Radiological characterisation of Artvin and Ardahan provinces of Turkey

Indoor radon concentration measurements were carried out and corresponding annual effective doses due to exposure to indoor radon were determined in Artvin and Ardahan provinces located in the eastern part of Turkey. The measurements were performed for four seasons in order to determine the seasonal fluctuations mostly observed in indoor environments. Indoor radon concentration values were observed to range from 21 to 321 Bq m⁻³ for the Artvin province and from 53 to 736 Bq m⁻³ for the Ardahan province. It was observed that minimum indoor radon concentration values were obtained in summer, while the highest ones were observed in winter. Indoor radon concentration values of the current study were compared with those of other provinces in Turkey. As elevated indoor radon concentrations are mostly correlated with high ²³⁸U activity concentrations in soil, a total of 57 and 33 soil samples were collected from the Artvin and Ardahan provinces, respectively, to determine ²³⁸U activity concentration as well as the concentration of ²³²Th and ⁴⁰K--naturally occurring radionuclides. It was also observed that soil samples collected from the study areas contained ¹³⁷Cs as an artificial radionuclide.

Medical clerkships do not reduce common prescription errors among medical students

Prescribing correctly represents one of the most essential skills of a doctor when it comes to patient safety. Unfortunately, prescribing errors still account for a large proportion of avoidable drug-related problems (DRP). Despite this shortcoming, many medical schools do not provide specific prescribing training and assume that students acquire sufficient prescribing skills during regular medical clerkships. We therefore investigated whether there is an association between the individual time spent by students in internal-medicine clerkships and the number of prescription errors committed in a standardized prescribing test for common drug-related problems in a medical inpatient setting. Seventy-four fifth-year medical students (25 +/- 3 yrs, 24 m, 50 f) who had completed their formal pharmacology training filled in prescription charts for two standardized patient paper cases. The charts were rated by two blinded consultants from the field of internal medicine using a checklist for common prescription errors. Students were divided into three groups according to the number of weeks previously spent in internal-medicine clerkships. Group differences in the number of prescription errors made were subsequently examined. Students committed 69% +/- 12% of all possible prescription mistakes. There was no significant difference between the group without clerkships in internal medicine (G1) (71 +/- 9%), the group with one to four weeks (G2) (67 +/- 15%), and the group with more than five weeks of clerkships (G3) (71 +/- 10%), p = .76. Medical students do not seem to acquire the necessary skills to avoid common prescription errors during regular clerkships in internal medicine. This study provides evidence to suggest that specific prescription training within medical education is warranted in order to prevent DRP.

Radon concentrations in three underground lignite mines in Turkey

Monitoring of radon in underground mines is important in order to assess the radiological hazards to occupational workers. Radon concentration levels in three underground lignite mines (Tunçbilek, Omerler and Eynez) of Turkey were obtained in this study. For this reason, atmospheric radon level measurements were carried out in mines using CR-39 track detectors. Chemical etching of the detector tracks and subsequent counting were performed at Cekmece Nuclear Research and Training Center. The obtained results were evaluated according to the International Commission of Radiation Protection and the Turkish Atomic Energy Authority whose radon action levels for workplaces are 500-1500 and 1000 Bq(-3), respectively. The radon gas concentrations in the lignite mines were determined to be between 50 +/- 7 and 587 +/- 16 Bq m(-3). The results obtained in these experiments are far under the action levels. The computed radon doses for the mine workers of Tunçbilek, Omerler and Eynez lignite mines are 1.23, 2.44 and 1.47 mSv y(-1), respectively.

Environmental radioactivity assessment for Bayburt, Turkey

This study assesses the results of environmental radioactivity measurements for Bayburt Province in the Eastern Black Sea area of Turkey. Using gamma-ray spectrometry, activity concentrations of the natural radionuclides (226)Ra, (232)Th and (40)K and a fission product (137)Cs were investigated in soil samples. The activity concentrations of (226)Ra, (232)Th and (40)K in various building materials such as sand, cement and marble and in drinking waters were determined. The activity concentrations vary from 16 to 54 Bq kg(-1) for (226)Ra, from 10 to 21 Bq kg(-1) for (232)Th and from 113 to 542 Bq kg(-1) for (40)K in building materials. The mean specific activity concentrations of (226)Ra, (232)Th and (40)K in drinking waters were 93, 30 and 504 mBq l(-1), respectively. The concentrations of gross alpha and beta radioactivity in drinking water samples collected from four different sampling stations have been determined. The results show that the gross alpha and beta activities are lower than the screening levels given by the World Health Organization (WHO), which are a maximum contaminant level of 0.5 Bq l(-1) and 1.0 Bq l(-1) gross alpha and beta radioactivity, respectively, in drinking water. Indoor radon measurements were made in 44 dwellings in Bayburt by using Cr-39 detectors. Radon concentrations in dwellings in Bayburt varied from 17 to 125 Bq m(-3) and the average value was 56 Bq m(-3). The results obtained in this study indicate that the region has a background radiation level that is within the typical natural range and shows no significant departures from other parts of the country.

