Work stress related lipid disorders and arterial hypertension in professional drivers: A cross-sectional study

Background/Aim. Occupational stress is a term used to define ongoing stress that is related to the workplace. The study was conducted to determine association of occupational stress index (OSI) and its aspects with arterial hypertension and lipid disorders using data from a cross-sectional survey of male professional drivers. Methods. The cross-sectional study was performed in 439 professional drivers divided into groups (city- and intercity bus drivers, truck and taxi drivers). The OSI and OSI aspects (high demands, strictness, underload, extrinsic time pressure, noxious exposure, avoidance and conflict) were calculated using the standardized questionnaire. Determination of serum lipids, blood pressure (BP) and cardiovascular risk factors were done. Results. A significant difference in prevalence of diagnosed hypertension and dyslipidemia was found along with a difference in total OSI and OSI aspects among examined subgroups of drivers. A total OSI was highest in city, high in intercity bus drivers, and the lowest one in truck and taxi drivers (82.79 ± 3.5, 81.28 ± 3.7, 73.75 ± 3.5, 71.61 ± 4.4, respectively; p < 0.01). Similar pattern showed triglycerides (TG), total cholesterol (TC) and LDL cholesterol and BP, while HDL-cholesterol showed reverse order (p < 0.01). Logistic regression analyses with multiple OSI aspects adjusted for age and years of exposure showed associations of total OSI with arterial hypertension [OR 5.5; 95% CI (2.24-7.95)] and dyslipidemia [OR 1.43 95% CI (1.09-2.80)]. Underload was the most important OSI aspect associated with the arterial hypertension [OR 1.18; 95% CI (1.04-2.58)] and elevated LDL cholesterol [1.26; 95 CI (1.19-2.1)]. A total OSI had a significant association with elevated LDL cholesterol [2.64; 95% CI (1.19- 7.7)], triglycerides [OR 3.27; 95% CI (1.20-5.1)] and low HDL cholesterol [OR 3.29; 95% CI (1.8-5.8)] (p < 0.01). Conclusion. The study provides the evidence for the significant association of total OSI and underload with lipid disorders and elevated blood pressure in professional drivers, which could be a possible link between job stress and coronary heart disease. Regular periodical examinations and workplace interventions aimed to decrease total OSI and underload are important aspects in primary prevention and additional reduction of cardiovascular risk. [Projekat Ministarstva nauke Republike Srbije, br. 43012 i br. 41018

