Biomedical subjects

Izzet Duyar

Publications and source records attributed to Izzet Duyar.

5 recordsLinked to original sources

PubMed2006

The ultrastructural alterations in rat corneas with experimentally-induced diabetes mellitus.

OBJECTIVE: To examine the ultrastructural changes of rat corneas in streptozotocin (STZ) induced diabetes mellitus and the follow-up insulin treatment. METHODS: Sprague-Dawley type rats was used for experimental procedures during the period from January to April 2003 at Baskent University, Ankara, Turkey. Rats were studied in 4 groups; group 1: controls, group 2: sham controls (single dose IV sodium citrate), group 3: STZ-induced diabetes mellitus (single dose 45 mg/kg STZ intravenously), group 4: diabetes mellitus + insulin treatment (8 U/day). RESULTS: We observed degenerative changes in the epithelial layer, stromal keratocytes and endothelial cells in diabetic group. In contrast, the corneal layers have revealed positive alterations in the insulin-treated group. The statistical analyses showed significant narrowing in the epithelial layer in the diabetic group (p=0.002), whereas thickening was observed in the epithelial basement membrane and Descemet's membrane (p=0.002). CONCLUSION: It was determined that diabetes mellitus causes degenerative changes in cornea, which are positively influenced by short-term insulin treatment.

Animals↗

PubMed2005

Growth and nutritional status of male adolescent laborers in Ankara, Turkey.

Undernutrition, pathogenic agents, and poor living conditions are of primary importance in the evaluation of adverse environmental conditions' effects on human growth; but child labor (an equally significant factor, especially in underdeveloped countries) is generally overlooked or ignored. The aim of this study is to focus on this subject and clarify the effects of labor on the physical growth and nutritional status of child and adolescent laborers. In this study, the height and weight of 532 male adolescent laborers aged 13.5-18.5 years and their non-laboring peers (n = 451) (the control group) were measured by standard anthropometric techniques and equipment. The individuals of both groups come from lower socioeconomic strata and share similar living conditions. Data were transformed to z-scores, using the US Center for Disease Control and Prevention's 2000 growth charts. The analyses show that the z-scores for height-for-age, weight-for-age, and body mass index (BMI)-for-age were negative in both groups. The z-scores of laborers' height-for-age and weight-for-age values lie below the controls', but there is no significant difference between the two groups' BMI-for-age scores. In the laboring group, the percentages of stunting (-2 SD of height-for-age), underweight (-2 SD of weight-for-age), and wasting (-2 SD of BMI-for-age) were 14.3, 2.6, and 0.2, respectively. These values suggest that malnutrition is not a common problem among adolescent laborers living in Ankara; but laboring is an important cause of faltering in growth, particularly in linear growth, in less or underdeveloped economic environments.

Adolescent↗

PubMed2005

Body height estimation based on dimensions of sacral and coccygeal vertebrae.

This study is to evaluate whether it is possible to predict living stature from sacral and coccygeal vertebral dimensions. Individual vertebral body heights, sacral height (SH), and sacrococcygeal height (SCH) were recorded from the magnetic resonance images of 42 adult males. Sum of the heights of five sacral vertebrae (sigmaS), the first four coccygeal vertebrae (sigmaC), and the total height of the sacral and the first four coccygeal vertebrae together (sigmaSC) were also recorded. Linear regression equations for stature estimation were produced using the above mentioned variables. The regression equations were constructed and tested by using jack-knife procedure. Statistical analyses indicated that the combined variables (SH, SCH, sigmaS, sigmaC, sigmaSC) were more accurate predictors of stature than the heights of individual vertebrae. The results of the study pointed out that the equations derived from sacrococcygeal dimensions perform somewhat better than ones based on foot and head variables, but worse than those based on long-bone length. As a conclusion, the dimensions of sacral and coccygeal vertebrae could be used for stature estimation when long bones are not available.

Aged↗

PubMed2003

Body height estimation based on tibia length in different stature groups.

Long bone length is one of the best-known indicators of human stature. Although the long bone length/height ratio differs in tall and short individuals, no detailed study has investigated whether specific formulae should be used to calculate height in different stature groups. This study proposes a new height estimation method. Body height and tibia length were measured in 121 male subjects aged 18.0-34.3 years. Three subgroups were established according to body height (short, medium, or tall), using the 15th and 85th percentiles as cutoff levels. The general formula and a group-specific regression formula were used to estimate height in each subgroup. A control group with the same properties as the study group was analyzed in the same manner. Particularly with "short" and "tall" subjects, the difference between true height and the height predicted by the group-specific formulae was smaller than the difference observed when the general formula was used. These discrepancies were statistically significant. When estimating height based on tibia length, the individual's general stature category should be taken into consideration, and group-specific formulae should be used for short and tall subjects.

Adolescent↗

PubMed2003

Estimating stature from tibia length: a comparison of methods.

Most forensic and biological anthropological studies use the stature-estimation formulae developed by Trotter and Gleser. In recent decades, studies of morphological differences between populations have indicated that population-specific formulae are necessary to obtain accurate estimates. A number of equations have been devised for the Turkish population. Previously, we introduced a "general formula" and three "stature-group-specific formulae" based on tibial length. The purpose of the present study was to determine whether formulae in the literature are suitable for estimating height in the Turkish population. To make this assessment, we compared the accuracy of formulae designed for Turkish people to the accuracy of formulae devised for other populations. We also evaluated the accuracy in short, medium, and tall height groupings. The formulae were tested on 110 healthy Turkish male adults, with estimated height compared to true height in each case. Analysis showed that the Trotter-Gleser formula for Mongoloids was most accurate for estimating stature in the study group as a whole. The formulae of Sağir for the Turkish population and our previously published "general formula" were the next most accurate methods, respectively. When the 110 subjects were categorized as short (1652 mm and below), medium (1653 to 1840 mm), and tall (1841 and above), the stature-group-specific formulae calculated in the present study were more accurate than all other equations for subjects at the height extremes. The results of this study indicate that stature-group-specific formulae are more reliable for forensic cases.

Adult↗