Transport evaluation of alendronate across Caco-2 cell monolayers

The transport of alendronate through Caco-2 monolayers in the absence and presence of absorption enhancers (sodium taurocholate-STC and dimethyl-beta-cyclodextrin-DM-beta-CD) was studied. The viability of Caco-2 cells was determined by MTT assay. The effects of the experiment period and serum existence in Dubelco's Modified Eagle's Medium (DMEM) on cell viability were examined. The least toxic concentrations of alendronate, STC and DM-beta-CD were found as 0.2% (w/v), 5 mM and 0.3% (w/v), respectively. Transport experiments were performed with these concentrations in DMEM supplemented with serum for an 8 h period. DM-beta-CD increased the transport of alendronate through Caco-2 monolayers significantly. No significance was observed with STC. Cell integrity was determined by measuring the electrical resistance values at the end of the transport experiments and found to be decreased to a greater extent with DM-beta-CD. These results indicate that DM-beta-CD is a promising agent for improving the transport of alendronate.

A study of indoor radon levels in rural dwellings of Ezine (Canakkale, Turkey) using solid-state nuclear track detectors

Indoor radon activity level and radon effective dose (ED) rate have been carried out in the rural dwellings of Ezine (Canakkale) during the summer season using Radosys-2000, a complete set suitable to radon concentration measurements with CR-39 plastic alpha track detectors. The range of radon concentration varied between 9 and 300 Bq m(-3), with an average of 67.9 (39.9 SD) Bq m(-3). Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, it has been found that the 222Rn ED rate in the dwellings studied ranges from 0.4 to 5.2 mSv y(-1), with an average value of 1.7 (1.0) mSv y(-1). There is a possibility that low radon concentrations exist indoors during the summer season in the study area because of relatively high ventilation rates in the dwellings. A winter survey will be needed for future estimation of the annual ED.

Indoor radon concentrations in Adana, Turkey

The indoor radon concentration in Adana, Turkey was measured in living rooms of 52 houses during winter 2005 and 57 houses during summer 2005. Forty-four houses were selected for both winter and summer researches for estimating seasonal variations. Indoor radon concentrations were measured seasonally over hotter and colder 2 months over the whole year, using CR-39 passive nuclear track radon detectors. The radon concentrations were ranged from 15 to 97 Bq m(-3) on January-February 2005 for 60 d and from 5 to 70 Bq m(-3) on June-July 2005 for 60 d. The average summer concentration measured was 25.8 Bq m(-3) and the average winter concentration was 48.9 Bq m(-3) in 44 houses that observed seasonal variations. The differences between winter and summer periods were ranged from 1 to 77 Bq m(-3). The average value in both winter and summer periods is 37 Bq m(-3) in 44 houses that observed seasonal variations. This value is below the worldwide indoor radon concentration distribution of 46 Bq m(-3). The annual effective dose equivalent from (222)Rn was 0.9 mSv y(-1).

Radon measurements in the Catalagzi Thermal Power Plant, Turkey

The Catalağzi Thermal Power Plant (CTPP) (41(0)30'48.4('')N and 0.31(0)53'41.5('')E) is located at nearly 13 km North-east of Zonguldak city, which is located at the West Black Sea coast in Turkey. The middling products with high ash content of bituminous coals are used in this plant. Seasonal radon concentration measurements have been carried out by using CR-39 plastic track detectors in and around the CTPP. The annual average radon concentration has been found to vary from a minimum of 39.8 +/- 28.9 Bq m(-3) in the ash area to a maximum of approximately 75.0 +/- 15.7 Bq m(-3) in the service building of the power plant. The annual average radon concentration in the dwellings of the thermal power plant colony of the plant is 71.0 +/- 33.4 Bq m(-3). The effective dose has been found to vary from 0.38 to 0.71 mSv y(-1) with a mean value of 0.56 mSv y(-1), which is lower than the effective dose values 3-10 mSv given as the range of action levels recommended by International Commission on Radiological Protection: Protection against radon-222 at home and at work, ICRP Publication 65 (1993).

Subhypnotic doses of midazolam prevent nausea and vomiting during spinal anesthesia for cesarean section

BACKGROUND

We aimed to evaluate the efficacy of subhypnotic doses of midazolam and propofol for peripartum nausea and vomiting during regional anesthesia for elective cesarean section in order to prevent emesis in at least 50% of patients.

