Boris Đinđić

Predicting the Biological Effects of Mobile Phone Radiation Absorbed Energy Linked to the MRI-obtained Structure

The nature of an electromagnetic field is not the same outside and inside a biological subject. Numerical bioelectromagnetic simulation methods for penetrating electromagnetic fields facilitate the calculation of field components in biological entities. Calculating energy absorbed from known sources, such as mobile phones when placed near the head, is a prerequisite for studying the biological influence of an electromagnetic field. Such research requires approximate anatomical models which are used to calculate the field components and absorbed energy. In order to explore the biological effects in organs and tissues, it is necessary to establish a relationship between an analogous anatomical model and the real structure. We propose a new approach in exploring biological effects through combining two different techniques: 1) numerical electromagnetic simulation, which is used to calculate the field components in a similar anatomical model and 2) Magnetic Resonance Imaging (MRI), which is used to accurately locate sites with increased absorption. By overlapping images obtained by both methods, we can precisely locate the spots with maximum absorption effects. This way, we can detect the site where the most pronounced biological effects are to be expected. This novel approach successfully overcomes the standard limitations of working with analogous anatomical models.

Evaluation of ghrelin and leptin levels in obese, lean and undernourished children

Background/Aim. Energy homeostasis is a balance between energy intake and energy expenditure. Leptin and ghrelin are two orexitropic hormones with opposite effect on energy homeostasis. We investigated fasting ghrelin and leptin serum levels in children with different nutritional conditions. Methods. In 30 obese children of both sexes, aged from 6 to 17.67 years (mean 13.04 ± 2.95 years), fasting ghrelin and leptin levels were determined in the serum, along with auxological assessment and pubertal staging. Obtained values were analyzed and compared with those of the same parameters in 33 lean and 25 undernourished (UN) children. Results. Mean ghrelin/body mass (BM) ratio was the lowest in obese children (21.75 ± 12.60 pg/mL/kg), which was significantly different in comparison with that in lean and UN subjects. Mean leptin/BM ratio of 0.62 ± 0.86 pg/mL/kg in obese children was significantly higher than that in lean and UN children (p < 0.01 and p < 0.001, respectively). Ghrelin and leptin levels showed different profiles in obese, lean and UN children. An inverse relationship was discovered among study groups in ghrelin/leptin and leptin/ghrelin ratios. Conclusion. Obese children, compared to other children, have significantly higher values of leptin, and UN children have significantly higher values of ghrelin per kilogram of body mass. The results also illustrate the inverse ratio of ghrelin and leptin, which has been demonstrated as a clinically reliable marker of the status of obesity or undernutrition in children, with significant implications concerning rather large variations in the concentration of these hormones in relation not only to the body mass but also to the childrens age.

OCCUPATIONAL DISEASES INDUCED BY VIBRATIONS

Vibration is physical noxiousness which is present in different branches of industry. Vibration disease is the disease caused by professional vibrations. The disorders caused by acute and chronic, local or general exposure are numerous and very nonspecific. Vibration disease signs are expressed late during natural course of disease, and diagnosis is made with significant delay. The occupational disorders caused by vibration represents important segment in occupational medicine and occupational protection. Pathogenetic factors are microtrauma, spasm of arterial blood vessels and ischemia. The vibration damages all tissues but the cardiovascular, muscular, nervous system and bones are specially damaged. High frequent vibration damages cardiovascular system and low frequent vibration damages bones. Vibrations may represent contributing factor in development of occupational accidents. In the estimation of working ability the demands of workplaces, noxiousness, health state, functional state, motivation, length of working must be examined. The preventive steps include technical, organisational, and medical procedures as well as using of personal protective means. The vibrational disease has great impact on workers’ health and demand further research and permanent labor regulation adjustment in this field.

Lipid Disorders And Inflammation in Patients With Diabetes Mellitus Type 2 Treated With Statins

