Ahmet Koç

Assessment of bone ages: Is the Greulich‐Pyle method sufficient for Turkish boys?

Abstract Background : The Greulich‐Pyle (GP) Atlas of skeletal maturation has been prepared in white children who born between 1917 and 1942 in the USA, and is frequently used for assessment of skeletal maturity. In this study, we investigated whether or not the GP method is sufficient for Turkish children for the determination of the skeletal age.

Altered anti-oxidant status and increased lipid peroxidation in marasmic children.

Abstract Background: Protein energy malnutrition (PEM) is a common pediatric health problem in developing countries. Although the clinical features of PEM are well known, its pathophysiology is still unclear. Free radicals have been implicated in pathogenesis of PEM. In the present study, oxidant/anti‐oxidant status in marasmus was investigated.

Genetic predisposition for tympanosclerotic degeneration

Abstract. Atherosclerosis and tympanosclerosis are disorders that affect different organs in the body. When tissue samples taken from atherosclerotic and tympanosclerotic lesions are compared under light and electron microscopes, common pathological characteristics become apparent in both tissues. These similarities indicate that genetic predisposition to atherosclerosis is also seen in the middle ear. For the purpose of evaluating this genetic predisposition, the incidence of tympanosclerosis in atherosclerotic patients was examined and compared with the normal population. Otoscopic examination of 1,024 atherosclerotic patients was performed, and myringosclerosis was revealed in 66.6%. Myringosclerosis was found in 36 out of 300 non-atherosclerotic patients (12%). In the group of atherosclerotic patients, 174 individuals had past histories of previous ear infections. Myringosclerosis was detected in 147 of these patients (84.5%) during ear examinations. In 637 non-atherosclerotic patients with histories of ear infections, this figure was 114 (17.7%). The high rate of tympanosclerosis observed in atherosclerotic patients in comparison to the normal population was found to be statistically significant. These findings indicate that there must be a genetic predisposition for sclerotic degeneration in some individuals.

Clinical and neurological findings of severe vitamin B12 deficiency in infancy and importance of early diagnosis and treatment.

Nutritional vitamin B12 deficiency among children in developing countries may lead to a severe clinical status. In this article, the clinical manifestations of vitamin B12 deficiency and the consequences of delay in its diagnosis have been evaluated.

Sex distribution in children with tympanosclerosis after insertion of a tympanostomy tube

Abstract Tympanostomy tube insertion is an accepted treatment for otitis media with effusion in children. Several clinical studies have shown that tube insertion may cause myringosclerosis. During the period 1988 to 1997 we treated 533 ears from 311 children who had otitis media with effusion by inserting tympanostomy tubes. Most of these (431 ears from 251 children) were re-examined in 1998 and sex and occurrence of myringosclerosis at the tube insertion site were noted. Myringosclerosis was observed in 31% of ears of girls treated with tubes, whereas in boys 71% of ears showed myringosclerosis. This difference between sexes may indicate a genetic predisposition such as that seen in atherosclerosis.

Paraoxonase and arylesterase activity with oxidative status in children with thalassemia major.

Purpose The aim of this study was to study paraoxonase and arylesterase activities along with oxidative status parameters, and to find out whether there is any increased susceptibility to atherogenesis, which might be reflected with increased oxidative stress and decreased serum paraoxonase/arylesterase activity in β-thalassemia major (BTM) patients. Patients and Methods Eighty-seven patients with BTM and 33 healthy individuals were enrolled in the study. Results Paraoxonase and arylesterase activities were significantly lower in BTM patients than controls (for all P<0.0001), whereas total oxidant status, total peroxide concentration levels, and oxidative stress index were significantly higher (P<0.0001, <0.0001, and <0.001, respectively). Correlations were found between serum iron and ferritin and levels of total oxidant status in BTM patients. Significant correlation was found with serum total peroxide concentration levels and paraoxonase and arylesterase activities in patients with BTM. Conclusions It was seen that oxidative stress increases, while serum paraoxonase activity is decreased in BTM patients. Decrease in paraoxonase activity seems to be associated with both the degree of oxidative stress and anemia. BTM patients may be more prone to development of atherogenesis because of low serum paraoxonase/arylesterase activity.

N-Acetylcysteine Supplementation Reduces Oxidative Stress and DNA Damage in Children with β-Thalassemia

Abstract There are several reports that increased oxidative stress and DNA damage were found in β-thalassemia major (β-TM) patients. In this study, we aimed to evaluate the effects of N-acetylcysteine (NAC) and vitamin E on total oxidative stress and DNA damage in children with β-TM. Seventy-five children with transfusion-dependent β-thalassemia (β-thal) were randomly chosen to receive 10 mg/kg/day of NAC or 10 IU/kg/day of vitamin E or no supplementation; 28 healthy controls were also included in the study. Serum total oxidant status (TOS) and total antioxidant capacity (TAC) were measured, oxidative stress index (OSI) was calculated, and mononuclear DNA damage was assessed by alkaline comet assay; they were determined before treatment and after 3 months of treatment. Total oxydent status, OSI, and DNA damage levels were significantly higher and TAC levels were significantly lower in the thalassemic children than in the healthy controls (p < 0.001). In both supplemented groups, mean TOS and OSI levels were decreased; TAC and pre transfusion hemoglobin (Hb) levels were significantly increased after 3 months (p ≤ 0.002). In the NAC group, DNA damage score decreased (p = 0.001). N-acetylcysteine and vitamin E may be effective in reducing serum oxidative stress and increase pre transfusion Hb levels in children with β-thal. N-acetylcysteine also can reduce DNA damage.

Effects of Topical Otic Preparations on Hearing in Chronic Otitis Media

Most of the topical otic preparations have been shown to cause ototoxicity. In this study ciprofloxacin hydrochloride, a relatively new topical agent, and gentamicin sulfate were studied in two groups of 20 patients with chronic otitis media. Patients were randomly selected to receive either ciprofloxacin (200 μg/ml) or gentamicin sulfate (5 mg/ml) locally, five drops three times a day for 10 days. Clinical response was seen in 20 of 20 patients in the ciprofloxacin group compared with 6 of 20 patients in the gentamicin group. Audiometric evaluation revealed no significant ototoxic effect in either group. In fact, hearing thresholds were slightly better than pretreatment levels in both groups.

Vitamin B12 treatment reduces mononuclear DNA damage

Background:  DNA damage effects of vitamin B12 deficiency were performed in vitro and in adults.

Ferrous sulfate (Fe2+) had a faster effect than did ferric polymaltose (Fe3+) on increased oxidant status in children with iron-deficiency anemia.

Objective: The purpose of this study was to compare the total oxidant and antioxidant effect of different oral iron preparations in children with iron-deficiency anemia (IDA). Methods: A total of 65 children with IDA were randomized to receive 5 mg Fe/kg/d iron (II) sulfate (Fe2+ group, n=33) or iron (III)-hydroxide polymaltose complex (Fe3+ group, n=32); healthy controls (n=28) were also included in the study. Serum total thiol (–SH), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), and hematological profile were evaluated at the baseline and on day 8 and day 30 of the therapy. Results: Serum TOS and OSI levels were significantly higher and total –SH and total antioxidant capacity levels were significantly lower in the study groups at the beginning of therapy than in the controls (P>0.001). In multivariate analysis, after controlling for multiple confounding factors, on days 8 and 30, serum TOS and OSI levels were not different in the Fe3+ group, whereas they were significantly reduced in the Fe2+ group (P⩽0.033). Conclusions: Serum total oxidant status was significantly increased in children with IDA, and Fe2+ was highly effective in correcting elevated oxidative status.