a koronária-ateroszklerózist és a nem szignifikáns szűkületek miatt konzervatívan lett kezelve. | Erectile dysfunction (ED) is a common problem affecting 15% of men in the age range of 40 to 50 years. We present an angina free male patient with newly presented erectile dysfunction, and CT angiography/coronary angiography de- tected coronary atherosclerosis treated conservatively

Induced Folding of Protein-Sized Foldameric β-Sandwich Models with Core β-Amino Acid Residues

The mimicry of protein-sized β-sheet structures with unnatural peptidic sequences (foldamers) is a considerable challenge. In this work, the de novo designed betabellin-14 β-sheet has been used as a template, and α→β residue mutations were carried out in the hydrophobic core (positions 12 and 19). β-Residues with diverse structural properties were utilized: Homologous β3-amino acids, (1R,2S)-2-aminocyclopentanecarboxylic acid (ACPC), (1R,2S)-2-aminocyclohexanecarboxylic acid (ACHC), (1R,2S)-2-aminocyclohex-3-enecarboxylic acid (ACEC), and (1S,2S,3R,5S)-2-amino-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxylic acid (ABHC). Six α/β-peptidic chains were constructed in both monomeric and disulfide-linked dimeric forms. Structural studies based on circular dichroism spectroscopy, the analysis of NMR chemical shifts, and molecular dynamics simulations revealed that dimerization induced β-sheet formation in the 64-residue foldameric systems. Core replacement with (1R,2S)-ACHC was found to be unique among the β-amino acid building blocks studied because it was simultaneously able to maintain the interstrand hydrogen-bonding network and to fit sterically into the hydrophobic interior of the β-sandwich. The novel β-sandwich model containing 25% unnatural building blocks afforded protein-like thermal denaturation behavior. Dissolving sandwiches: A water-soluble β-sandwich has been constructed by using cyclic β-amino acids in the hydrophobic core (see figure). The structural stability is highly dependent on the side-chain, and the destructuring effects of the β-residues could be minimized by using (1R,2S)-2-aminocyclohexanecarboxylic acid. The β-sandwich displays protein-like thermal denaturation behavior