Lipid Disorders And Inflammation in Patients With Diabetes Mellitus Type 2 Treated With Statins The research focused on 40 patients (22 women and 18 men) with DM type 2, 26 of who underwent statin therapy and 14 of them followed a hygienic-dietetic regime. After a year of careful observation, the concentration of triglycerides (TG) was determined, as well as the overall cholesterol (TC), LDL-C, HDL-C, nonHDL cholesterol and atherogenic indices. As far as inflammatory indicators are concerned, the concentrations of highly sensitive C reactive protein (hsCRP), intracellular adhesion molecule (ICAM-1) and vascular adhesion molecule (VCAM-1) were determined; they were also compared among the therapy groups. The average TC and LDL-C values were considerably lower in the group treated by statins (5.6 ± 1.2 vs. 6.3 ± 1.4 mmol/L and 3.5 ± 0.9 vs. 4 ± 1.3 mmol/L, p<0.05). The values of TG, HDL-C, atherogenic indices LDL-C/HDL-C and TC/HDL-C and inflammatory indicators ICAM-1 and VCAM-1 did not differ significantly among the groups. The values of nonHDL-C were considerably lower in the group treated by statins (4.5 ± 1.1 vs. 5.1 ± 1.3 mmol/L, p<0.05), as well as the values of hsCRP (3.3 ± 2.2 vs. 5.6 ± 2.17 mg/dl, p<0.01). Parallel analysis showed a significant correlation between the concentration of TC and LDL-C and the values of ICAM-1 (C=0.55 and C=0.65, p<0.05). Anti-lipoid effects of statins are complemented with their significant antiinflammatory influence on the reduction of the value of hsCRP, which proved to be the most important prognostic factor for the onset of atherosclerosis. Antiinflammatory effects of statins are supplemented by a significant decrease in the concentration of ICAM-1 in the conditions where the value of TC and LDL-C is reduced in patients with DM type 2. Lipidni Poremećaji I Inflamacija Kod Bolesnika S Diabetes Mellitusom Tipa 2 Na Terapiji Statinima Ispitivanjem je obuhvaćeno 40 bolesnika (22 žene i 18 muškaraca) sa DM tipa 2, pri čemu je 26 bilo na terapiji statinima a 14 na higijensko-dijetetskom režimu. Nakon praćenja od godinu dana određivane su koncentracije triglicerida (TG), ukupnog holesterola (TC), LDL-C, HDL-C, nonHDL holesterola i aterogenih indeksa. Od inflamatornih pokazatelja određivana je koncentracija visokosenzitivnog C-reaktivnog proteina (hsCRP), intracelularnog adhezionog molekula (ICAM-1) i vaskularnog adhezionog molekula (VCAM-1), pri čemu su komparirani rezultati terapijskih grupa. Prosečne vrednosti TC i LDL-C bile su značajno manje u grupi na terapiji statinima (5,6 ± 1,2 vs. 6,3 ± 1,4 mmol/L i 3,5 ± 0,9 vs. 4 ± 1,3 mmol/L, p<0,05). Vrednosti TG, HDL-C, aterogenih indeksa LDL-C/HDL-C i TC/HDL-C i inflamatornih pokazatelja ICAM-1 i VCAM-1 nisu se značajnije razlikovale između grupa. Vrednosti nonHDL-C značajno su manje u grupi na statinima (4,5 ± 1,1 vs. 5,1 ± 1,3 mmol/L, p<0,05), kao i vrednosti hsCRP (3,3 ± 2,2 vs. 5,6 ± 2,17 mg/L, p<0,01). Korelaciona analiza je pokazala značajnu povezanost koncentracije TC i LDL-C sa vrednostima ICAM-1 (C=0,55 i C=0,65, p<0,05). Antilipemični efekti statina upotpunjeni su njihovim značajnim antiinflamatornim delovanjem na smanjenje vrednosti hsCRP, koji se pokazao kao najvažniji prognostički faktor za pojavu ateroskleroze. Antiinflamatorni efekti statina su upotpunjeni značajnim padom koncentracije ICAM-1 u uslovima redukcije vrednosti TC i LDL-C kod bolesnika sa DM tipa 2.

Disturbance In The Composition of Lipoprotein Particles And Chronic Inflammation As Prognostic Factors In The Development of Coronary Disease

Disturbance In The Composition of Lipoprotein Particles And Chronic Inflammation As Prognostic Factors In The Development of Coronary Disease The study focused on 30 dyslipidemic patients (12 women and 18 men); 16 of them had coronary disease (CD). The concentrations of apoA and apoB were determined in all patients, as well as the calculated ratio between apoA and apoB. As far as inflammatory indicators are concerned, the concentrations of sensitive C reactive protein (hsCRP), albumin, fibrinogen, intracellular adhesive molecule (ICAM-1) and vascular adhesive molecule (VCAM -1) were determined. In patients with CD there were considerably higher concentrations of fibrinogen (3.1 ± 1.2 vs. 2.7 ± 0.7 g/L) and VCAM-1 (10.9 ± 3.6 vs. 8.3 ± 2.8 g/L) (p<0.05) while the numerical values of hsCRP and ICAM-1 were not significantly different in relation to the patients without CD. The concentration of apoB and the value of apoB/apoA ratio were considerably higher in patients with CD (1.7 ± 0.8 vs. 1.3 ± 0.4 and 1.3 ± 0.4 vs. 0.9 ± 0.4; p<0.05), whereas the concentration of apoA did not differ in relation to the patients without CD. The research confirmed the significance of the disturbance in the composition of lipoprotein particles and the systemic inflammatory response in the pathogenesis of atherosclerosis, whereas their significant mutual connection was not shown. This indicates their cumulative effect and different mechanisms at the base of these disturbances. Poremećaji Kompozicije Lipoproteinskih Čestica I HroničNa Inflamacija Kao PrognostičKi Faktori Za Razvoj Koronarne Bolesti Ispitivanjem je obuhvaćeno 30 dislipidemičnih bolesnika (12 žena i 18 muškaraca), od kojih je 16 imalo koronarnu bolest (KB). Kod svih bolesnika određivane su koncentracije apoA, apoB i izračunavan odnos apoB/apoA. Od inflamatornih pokazatelja, određivane su koncentracije visokosenzitivnog C-reaktivnog proteina (hsCRP), albumina, fibrinogena, intracelularnog adhezionog molekula (ICAM-1) i vaskularnog adhezionog molekula (VCAM-1). Kod bolesnika sa KB postoji značajno veća koncentracija fibrinogena (3,1 ± 1,2 vs. 2,7 ± 0,7 g/L) i VCAM-1 (10,9 ± 3,6 vs. 8,3 ± 2,8 g/L) (p<0,05), dok se vrednosti hsCRP i ICAM-1 nisu značajnije razlikovale u odnosu na bolesnike bez KB. Koncentracija apoB i vrednosti apoB/apoA odnosa bile su značajno veće kod bolesnika sa KB (1,7 ± 0,8 vs. 1,3 ± 0,4 i 1,3 ± 0,4 vs. 0,9 ± 0,4; p<0,5), dok se koncentracija apoA nije razlikovala u odnosu na bolesnike bez KB. Ispitivanjem je potvrđen značaj poremećaja kompozicije lipoproteinskih čestica i sistemskog inflamatornog odgovora u patogenezi ateroskleroze, pri čemu nije utvrđena značajna međusobna povezanost. Ovo ukazuje na njihov kumulativni efekat i različite mehanizme koji stoje u osnovi ovih poremećaja.