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Biomedical subjects

N Celebi

Publications and source records attributed to N Celebi.

At least 19 recordsLinked to original sources
PubMed2007

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.

Adolescent↗
PubMed2006

Perioperative anxiety and postoperative behavioural disturbances in children: comparison between induction techniques.

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.

Adenoidectomy↗
PubMed2005

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)).

Air Pollutants, Occupational↗
PubMed2005

Radon measurements in the caves of Zonguldak (Turkey).

There are approximately 20 caves of limestone origin in Zonguldak (Turkey). In this study, the results of atmospheric radon measurements performed for two caves are presented. These caves, Gökgöl and Cehennemağzi, are open to tourism. Gökgöl Cave is the longer, at nearly 3,200 m in length. Cehenennemağzi is a pit-type cave with a total length of 85 m. The radon measurements were performed for 2 months between July 2004 and September 2004 using passive polycarbonate detectors. The mean radon concentrations were recorded as 1,918.8 Bq m(-3) in Gökgöl Cave and 657 Bq m(-3) in Cehennemağzi Cave. The maximum value corresponds to a site located 400 m from the entrance of Gökgöl Cave. Mean effective dose values for tourists of 0.86 microSv per visit to Cehennemağzi Cave and 3.76 microSv to Gökgöl Cave were obtained. These results show that protection against radiological hazards would not be necessary for visitors to these two caves.

Air Pollutants, Radioactive↗
PubMed2005

Determination of radon concentrations of the Dikili geothermal area in western Turkey.

For this study, a geothermal area around Izmir-Dikili, located in the western part of Turkey, was chosen as a measuring site and the radon concentrations of environmental samples were determined. Indoor radon monitoring was performed for 3 months in dwellings located in different part of the region using passive CR-39 nuclear track detectors. The radon concentrations of water samples drawn from wells, municipal supplies, village fountains and spas in the area were measured using a liquid scintillation detector (Packard Tri-Carb 2770 TR/SL, A-277001). Soil samples collected from each location were analysed and (226)Ra concentrations were determined using a gamma ray spectrometer connected to an HPGe detector. Annual effective doses from radon inhalation and ingestion were calculated.

Air Pollutants, Radioactive↗
PubMed2005

Natural radioactivity in tap waters of Eastern Black Sea region of Turkey.

In this study, the activity concentrations of some radionuclides in tap water samples of the Eastern Black Sea region of Turkey were measured. The activity concentrations of radionuclides (214)Pb, (214)Bi, (40)K, (226)Ra and (137)Cs were determined using high resolution gamma ray spectrometry. Furthermore, (222)Rn activity concentrations in tap water samples were measured using Liquid Scintillation Counting. The mean specific activities of (214)Pb, (214)Bi, (226)Ra, (40)K, (137)Cs and (222)Rn in tap water samples were 6.73, 6, 19.16, 168.57, 5.45 mBq l(-1) and 10.82 Bq l(-1), respectively. These values are comparable with concentrations reported for other countries. The effective doses were determined due to intake of these radionuclides as a consequence of direct consumption of tap water samples. The estimated effective doses were 6.878 x 10(-4) microSv y(-1) for (214)Pb, 4.800 x 10(-4) microSv y(-1) for (214)Bi, 3.916 microSv y(-1) for (226)Ra, 0.763 microSv y(-1) for (40)K, 0.052 microSv y(-1) for (137)Cs and 5.848 microSv y(-1) for (222)Rn.

Humans↗
PubMed2005

A lecithin-based microemulsion of rh-insulin with aprotinin for oral administration: Investigation of hypoglycemic effects in non-diabetic and STZ-induced diabetic rats.