METHODS

A prospective, double blind, placebo-controlled study was carried out. Patients were randomly allocated to one of three groups to receive placebo (saline, N=28), propofol (20 mg bolus and 1.0 mg x kg(-1) x h(-1) infusion, N=30), and midazolam (1 mg bolus and 1.0 mg x h(-1) infusion, N=30) at subhypnotic doses intravenously (i.v.) immediately after the umbilical cord was clamped. Bupivacaine hydrochloride (8-10 mg) and fentanyl (10 microg) were injected into the intervertebral space for spinal anesthesia. Blood pressure was monitored at 2 min intervals and intraoperative postdelivery emetic episodes and ephedrine consumption were recorded. The study was carried out at the Anesthesiology Department, Hacettepe University, Turkey, hospitalized care. We included 90 parturients with ASA physical status I and II between the ages of 20 and 38 years undergoing spinal anesthesia for elective cesarean delivery to evaluate the efficacy of subhypnotic doses of propofol and midazolam and, in particular, the incidence of nausea, retching, and vomiting intraoperatively.

RESULTS

The incidence of nausea, retching, and vomiting was significantly higher in the control group, compared to the propofol and midazolam groups. Total ephedrine consumption was significantly higher in the control group compared to the propofol and midazolam groups.

CONCLUSION

A subhypnotic dose of midazolam (1 mg x h(-1)) was as effective as the subhypnotic dose of propofol (1 mg x kg(-1) x h(-1)) for the prevention of nausea and vomiting in parturients undergoing cesarean section under spinal anesthesia.

Mandibular symphyseal distraction osteogenesis: review of three techniques

Mandibular symphyseal distraction osteogenesis (MSDO) is an alternative strategy to correct mandibular transverse deficiencies and dental crowding. Only a limited number of practitioners have reported their clinical experience and potential complications of this procedure to widen the mandible in a large case series. This study involved retrospective analysis of 40 patients who underwent mandibular symphyseal distraction osteogenesis. Three different types of distractor were used to widen the mandible: tooth-borne in 21 patients, bone-borne in 5 patients and hybrid (both bone and tooth-borne) in 14 patients. The distraction amount ranged from 7 to 11 mm (mean 7.31 mm). While 39 patients underwent successful mandibular symphyseal distraction, there was one failure. Most of the complications were experienced in bone-borne distractors, such as breakage of the distractor rod, gingival recession, secondary infection and ptosis of the chin. In the light of these findings, it is suggested that a lingually placed tooth-borne hyrax appliance is more suitable and reliable than the other distraction devices. Further larger studies are needed in order to better evaluate the effectiveness of bone-borne or hybrid devices.

Controlled Delivery of Peptides and Proteins

The final aim/target of Pharmaceutical Sciences is to design successful dosage forms for effective therapy, considering individual patient needs and compliance. Development of new drug entities, particularly using peptides and proteins, is growing in importance and attracting increased interest, as they are specifically effective at a comparably low dose. These very potent and specific peptides and proteins can now be produced in large quantities due to increased knowledge and advancements in biotechnological and pharmaceutical applications. A number of peptide and protein products are now available on the market, and numerous studies investigating them have been published in the literature. Although many peptide/protein like products are generally designed for parenteral administration, some other noninvasive routes have also been used. For example, desmopressin is delivered nasally and deoxyribonuclease by inhalation. Although peptides and proteins are generally orally inactive, cyclosporine is an exception. In order to design and develop long-acting, more effective peptide/protein drugs, the controlled release mechanisms and effective parameters need to be understood and clarified. Therefore, we review herein various peptide/protein delivery systems, including biodegradable and nondegradable microspheres, microcapsules, nanocapsules, injectable implants, diffusion-controlled hydrogels and other hydrophilic systems, microemulsions and multiple emulsions, and the use of iontophoresis or electroporation, and discuss the results of recent researches.

Perioperative anxiety and postoperative behavioural disturbances in children

BACKGROUND AND OBJECTIVE

This study was designed to determine if subhypnotic propofol reduces postoperative behavioural disturbances in children undergoing sevoflurane induction compared with intravenous propofol induction for elective adenoidectomy and tonsillectomy.

