Hulki Basaloglu

Stereological Estimation of the Orbital Volume: A Criterion Standard Study

Several methodologies have been proposed to assess the orbital volume (OV). However, we have not seen a criterion standard study evaluating the results of the methodologies for the assessment of OV. In the current study, the actual OV of 9 dry skulls was measured using the water filling method as the criterion standard. Consecutive computed tomographic sections at a thickness of 1.5 mm were used to estimate the OV by means of the point counting method. The mean (SD) of the OV measured by the water filling method was 17.84 (1.56) cm3. By using the point counting method, it was 17.05 (1.69) cm3. There was no statistically significant difference between sides (P > 0.001). The results of the OV values obtained by the two methods were compared statistically. The agreements between the two methods were also evaluated using the Bland-Altman plots. There was no statistically significant difference between the OV measurements obtained by the stereological technique and water filling method. The described method could be used for the assessment of OV in vivo.

Relation between intracranial volume and the surface area of the foramen magnum.

Several investigators have estimated the intracranial volume (ICV) in the past which indirectly reflects the brain volume. Most of these studies have been made on the dry skulls using linear dimensions, packing methods or occasionally radiological methods. It is also reported that the etiology of cerebellar tonsillar herniation is closely related to the size of the foramen magnum (FM). In the present study the ICVs have been estimated in 28 dry skulls using filling water method and the surface area of FMs were measured planimetry method. The estimated mean ICV was 1311 ± 133 cm3. Surface area of FM was 760 ± 144 mm2. Antero-posterior and lateral direct roentgenograms of the skulls were also taken and the width, height and length (WHL) of the skull were measured by means of the cephalometry on radiograms. The relationship between the ICV, WHL and surface area of FM were analyzed statistically. The ICV, WHL and surface area of FM was correlated well (r = 0.271, P < 0.005; r = 0.265, P < 0.005, respectively) and a regression formula was proposed. Our results showed that skulls with larger ICV and WHL have larger FM surface area. We also suggested a regression formula that could be used to predict the surface area of FM regarding to the ICV and WHL values. In the next step, we took roentgenograms of skulls and obtain ICV measuring the width, length and height of skulls by means of cephalometry and investigate the relation between the findings of cephalometry and surface area of FM. The cephalometry could apply on living subjects and, thereby, our findings could provide some data to evaluate the etiology of Arnold Chiari malformation and achondroplasia for living subjects.

Morphometry of the sacrum for clinical use.

Degenerative disease and instability in the lower lumbar spine may necessitate fusion and stabilization supplemented by instrumentation to the sacrum. However, screw placement in a reasonable position is more difficult to achieve because of the unique anatomy of the first sacral (S1) vertebra. Therefore, this study has been conducted to evaluate sacrum anatomy of the Western Anatolian population in terms of morphometric measurements and make a comparison with previous studies as well as giving a guidance to the surgeons. In this study, 60 dry adult sacrums (30 male and 30 female) were assessed for morphometric analysis. The measurement data for the sacrum and S1 vertebra revealed that there was no significant difference between both sexes except the sacral width and sacral canal width (p<0.05). In the present study, the ratio of S1 corpus’ width to sacral width was lower in females compared with males. A detailed knowledge of the morphometric data about sacrum is very important for spinal surgery, as pedicle screw insertion is crucial in spinal instrumentation in order to prevent neurological injury and/or fixation failure.

Effects of Constant Lightness, Darkness and Parachlorophenylalanine Treatment on Tail Regeneration in the Lizard Ophisops elegans macrodactylus: Macroscopic, Biochemical and Histological Changes

A better understanding of regenerative growth is very important for the development of new potential strategies. Recently, the pineal secretory product melatonin was shown to stimulate the regeneration process. In this study, we carried out an experimental investigation of tail regeneration in young adult lizards, Ophisops elegans macrodactylus Berthold, 1842, addressing the role of melatonin on the regeneration process. Lizards were divided into three groups: constant light‐exposed control group (n = 13), constant dark‐exposed group (n = 15) and parachlorophenylalanine (p‐CPA) treatment group exposed to constant light (n = 15). Using a tail autotomy procedure, the effects of p‐CPA treatment on connective tissue together with neural tissue and vascular tissue in regenerating tail in lizards were investigated. p‐CPA (400 μg/kg body mass) was injected from day 0 to 30 days after autotomy. p‐CPA treatment produced a significant increase in the length of the regenerated tail compared with light‐exposed control and dark‐exposed lizards. Total collagen content was found to be higher in p‐CPA‐treated animals in comparison with other groups. Histologically, a higher percentage of connective tissue and vascular tissue and a lower percentage of neural tissue were found in the regenerated tails of the p‐CPA‐treated lizards. Importantly, the percentage of neural tissue in lizards in the dark‐exposed animals was higher than that in animals of both light‐exposed and p‐CPA treatment groups. Thus, it is clear that p‐CPA has a stimulatory influence on fibroblast collagen production and vascularization of the regenerated tail in the lizards. Furthermore, it seems that the neural regeneration process was markedly enhanced in lizards exposed to continuous darkness. Based on the results of our study, it is suggested that melatonin may be an active factor that speeds up the rate of tail regeneration in lacertilians.

Unbiased estimation of the calcaneus volume using the Cavalieri principle on computed tomography images

The size and shape of tarsal bones are especially relevant when considering some orthopedic diseases such as clubfoot. For this reason, the measurements of the tarsal bones have been the subject of many studies, none of which has used stereological methods to estimate the volume. In the present stereological study, we estimated the volume of calcaneal bone of normal feet and dry bones. We used a combination of the Cavalieri principle and computer tomographic scans taken from eight males and nine dry calcanei to estimate the volumes of calcaneal bones. The mean volume of dry calcaneal bones was estimated, producing mean results using the point-counting method and Archimedes principle being 49.11+/-10.7 or 48.22+/-11.92 cm(3), respectively. A positive correlation was found between anthropometric measurements and the volume of calcaneal bones. The findings of the present study using the stereological methods could provide data for the evaluation of normal and pathological volumes of calcaneal bones.

Extremely rare type of conjoined twins: cephalothoracopagus deradelphus.

Occurrence of conjoined twins (CT) with a chromosomal abnormality is a very rare event. The case presented is that of a cephalothoracopagus Deradelphus twin with one cerebrum and two brain stems joined at the cranial end of the midbrain. This rare condition and its diagnosis and management are discussed with regard to counselling and obstetrical care.