BIOCHEMICAL AND HISTOPATHOLOGICAL EFFECTS OF MOBILE PHONE EXPOSURE ON RAT HEPATOCYTES AND BRAIN

Microwave radiation MWR is widespread in human environment. The most frequent sources of MWR are mobile phones and cell towers. The effects of MWR are still unknown and there are insufficient data about long-term MWR effects on hepatocytes and brain structures.The aim of this paper was to investigate the biological effects of mobile phone microwave radiation on the brain and liver of experimental animals and to determine the increase in oxidative stress as a possible pathogenetic mechanism for harmful effects of long-term exposure.Wistar rats, 3 months old, were divided into two groups: I-rats constantly exposed to MWR (3 female and 2 male) and II-control animals without near source of electromagnetic field (EMF) (3 female and 2 male). The microwave radiation was produced by a mobile test phone (model NOKIA 3110; Nokia Mobile Phones Ltd.) connected to a Communication Test Set (model 4202S; Wavetek, Germany). A 900 MHz electromagnetic near-field signal for GSM (Global System for Mobile communication at 900 MHz, continuous wave, analog phone) system was used. The whole-body specific energy absorption (SAR) rate was estimated as 0.025-0.05 W/kg (E=9.8-18.3 V/m, B=4.8-8.6 µT). Rats were sacrificed after 3 months of MWR exposure. The liver and brain were fixed in 10% formaldehyde and paraffin sections were stained by HE. The biochemical analyses comprised the determination of serum activity of AST (Aspartate aminotransferase), ALT (Alanine transaminase), GGT (Gamma-glutamyl transpeptidase) and LDH (Lactate dehydrogenase), as well as determination of serum concentration of sodium, potassium and chloride. Lipid peroxidation was determined by measuring the quantity of malondialdehyde (MDA).Slightly increased number of micronuclei and discrete perivenular fatty changes were only histopathological findings in the liver of exposed rats. The discrete reduction of gray matter and reduced size and number of dendritic spines of Purkinje cells in cerebellum were notified as well. The serum activity of ALT was significantly increased (p<0.05), while activities of AST, GGT and LDH did not changed in the exposed rats. Potassium serum concentration was significantly higher in the exposed rats, while the concentration of sodium and chloride did not differ. The MDA concentration was significantly higher in the brain and liver tissues of MWR-exposed rats.The results in this study show significant increase in lipid peroxidation as a direct indicator of the hepatocytes and brain cells’ injury under a long-term (90 days) mobile phone microwave exposure. The hyperkalemia could be the possible systemic marker of impaired cells membrane fluidy and increased permeability, alongside with increased ALT activity as marker of hepatocelular damage. Disorders of hypothalamo- hypophyseal axis lead to disturbances in affective behaviour, but also to disturbances of neurovegetative functions, which leads to behavioral changes and increased appetite and weight gain in exposed animals

Model za predviđanje bioloških efekata zračenja mobilnih telefona: numerički rezultati apsorbirane energije povezani s realnom strukturom dobivenom metodom MRI

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.Numeričke bioelektromagnetne simulacijske metode prodrlih elektromagnetnih polja koriste se za izračunavanje komponenata polja u biološkim jedinkama. Elektromagnetno polje nije jednako izvan i unutar biološkog subjekta. Izračunavanje energije apsorbirane iz poznatog izvora, kao što su mobilni telefoni u području glave, preduvjet je za ispitivanje biološkog utjecaja elektromagnetnog polja. Pri ovim istraživanjima koriste se približni anatomski modeli i na osnovi njih se izračunavaju komponente polja i apsorbirana energija. Nužno je uspostaviti vezu između odgovarajućih približnih anatomskih modela s realnom strukturom, kako bi se mogli istraživati biološki efekti u dijelovima organa i tkiva. Zbog toga se u ovom radu predlaže novi pristup istraživanju bioloških efekata. U osnovi metode je kombinacija dviju različitih tehnika: 1) numeričke elektromagnetne simulacije kojom se izračunavaju komponente polja u približnom anatomskom modelu i 2) MRI metoda (Magnetic resonance imaging) kojom se precizno lociraju mjesta s povišenom apsorpcijom. Kombiniranje se postiže preklapanjem slika dobivenih jednom i drugom metodom, čime se utvrđuje precizna lokacija mjesta s maksimalnim efektima apsorpcije. Na taj način mogu se pronaći mjesta na kojima bi trebao biti najizraženiji biološki učinak. Novi pristup uspješno prevladava ograničenja koja su postojala pri radu s približnim anatomskim modelima

Relationship of adipokine to insulin sensitivity and glycemic regulation in obese women: The effect of body weight reduction by caloric restriction

Bacground/Aim. Visceral fat is highly active metabolic and endocrine tissue which secretes many adipokines that act both on local and systemic level. It is believed that adipokines and "low-grade inflammatory state" represent a potential link between obesity, metabolic syndrome, insulin resistance and cardiovascular disease. Leptin and adiponectin are considered to be the most important adipokines with the potential metabolic and cardiovascular effects. Body weight loss improves insulin sensitivity and decreases risk for most complications associated with obesity. The aim of this study was to determine the effects of moderate loss of body weight on the level of leptin and adiponectin, insulin sensitivity and abnormalities of glycoregulation in obese women, to determine whether and to what extent the secretory products of adipose tissue, leptin and adiponectin contribute to insulin sensitivity, as well as to assess their relationship and influence on glycemia and insulinemia during the period of losing body weight using a calorie restricted diet. Methods. The study involved 90 obese female subjects (BM

