Biomedical subjects

O C Demirtas

Publications and source records attributed to O C Demirtas.

3 recordsLinked to original sources

PubMed2001

Intravesical oxybutynin affects bladder permeability.

To investigate the effects of intravesical application of oxybutynin chloride on bladder permeability we designed an animal model. Female Guinea pigs were given 3 different test solutions: phosphate buffered saline (PBS), 50% acetone and 1.27 x 10(-2) M oxybutynin chloride solution. Then 99mTc-DTPA 45 microCi in 2 ml normal saline was instilled into the bladder lumen in each animals and allowed to dwell for 30 minutes. At the end of exposure time, the net count data in each 1 ml serum sample were corrected for radioactive decay and converted to the total percentage of administered dose. 99mTc-DTPA absorption percentages of both acetone and oxybutynin groups were significantly higher than that of PBS group (mean 3.2 +/- 2.9% p < 0.001). Intravesical oxybutynin application increases bladder permeability 5 times compared with PBS administration. This observation can also explain how rapid absorption of oxybutynin through the bladder into the systemic circulation occurs.

Administration, Intravesical↗

PubMed1999

Whole-body microwave exposure emitted by cellular phones and testicular function of rats.

This study investigated whether there are adverse effects due to microwave exposure emitted by cellular phones in male rats. Eighteen Wistar Albino rats were separated into three groups, a sham group and two experimental groups. The rats were confined in Plexiglas cages and cellular phones were placed 0.5 cm under the cages. In the first experimental group, cellular phones were in standby position for 2 h. In the second experimental group, phones were turned to the speech position three times each for 1 min duration over 2 h. Rats in the first and second experimental groups were exposed to microwaves emitted by phones for 2 h/day for a duration of 1 month. After the last exposure the rats were killed. Brain, eyes, ears, liver, heart, lungs, stomach, kidneys, testes, small and large intestines and skin of the rats were observed histologically. The decrease of epididymal sperm counts in the speech groups were not found to be significant (P > 0.05). Differences in terms of normal and abnormal sperm forms were not observed (P > 0.05). Histological changes were especially observed in the testes of rats of the speech groups. Seminiferous tubular diameter of rat testes in the standby and speech groups was found to be lower than the sham group (P < 0.05). Rectal temperatures of rats in the speech group were found to be higher than the sham and standby groups (P < 0.05). The rectal temperatures of rats before and after exposure were also found to be significantly higher in the speech group (P < 0.05). Specific absorption rate (SAR) was determined as 0.141 W/kg.

Animals↗

PubMed1999

Quantitative residual cortical activity measurement: appropriate test for diagnosis of renal artery stenosis?

OBJECTIVES: To evaluate the diagnostic validity of quantitative measurement of residual cortical activity (RCA) in renal artery stenosis (RAS). METHODS: In 45 patients with a high clinical likelihood of renovascular hypertension (RVH) and unimpaired renal function, dynamic imaging was performed after an intravenous bolus injection of 148 MBq (99m)Tc MAG3 for both baseline renoscintigraphy and captopril renography following oral application of 50 mg captopril. RCA was measured according to the Sfakianakis method: RCA = cortical counts at 20 min/counts at peak x100%. An increase in RCA of >/=5% from baseline was considered indicative of RAS. After renography, all patients underwent selective transfemoral angiography with the digital subtraction technique. A luminal reduction of >/=50% was considered as proof of RAS. RESULTS: The number of kidneys that had a change of >/=5% in RCA values was 12 (27.2%) in normal kidneys, 7 (58.3%) in the patients with bilateral RAS, 14 (82.3%) in the patients with unilateral RAS, and 21 (72.4%) in overall kidneys with RAS. The positive test ratio in pathologic groups was significantly higher than normal (p < 0.05). The sensitivity and specificity of the RCA test were 72.4 and 72.7%, respectively; the positive and negative predictive values were 63.6 and 80%, respectively. CONCLUSION: Quantitative measurements of RCA can be used as a diagnostic parameter of renal artery stenosis and may contribute of the diagnostic accuracy of visual interpretation and other renographic diagnostic criteria.

Angiography↗