The aim of this study was to develop a microemulsion formulation providing an improved efficacy of orally administered insulin. The microemulsions were prepared using Labrafil M 1944 CS, Phospholipon 90 G (lecithin), absolute alcohol and bi-distilled water. The microemulsions of recombinant human (rh)-insulin and aqueous solution (200 IU/kg) were administered intragastrically by a canulla to diabetic and non-diabetic rats. Aprotinin (2500 KIU/g) was added as the enzyme inhibitor to the formulation. Upon the administration of intragastric rh-insulin solution (IS) to non-diabetic rats, the plasma glucose and insulin levels were not changed significantly. Therefore, the hypoglycemic effect caused by subcutaneous rh-insulin solution (SC), microemulsion containing rh-insulin (IME) and microemulsion containing rh-insulin and aprotinin (IMEA) were analyzed in diabetic rats. The area above the plasma glucose levels time curves (AAC), minimum glucose concentration (Cmin) and time to Cmin (tmin) were derived from the plasma glucose profiles. IME and IMEA caused approximately 30% decrease in plasma glucose levels. The decrease in the plasma glucose levels continued after the 90th min. The highest AAC value was obtained when IMEA was administered to rats. The maximum plasma insulin concentration (Cmax), time to reach Cmax (tmax), terminal half-life (t(1/2)), area under the plasma concentration-time curve (AUC), mean residence time (MRT) and elimination rate constant (k(el)) values were also calculated. It was observed that t(1/2) values varied between 0.53 and 1.31h. No significant difference could be found between the pharmacokinetic parameters of the IME and IMEA administered groups. Addition of aprotinin to the microemulsion containing rh-insulin increased bioavailability when compared to those not containing it, although the difference is not significant.

Administration, Oral↗
PubMed2005

Natural radioactivity levels in granitic plutons and groundwaters in Southeast part of Eskisehir, Turkey.

The present work investigated the radioactivity level of the granitoid plutons and its effect on the groundwaters in the southeast part of Eskisehir. Fourteen granitic samples from the Kaymaz and Sivrihisar plutons and 11 groundwater samples from the near vicinity of the pluton were analyzed. The activity concentrations measured for (238)U and (232)Th ranged from 43.59+/-2 to 651.80+/-24 Bq/kg, and 51.16+/-3 to 351.94+/-13 Bq/kg, respectively. The activity concentrations obtained for (40)K varied from 418.50+/-17 to 1618.03+/-66 Bq/kg. The absorbed dose rates in air outdoors ranged from 87.14 to 531.81 nGy/h. All the results obtained from the Kaymaz pluton are higher than those from the Sivrihisar. The U (ave. 16.6 ppm) and Th (ave. 49.9 ppm) values of the Kaymaz pluton are higher than the average concentrations of the magmatic rocks of granitic composition. These results are consistent with high dose rates of the pluton. The gross-alpha activities in the groundwater samples ranged from 0.009 to 1.64 Bq/l and the gross-beta activities from 0.006 to 0.89 Bq/l. The highest gross-alpha value was found in the sample taken from near the Kaymaz pluton. The concentrations of (222)Rn varied from 0.060 to 0.557 Bq/l.

Background Radiation↗
PubMed2005

Indoor radon determination in dwellings located at Dikili geothermal area in Western Turkey.

This paper presents the indoor radon concentrations in dwellings located in the Dikili geothermal area in western Turkey. Indoor radon monitoring was performed for 3 mo using 121 detectors installed in the living rooms and bedrooms of 62 houses selected from the region. A passive time-integrating radon measuring technique was applied by using CR-39 solid-state nuclear track detectors. Average indoor radon levels for the houses varied from 31 to 280 Bq m(-3). Corresponding annual effective doses were calculated, and risks for lung cancer due to inhalation of indoor radon were estimated.

Air Pollution, Indoor↗
PubMed2005

The evaluation of propofol dosage for anesthesia induction in children with cerebral palsy with bispectral index (BIS) monitoring.

BACKGROUND: We designed a randomized prospective study to investigate whether developmentally delayed children with cerebral palsy (CP) need a lower dosage of propofol for induction than normal children using bispectral index (BIS) monitoring criteria. METHODS: After approval by the University Ethical Committee and written informed consent obtained from parents, 20 children with noncommunicative/nonverbal CP and 20 normal children requiring general anesthesia for elective orthopedic surgery were enrolled in the study. The patients were not premedicated. BIS leads were placed before the induction of anesthesia. Propofol was administered at a rate of 20 mg.30 s(-1) (i.e. 40 mg.min(-1)). When BIS value had reached a steady number of 35-45, infusion was stopped. RESULTS: There was no significant difference between Group N and Group CP in age and sex distribution (P > 0.05), however children in Group CP weighed less than Group N (P = 0.05). The propofol dosage for induction was significantly lower in Group CP than Group N (P = 0.03). There were no differences in propofol doses administered to children using anticonvulsants and those not on anticonvulsants in Group CP. BIS values were comparable between the two groups (i.e. Group N and Group CP) at baseline and after propofol administration. CONCLUSIONS: Our data suggest that noncommunicative/nonverbal children with CP require less propofol to obtain the same BIS values (i.e. 35-45) than do otherwise healthy children.