METHODS

Following Ethics Committee approval and parental informed consent, ASA I-II, 120 children (2-10 yr) were recruited. Parents were not allowed to accompany their child. Unpremedicated children were randomly allocated to groups receiving inhalation induction with sevoflurane, 2-2.5 mg kg-1 intravenous propofol induction or inhalation induction with sevoflurane followed by subhypnotic dose of propofol (1 mg kg-1). Anaesthesia was maintained with 2-4% sevoflurane, O2 and N2O. Anxiety on arrival to operating theatre, at anaesthesia induction and 30 min after emergence was assessed. Parents completed a state-trait anxiety inventory test preoperatively and a post hospitalization behaviour questionnaire a week later to assess children's postoperative behavioural disturbances. Kruskal-Wallis test, Wilcoxon signed rank sum test, Bonferroni's test, Paired t-test, t-test, Pearson and Spearman's rank correlation test, chi2-test were used for statistical analysis.

RESULTS

The anxiety level at induction was high in all groups (P < 0.05). There was no difference between groups in respect to anxiety at other measurement times. A relation between preoperative anxiety level and postoperative behavioural disturbances was determined (P < 0.05). Some behavioural disturbances as nightmare/night fear and desire of sleeping with parents were rarely seen in intravenous propofol induction group (P < 0.05).

CONCLUSION

Addition of subhypnotic dose of propofol to sevoflurane induction did not reduce the incidence of postoperative behavioural disturbances.

An investigation on burn wound healing in rats with chitosan gel formulation containing epidermal growth factor

Various studies have shown that chitosan is effective in promoting wound healing. In this study, we aimed to develop an effective chitosan gel formulation containing epidermal growth factor (EGF), and to determine the effect on healing of second-degree burn wounds in rats. Ten micrograms per millilitre EGF in 2% chitosan gel was prepared. In an in vitro study to investigate release of EGF from the formulations, the release rate was 97.3% after 24 h. In in vivo studies, animals were divided into six groups as follows: silver sulfadiazine [Silverdin cream (SIL)], chitosan gel with and without EGF (EJ, J), EGF solution (ES) and untreated control groups [unburned (S) and untreated (Y) rats] applied groups, respectively. A uniform deep second-degree burn of the backskin was performed with water heated to 94+/-1 degrees C during a 15-s exposure. The EGF formulations were repeatedly applied on the burned areas with a dose of 0.160 microg/cm2 for 14 days (one application per day). Healing of the wounds was evaluated immunohistochemically, histochemically and histologically on the tissue samples. When the results were evaluated immunohistochemically, there were significant increases in cell proliferation observed in the EGF containing gel applied group (p<0.001). The histochemical results showed that the epithelization rate in the EJ group was the highest compared to the ES group results (p<0.001). The histological results indicated and supported these findings. It can be concluded that a better and faster epithelization was observed in the EJ group compared to the other groups.

Lecithin-based microemulsion of a peptide for oral administration: preparation, characterization, and physical stability of the formulation

The objective of our study was to prepare and characterize a stable microemulsion formulation for oral administration of a peptide, e.g., rh-insulin. The microemulsions were prepared using Labrafil M 1944 CS, Phospholipon 90G (lecithin), absolute alcohol, and bidistilled water. Commercially available soybean lecithins (namely, Phospholipon 80, phosphatidylcholine purity 76 +/- 3%, and Phospholipon 90G, phosphatidylcholine purity 93 +/- 3%) were used in the study. The results showed that the phase diagram obtained using a low purity lecithin was not similar to that obtained with a high purity lecithin. We observed that the microemulsion area was wider at the phase diagram obtained with the higher purity lecithin. We found that the extent of the microemulsion region depended upon both the purity of the lecithin and the surfactant/co-surfactant (s/co-s) mixing ratios (K(m)). The rheological studies showed that microemulsions followed a Newtonian behavior. Such physical characteristics as viscosity, turbidity, density, conductivity, refractive index, droplet size, physical appearance, and phase separation of the microemulsion were measured at different temperatures (4 degrees C, 25 degrees C, and 40 degrees C) during 6 months. The results indicated that the physical characteristics of the developed microemulsions did not change under different storage temperatures (p > 0.05).

Radon concentration measurements in the Amasra coal mine, Turkey

In this study, the results of atmospheric radon measurements that were performed for the Amasra underground coal mine in Zonguldak bituminous coal basin (Turkey) are presented. The radon measurements were performed for 40 days between November 2004 and December 2004 using passive nuclear etched track detectors. The radon concentrations vary from a minimum value 49 Bq m(-3) in a site located at +40 m to a maximum value 223 Bq m(-3) in a site located at -100 m. Mean concentration is 117 (Bq m(-3)). This value is well below the action level of 500-1,500 Bq m(-3) recommended by the International Commission on Radiological Protection (ICRP) (1993). The mean effective dose value for workers of this mine of 3.4 microSv per day was obtained. This result shows that protection against radiological hazards would not be necessary for workers of this mine((2)).