MORPHOLOGICAL AND IMMUNOCYTOCHEMICAL CHARACTERISTICS OF STROMAL GASTROINTESTINAL TUMORS

Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumors of gastrointestinal system and they are characterised by extreme variability in clinical, hystopathological and genetic features. It is considered that all GISToms have a malignant potential. Ethiological factors which cause GISToms have not been clarified yet, and genetic basis is not easy to be determined since GISToms are mostly sporadic. However, certain genetic and cytogenetic aberations which have been determined can be considered to have an impact on the onset of GISToms. Macroscopic picture is polymorphic, but they can most frequently be seen as large, mushroom-like, intraluminal, clearly limited pseudo-incapsulated submucosal masses. Hystomorphology of these tumors shows a high spectar of structural and cellular variations. They are most frequently built out of spindle cells (60-70% of cases), rarely of epitheloid (about 30% of cases) and very rarely of mixed and transitional type (intermedial). Stroma is predominantly loose or poorly colagenized with neoangiogenesis, which is markedly in GISToms with a higher malignant potential. Most of GISToms (95%) express transmembrane receptors KIT (CD 117), CD 34, vimentine, specific neurogenic and smooth muscle cells markers. The most successful therapies are: surgical ressection, imatinib and sunitinib (in case of imatinib resistence) therapy (tyrosine kinase receptor blockers). Research are being conducted all over the world with the aim of finding new and more efficient drug therapies that would not manifest resistency

ALCOHOL CONSUMPTION HABITS AND SLEEP QUALITY

Alcohol is the most widely used psychoactive substance, due to its easy production, availability of alcoholic beverages and fast action. Drinking alcohol can cause sleep disorders because it disrupts the sequence and duration of sleep stage. The aim of this study was to examine the influence of alcohol consumption on the quality and length of sleep of the first year students of doctoral studies at the Faculty of Medicine. Our study group included 42 patients who were in the first year of doctoral studies at the Faculty of Medicine in Niš. The research was conducted from November 2011 until April 2012 at the Faculty of Medicine. Out of the 42 subjects who were included in the research, 25 of them or 59.5% consumed alcohol, while 17 of them or 45% did not. Comparing the length of sleep of those who consumed alcohol with those who did not, the difference was not statistically significant. Alcohol consumption leads to poor quality of sleep, but it does not affect the length of sleep

RADIOFREQUENCY AND MICROWAVE RADIATION HEALTH EFFECTS AND OCCUPATIONAL EXPOSURE

In the recent years, there have been considerable discussion and concern about the possible hazards of RF/MW radiation. More recently, the growth and development in personal mobile communications have focused attention on the frequencies associated with this technology. A number of studies have examined the health effects of RF/MW electromagnetic fields (EMFs), originating from occupational exposure, hobbies, or residence near the radio or television transmitters. Particularly controversial are the biophysical mechanisms by which these RF fields may affect biological systems. General health effects reviews explore possible carcinogenic, reproductive and neurological effects. Health effects by exposure source have been observed in radar traffic devices, wireless communications with cellular phones, radio transmission, and magnetic resonance imaging (MRI). Several epidemiological surveys have suggested associations with non-specific complaints such as headache, tiredness, sleep disturbance, loss of memory, and dizziness. These findings, which echo reports of illness associated with other types of radiofrequency (RF) radiation, relate not only to the use of mobile phones, but also to residence near the mobile phone base stations and other settings involving occupational exposure. The biological effects suggest that some precautions are necessary, and preventive approaches are highly recommended. Further researches are required to give more information about the effects of microwave radiation on our health, especially in occupational setting and professionally exposed workers