Anesthesia, General↗
PubMed2004

The healing effect of TGF-alpha on gastric ulcer induced by acetylsalicylic acid in rats.

The present study was designed to investigate the effects of microemulsion and aqueous solution containing transforming growth factor alpha (TGF-alpha) and/or aprotinin administered intragastrically (i.g.) on healing of acute gastric ulcers induced by acetylsalicylic acid (ASA). The microemulsion was prepared by modification of the microemulsion formulation described in our previous study. Acute gastric lesions were induced by the application of ASA (150 mg/kg in 1.5 ml of 0.2N HCl i.g.). TGF-alpha in solution or microemulsion formulations were administered at a dose of 10 microg/kg per 24h i.g. for 2 days. The effects of TGF-alpha on the healing was evaluated with the measurement of ulcer score, basal gastric acid secretion, total protein content of gastric fluid, gastric mucus level and histological analysis. The results indicated that the highest decrease in ulcer area was observed in group treated with microemulsion containing TGF-alpha plus aprotinin (TA-ME). TGF-alpha in microemulsion formulation was more effective than TGF-alpha in solution formulation in the increase of gastric mucus secretion, in the decrease of gastric acid secretions and ulcer scores. Histological evaluation of the gastric mucosa samples revealed that, best recovery was obtained in the TA-ME treated group.

Animals↗
PubMed2002

An investigation on skin wound healing in mice with a taurine-chitosan gel formulation.

The process of wound healing begins immediately following surface lesions or just after exposure to radiation, chemical agents or extreme temperatures. Taurine (2-aminoethane sulfonic acid), an amino acid containing sulfur, is found in almost all tissues in mammals, playing various important physio-logical roles in each organ. Taurine exhibits an antioxidant effect and is also known to have effects on cell proliferation, inflammation and collagenogenesis. Many antioxidants have been used to eliminate the negative effects of oxygen free radicals on wound healing. The objective of the present study was to examine the wound healing effect in mice of taurine-chitosan gel, which releases taurine slowly over a long time period. Fifty mM of taurine in 1.5% chitosan polymer (TAU-GEL) and 1.5% chitosan polymer (CHI-GEL) were applied to full thickness skin wounds of mice once a day for seven days. After seven days of treatment, lipid peroxide formation-malondialdehyde (MDA) and hydroxyproline (HPX) levels and the tensile strength of wound tissues were measured. All results were compared with those of the untreated control group (CONT). The structural alterations in the skin layers were also histologically investigated. It was found that locally administered TAU-GEL form significantly increased wound tensile strength by decreasing the MDA and increasing HPX levels. These results were supported by histological findings. All observations suggest that taurine gel may be effective in wound healing.

Animals↗
PubMed2000

Prevention of selenite-induced opacification and biochemical changes in the rat pup lens through amiloride pretreatment.

