Osman Fikret Sonmez

A new approach for the estimation of intervertebral disc volume using the Cavalieri principle and computed tomography images

This study was carried out to describe a simple, accurate and practical technique for estimating the volume of intervertebral disc (ID) by the combination of the Cavalieri principle and computed tomography (CT) images. Total eight lumbar IDs from two cadavers were CT scanned in axial, sagittal and coronal sections. The consecutive sections with 5 and 3mm thickness were used to estimate the volume of the IDs by the Cavalieri principle. Three investigators estimated the volume of IDs independently to evaluate inter-observer differences. When the results were compared to the real volumes of IDs measured by the fluid displacement technique, there was no significant difference between the real volume measurements and the Cavalieri estimation results of ID volumes (P > 0.05). Moreover, findings of three investigators did not show significant variations (P > 0.05). Our results indicate that the section thickness and the section planes did not affect the accuracy of the disc volume estimation. Thus the combination of CT scanning with the Cavalieri principle may be used as a direct and reliable technique to estimate the volume of IDs with a mean of 4 min workload per ID.

Therapeutic Effects of Intracarotid Infusion of Spermine/Nitric Oxide Complex on Cerebral Vasospasm

Summary. Background: Vasospasm is one of the underlying causes of morbidity and mortality in subarachnoid haemorrhage (SAH). The therapeutic effects of intracarotid infusion of spermine/nitric oxide complex (SPER/NO) on cerebral vasospasm in an experimental model of SAH were investigated. Method: Twenty-four adult male New Zealand white rabbits (2.6–3.4 kg in weight) were randomly divided into four groups (n=6), as follows: (I) control group (without SAH and drug), (II) SAH alone group (with SAH, without drug), (III) SAH placebo group (with SAH and saline), and (IV) SAH-SPER/NO group (with SAH and SPER/NO). The fresh autologous non-heparinized blood was injected into the cisterna magna to induce a SAH, after 24 hour SAH, the substance (saline or SPER/NO) was delivered to animals. All rabbits were scarified at 48-hours of induced SAH. The basilar artery with surrounding tissue was removed from the cranium and processed for paraffin embedding. Histopathological and stereological examinations of the basilar artery were done. Findings: In the SPER/NO treated group of rabbits, the histopathological changes were less severe than in the SAH-alone and SAH-placebo groups. Regarding the intracarotid pressure, there was a statistically significant difference between SAH-alone and SAH-SPER/NO groups and also between SAH-SPER/NO and control groups (p<0.05). The mean cross sectional area of basilar arteries was 0.26 mm2 in the control, whereas in SAH alone, placebo and SAH-SPER/NO groups were 0.13, 0.15 and 0.20 mm2, respectively. Interpretation: It is well known that NO is a critical substance involved in cerebral vascular dynamics. Present results indicate that treatment of vasospasm with SPER/NO in SAH may be promising. However, further studies should be done on this substance to clarify its effect on vasospasm before using the drug in clinical situations.

A stereological study of MRI and the Cavalieri principle combined for diagnosis and monitoring of brain tumor volume.

In this study, we aimed to describe the application of the Cavalieri principle for the assessment of tumor volume using MRI without an over-projection/estimation effect. For this purpose, the volume of a patients brain and the brain tumor volume, or the volume of the former tumor region, were estimated preoperatively and postoperatively using a combination of the Cavalieri principle and MRI. The previously described formula was modified for MRI measurements to eliminate the over-estimation effects of imaging. The total brain and tumor volumes estimated using the MRI of a representative patient with glioblastoma multiforme were: preoperative, 1562.46 cm³ and 81.59 cm³, respectively; and postoperative, 1571.72 cm³ and 86.92 cm³, respectively. The mean time to count points for an estimation of brain and tumor volume (or the volume of the former tumor region) were 14 minutes and 3 minutes, respectively. The coefficients of the errors of the estimates for brain and tumor volume (former tumor volume, postoperative) measurements were: preoperative 0.01 and 0.02; and postoperative 0.01 and 0.03, respectively. Our results show that the combination of MRI and the Cavalieri principle can provide an unbiased, direct and assumption-free estimate of the regions of interest. Therefore, the presented method could be applied efficiently without any need for special software, additional equipment or personnel other than that required for routine MRI in daily use.

Deleterious impacts of a 900-MHz electromagnetic field on hippocampal pyramidal neurons of 8-week-old Sprague Dawley male rats

