Frog skin active peptides (FSAP) as a highy effective antimicrobial agents

During last ten to fifteen years a considerable scientific attention has been paid to biologically active substances as known as frog skin active peptides (FSAP). These substances are naturally produced by many Amphibian organisms and could be found within skin secretion of most frog families, especially Ranidae. Biomolecules of that class possess extremely valuable properties: show high antimicrobial and antifungal activity - especially effective against multiresistant bacterial infections; act as protease inhibitors and components of an innate immune system; demonstrate relatively weak hemolytic activity. Such a combination makes frog skin active peptides a potential candi dates for drug development with possible application in therapy, traumatology, surgery, etc. In present paper an origin, classification, function as well as methods for determination of FSAP are summarized. It is underlined that Bulgarian region is definitely suitable for extensive FSAP investigations due to the naturally abundance of genus Rana species.Scripta Scientifica Medica 2009; 41(2): 195-200

A new concept for radionuclide generator systems

Radiodiagnostic methods of nuclear medicine use short-lived isotopes for variety of imaging purposes. Inmedical centers these isotopes are produced commonly by special equipment, as known as ‘radionuclide generators`. The radionuclide generated by them can be periodically extracted and, after simple chemical processing, used for appropriate medical application. In developed and commercially available radionuclide generators, the separation and extraction of isotopes is setup on the principles of forced column chromatography, i.e. by means of positive (or negative) pres sure-driven elution. Al though these sorption-type generators work fine and, in general, accomplish most of the requirements for medical application, yet an other principle of generator's construction appears to be also possible. In this paper a new concept for developing a generator system, in which the separation and extraction of radionuclides is carried out on an electrophoretic basis is discussed. Details such as construction possibility, theoretical motivation as well as expected effectiveness are considered. Some possible advantages, concerning radiopharmaceutical usage of proposed electro phoretic generators are outlined.Scripta Scientifica Medica 2009; 41(2): 201-207

In Vitro Evaluation of a Stable Monomeric Gold(II) Complex with Hematoporphyrin IX: Cytotoxicity against Tumor and Kidney Cells, Cellular Accumulation, and Induction of Apoptosis

The antineoplastic potential of a stable monomeric Au(II) complex with hematoporphyrin IX (Hp), namely [Au(II)Hp−2H.(H2O)2], was investigated in a panel of tumor cell lines. The complex exhibits strong cytotoxicity, whereby the leukaemia- and lymphoma-derived cell lines are more sensitive, with IC50 values comparable to those of the reference anticancer drug cisplatin. In contrast, the solid tumor models are more sensitive to the platinum drug. A comparative assessment of both agents against the human kidney cell line 293T has shown that [Au(II)Hp−2H.(H2O)2] is less cytotoxic. The gold complex induces oligonucleosomal DNA fragmentation in tumour cells following 24-hour treatment and hence its cytotoxic effect is at least partly mediated by induction of apoptotic cell death. A prominent intracellular gold accumulation was detected after treating tumor cells with [Au(II)Hp−2H.(H2O)2] which shows that its putative pharmacological targets are readily accessible after a short incubation period

An electrophoretic investigation on the properties of the hexavalent plutonium ions in ultradiluted aqueous solutions

Investigation on the chem is try of transuranic elements is an ex tremely com plex task. None of these elements are sta ble, they de cay ra dio ac tively and are not avail able in large amounts. Heavy transuranic elements are difficult and expensive to produce, and their prices go up rapidly with atomic num ber. As of 2008, weap -ons-grade Plutonium cost around $4,000/gram, and Cal i for nium cost$60,000,000/gram. More over, working even with mi cro gram quan ti ties of these chem i cals con tains a sub stan tial health risk due to their ra dio activity and toxicity. How ever, us ing the method of ra dio ac tive in di ca tors as well as ap pro pri ate in stru ments it is pos - si ble to study transuranic ions be hav ior in wa ter so lu tions at sub-microconcentration lev els as low as 10-8 -10-10 mol.l-1. In this pa per the highly suit able electromigration tech nique is dis cussed and applied to examine some hexavalent Plu to nium prop er ties. A set of col lected radioanalytical data, in cluding values of parameters such as ion mobilities, molar volumes, Stocks radii, hydration num bers, diffusion coefficients as well as their temperature dependence in aqueous solutions is presented. Scripta Scientifica Medica 2010;42(1):77-8

Difficulties met by medical students in the course of biophysics: a comparative analysis

The systematical observation on students studying biophysics draws attention on some difficulties, regularly appearing during laboratory exercises. These difficulties could be easily defined as well as split in groups by their origins, which is clearly proven using an appropriate questionnaire technique. Meeting some requirements arisen in last few years, the educational process in biophysical labs undergoes certain rearrangements. Tracking the distribution of main difficulties met in experimental work and analyzing the students` response one can judge the capability of academic work. The aim of this pedagogical research is to find out the main difficulties met by the medical students studying biophysics, to retrieve the origins of these difficulties and, if it possible, to suggest some measures concerning their elimination. Furthermore, the presented pedagogical analysis is focused on answering the question: ‘Which organization of laboratory exercises is most effective?`. Thus, we can achieve a substantial growth in quality of education.Scripta Scientifica Medica 2008; 40(2): 121-123

CO-57: an electrophoretic investigation on the properties in the ultradiluted aqueous solutions

Radioactive Cobalt is used in nuclear medicine mainly for radiotherapy as well as radiodiagnostics. Radiotherapeutic application usually includes extracorporeal gamma irradiation by means of nuclide Co-60, which spectrum is rich of very high energy gamma quanta. At the contrary, the isotope Co-57 emits merely low energy gamma quanta, thus represents a soft gamma emitter, highly suitable for the clinical radiodiagnostics. In-vivo treatment with the radioactive Cobalt drugs, however, provokes the risk of patient`s blood and tissue radioactive contamination, due to appearance of simple Cobalt ions and their insoluble forms. Therefore, it could be of a practical interest to know chemical properties as well as the behavior of the hydrated Cobalt ions in water solutions at microconcentrations as low as 10-6 - 10-7 mol.l-1. In this paper the highly suitable electromigration technique is discussed and applied. A set of collected radioanalytical data, including values of parameters such as ion mobilities, molar volumes, Stocks radii, hydration numbers and diffusion coefficients as well as their temperature dependence in water solutions is presented.Scripta Scientifica Medica 2008; 40(1):13-1