PURPOSE: To determine the effects of amiloride on selenite-induced cataracts, to identify this agent's role as an anti-oxidant, and to study related effects on ion levels in the rat lens. METHODS: Wistar albino rat pups were assigned to one of three groups, one control and two experimental. The first experimental group (Group 1; n = 22) received a subcutaneous injection of sodium selenite (30 nmol/g body weight) on postpartum day 10. The second experimental group (Group 2; n = 21) received a subcutaneous injection of amiloride (1 nmol/g body weight) 15 minutes before the sodium selenite injection. The control group (n = 22) received no injection. The pups in each group were observed during three weeks after the injection date. At the end of this period, the stage of cataract development was identified by comparison with slit lamp photographs and then the pups were sacrificed and their lenses were removed intracapsularly using a posterior approach. Cation analysis was carried out and glutathione and malondialdehyde levels were measured for each group. RESULTS: Cataract stage in Group 1 was significantly higher than Group 2. Mean cataract stages in Groups 1 and 2 were 3.8+/-0.12 and 1.6+/-0.25 respectively. None of the control animals developed cataracts. Amiloride-pretreated group contained significantly higher glutathione levels than Group 1. The level of malondialdehyde in Group 1 lenses was approximately twice that in the lenses of the Group 2 amiloride+selenite-treated animals. The Ca(2+) level was significantly higher in Group 1 lenses compared to the amiloride-pretreated rats, but there was no significant difference between Groups 1 and 2 with regard to Na(+) and K(+) levels. CONCLUSION: Amiloride was very effective in preventing cataract formation in the selenite-induced cataract model. This protective effect of amiloride was accompanied by higher glutathione levels and lower malondialdehyde levels in the rat pups' lenses compared to levels in animals that received selenite alone. These results suggest an anti-oxidant role for this agent, in addition to its effects on lens ion homeostasis.

Amiloride↗
PubMed1998

Effects of epidermal growth factor dosage forms on mice full-thickness skin wound zinc levels and relation to wound strength.

Epidermal growth factor (EGF) and zinc promote re-epithelization and reparative tissue strength by enhancing deposition of collagen at the site of the wound. In this study two EGF dosage forms were chosen to assess the effect of zinc levels on wound healing and for comparison with wound tear strengths. A solution of EGF in 0.9% w/v NaCl and an EGF gel in 0.2% Carbopol 940 polymer (5 microL) were applied to full-thickness skin wounds of mice twice a day for 7 and 15 days. Wound zinc levels were higher on day 7 than on day 15, especially in wounds treated with EGF. The wound zinc levels of the gel + EGF group on day 15 were similar to those of normal control skin. These results imply that there is a close connection, but no direct relationship, between EGF application in both dosage forms and wound zinc levels during healing.

Animals↗
PubMed1995

Effect of EGF dosage forms on alkali burned corneal wound healing of mice.

The local treatment effects of EGF forms on alkali burned mice corneal wounds were identified. The corneal wounds were induced by 0.5 M NaOH solution on the corneal surfaces of the mice. The local epidermal growth factor solutions (100 ng/ml) and gel form in 0.2 per cent w/w carbopol 940 (100 ng/ml) were dropped in 5 microliters aliquots into the eye twice a day. The corneal wounds were measured for 15 days at 7-day intervals and examined histologically at the end of 15th day of the experimental period. The results indicated that topical epidermal growth factor treatment in solution improved the healing of alkali burned corneal wounds when compared with epidermal growth factor delivered in a polymer system.

Administration, Topical↗
PubMed1995

Development and evaluation of a buccoadhesive propranolol tablet formulation.

Buccoadhesive tablets were prepared by directly compressing propranolol with poly(acrylic)acid (PAA), hydroxypropylmethylcellulose (HPMC) and hydroxypropylcellulose (HPC) in different ratios. The release data were fitted to Mt/M infinity = ktn simple equation. The release characteristics has shown a non-Fickian mechanism of release. The best kinetic fit were zero order and slab erosion kinetic. The detachment force between buccoadhesive tablets and bovine buccal mucosa was carried out by the tensile tester apparatus. The high amount of PAA containing formulation demonstrated the greatest adhesive force.

Acrylic Resins↗
PubMed1994

Effects of epidermal growth factor dosage forms on dermal wound strength in mice.

The effect of topically administered epidermal growth factor (EGF) dosage forms was investigated on skin wound healing in mice. Two EGF dosage forms were prepared containing 100 ng mL-1 EGF. The solution dosage form was prepared in 0.9% w/v NaCl. A bioadhesive gel form was prepared in 0.2% Carbopol 940 polymer. The two dosage forms were applied on the skin incision wounds of mice at the rate of 5 microL twice a day for 7 and 15 days. The wound tear strength was tested for skin wound healing at the 7th and 15th days of treatment and compared with controls. The results indicate that the wound tear strength of mice were significantly higher at the 15th day of treatment in the gel-treated group compared with the solution-treated mice and controls (P < 0.001).

Administration, Cutaneous↗