CYTOKINES AND HEMOKINES IN THE ASTHMA

The cytokines are regulatory proteins of low molecular weight whose role is ininter-cellular communication. They exhibit the following characteristics: pleitropisni,svnergism, anfagonism, redundancy, as wcll as autocrine, paracrine andendocrine action. The activity of one cylokine can start the release of anothercytokine. Since the asthma is an immunological discases the cytokines have a uniquerole in regulating the inflammatory process induced in the lungs. Various cytokinesac! in acomplex network an that is crucial for determining the nature and the chronicoccurrence of an asthmatic inflammatory process. The Th2 lymphocytes do asynihesisof II-4,II-5,II-9, II-10,II-13 and GM-CSF involved in the process of joiningthe B-ceils immunoglobulin isotype with the SgE production, maintain the Th2 cellpopulation with increased cylokines' production encoded by the so-called II-4 geneticgroup as well as attraction and proiongation of the cell mast, basophils and eosinophils'survival. The hemokines are small proteins classified into four subclasses,namely CC, CXC, C and Cx3C on the basis of the first two cysteine position in theirsequences. The members of the CC subclass lead 1o attraction and activation ofbasophits, eosinophils, monocytes and T-lymphocytcs as well as degranulation ofbasophils and cell mast independently of the IgE mechanism

THE ROLE OF Th1 AND Th2 CELLS IN ATOPIC AND AUTOIMMUNE DISEASES

–helper cells can be divided into two distinct subtypes of effector cells based on the profile of cytokines they produce. Th1 cells produce interferon– γ (IFN– γ) and tumor necrosis factor β (TNF– β), and are associated with cell– mediated responses, particularly with resistance to intracellular pathogens (bacteria, parasites, yeasts and viruses). In contrast, Th2 . cells produce IL– 4, IL– 5, IL– 9 and IL– 13. Th2 cells are involved in antibody responses and IgE production, as well as tissue fibrosis, and eosinophilia. Th2 responses are important in the resistance to infection with helminth parasites. Although both Th responses are protective against certain infectious pathogens, they can themselves be pathogenic: Th1 cell responses can mediate autoimmune diseases, whereas dysregulation of Th2 responses is implicated inatopic diseases (allergic rhinitis, asthma, atopic eczema, food allergy and anaphylaxis). The recent progress in our understanding of the mechanism of initiation and control of Th1 and Th2 cell responses will eventually lead to new therapeutic strategies

Cytogenetic Damages Induced by Chronic Exposure to Microwave Non-Ionizing Radiofrequency Fields

Non-ionizing radiation has a significant and positive impact on modern society through a number of uses. There is increasing public concern regarding the health risks of radio-frequency (RF) radiation, particularly that produced by mobile phones. Concern regarding the potential risks of exposure to EMFs has led to many epidemiological investigations, but the effects of EMF exposure on human and other mammalian cells are still unclear. One of the most frequently asked questions about the effects of microwave radiation on biological systems is whether they produce genotoxic effects and could be there a possible link with oncogenic processes. It is most difficult to get accurate and reproducible results for the studies that tell us most about the effects of EMF on humans. Based on some “weak” evidence suggesting an association between exposure to radiofrequency fields (RF) emitted from mobile phones and two types of brain cancer, glioma and acoustic neuroma, the International Agency for Research on Cancer has classified RF as ‘possibly carcinogenic to humans’ in group 2B. Literature results suggest that pulsed microwaves from working environment can be the cause of genetic and cell alterations. Taken together, the increased frequency of DNA damages, increased intensity of oxydative stress and production of reactive oxygen species as well as prolonged disruption in DNA repair mechanisms could be possible mechanisms for microwave induced cytogenetic damages even at low-level electromagnetic fields. Although there were contradictory results about harmful effects of electromagnetic fields we recommend that the mobile phone should be kept as far as possible from the body during conversations and also during usual daily activities to reduce the absorption of radiation by cells. In addition, the appropriate intake of antioxidant-rich food or drugs may be helpful for preventing the genotoxic effects that could be caused by mobile phone use