Ömer Faruk Tekbaş

Melatonin as an antibiotic: new insights into the actions of this ubiquitous molecule

Abstract:  The incidence of serious infections caused by multidrug‐resistant gram‐positive and gram‐negative bacteria has been increasing rapidly worldwide despite advances in antibacterial therapy in the last two decades. Among multidrug‐resistant gram‐positive and gram‐negative bacteria, methicillin‐resistant Staphylococcus aureus, carbapenem‐resistant Pseudomonas aeruginosa and Acinetobacter baumannii are of great importance, because they have emerged as primary nosocomial pathogens in hospital outbreaks. In this study, we investigated whether melatonin has antibacterial effects against these microorganisms in vitro. The minimum inhibitory concentration of melatonin was determined using a standard microdilution method at 24 and 48 hr. Melatonin inhibited microbial growth at both 24 and 48 hr; but results showed that melatonin had antibacterial effects against these microorganisms after 48 hr of incubation in lower doses [concentrations between 31.25 to 125 μg/mL (0.13–0.53 mm)]. Also, it was determined that melatonin has a more potent antimicrobial effect on gram‐negative microorganism. Among possible mechanisms, it is concluded that melatonin showed antibacterial effects by reducing intracellular substrates.

How Medical Students Use the Computer and Internet at a Turkish Military Medical School

The aim of this study was to determine how medical students use the computer and World Wide Web at a Turkish military medical school and to discuss characteristics related to this computer use. The study was conducted in 2003 in the Department of Public Health at the Gulhane Military Medical School in Ankara, Turkey. A survey developed by the authors was distributed to 508 students, after pretest. Responses were analyzed statistically by using a computer. Most of the students (86.4%) could access a computer and the Internet and all of the computers that were used by students had Internet connections, and a small group (8.9%) had owned their own computers. One-half of the students use notes provided by attending stuff and textbooks as assistant resources for their studies. The most common usage of computers was connecting to the Internet (91.9%), and the most common use of the Internet was e-mail communication (81.6%). The most preferred site category for daily visit was newspaper sites (62.8%). Approximately 44.1% of students visited medical sites when they were surfing. Also, there was a negative correlation between school performance and the time spent for computer and Internet use (-0.056 and -0.034, respectively). It was observed that medical students used the computer and Internet essentially for nonmedical purposes. To encourage students to use the computer and Internet for medical purposes, tutors should use the computer and Internet during their teaching activities, and software companies should produce assistant applications for medical students. Also, medical schools should build interactive World Wide Web sites, e-mail groups, discussion boards, and study areas for medical students.

A Commonly Used Pesticide Endosulfan in Diet Could Cause Hepatomegaly and Kidney Tumor When Combined with Nitrosamines

Pesticides and nitrites which could be available in foods are generally investigated individually, although they could be found in foods together and exhibit combined health effects. In this study we aimed to determine the combined effects of endosulfan which is a commonly used pesticide and N-nitroso-N-methylurea (NMU) which is a prototype for mammary tumor development in Sprague Dawley rats and could be formed in brine foods or also in body from nitrites which is commonly used in meat. Ninety female Sprague Dawley rats had been used. Animals were divided three groups which consisted 30 animals. The first group took a single dose endosulfan intraperitoneal (ip) on 19th day and a single dose NMU ip on 21 day, the second group took endosulfan by their drinking waters for the first 60 days of their life and a single dose NMU ip on 21 day, and the third group took only a single dose NMU ip on 21 day. Animals were controlled for their general health status, mammary mass develeopment, daily water consumption and weekly weight gain. At the end of the study rats were examinated carefully under anesthesia, and tissue samples were prepared from their mammary glands and intraabdominal organs. Tissue samples taken from mammary glands, liver and kidneys were histopathalogically examined. It was determined a statistically significant hepatomegally in the second group when we compared to other groups (p < 0.05). No animals developed mammary tumors. On the macroscopic examination and manual palpation of intraabdominal region, it was showed that solid tumors in kidneys as a ratio of 76.7% of the animals in the second group (bilateral in 1,3% of them, the others are unilaterally and 70% of the unilateral tumors are in the left kidneys while the rest of them are right localized). Also it was found that in the first group, 13.4% of the animals developed unilateral kidney tumors. The third group which had been applied only NMU developed no kidney or liver pathalogy macroscopically. As a result it was considered that a diversity which is named as “genetic shift” could be developed in our animal research center and because of this shift we could not developed NMU induced mammary tumors in our Sprague Dawley rats. But it has been showed that long term endosulfan expose has resulted in kidney tumor development for the first time. Because of the genetic shifting mentioned above, it should be tested whether this experimental animal cancer model is limited for our research center or not by obtaining sprague dawley animals from different centers. Interactions of living style, environmental factors and genetic properties in the development of cancer and its necessary to control all of three factors in order to reduce cancer frequency in public showed that the importance of interdiciplinary collaboration and public education. Consumers and appliers should be educated about using pestices, and healthy and safety food production and concumption should be considered as one of the primary subjects in public health studies.