Children are at potential risk due to their intense use of mobile phones. We examined 8-week-old rats because this age of the rats is comparable with the preadolescent period in humans. The number of pyramidal neurons in the cornu ammonis of the Sprague Dawley male rat (8-weeks old, weighing 180-250 g) hippocampus following exposure to a 900 MHz (MHz) electromagnetic field (EMF) were examined. The study consisted of control (CN-G), sham exposed (SHM-EG) and EMF exposed (EMF-EG) groups with 6 rats in each. The EMF-EG rats were exposed to 900 MHz EMF (1h/day for 30 days) in an EMF jar. The SHM-EG rats were placed in the EMF jar but not exposed to the EMF (1h/day for 30 days). The CN-G rats were not placed into the exposure jar and were not exposed to the EMF during the study period. All animals were sacrificed at the end of the experiment, and their brains were removed for histopathological and stereological analysis. The number of pyramidal neurons in the cornu ammonis of the hippocampus was estimated on Cresyl violet stained sections of the brain using the optical dissector counting technique. Histopathological evaluations were also performed on these sections. Histopathological observation showed abundant cells with abnormal, black or dark blue cytoplasm and shrunken morphology among the normal pyramidal neurons. The largest lateral ventricles were observed in the EMF-EG sections compared to those from the other groups. Stereological analyses showed that the total number of pyramidal neurons in the cornu ammonis of the EMF-EG rats was significantly lower than those in the CN-G (p<0.05) and the SHM-EG (p<0.05). In conclusion, our results suggest that pyramidal neuron loss and histopathological changes in the cornu ammonis of 8-week-old male rats may be due to the 900-MHz EMF exposure.

Morphological and antioxidant impairments in the spinal cord of male offspring rats following exposure to a continuous 900MHz electromagnetic field during early and mid-adolescence.

The effects of devices emitting electromagnetic field (EMF) on human health have become the subject of intense research among scientists due to the rapid increase in their use. Children and adolescents are particularly attracted to the use of devices emitting EMF, such as mobile phones. The aim of this study was therefore to investigate changes in the spinal cords of male rat pups exposed to the effect of 900MHz EMF. The study began with 24 Sprague-Dawley male rats aged 3 weeks. Three groups containing equal numbers of rats were established-control group (CG), sham group (SG) and EMF group (EMFG). EMFG rats were placed inside an EMF cage every day between postnatal days (PD) 21 and 46 and exposed to the effect of 900MHz EMF for 1h. SG rats were kept in the EMF cage for 1h without being exposed to the effect of EMF. At the end of the study, the spinal cords in the upper thoracic region of all rats were removed. Tissues were collected for biochemistry, light microscopy (LM) and transmission electron microscopic (TEM) examination. Biochemistry results revealed significantly increased malondialdehyde and glutathione levels in EMFG compared to CG and SG, while SG and EMFG catalase and superoxide dismutase levels were significantly higher than those in CG. In EMFG, LM revealed atrophy in the spinal cord, vacuolization, myelin thickening and irregularities in the perikarya. TEM revealed marked loss of myelin sheath integrity and invagination into the axon and broad vacuoles in axoplasm. The study results show that biochemical alterations and pathological changes may occur in the spinal cords of male rats following exposure to 900MHz EMF for 1h a day on PD 21-46.

A new evaluation method for the intracranial volume changes and subdural effusion of patients following endoscopic third ventriculostomy

OBJECTIVE Endoscopic third ventriculostomy (ETV) is a procedure commonly applied in the treatment of non-communicating (obstructive) hydrocephalus. One of the rare complications that can occur following ETV is a subdural effusion, even though this procedure is considered to be a more controlled and natural method of cerebrospinal fluid drainage compared to external drainage. In this study, we evaluated the intracranial volume changes and subdural effusion of patients following ETV using Cavalieri method. METHOD Volumes analysis of the cranial cavity, brain, ventricles and subdural effusions of two patients after ETV were performed on computed tomography images using the Cavalieri principle, one of the stereological methods. RESULTS The preoperative total intracranial volumes and the preoperative brain volumes decreased for both patients during the postoperative 3rd, 10th and 30th days. Following ETV, the volumes of the lateral ventricles of both patients initially decreased during the postoperative 3rd and 10th days, however, the volumes returned almost to their preoperative size by the end of the 30th day. The effusions were seen on the postoperative 3rd and 10th days resolved by the end of the 30th day. CONCLUSION Our results show that the Cavalieri method can be used to unbiased prediction of intracranial volume changes and to follow the subdural effusion after the ETV surgery.

Variations of the superficial peroneal nerve and its terminal branches in the Turkish newborn fetuses.

AIM The topography of the superficial peroneal nerve (SPN) and its terminal branches were studied, with the aim of providing further anatomical details for leg and foot in the Turkish newborn fetuses. MATERIAL AND METHODS Limbs from twenty newborn cadavers were dissected. The course of the SPN on the leg and its terminal branches on the foot were investigated. RESULTS The SPN was lateral (75%), anterior (15%), or branched in both areas (10%) of the cases. The SPN in the dorsum of the feet branched further into medial dorsal cutaneous nerve (MDCn) and intermediate dorsal cutaneous nerve (IDCn). In 82.5% of the cases the MDCn and the IDCn split into three and two branches, respectively. In 10% of the cases, the MDCn gave off three, and the IDCn one terminal branches. In 7.5% of the cases, the MDCn had three while the IDCn had two branches that communicated with the lateral dorsal cutaneous nerve. CONCLUSION The course of SPN on the anterolateral surface of the leg and its terminal branches on the dorsal surface of the foot were quite different. This unusual variant location will enable the surgeon to find and preserve the SPN and its terminal branches.