Erythromycin Series. X. Inhibitory Activity of Several New Erythromycin Derivatives in Cell-Free Amino Acid Polymerization Systems

Erythromycin A (I), erythromycin A 9-oxime (11), 9(S)-erythromycylamine (V), and several new derivatives of these compounds, were assayed for their ability to inhibit the poly(A)-directed synthesis of polylysine and the poly(C)-directed synthesis of polyproline in cell-free systems from Escherichia coli. The rate of polypeptide synthesis was inhibited 500/o by concentrations between 0.5 and 1.5 ~tmol · dm-3 of the eight examined compounds, in the following decreasing order of activity: methylsuccinate of V (VI), I, V, II, methylsuccinate of II (111), p-toluenesulfonyl-V (VII), p- acetylamino-benzenesulfonyl-V (VIII), and ethylsuccinate of I (IV). The derivative of VII lacking cladinose (IX) showed lower but still significant activity. Hence, none of the substitutions in the position 9 of the macrolide ring, present in these compounds, impairs the ability of I to bind the prokaryotic ribosome and inhibit its function, which is the basis for antibacterial activity of erythromycines

Antibacterial potential of electrochemically exfoliated graphene sheets

Electrochemically exfoliated graphene is functionalized graphene with potential application in biomedicine. Two most relevant biological features of this material are its electrical conductivity and excellent water dispersibility. In this study we have tried to establish the correlation between graphene structure and its antibacterial properties. The exfoliation process was performed in a two electrode-highly oriented pyrolytic graphite electrochemical cell. Solution of ammonium persulfate was used as an electrolyte. Exfoliated graphene sheets were dispersed in aqueous media and characterized by atomic force microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X photoelectron spectroscopy, X-ray diffraction, electron paramagnetic resonance, zeta potential, contact angle measurements and surface energy. Antibacterial assays have shown lack of the significant antibacterial activity. Major effect on bacteria was slight change of bacteria morphology. Membrane remained intact despite significant change of chemical content of membrane components.This is the peer reviewed version of the paper: Marković, Z. M., Matijašević, D. M., Pavlović, V. B., Jovanović, S. P., Holclajtner-Antunović, I. D., Špitalský, Z., Mičušik, M., Dramićanin, M. D., Milivojević, D. D., Nikšić, M. P., & Todorović Marković, B. M. (2017). Antibacterial potential of electrochemically exfoliated graphene sheets. Journal of Colloid and Interface Science, 500, 30–43. [https://doi.org/10.1016/j.jcis.2017.03.110][https://www.sciencedirect.com/science/article/abs/pii/S0021979717303776?via%3Dihub

School Choice and Vocational Guidance for Schoolchildren with Chronic Diseases and Other Health Problems

Osim praćenja rasta, razvoja i zdravstvenog stanja učenika tijekom školovanja, liječnik školske medicine razmišlja i o njihovu profesionalnom razvoju. Posebnu pozornost zahtijevaju učenici s kroničnim bolestima, kojih je prema istraživanjima 10 % do 15 %. Prije izbora zanimanja potrebno je upoznati roditelje i učenike s ograničenjima koja proizlaze iz prirode bolesti ili stanja. To omogućuje učenicima da razviju interes za zanimanja za koja nemaju kontraindikaciju. Sistematski pregled u osmom razredu osnovne škole procjena je učenikovih psihofi zičkih sposobnosti za nastavak srednjoškolskog obrazovanja. Tijekom pregleda provodi se profesionalno informiranje za sve učenike. Učenici s kroničnim bolestima, teškoćama u razvoju i drugim poremećajima zdravlja upućuju se na profesionalno usmjeravanje. Cilj ovog rada bio je prikaz razloga upućivanja na školsko i profesionalno usmjeravanje učenika osmih razreda, deset osnovnih škola iz Varaždinske županije, u razdoblju od školske godine 1998./99. do 2007./08. Od ukupno 4939 pregledanih učenika, na profesionalno usmjeravanje bilo je upućeno njih 458 (9,3 %). Najčešći razlozi upućivanja bili su bolesti i stanja iz skupine duševnih poremećaja i poremećaja ponašanja, sa zastupljenošću od 41,3 %. Preporuke stručnog tima za profesionalno usmjeravanje za daljnje školovanje nije slijedilo 10,5 % učenika. Za učenike s kroničnim bolestima i drugim poremećajima zdravlja bilo bi potrebno osigurati dovoljan broj upisnih mjesta u srednjim školama te kontinuirano pratiti njihov profesionalni razvoj radi intervencije u slučaju potrebe promjene škole i uvida u ishod obrazovanja. To bi se postiglo koordiniranim radom školskih liječnika, timova za profesionalno usmjeravanje, srednjih škola i županijskih upravnih odjela za prosvjetu, kulturu i šport.By following a child’s growth, development, and health, school medicine specialist can see opportunities for career choice. Special attention is needed for schoolchildren with chronic diseases and developmental difficulties, because of limited occupation choices. Studies report 10 % to 15 % prevalence of chronic diseases among schoolchildren. Parents and children should be informed about child’s limitations before career choice. It would be helpful for the students to develop interests for occupations that are not contraindicated for their condition. Physical examination gives an insight into the psycho-physical abilities of an eighth-grade primary school student for further education. During examination, counselling and vocational guidance is provided for all students with chronic diseases and other health problems. All procedures are oriented to personal abilities and preferences. The aim of this study was to analyse the reasons for vocational guidance in the Varaždin County of Croatia. It included eighth-grade students from ten primary schools from 1998/99 to 2007/08. Of 4939 students, 458 (9.3 %) with chronic diseases and health difficulties were referred to vocational guidance. Of these, 41.3 % were referred due to mental and behavioural disorders. These students were assessed and received a recommendation for at least two occupations. Forty-eight students (10.5 %) did not follow the recommendation. In a coordinated effort, school physicians, vocational guidance experts, and school and local authorities should secure enrollment of students with chronic diseases and health difficulties in secondary schools and follow their development and education to provide them the best available career opportunities