Determination of Carbon Monoxide Levels in Coffee Shops in Ankara

Indoor environments are where people spend 80—90% of their time. They are at their riskiest in terms of air pollution when smoking is not prohibited and various combustion and/or cooking applications are performed. If such environments are where people live or work, or are recreation facilities open to everybody, experience has shown that pollution levels to which they are exposed can reach levels that are a threat to their health. This study is an investigation of coffee shops, which are such communal environments, identified according to factors such as clientele and physical accommodation. The pollution parameter chosen was the level of carbon monoxide in the air, evaluated according to its compliance to the existing standards and setting forth measures that might be taken against probable health risks. The study was performed in 384 coffee shops selected randomly from amongst those (N = 7646) located in five central municipal districts of Ankara province. Most of the environments investigated were observed to have deficiencies in respect of accident risk, hygienic features and accommodation conditions. The mean carbon monoxide level was found to be below the short and long-term threshold values. However, CO levels above long-term threshold levels were observed in 34% of the coffee shops. In conclusion, the environments investigated were found to pose risks in terms of both accommodation conditions and indoor environment air quality. It was concluded that these risks, which could affect the health of workers and clientele, could be eliminated by environmental health measures.

Evaluation of some physical hazards which may affect health in primary schools

AIM This study was performed with the objective to determine the levels of some physical hazards in primary schools. MATERIAL AND METHODS This study is a cross-sectional field survey. In this study which was conducted in 31 primary schools selected by appropriate sampling from the district of Keçiören of the province of Ankara, measurements related with temperature, light, electromagnetic field (EMF) and noise levels were done at hundreds of points. Approval was obtained from Gülhane Military Medical Faculty Ethics Committee (2007/97). RESULTS Only 47.1% of the classes had a temperature value within the recommended limits (20-21°C). It was found that the illumination levels in 96.8% of the schools were above the standard values. However, the levels of illumination were found to be statistically significantly decreased towards the door and the back line (p<0.05). It was found that electromagnetic field levels were significantly higher in the schools who had a source of electromagnetic field nearby compared to the schools who did not have such a source nearby (p<0.001). It was found that the electromagnetic field levels in computer classes were statistically significantly higher compared to the other classes (p<0.001). Noise levels were found to be statistically significantly higher in classes which had 35 and more students (p<0.05). No statistically significant difference was found in schools near intensive vehicle traffic in terms of noise levels (62.8±5.0 (n=72), 62.0±6.4 (n=79), respectively, p>0.05). CONCLUSIONS It was found that primary schools in the region of Keçiören had aspects which had to be improved in terms of building age, building location, brightness, electromagnetic field and noise levels. School health programs directed to improve negative enviromental factors should be developed.

Halk Sağlığı Uzmanlık Eğitiminde Çevre Sağlığı Eğitimi: Kavramsal Çerçeve -

Cevresel etkilenimlerin insan sagligina olan etkilerinin her gecen gun artmakta oldugu gunumuzde, insanlarin cevreleriyle olan etkilesimlerinin degerlendirilmesi, yorumlanmasi ve topluma yonelik koruyucu uygulamalar seklinde hayata gecirilmesi gerekliligi, halk sagligi uzmaninin sorumlulugunu bir kat daha artirmaktadir. Bu derleme ile cevre sagligi, cevre hekimligi kavramlari ve halk sagligi uzmanlik egitiminde yer almasi gereken cevre sagligi konulari, kavramsal bir cerceve onerisiyle sunulmustur.

Effect of Smoking on the Level of Ionising Radiation in Student Rooms

This descriptive study was designed to investigate whether there was a difference in the levels of ionising radiation in rooms where smoking was permitted and rooms where it was not permitted. The study was conducted in residential student rooms of a school of medicine. A total of 60h of measurement was conducted, measuring for 1 h in each room. Measurements were made with a “RAD-ALERT 50 Nuclear Radiation Monitor”. Although significant differences were found in the level of ambient ionising radiation between rooms where smoking was allowed and those where it was not allowed it was inconclusive whether this difference was due to cigarette smoking or was affected by other external factors. The increase in the radiation level was below that where there would be an effect on health.